Fixed some bugs. Caused some bugs

(Mostly) Finished extraction (currently infinitely hanging)
Added DataExtract Added LookupTable
2026-05-28 03:56:43 -05:00 · 2026-05-27 19:17:17 -05:00 · 2026-05-27 11:59:47 -05:00 · 2026-05-27 06:03:54 -05:00 · 2026-04-02 06:27:34 -05:00
41 changed files with 1416 additions and 2374 deletions
@@ -2,3 +2,4 @@ testing/

 .zig-cache/
 zig-out/
+zig-pkg/
@@ -0,0 +1,18 @@
+// Folder-specific settings
+//
+// For a full list of overridable settings, and general information on folder-specific settings,
+// see the documentation: https://zed.dev/docs/configuring-zed#settings-files
+{
+	"lsp": {
+		"zls": {
+			"initialization_options": {
+				"usePlaceholders": false,
+			},
+			"settings": {
+				"build_on_save": true,
+				"use_placeholders": false,
+				"build_on_save_args": ["-fincremental", "-Dallow_lzo=true"],
+			},
+		},
+	},
+}
@@ -1,99 +1,118 @@
 const std = @import("std");
+const Build = std.Build;
+const Step = Build.Step;

 pub fn build(b: *std.Build) !void {
    const use_zig_decomp = b.option(bool, "use_zig_decomp", "Use zig standard library for decompression.") orelse false;
-    // const allow_lzo = b.option(bool, "allow_lzo", "Compile with lzo support") orelse false;
-    const debug = b.option(bool, "debug", "Enable options to make debugging easier.") orelse false;
-    const version_string_option = b.option([]const u8, "version", "Version of the library/binary");
+    const allow_lzo = b.option(bool, "allow_lzo", "Compile with lzo support") orelse false;
+    var debug = b.option(bool, "debug", "Enable options to make debugging easier.") orelse false;
+    const dynamic = b.option(bool, "dynamic", "Use dynamic linking for C libraries (if used).") orelse false;
+    var version_string = b.option([]const u8, "version", "Version of the library/binary") orelse "0.0.0-testing";
+
+    const target = b.standardTargetOptions(.{});
+    var optimize = b.standardOptimizeOption(.{});

    const zig_squashfs_options = b.addOptions();
    zig_squashfs_options.addOption(bool, "use_zig_decomp", use_zig_decomp);
-    // zig_squashfs_options.addOption(bool, "allow_lzo", allow_lzo);
+    zig_squashfs_options.addOption(bool, "allow_lzo", allow_lzo);

-    const target = b.standardTargetOptions(.{});
-    const optimize = b.standardOptimizeOption(.{});
-    const mod = b.addModule("zig_squashfs", .{
-        .root_source_file = b.path("src/root.zig"),
-        .target = target,
-        .optimize = if (debug == true) .Debug else optimize,
-        .link_libc = !use_zig_decomp,
-        .valgrind = debug,
-        .error_tracing = debug,
-        .strip = if (debug == true) false else null,
-    });
-    mod.addOptions("config", zig_squashfs_options);
-    if (!use_zig_decomp) {
-        var zlib_ng = b.dependency("zlib_ng", .{
-            .target = target,
-            .optimize = optimize,
-        });
-        mod.linkLibrary(zlib_ng.artifact("zng"));
-
-        mod.linkSystemLibrary("lzma", .{ .preferred_link_mode = .static });
-
-        var minilzo = b.dependency("minilzo", .{
-            .target = target,
-            .optimize = optimize,
-        });
-        mod.linkLibrary(minilzo.artifact("minilzo"));
-
-        var lz4 = b.dependency("lz4", .{
-            .target = target,
-            .optimize = optimize,
-        });
-        mod.linkLibrary(lz4.artifact("lz4"));
-
-        var zstd = b.dependency("zstd", .{
-            .target = target,
-            .optimize = optimize,
-        });
-        mod.linkLibrary(zstd.artifact("zstd"));
-    }
-
-    var version = version_string_option orelse "0.0.0-testing";
-    if (version[0] == 'v') version = version[1..];
+    version_string = std.mem.trimStart(u8, version_string, "v");
+    const version = try std.SemanticVersion.parse(version_string);
    const unsquashfs_options = b.addOptions();
    unsquashfs_options.addOption(
        std.SemanticVersion,
        "version",
-        try std.SemanticVersion.parse(version),
+        version,
    );

-    var exe_mod = b.createModule(.{
+    if (debug) optimize = .Debug;
+    if (optimize == .Debug) debug = true;
+
+    const c_import = b.addTranslateC(.{
+        .root_source_file = b.path("src/c.h"),
+        .target = target,
+        .optimize = optimize,
+    });
+    if (allow_lzo) c_import.defineCMacro("ALLOW_LZO", null);
+    if (dynamic) {
+        c_import.linkSystemLibrary("zlib-ng", .{});
+        c_import.linkSystemLibrary("lzma", .{});
+        if (allow_lzo)
+            c_import.linkSystemLibrary("minilzo", .{});
+        c_import.linkSystemLibrary("lz4", .{});
+        c_import.linkSystemLibrary("zstd", .{});
+    }
+
+    var lib = b.addLibrary(.{
+        .name = "squashfs",
+        .root_module = b.addModule("squashfs", .{
+            .root_source_file = b.path("src/root.zig"),
+            .target = target,
+            .optimize = optimize,
+            .valgrind = debug,
+            .error_tracing = debug,
+            .strip = !debug,
+            .imports = &.{
+                .{ .name = "config", .module = zig_squashfs_options.createModule() },
+                .{ .name = "c", .module = c_import.createModule() },
+            },
+        }),
+        .use_llvm = debug,
+        .version = version,
+    });
+
+    const deps = try getDependencies(b, target, optimize, allow_lzo, dynamic);
+
+    for (deps) |d|
+        lib.root_module.linkLibrary(d);
+
+    const exe = b.addExecutable(.{
+        .name = "unsquashfs",
+        .root_module = b.createModule(.{
            .root_source_file = b.path("src/bin/unsquashfs.zig"),
            .target = target,
-        .optimize = if (debug == true) .Debug else optimize,
-        .link_libc = !use_zig_decomp,
+            .optimize = optimize,
            .imports = &.{
-            .{ .name = "zig_squashfs", .module = mod },
+                .{ .name = "config", .module = unsquashfs_options.createModule() },
+                .{ .name = "squashfs", .module = lib.root_module },
            },
            .valgrind = debug,
            .error_tracing = debug,
-        .strip = if (debug == true) false else null,
-    });
-    exe_mod.addOptions("config", unsquashfs_options);
-    const exe = b.addExecutable(.{
-        .name = "unsquashfs",
-        .root_module = exe_mod,
-        .use_llvm = debug,
-    });
-
-    const lib = b.addLibrary(.{
-        .name = "squashfs",
-        .root_module = mod,
+            .strip = !debug,
+        }),
        .use_llvm = debug,
+        .version = version,
    });

    b.installArtifact(lib);
    b.installArtifact(exe);

    const mod_tests = b.addTest(.{
-        .root_module = mod,
-        .test_runner = .{
-            .mode = .simple,
-            .path = b.path("src/test.zig"),
+        .root_module = b.createModule(.{
+            .root_source_file = b.path("src/root.zig"),
+            .target = target,
+            .optimize = optimize,
+            .valgrind = true,
+            .error_tracing = true,
+            .strip = false,
+            .imports = &.{
+                .{ .name = "config", .module = zig_squashfs_options.createModule() },
+                .{ .name = "c", .module = c_import.createModule() },
            },
+        }),
+        .use_llvm = debug, // Helps with lldb degugging
    });
+
+    for (deps) |d|
+        mod_tests.root_module.linkLibrary(d);
+
+    if (dynamic) {
+        mod_tests.root_module.linkSystemLibrary("zlib-ng", .{});
+        mod_tests.root_module.linkSystemLibrary("lzma", .{});
+        mod_tests.root_module.linkSystemLibrary("minilzo", .{});
+        mod_tests.root_module.linkSystemLibrary("lz4", .{});
+    }
+
    const run_mod_tests = b.addRunArtifact(mod_tests);
    const test_step = b.step("test", "Run tests");
    test_step.dependOn(&run_mod_tests.step);
@@ -101,13 +120,54 @@ pub fn build(b: *std.Build) !void {
    // zls build check steps
    const lib_check = b.addLibrary(.{
        .name = "squashfs",
-        .root_module = mod,
+        .root_module = lib.root_module,
    });
    const exe_check = b.addExecutable(.{
        .name = "unsquashfs",
-        .root_module = exe_mod,
+        .root_module = exe.root_module,
    });
    const check = b.step("check", "Check if unsquashfs compiles");
    check.dependOn(&lib_check.step);
    check.dependOn(&exe_check.step);
 }
+
+fn getDependencies(b: *Build, target: Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, allow_lzo: bool, dynamic: bool) ![]*Step.Compile {
+    if (dynamic) return &.{};
+
+    var list: std.ArrayList(*Step.Compile) = .empty;
+    errdefer list.clearAndFree(b.allocator);
+
+    var zlib_ng = b.dependency("zlib_ng", .{
+        .target = target,
+        .optimize = optimize,
+    });
+    try list.append(b.allocator, zlib_ng.artifact("zng"));
+
+    var xz = b.dependency("xz", .{
+        .target = target,
+        .optimize = optimize,
+    });
+    try list.append(b.allocator, xz.artifact("lzma"));
+
+    if (allow_lzo) {
+        var minilzo = b.dependency("minilzo", .{
+            .target = target,
+            .optimize = optimize,
+        });
+        try list.append(b.allocator, minilzo.artifact("minilzo"));
+    }
+
+    var lz4 = b.dependency("lz4", .{
+        .target = target,
+        .optimize = optimize,
+    });
+    try list.append(b.allocator, lz4.artifact("lz4"));
+
+    var zstd = b.dependency("zstd", .{
+        .target = target,
+        .optimize = optimize,
+    });
+    try list.append(b.allocator, zstd.artifact("zstd"));
+
+    return list.toOwnedSlice(b.allocator);
+}
@@ -2,7 +2,7 @@
    .name = .squashfs,
    .version = "0.0.6",
    .fingerprint = 0x37ba29474b87f145, // Changing this has security and trust implications.
-    .minimum_zig_version = "0.15.2",
+    .minimum_zig_version = "0.16.1",
    .dependencies = .{
        .zlib_ng = .{
            .url = "git+https://github.com/CalebQ42/zig-zlib-ng#5f2f02dfb28acca2517dacbbd09e9b987f57b133",
@@ -20,6 +20,10 @@
            .url = "git+https://github.com/CalebQ42/zig-minilzo.git#7cbae997b91a44d74b7cd6c073584dc9562a6c90",
            .hash = "minilzo-2.10.0-Ij7BO8wLAADeWI4Pe4jp8XTDsDaquZR14oZ7_9yKKDWP",
        },
+        .xz = .{
+            .url = "git+https://github.com/akunaakwei/zig-xz.git#e2d389262c8291907e3e4c6fb119819141c16c0f",
+            .hash = "xz-5.8.2-6v47_JYeAABSL-jonprpL5-E_YaaGc4B5xrbe93WsJ3G",
+        },
    },
    .paths = .{
        "build.zig",
@@ -0,0 +1,2 @@
+[tools]
+zig = "0.16.0"
@@ -1,121 +1,100 @@
-//! A squashfs archive read from a file.
-//! Can be used to directly access File's contents or extract to the filesystem.
-
 const std = @import("std");
-const File = std.fs.File;
-const builtin = @import("builtin");
+const Io = std.Io;
+const MemoryMap = Io.File.MemoryMap;

+const c = @import("c");
 const config = @import("config");

-const cDecomp = @import("decomp/misc_c.zig");
-const Decomp = @import("decomp/zig_decomp.zig");
 const ExtractionOptions = @import("options.zig");
+const File = @import("file.zig");
 const Inode = @import("inode.zig");
-const InodeRef = Inode.Ref;
-const BlockSize = @import("inode_data/file.zig").BlockSize;
-const SfsFile = @import("file.zig");
 const Superblock = @import("super.zig").Superblock;
-const Tables = @import("tables.zig");
-const MetadataReader = @import("util/metadata.zig");
-const OffsetFile = @import("util/offset_file.zig");
-const XattrTable = @import("xattr.zig");
+const DecompCache = @import("util/decomp_cache.zig");
+const CompressionType = @import("util/decompress.zig").CompressionType;

 const Archive = @This();

-alloc: std.mem.Allocator,
+const CACHE_MIN = 16 * 1024 * 1024;
+const CACHE_MAX = 1 * 1024 * 1024 * 1024;

-fil: OffsetFile,
+cache: DecompCache,

 super: Superblock,

-tables: ?Tables = null,
-
-decomp: if (config.use_zig_decomp) Decomp.DecompFn else union(enum) {
-    gzip: @import("decomp/gzip.zig"),
-    lzma: @import("decomp/lzma.zig"),
-    lzo: void,
-    xz: @import("decomp/lzma.zig"),
-    lz4: void,
-    zstd: @import("decomp/zstd.zig"),
-
-    pub fn decomp(self: @This(), in: []u8, out: []u8) !usize {
-        return switch (self) {
-            .gzip => |*g| g.decompress(in, out),
-            .zstd => |*z| z.decompress(in, out),
-            .lzma, .xz => |*d| d.decompress(in, out),
-            .lz4 => cDecomp.lz4(in, out),
-            .lzo => cDecomp.lzo(in, out),
-        };
+/// Open a squashfs archive from an Io.File.
+pub fn init(alloc: std.mem.Allocator, io: Io, fil: Io.File) !Archive {
+    return initAdvanced(alloc, io, fil, 0, 0);
 }
-},
+/// If max_cache_size is zero, a size is selected based on system ram, up to 1GB with a minimum of 16MB.
+pub fn initAdvanced(alloc: std.mem.Allocator, io: Io, file: Io.File, offset: u64, max_cache_size: u64) !Archive {
+    var rdr = file.reader(io, &[0]u8{});
+    try rdr.seekTo(offset);

-/// Default settings using std.Thread.getCpuCount() threads and the minimum of 4gb or half of system memory for memory usage.
-pub fn init(alloc: std.mem.Allocator, fil: File, offset: u64) !Archive {
    var super: Superblock = undefined;
-    const red = try fil.pread(@ptrCast(&super), offset);
-    std.debug.assert(red == @sizeOf(Superblock));
+    try rdr.interface.readSliceEndian(Superblock, @ptrCast(&super), .little);
    try super.validate();
-    const off_fil: OffsetFile = .init(fil, offset);
+
+    if (!config.use_zig_decomp and config.allow_lzo)
+        _ = c.lzo_init();
+
+    const cache_size = blk: {
+        if (max_cache_size > CACHE_MIN) break :blk CACHE_MIN;
+        const sys_mem = std.process.totalSystemMemory() catch break :blk CACHE_MIN;
+        var min = @min(CACHE_MAX, sys_mem / 4);
+        if (min < CACHE_MIN and sys_mem > CACHE_MIN)
+            min = CACHE_MIN;
+        break :blk min;
+    };
    return .{
-        .alloc = alloc,
-        .fil = off_fil,
-        .decomp = if (config.use_zig_decomp)
-            switch (super.compression) {
-                .lz4 => return error.Lz4Unsupported,
-                .lzo => return error.LzoUnsupported,
-                .gzip => Decomp.gzip,
-                .lzma => Decomp.lzma,
-                .xz => Decomp.xz,
-                .zstd => Decomp.zstd,
-            }
-        else switch (super.compression) {
-            .gzip => .{ .gzip = .init(alloc) },
-            .zstd => .{ .zstd = .init(alloc) },
-            .xz => .{ .xz = .init(alloc, true) },
-            .lzma => .{ .lzma = .init(alloc, false) },
-            .lzo => .{ .lzo = .{} },
-            .lz4 => .{ .lz4 = .{} },
+        .cache = try .init(
+            alloc,
+            try file.createMemoryMap(
+                io,
+                .{
+                    .offset = offset,
+                    .len = super.size,
+                    .protection = .{ .read = true },
                },
+            ),
+            super.compression,
+            cache_size,
+        ),
+
        .super = super,
    };
 }
-pub fn deinit(self: *Archive) void {
-    if (self.tables != null)
-        self.tables.?.deinit();
+pub fn deinit(self: *Archive, io: Io) void {
+    self.cache.deinit(io);
 }

-pub fn inode(self: *Archive, alloc: std.mem.Allocator, num: u32) !Inode {
-    if (self.tables == null)
-        self.tables = try .init(alloc, self);
-    const ref = try self.export_table.get(num - 1);
-    var rdr = try self.fil.readerAt(ref.block_start + self.super.inode_start, &[0]u8{});
-    var meta: MetadataReader = .init(alloc, &rdr.interface, &self.decomp);
-    try meta.interface.discardAll(ref.block_offset);
-    return try .read(alloc, &meta.interface, self.super.block_size);
+pub fn root(self: *Archive, alloc: std.mem.Allocator, io: Io) !File {
+    return .fromRef(alloc, io, self, "", self.super.root_ref);
 }

-pub fn root(self: *Archive, alloc: std.mem.Allocator) !SfsFile {
-    if (self.tables == null)
-        self.tables = try .init(alloc, self);
-    var rdr = try self.fil.readerAt(self.super.root_ref.block_start + self.super.inode_start, &[0]u8{});
-    var meta: MetadataReader = .init(alloc, &rdr.interface, self.decomp);
-    try meta.interface.discardAll(self.super.root_ref.block_offset);
-    const in: Inode = try .read(alloc, &meta.interface, self.super.block_size);
-    return .init(self, in, "");
+pub fn open(self: *Archive, alloc: std.mem.Allocator, io: Io, filepath: []const u8) !File {
+    const path = std.mem.trim(u8, filepath, "/");
+
+    var root_file = try self.root(alloc, io);
+
+    if (path.len == 0 or std.mem.eql(u8, path, ".")) return root_file;
+    defer root_file.deinit();
+
+    return root_file.open(alloc, io, path);
 }

-pub fn open(self: *Archive, alloc: std.mem.Allocator, path: []const u8) !SfsFile {
-    if (self.tables == null)
-        self.tables = try .init(alloc, self);
-    var root_fil = try self.root(alloc);
-    defer if (!SfsFile.pathIsSelf(path)) root_fil.deinit();
-    return root_fil.open(path);
-}
-
-pub fn extract(self: Archive, alloc: std.mem.Allocator, path: []const u8, options: ExtractionOptions) !void {
-    var rdr = try self.fil.readerAt(self.super.root_ref.block_start + self.super.inode_start, &[0]u8{});
-    var meta: MetadataReader = .init(self.alloc, &rdr.interface, self.decomp);
-    try meta.interface.discardAll(self.super.root_ref.block_offset);
-    const in: Inode = try .read(self.alloc, &meta.interface, self.super.block_size);
-    try in.extractTo(alloc, self, path, options);
+pub fn extract(self: *Archive, alloc: std.mem.Allocator, io: Io, ext_dir: []const u8, options: ExtractionOptions) !void {
+    const root_inode: Inode = try .fromRef(alloc, io, &self.cache, self.super.inode_start, self.super.block_size, self.super.root_ref);
+    return root_inode.extract(
+        alloc,
+        io,
+        &self.cache,
+        self.super.dir_start,
+        self.super.inode_start,
+        self.super.frag_start,
+        self.super.block_size,
+        self.super.id_start,
+        self.super.xattr_start,
+        ext_dir,
+        options,
+    );
 }
@@ -1,9 +1,10 @@
 const std = @import("std");
+const Io = std.Io;
 const Writer = std.Io.Writer;
 const builtin = @import("builtin");

 const config = @import("config");
-const squashfs = @import("zig_squashfs");
+const squashfs = @import("squashfs");

 //TODO: Add more options
 const help_mgs =
@@ -38,40 +39,43 @@ var ignore_xattrs: bool = false;
 var ignore_permissions: bool = false;
 var force: bool = false;

-pub fn main() !void {
-    const alloc = std.heap.smp_allocator;
-    var stdout = std.fs.File.stdout();
-    var out = stdout.writer(&[0]u8{});
+pub fn main(init: std.process.Init) !void {
+    const alloc = init.gpa;
+    const io = init.io;
+
+    var stdout = Io.File.stdout();
+    var out = stdout.writer(io, &[0]u8{});
    defer out.interface.flush() catch {};
-    try handleArgs(alloc, &out.interface);
+
+    try handleArgs(&out.interface, init.minimal.args);
    if (archive.len == 0) {
        try out.interface.print("You must provide a squashfs archive\n", .{});
        try out.interface.print(help_mgs, .{});
        return;
    }
-    var fil: std.fs.File = try std.fs.cwd().openFile(archive, .{}); //TODO: Handle error gracefully.
-    defer fil.close();
-    var arc: squashfs.Archive = try .init(alloc, fil, offset); //TODO: Update when memory size matters. //TODO: Handle error gracefully.
-    defer arc.deinit();
+
+    var fil: std.Io.File = try Io.Dir.cwd().openFile(io, archive, .{}); //TODO: Handle error gracefully.
+    defer fil.close(io);
+    var arc: squashfs.Archive = try .initAdvanced(alloc, io, fil, offset, 0); //TODO: Update when memory size matters. //TODO: Handle error gracefully.
+    defer arc.deinit(io);
    const options: squashfs.ExtractionOptions = .{
-        .threads = if (threads == 0) try std.Thread.getCpuCount() else threads,
+        .single_threaded = threads == 1,
        .verbose = verbose,
        .verbose_writer = if (verbose) &out.interface else null,
        .ignore_xattr = ignore_xattrs,
        .ignore_permissions = ignore_permissions,
    };
    if (force)
-        try std.fs.cwd().deleteTree(extLoc);
-    try arc.extract(alloc, extLoc, options); //TODO: Handle error gracefully.
+        try Io.Dir.cwd().deleteTree(io, extLoc);
+    try arc.extract(alloc, io, extLoc, options); //TODO: Handle error gracefully.
 }

-fn handleArgs(alloc: std.mem.Allocator, out: *Writer) !void {
-    var args = try std.process.argsWithAllocator(alloc);
-    defer args.deinit();
-    _ = args.next(); // args[0] is the application launch command.
-    while (args.next()) |arg| {
+fn handleArgs(out: *Writer, args: std.process.Args) !void {
+    var arg_iter = args.iterate();
+    _ = arg_iter.next(); // args[0] is the application launch command.
+    while (arg_iter.next()) |arg| {
        if (std.mem.eql(u8, arg, "-o")) {
-            const nxt = args.next();
+            const nxt = arg_iter.next();
            if (nxt == null or nxt.?.len == 0) {
                try out.print("-o must be followed by a number\n", .{});
                return errors.InvalidArguments;
@@ -82,7 +86,7 @@ fn handleArgs(alloc: std.mem.Allocator, out: *Writer) !void {
            };
            continue;
        } else if (std.mem.eql(u8, arg, "-d")) {
-            const nxt = args.next();
+            const nxt = arg_iter.next();
            if (nxt == null or nxt.?.len == 0) {
                try out.print("-d must be followed by a location\n", .{});
                return errors.InvalidArguments;
@@ -90,7 +94,7 @@ fn handleArgs(alloc: std.mem.Allocator, out: *Writer) !void {
            extLoc = nxt.?;
            continue;
        } else if (std.mem.eql(u8, arg, "-p")) {
-            const nxt = args.next();
+            const nxt = arg_iter.next();
            if (nxt == null or nxt.?.len == 0) {
                try out.print("-p must be followed by a number\n", .{});
                return errors.InvalidArguments;
@@ -131,3 +135,7 @@ fn handleArgs(alloc: std.mem.Allocator, out: *Writer) !void {
        archive = arg;
    }
 }
+
+test {
+    std.testing.refAllDecls(squashfs.Archive);
+}
@@ -0,0 +1,7 @@
+#ifdef ALLOW_LZO
+#include <lzo/minilzo.h>
+#endif
+#include <zlib-ng.h>
+#include <zstd.h>
+#include <lz4.h>
+#include <lzma.h>
@@ -1,25 +0,0 @@
-const std = @import("std");
-
-const Decompressor = @This();
-
-pub const Error = error{
-    OutOfMemory,
-    BadInput,
-    OutputTooSmall,
-    ReadFailed,
-    WriteFailed,
-    EndOfStream,
-};
-
-vtable: *const struct {
-    decompress: *const fn (*Decompressor, []u8, []u8) Error!usize = DefaultDecompress,
-    stateless: *const fn (std.mem.Allocator, []u8, []u8) Error!usize,
-},
-
-pub fn decompress(self: *Decompressor, in: []u8, out: []u8) Error!usize {
-    return self.vtable.decompress(self, in, out);
-}
-
-fn DefaultDecompress(self: *Decompressor, in: []u8, out: []u8) Error!usize {
-    return self.vtable.stateless(std.heap.smp_allocator, in, out);
-}
@@ -1,14 +0,0 @@
-const std = @import("std");
-const Reader = std.Io.Reader;
-const builtin = @import("builtin");
-
-const config = @import("config");
-
-pub const c = @cImport({
-    @cInclude("zlib-ng.h");
-    @cInclude("lzma.h");
-    @cInclude("lz4.h");
-    @cInclude("zstd.h");
-    @cInclude("zstd_errors.h");
-    @cInclude("lzo/minilzo.h");
-});
@@ -1,114 +0,0 @@
-const std = @import("std");
-const Reader = std.Io.Reader;
-const builtin = @import("builtin");
-
-const Decompressor = @import("../decomp.zig");
-const c = @import("c.zig").c;
-const zng_stream = c.zng_stream;
-
-const ZlibErrors = error{
-    OutOfMemory,
-    OutputBufferTooSmall,
-    BadData,
-    StreamError,
-    Unknown,
-};
-
-const Self = @This();
-
-alloc: std.mem.Allocator,
-
-streams: std.AutoHashMap(std.Thread.Id, zng_stream),
-interface: Decompressor = .{ .vtable = &.{
-    .decompress = decompress,
-    .stateless = stateless,
-} },
-
-err: ?ZlibErrors = null,
-
-pub fn init(alloc: std.mem.Allocator) !Self {
-    return .{
-        .alloc = alloc,
-        .streams = .init(alloc),
-    };
-}
-pub fn deinit(self: Self) void {
-    var iter = self.streams.keyIterator();
-    while (iter.next()) |key| {
-        _ = c.inflateEnd(self.streams.getPtr(key).?);
-    }
-    self.streams.deinit(self.alloc);
-}
-
-fn decompress(decomp: *Decompressor, in: []u8, out: []u8) Decompressor.Error!usize {
-    var self: *Self = @fieldParentPtr("interface", decomp);
-
-    var stream = try self.getOrCreate();
-    stream.next_in = in.ptr;
-    stream.avail_in = @truncate(in.len);
-    stream.next_out = out.ptr;
-    stream.avail_out = @truncate(out.len);
-    var res = c.zng_inflateReset(stream);
-    switch (res) {
-        c.Z_OK => {},
-        c.Z_STREAM_ERROR => {
-            self.err = ZlibErrors.StreamError;
-            return Decompressor.Error.BadInput;
-        },
-        else => {
-            self.err = ZlibErrors.Unknown;
-            return Decompressor.Error.BadInput;
-        },
-    }
-    res = c.zng_inflate(stream, c.Z_FINISH);
-    switch (res) {
-        c.Z_OK => return stream.total_out,
-        c.Z_MEM_ERROR => {
-            self.err = ZlibErrors.OutOfMemory;
-            return Decompressor.Error.OutOfMemory;
-        },
-        c.Z_BUF_ERROR => {
-            self.err = ZlibErrors.OutputBufferTooSmall;
-            return Decompressor.Error.OutputTooSmall;
-        },
-        c.Z_DATA_ERROR => {
-            self.err = ZlibErrors.BadData;
-            return Decompressor.Error.BadInput;
-        },
-        else => {
-            self.err = ZlibErrors.Unknown;
-            return Decompressor.Error.BadInput;
-        },
-    }
-}
-inline fn getOrCreate(self: *Self) Decompressor.Error!*zng_stream {
-    const res = try self.streams.getOrPut(std.Thread.getCurrentId());
-    if (res.found_existing) return res.value_ptr;
-    res.value_ptr.* = .{
-        .zalloc = zalloc,
-        .zfree = zfree,
-        .@"opaque" = @ptrCast(self),
-    };
-    return res.value_ptr;
-}
-
-fn zalloc(self_ptr: ?*anyopaque, items: c_uint, size: c_uint) callconv(.c) ?*anyopaque {
-    var self: *Self = @ptrCast(@alignCast(self_ptr));
-    return self.alloc.rawAlloc(items * size, .@"1", 0);
-}
-fn zfree(self_ptr: ?*anyopaque, alloc_ptr: ?*anyopaque) callconv(.c) void {
-    var self: *Self = @ptrCast(@alignCast(self_ptr));
-    self.alloc.rawFree(@ptrCast(alloc_ptr), .@"1", 0);
-}
-
-fn stateless(_: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
-    var out_len = out.len;
-    const res = c.zng_uncompress(out.ptr, &out_len, in.ptr, in.len);
-    return switch (res) {
-        c.Z_OK => out_len,
-        c.Z_MEM_ERROR => Decompressor.Error.OutOfMemory,
-        c.Z_BUF_ERROR => Decompressor.Error.OutputTooSmall,
-        c.Z_DATA_ERROR => Decompressor.Error.BadInput,
-        else => Decompressor.Error.BadInput,
-    };
-}
@@ -1,146 +0,0 @@
-const std = @import("std");
-const builtin = @import("builtin");
-
-const Decompressor = @import("../decomp.zig");
-const c = @import("c.zig").c;
-const stream = c.lzma_stream;
-
-const Self = @This();
-
-alloc: std.mem.Allocator,
-streams: std.AutoHashMap(std.Thread.Id, stream),
-
-xz: bool,
-interface: Decompressor = .{ .vtable = &.{
-    .decompress = decompress,
-    .stateless = stateless,
-} },
-
-err: ?LzmaError = null,
-
-pub fn init(alloc: std.mem.Allocator, xz: bool) !Self {
-    return .{
-        .alloc = alloc,
-        .streams = .init(alloc),
-        .xz = xz,
-    };
-}
-pub fn deinit(self: Self) void {
-    var iter = self.streams.keyIterator();
-    while (iter.next()) |key|
-        c.lzma_end(self.streams.getPtr(key));
-    self.streams.deinit();
-}
-
-pub fn decompress(decomp: *Decompressor, in: []u8, out: []u8) Decompressor.Error!usize {
-    var self: *Self = @fieldParentPtr("interface", decomp);
-
-    var strm = try self.getOrCreate();
-    strm.next_in = in.ptr;
-    strm.avail_in = in.len;
-    strm.next_out = out.ptr;
-    strm.avail_out = out.len;
-
-    var res = if (self.xz)
-        c.lzma_stream_decoder(strm, in.len * 2, 0)
-    else
-        c.lzma_alone_decoder(strm, in.len * 2);
-    switch (res) {
-        c.LZMA_OK => {},
-        c.LZMA_MEM_ERROR => {
-            self.err = LzmaError.LzmaMemoryError;
-            return Decompressor.Error.OutOfMemory;
-        },
-        c.LZMA_PROG_ERROR => {
-            self.err = LzmaError.LzmaProgramError;
-            return Decompressor.Error.BadInput;
-        },
-        else => {
-            self.err = LzmaError.Unknown;
-            return Decompressor.Error.BadInput;
-        },
-    }
-    while (res == c.LZMA_OK)
-        res = c.lzma_code(strm, c.LZMA_RUN);
-    switch (res) {
-        c.LZMA_STREAM_END => return strm.total_out,
-        c.LZMA_MEM_ERROR => {
-            self.err = LzmaError.LzmaMemoryError;
-            return Decompressor.Error.OutOfMemory;
-        },
-        c.LZMA_MEMLIMIT_ERROR => {
-            self.err = LzmaError.LzmaMemoryLimit;
-            return Decompressor.Error.OutOfMemory;
-        },
-        c.LZMA_FORMAT_ERROR => {
-            self.err = LzmaError.LzmaBadFormat;
-            return Decompressor.Error.BadInput;
-        },
-        c.LZMA_DATA_ERROR => {
-            self.err = LzmaError.LzmaDataCorrupt;
-            return Decompressor.Error.BadInput;
-        },
-        c.LZMA_BUF_ERROR => {
-            self.err = LzmaError.LzmaCannotProgress;
-            return Decompressor.Error.BadInput;
-        },
-        c.LZMA_PROG_ERROR => {
-            self.err = LzmaError.LzmaProgramError;
-            return Decompressor.Error.BadInput;
-        },
-        else => {
-            self.err = LzmaError.Unknown;
-            return Decompressor.Error.BadInput;
-        },
-    }
-}
-pub fn stateless(_: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
-    var strm = c.lzma_stream{
-        .next_in = in.ptr,
-        .avail_in = in.len,
-        .next_out = out.ptr,
-        .avail_out = out.len,
-    };
-
-    var res = c.lzma_auto_decoder(&strm, out.len * 2, 0);
-    switch (res) {
-        c.LZMA_OK => {},
-        c.LZMA_MEM_ERROR => return Decompressor.Error.OutOfMemory,
-        c.LZMA_PROG_ERROR => return Decompressor.Error.BadInput,
-        else => return Decompressor.Error.BadInput,
-    }
-    while (res == c.LZMA_OK)
-        res = c.lzma_code(&strm, c.LZMA_RUN);
-    return switch (res) {
-        c.LZMA_STREAM_END => strm.total_out,
-        c.LZMA_MEM_ERROR => Decompressor.Error.OutOfMemory,
-        c.LZMA_MEMLIMIT_ERROR => Decompressor.Error.OutOfMemory,
-        c.LZMA_FORMAT_ERROR => Decompressor.Error.BadInput,
-        c.LZMA_DATA_ERROR => Decompressor.Error.BadInput,
-        c.LZMA_BUF_ERROR => Decompressor.Error.BadInput,
-        c.LZMA_PROG_ERROR => Decompressor.Error.BadInput,
-        else => Decompressor.Error.BadInput,
-    };
-}
-
-inline fn getOrCreate(self: *Self) Decompressor.Error!*stream {
-    const res = try self.streams.getOrPut(std.Thread.getCurrentId());
-    if (res.found_existing) return res.value_ptr;
-
-    // Ideally, the zero value should be LZMA_STREAM_INIT, but translate-c can't handle it properly.
-    // According to lzma, setting it to entirely zero values *should* work.
-    // res.value_ptr.* = c.LZMA_STREAM_INIT;
-    res.value_ptr.* = std.mem.zeroInit(stream, .{});
-    return res.value_ptr;
-}
-
-pub const LzmaError = error{
-    OutOfMemory,
-    LzmaMemoryError,
-    LzmaMemoryLimit,
-    LzmaBadFormat,
-    LzmaDataCorrupt,
-    LzmaCannotProgress,
-    LzmaProgramError,
-    Unknown,
-};
@@ -1,43 +0,0 @@
-const std = @import("std");
-
-const Decompressor = @import("../decomp.zig");
-const c = @import("c.zig").c;
-
-pub const Lzo = struct {
-    interface: Decompressor = .{ .vtable = &.{ .stateless = lzo } },
-};
-
-fn lzo(_: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
-    var res = c.lzo_init();
-    if (res != 0) return Decompressor.Error.BadInput;
-    var out_len: usize = out.len;
-    res = c.lzo1x_decompress(in.ptr, in.len, out.ptr, &out_len, null);
-
-    return switch (res) {
-        c.LZO_E_OK => out_len,
-        c.LZO_E_OUT_OF_MEMORY => Decompressor.Error.OutOfMemory,
-        c.LZO_E_ERROR,
-        c.LZO_E_INPUT_OVERRUN,
-        c.LZO_E_LOOKBEHIND_OVERRUN,
-        c.LZO_E_EOF_NOT_FOUND,
-        c.LZO_E_NOT_YET_IMPLEMENTED,
-        c.LZO_E_INVALID_ARGUMENT,
-        c.LZO_E_INVALID_ALIGNMENT,
-        => Decompressor.Error.BadInput,
-        c.LZO_E_INPUT_NOT_CONSUMED,
-        c.LZO_E_OUTPUT_NOT_CONSUMED,
-        c.LZO_E_OUTPUT_OVERRUN,
-        => Decompressor.Error.OutputTooSmall,
-        else => Decompressor.Error.BadInput,
-    };
-}
-
-pub const Lz4 = struct {
-    interface: Decompressor = .{ .vtable = &.{ .stateless = lz4 } },
-};
-
-fn lz4(_: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
-    const res = c.LZ4_decompress_safe(in.ptr, out.ptr, @intCast(in.len), @intCast(out.len));
-    if (res > 0) return @abs(res);
-    return Decompressor.Error.BadInput; // TODO: Find out what error values it can return.
-}
@@ -1,51 +0,0 @@
-const std = @import("std");
-const Reader = std.Io.Reader;
-const builtin = @import("builtin");
-
-const Decompressor = @import("../decomp.zig");
-
-pub const Gzip = struct {
-    interface: Decompressor = .{ .vtable = &.{ .stateless = gzip } },
-};
-
-pub fn gzip(alloc: std.mem.Allocator, in: []u8, out: []u8) anyerror!usize {
-    var rdr: Reader = .fixed(in);
-    const buf = try alloc.alloc(u8, out.len);
-    defer alloc.free(buf);
-    var decomp = std.compress.flate.Decompress.init(&rdr, .zlib, buf);
-    return decomp.reader.readSliceShort(out);
-}
-
-pub const Lzma = struct {
-    interface: Decompressor = .{ .vtable = &.{ .stateless = lzma } },
-};
-
-pub fn lzma(alloc: std.mem.Allocator, in: []u8, out: []u8) anyerror!usize {
-    var rdr: Reader = .fixed(in);
-    var decomp = try std.compress.lzma.decompress(alloc, rdr.adaptToOldInterface());
-    return decomp.read(out);
-}
-
-pub const Xz = struct {
-    interface: Decompressor = .{ .vtable = &.{ .stateless = xz } },
-};
-
-pub fn xz(alloc: std.mem.Allocator, in: []u8, out: []u8) anyerror!usize {
-    var rdr: Reader = .fixed(in);
-    var decomp = try std.compress.xz.decompress(alloc, rdr.adaptToOldInterface());
-    return decomp.read(out);
-}
-
-pub const Zstd = struct {
-    interface: Decompressor = .{ .vtable = &.{ .stateless = zstd } },
-};
-
-pub fn zstd(alloc: std.mem.Allocator, in: []u8, out: []u8) anyerror!usize {
-    var rdr: Reader = .fixed(in);
-    const buf = try alloc.alloc(u8, 1024 * 1024);
-    defer alloc.free(buf);
-    var decomp = std.compress.zstd.Decompress.init(&rdr, buf, .{});
-    return decomp.reader.readSliceShort(out) catch |err| {
-        return decomp.err orelse err;
-    };
-}
@@ -1,216 +0,0 @@
-const std = @import("std");
-const builtin = @import("builtin");
-
-const Decompressor = @import("../decomp.zig");
-const c = @import("c.zig").c;
-const DCtx = c.ZSTD_DCtx;
-
-const Self = @This();
-
-alloc: std.mem.Allocator,
-ctx: std.AutoHashMap(std.Thread.Id, *DCtx),
-
-interface: Decompressor = .{ .vtable = &.{
-    .decompress = decompress,
-    .stateless = stateless,
-} },
-err: ?ZstdError = null,
-
-pub fn init(alloc: std.mem.Allocator) !Self {
-    return .{
-        .alloc = alloc,
-        .ctx = .init(alloc),
-    };
-}
-pub fn deinit(self: Self) void {
-    var iter = self.ctx.keyIterator();
-    while (iter.next()) |key| {
-        _ = c.ZSTD_freeDCtx(self.ctx.getPtr(key));
-    }
-    self.ctx.deinit(self.alloc);
-}
-
-pub fn decompress(decomp: *Decompressor, in: []u8, out: []u8) Decompressor.Error!usize {
-    var self: *Self = @fieldParentPtr("interface", decomp);
-
-    const ctx = try self.getOrCreate();
-    const res = c.ZSTD_decompressDCtx(ctx, out.ptr, out.len, in.ptr, in.len);
-    try self.checkError(res);
-    return res;
-}
-inline fn getOrCreate(self: *Self) Decompressor.Error!*DCtx {
-    const res = try self.ctx.getOrPut(std.Thread.getCurrentId());
-    if (res.found_existing) {
-        try self.checkError(c.ZSTD_DCtx_reset(res.value_ptr.*, c.ZSTD_reset_session_only));
-        return res.value_ptr.*;
-    }
-    res.value_ptr.* = c.ZSTD_createDCtx() orelse return Decompressor.Error.OutOfMemory;
-    return res.value_ptr.*;
-}
-
-fn stateless(_: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
-    const res = c.ZSTD_decompress(out.ptr, out.len, in.ptr, in.len);
-    if (c.ZSTD_isError(res) == 0) return res;
-    return switch (c.ZSTD_getErrorCode(res)) {
-        c.ZSTD_error_memory_allocation => Decompressor.Error.OutOfMemory,
-        c.ZSTD_error_workSpace_tooSmall,
-        c.ZSTD_error_dstSize_tooSmall,
-        c.ZSTD_error_dstBuffer_null,
-        c.ZSTD_error_noForwardProgress_destFull,
-        => Decompressor.Error.OutputTooSmall,
-        else => Decompressor.Error.BadInput,
-    };
-}
-
-inline fn checkError(self: *Self, res: usize) Decompressor.Error!void {
-    if (res == 0) return;
-    if (c.ZSTD_isError(res) == 0) return;
-    switch (c.ZSTD_getErrorCode(res)) {
-        c.ZSTD_error_prefix_unknown => {
-            self.err = ZstdError.PrefixUnknown;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_version_unsupported => {
-            self.err = ZstdError.VersionUnsupported;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_frameParameter_unsupported => {
-            self.err = ZstdError.FrameParameterUnsupported;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_frameParameter_windowTooLarge => {
-            self.err = ZstdError.FrameParameterWindowTooLarge;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_corruption_detected => {
-            self.err = ZstdError.CorruptionDetected;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_checksum_wrong => {
-            self.err = ZstdError.ChecksumWrong;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_literals_headerWrong => {
-            self.err = ZstdError.LiteralsHeaderWrong;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_dictionary_corrupted => {
-            self.err = ZstdError.DictionaryCorrupted;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_dictionary_wrong => {
-            self.err = ZstdError.DictionaryWrong;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_dictionaryCreation_failed => {
-            self.err = ZstdError.DictionaryCreationFailed;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_parameter_unsupported => {
-            self.err = ZstdError.ParameterUnsupported;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_parameter_combination_unsupported => {
-            self.err = ZstdError.ParameterCombinationUnsupported;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_parameter_outOfBound => {
-            self.err = ZstdError.ParameterOutOfBound;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_tableLog_tooLarge => {
-            self.err = ZstdError.TableLogTooLarge;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_maxSymbolValue_tooLarge => {
-            self.err = ZstdError.MaxSymbolValueTooLarge;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_maxSymbolValue_tooSmall => {
-            self.err = ZstdError.MaxSymbolValueTooSmall;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_stabilityCondition_notRespected => {
-            self.err = ZstdError.StabilityConditionNotRespected;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_stage_wrong => {
-            self.err = ZstdError.StageWrong;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_init_missing => {
-            self.err = ZstdError.InitMissing;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_memory_allocation => {
-            self.err = ZstdError.MemoryAllocation;
-            return Decompressor.Error.OutOfMemory;
-        },
-        c.ZSTD_error_workSpace_tooSmall => {
-            self.err = ZstdError.WorkSpaceTooSmall;
-            return Decompressor.Error.OutputTooSmall;
-        },
-        c.ZSTD_error_dstSize_tooSmall => {
-            self.err = ZstdError.DstSizeTooSmall;
-            return Decompressor.Error.OutputTooSmall;
-        },
-        c.ZSTD_error_srcSize_wrong => {
-            self.err = ZstdError.SrcSizeWrong;
-            return Decompressor.Error.BadInput;
-        },
-        c.ZSTD_error_dstBuffer_null => {
-            self.err = ZstdError.DstBufferNull;
-            return Decompressor.Error.OutputTooSmall;
-        },
-        c.ZSTD_error_noForwardProgress_destFull => {
-            self.err = ZstdError.NoForwardProgressDestFull;
-            return Decompressor.Error.OutputTooSmall;
-        },
-        c.ZSTD_error_noForwardProgress_inputEmpty => {
-            self.err = ZstdError.NoForwardProgressInputEmpty;
-            return Decompressor.Error.BadInput;
-        },
-        else => {
-            self.err = ZstdError.Generic;
-            return Decompressor.Error.BadInput;
-        },
-    }
-}
-pub const ZstdError = error{
-    OutOfMemory,
-    Generic,
-    PrefixUnknown,
-    VersionUnsupported,
-    FrameParameterUnsupported,
-    FrameParameterWindowTooLarge,
-    CorruptionDetected,
-    ChecksumWrong,
-    LiteralsHeaderWrong,
-    DictionaryCorrupted,
-    DictionaryWrong,
-    DictionaryCreationFailed,
-    ParameterUnsupported,
-    ParameterCombinationUnsupported,
-    ParameterOutOfBound,
-    TableLogTooLarge,
-    MaxSymbolValueTooLarge,
-    MaxSymbolValueTooSmall,
-    CannotProduceUncompressedBlock,
-    StabilityConditionNotRespected,
-    StageWrong,
-    InitMissing,
-    MemoryAllocation,
-    WorkSpaceTooSmall,
-    DstSizeTooSmall,
-    SrcSizeWrong,
-    DstBufferNull,
-    NoForwardProgressDestFull,
-    NoForwardProgressInputEmpty,
-    FrameIndexTooLarge,
-    SeekableIo,
-    DstBufferWrong,
-    SrcBufferWrong,
-    SequenceProducerFailed,
-    ExternalSequencesInvalid,
-    MaxCode,
-};
@@ -1,60 +1,67 @@
-//! Directory entry from the directory table.
-
 const std = @import("std");
 const Reader = std.Io.Reader;

-const InodeType = @import("inode.zig").InodeType;
+const Inode = @import("inode.zig");

-const Entry = @This();
-
-const Header = extern struct { // use extern due to bad alignment with packed.
+const Header = extern struct {
    count: u32,
    block_start: u32,
    num: u32,
 };
-
-const RawEntry = packed struct {
-    offset: u16,
-    inode_offset: i16,
-    inode_type: InodeType,
+const Entry = extern struct {
+    block_offset: u16,
+    num_offset: i16,
+    inode_type: Inode.Type,
    name_size: u16,
 };

-block_start: u32,
-block_offset: u16,
-num: u32,
-inode_type: InodeType,
+pub const Error = error{OutOfMemory} || std.Io.Reader.Error;
+
+const DirEntry = @This();
+
+inode_type: Inode.Type,
 name: []const u8,

-pub fn readDir(alloc: std.mem.Allocator, rdr: *Reader, size: u32) ![]Entry {
-    var cur_red: u32 = 3; // start at 3 due to "." & ".." being counted in the dir size.
-    var hdr: Header = undefined;
-    var raw: RawEntry = undefined;
-    var out: std.ArrayList(Entry) = try .initCapacity(alloc, 100); // Start out with a decent capacity instead of needing to allocate per header.
-    errdefer out.deinit(alloc);
-    while (cur_red < size) {
-        try rdr.readSliceEndian(Header, @ptrCast(&hdr), .little);
-        cur_red += @sizeOf(Header);
-        try out.ensureUnusedCapacity(alloc, hdr.count + 1);
-        for (0..hdr.count + 1) |_| {
-            try rdr.readSliceEndian(RawEntry, @ptrCast(&raw), .little);
-            const name = try alloc.alloc(u8, raw.name_size + 1);
-            errdefer alloc.free(name);
-            try rdr.readSliceEndian(u8, name, .little);
-            const val = out.addOneAssumeCapacity();
-            val.* = .{
-                .block_start = hdr.block_start,
-                .block_offset = raw.offset,
-                .num = @abs(hdr.num + raw.offset),
-                .inode_type = raw.inode_type,
-                .name = name,
-            };
-            cur_red += @sizeOf(RawEntry) + raw.name_size + 1;
-        }
-    }
-    return out.toOwnedSlice(alloc);
-}
+block_start: u32,
+block_offset: u32,
+num: u32,

-pub fn deinit(self: Entry, alloc: std.mem.Allocator) void {
+pub fn deinit(self: DirEntry, alloc: std.mem.Allocator) void {
    alloc.free(self.name);
 }
+
+pub fn readEntries(alloc: std.mem.Allocator, rdr: *Reader, size: u32) Error![]DirEntry {
+    var out: std.ArrayList(DirEntry) = try .initCapacity(alloc, 50);
+    errdefer out.deinit(alloc);
+
+    var tot_read: u32 = 3;
+    while (tot_read < size) {
+        var hdr: Header = undefined;
+        try rdr.readSliceEndian(Header, @ptrCast(&hdr), .little);
+        tot_read += @sizeOf(Header);
+
+        try out.ensureUnusedCapacity(alloc, hdr.count + 1);
+
+        for (0..hdr.count + 1) |_| {
+            var ent: Entry = undefined;
+            try rdr.readSliceEndian(Entry, @ptrCast(&ent), .little);
+            tot_read += @sizeOf(Entry) + ent.name_size + 1;
+
+            const name = try alloc.alloc(u8, ent.name_size + 1);
+            errdefer alloc.free(name);
+
+            try rdr.readSliceEndian(u8, name, .little);
+
+            out.appendAssumeCapacity(.{
+                .inode_type = ent.inode_type,
+                .name = name,
+
+                .block_offset = ent.block_offset,
+                .block_start = hdr.block_start,
+                .num = @intCast(@as(i64, @intCast(hdr.num)) + ent.num_offset),
+            });
+        }
+    }
+
+    return out.toOwnedSlice(alloc);
+}
@@ -1,202 +1,126 @@
-//! A file/directory within the squashfs archive.
+//! A wrapper around an Inode to make common activities easier.

 const std = @import("std");
-const File = std.fs.File;
-const WaitGroup = std.Thread.WaitGroup;
-const Mutex = std.Thread.Mutex;
+const Io = std.Io;

 const Archive = @import("archive.zig");
 const DirEntry = @import("dir_entry.zig");
 const ExtractionOptions = @import("options.zig");
 const Inode = @import("inode.zig");
-const BlockSize = @import("inode_data/file.zig").BlockSize;
-const DataReader = @import("util/data.zig");
+const LookupTable = @import("lookup_table.zig");
 const MetadataReader = @import("util/metadata.zig");

-const FileError = error{
-    NotDirectory,
-    NotRegularFile,
-    NotSymlink,
-    NotDevice,
+pub const Error = error{
    NotFound,
-    ExtractionPathExists,
 };

-const SfsFile = @This();
+const File = @This();

+alloc: std.mem.Allocator,
 archive: *Archive,

-inode: Inode,
 name: []const u8,
+inode: Inode,
+
+pub fn fromEntry(alloc: std.mem.Allocator, io: Io, archive: *Archive, entry: DirEntry) !File {
+    var meta: MetadataReader = .init(io, &archive.cache, archive.super.inode_start + entry.block_start);
+    defer meta.deinit();
+    try meta.interface.discardAll(entry.block_offset);
+
+    const new_name = try alloc.alloc(u8, entry.name.len);
+    errdefer alloc.free(new_name);
+    @memcpy(new_name, entry.name);

-/// Initialize a new File.
-/// name is copied to the File so can be safely freed afterwards.
-pub fn init(archive: *Archive, inode: Inode, name: []const u8) !SfsFile {
-    const new_name = try archive.allocator().alloc(u8, name.len);
-    @memcpy(new_name, name);
    return .{
+        .alloc = alloc,
        .archive = archive,
-        .inode = inode,
+
+        .name = new_name,
+        .inode = try .fromReader(alloc, &meta.interface, archive.super.block_size),
+    };
+}
+/// Create a File from an Inode.Ref. name should be created using the alloc given.
+pub fn fromRef(alloc: std.mem.Allocator, io: Io, archive: *Archive, name: []const u8, ref: Inode.Ref) !File {
+    return .{
+        .alloc = alloc,
+        .archive = archive,
+
+        .name = name,
+        .inode = try .fromRef(
+            alloc,
+            io,
+            &archive.cache,
+            archive.super.inode_start,
+            archive.super.block_size,
+            ref,
+        ),
+    };
+}
+pub fn copy(alloc: std.mem.Allocator, from: File) !File {
+    const new_name = try alloc.alloc(u8, from.name.len);
+    errdefer alloc.free(new_name);
+    @memcpy(new_name, from.name);
+
+    return .{
+        .alloc = alloc,
+        .archive = from.archive,
+
+        .inode = try .copy(alloc, from.inode),
        .name = new_name,
    };
 }
-pub fn fromEntry(archive: *Archive, entry: DirEntry) !SfsFile {
-    var rdr = try archive.fil.readerAt(entry.block_start + archive.super.inode_start, &[0]u8{});
-    var meta: MetadataReader = .init(archive.allocator(), &rdr.interface, archive.decomp);
-    try meta.interface.discardAll(entry.block_offset);
-    const inode: Inode = try .read(archive.allocator(), &meta.interface, archive.super.block_size);
-    errdefer inode.deinit(archive.allocator());
-    return .init(archive, inode, entry.name);
+pub fn deinit(self: File) void {
+    self.alloc.free(self.name);
+    self.inode.deinit(self.alloc);
 }

-pub fn deinit(self: SfsFile) void {
-    var alloc = self.archive.allocator();
-    alloc.free(self.name);
-    self.inode.deinit(alloc);
-}
+pub fn open(self: File, alloc: std.mem.Allocator, io: Io, filepath: []const u8) !File {
+    const path = std.mem.trim(u8, filepath, "/");

-fn getEntries(self: SfsFile) ![]DirEntry {
-    return self.inode.dirEntries(self.archive.allocator(), self.archive.*);
-}
+    if (path.len == 0 or std.mem.eql(u8, path, ".")) return .copy(alloc, self);

-pub fn ownerUid(self: SfsFile) !u16 {
-    return self.archive.id(self.inode.hdr.uid_idx);
-}
-pub fn ownerGid(self: SfsFile) !u16 {
-    return self.archive.id(self.inode.hdr.gid_idx);
-}
-pub fn permissions(self: SfsFile) u16 {
-    return self.inode.hdr.permissions;
-}
+    const first_element = std.mem.sliceTo(path, '/');

-pub fn isRegular(self: SfsFile) bool {
-    return switch (self.inode.hdr.inode_type) {
-        .file, .ext_file => true,
-        else => false,
-    };
-}
-/// The returned DataReader will no longer work if the File's deinit function is called
-/// or, more specifically, it's inode's deinit function is called.
-pub fn dataReader(self: SfsFile) !DataReader {
-    return self.inode.dataReader(self.archive);
-}
-
-pub fn isDir(self: SfsFile) bool {
-    return switch (self.inode.hdr.inode_type) {
-        .dir, .ext_dir => true,
-        else => false,
-    };
-}
-pub fn iterate(self: SfsFile) !Iterator {
-    if (!self.isDir()) return FileError.NotDirectory;
-    return .{
-        .entries = try self.getEntries(),
-        .archive = self.archive,
-    };
-}
-/// Open a sub-file/folder within a directory at the given path.
-/// If path is "", ".", "/", or "./", this File is returned.
-pub fn open(self: SfsFile, alloc: std.mem.Allocator, path: []const u8) !SfsFile {
-    if (!self.isDir()) return FileError.NotDirectory;
-    if (pathIsSelf(path)) return self;
-
-    // Recursively stip ending & leading path separators.
-    if (path[0] == '/') return self.open(path[1..]);
-    if (path[path.len - 1] == '/') return self.open(path[0 .. path.len - 1]);
-
-    const idx = std.mem.indexOf(u8, path, "/") orelse path.len;
-    const first_element = path[0..idx];
-    if (std.mem.eql(u8, first_element, ".")) return self.open(path[idx + 1 ..]);
-    const entries = try self.getEntries();
+    const entries = try self.inode.readDirectory(alloc, io, &self.archive.cache, self.archive.super.dir_start);
    defer {
-        for (entries) |e| {
-            e.deinit(alloc);
-        }
+        for (entries) |entry|
+            entry.deinit(alloc);
        alloc.free(entries);
    }
-    var cur_slice = entries;
-    var split = cur_slice.len / 2;
-    while (cur_slice.len > 0) {
-        split = cur_slice.len / 2;
-        const comp = std.mem.order(u8, first_element, cur_slice[split].name);
-        switch (comp) {
-            .eq => {
-                var fil: SfsFile = try .fromEntry(self.archive, cur_slice[split]);
-                if (idx == path.len) {
-                    return fil;
+
+    // Potentially I could use linear searching on small dir tables...
+    var search_slice = entries;
+    var idx = search_slice.len / 2;
+    while (search_slice.len > 0) {
+        const order = std.mem.order(u8, first_element, search_slice[idx].name);
+        switch (order) {
+            .eq => break,
+            .gt => search_slice = search_slice[idx..],
+            .lt => search_slice = search_slice[0..idx],
        }
+        idx = search_slice.len / 2;
+    }
+    if (search_slice.len == 0) return Error.NotFound;
+
+    var fil: File = try .fromEntry(alloc, io, self.archive, search_slice[idx]);
+    if (path.len == first_element.len) return fil;
    defer fil.deinit();
-                return fil.open(alloc, path[idx + 1 ..]);
-            },
-            .lt => cur_slice = cur_slice[0..split],
-            .gt => cur_slice = cur_slice[split + 1 ..],
-        }
-    }
-    return FileError.NotFound;
+
+    return fil.open(alloc, io, filepath[first_element.len..]);
 }

-pub fn isSymlink(self: SfsFile) bool {
-    return switch (self.inode.hdr.inode_type) {
-        .symlink, .ext_symlink => true,
-        else => false,
-    };
+pub fn extract(self: File, alloc: std.mem.Allocator, io: Io, path: []const u8, options: ExtractionOptions) !void {
+    return self.inode.extract(
+        alloc,
+        io,
+        &self.archive.cache,
+        self.archive.super.dir_start,
+        self.archive.super.inode_start,
+        self.archive.super.frag_start,
+        self.archive.super.block_size,
+        self.archive.super.id_start,
+        self.archive.super.xattr_start,
+        path,
+        options,
+    );
 }
-pub fn symlinkPath(self: SfsFile) ![]const u8 {
-    if (!self.isSymlink()) return FileError.NotSymlink;
-    return switch (self.inode.data) {
-        .symlink => |s| s.target,
-        .ext_symlink => |s| s.target,
-        else => unreachable,
-    };
-}
-
-/// Check if the File is a block or character device.
-pub fn isDevice(self: SfsFile) bool {
-    return switch (self.inode.hdr.inode_type) {
-        .block_dev, .char_dev, .ext_block_dev, .ext_char_dev => true,
-        else => false,
-    };
-}
-/// If the File is a block or character device, get's it's device number.
-pub fn devNum(self: SfsFile) !u32 {
-    if (!self.isDevice()) return FileError.NotDevice;
-    return switch (self.inode.data) {
-        .block_dev, .char_dev => |d| d.dev,
-        .ext_block_dev, .ext_char_dev => |d| d.dev,
-        else => unreachable,
-    };
-}
-
-/// Extract the given File to the path. If File is a regular file, the path must be a directory or not exist.
-/// If the gievn path is a folder, the File's contents will be extracted within.
-pub fn extract(self: *SfsFile, alloc: std.mem.Allocator, path: []const u8, options: ExtractionOptions) !void {
-    return self.inode.extractToThreaded(alloc, self.archive, path, options);
-}
-
-/// Utility function.
-pub fn pathIsSelf(path: []const u8) bool {
-    if (path.len == 0) return true;
-    if (path.len == 1 and (path[0] == '/' or path[0] == '.')) return true;
-    if (path.len == 2 and (path[0] == '.' and path[1] == '/')) return true;
-    return false;
-}
-
-pub const Iterator = struct {
-    entries: []DirEntry,
-    archive: *Archive,
-
-    idx: u32 = 0,
-
-    pub fn next(self: *Iterator) !?SfsFile {
-        if (self.idx >= self.entries.len) return null;
-        defer self.idx += 1;
-        return try SfsFile.fromEntry(self.archive, self.entries[self.idx]);
-    }
-    pub fn deinit(self: Iterator) void {
-        var alloc = self.archive.allocator();
-        for (self.entries) |e| {
-            e.deinit(alloc);
-        }
-        alloc.free(self.entries);
-    }
-};
@@ -0,0 +1,7 @@
+const BlockSize = @import("inode_data/file.zig").BlockSize;
+
+pub const FragEntry = extern struct {
+    start: u64,
+    size: BlockSize,
+    _: u32,
+};
@@ -1,32 +1,27 @@
 //! A file-system object. Represents a File or directory.

 const std = @import("std");
-const Reader = std.Io.Reader;
-const WaitGroup = std.Thread.WaitGroup;
-const Pool = std.Thread.Pool;
-const Mutex = std.Thread.Mutex;
+const Io = std.Io;
+const Reader = Io.Reader;

-const Archive = @import("archive.zig");
 const DirEntry = @import("dir_entry.zig");
 const ExtractionOptions = @import("options.zig");
-const dir = @import("inode_data/dir.zig");
-const file = @import("inode_data/file.zig");
-const misc = @import("inode_data/misc.zig");
-const Tables = @import("tables.zig");
-const DataReader = @import("util/data.zig");
-const ThreadedDataReader = @import("util/data_threaded.zig");
-const InodeExtract = @import("util/extract.zig");
-const InodeFinish = @import("util/inode_finish.zig");
-const FinishUnion = InodeFinish.FinishUnion;
+const FragEntry = @import("frag.zig").FragEntry;
+const DirTypes = @import("inode_data/dir.zig");
+const FileTypes = @import("inode_data/file.zig");
+const MiscTypes = @import("inode_data/misc.zig");
+const LookupTable = @import("lookup_table.zig");
+const DataExtract = @import("util/data_extract.zig");
+const DecompCache = @import("util/decomp_cache.zig");
 const MetadataReader = @import("util/metadata.zig");

-pub const Ref = packed struct {
+pub const Ref = packed struct(u64) {
    block_offset: u16,
    block_start: u32,
    _: u16,
 };

-pub const InodeType = enum(u16) {
+pub const Type = enum(u16) {
    dir = 1,
    file,
    symlink,
@@ -43,25 +38,25 @@ pub const InodeType = enum(u16) {
    ext_socket,
 };

-pub const InodeData = union(InodeType) {
-    dir: dir.Dir,
-    file: file.File,
-    symlink: misc.Symlink,
-    block_dev: misc.Dev,
-    char_dev: misc.Dev,
-    fifo: misc.IPC,
-    socket: misc.IPC,
-    ext_dir: dir.ExtDir,
-    ext_file: file.ExtFile,
-    ext_symlink: misc.ExtSymlink,
-    ext_block_dev: misc.ExtDev,
-    ext_char_dev: misc.ExtDev,
-    ext_fifo: misc.ExtIPC,
-    ext_socket: misc.ExtIPC,
+pub const Data = union(Type) {
+    dir: DirTypes.Dir,
+    file: FileTypes.File,
+    symlink: MiscTypes.Symlink,
+    block_dev: MiscTypes.Dev,
+    char_dev: MiscTypes.Dev,
+    fifo: MiscTypes.IPC,
+    socket: MiscTypes.IPC,
+    ext_dir: DirTypes.ExtDir,
+    ext_file: FileTypes.ExtFile,
+    ext_symlink: MiscTypes.ExtSymlink,
+    ext_block_dev: MiscTypes.ExtDev,
+    ext_char_dev: MiscTypes.ExtDev,
+    ext_fifo: MiscTypes.ExtIPC,
+    ext_socket: MiscTypes.ExtIPC,
 };

 pub const Header = packed struct {
-    inode_type: InodeType,
+    inode_type: Type,
    permissions: u16,
    uid_idx: u16,
    gid_idx: u16,
@@ -69,12 +64,22 @@ pub const Header = packed struct {
    num: u32,
 };

+pub const Error = error{
+    NotDirectory,
+};
+
 const Inode = @This();

 hdr: Header,
-data: InodeData,
+data: Data,

-pub fn read(alloc: std.mem.Allocator, rdr: *Reader, block_size: u32) !Inode {
+pub fn fromRef(alloc: std.mem.Allocator, io: Io, cache: *DecompCache, inode_start: u64, block_size: u32, ref: Ref) !Inode {
+    var meta: MetadataReader = .init(io, cache, ref.block_start + inode_start);
+    defer meta.deinit();
+    try meta.interface.discardAll(ref.block_offset);
+    return fromReader(alloc, &meta.interface, block_size);
+}
+pub fn fromReader(alloc: std.mem.Allocator, rdr: *Reader, block_size: u32) !Inode {
    var hdr: Header = undefined;
    try rdr.readSliceEndian(Header, @ptrCast(&hdr), .little);
    return .{
@@ -97,13 +102,31 @@ pub fn read(alloc: std.mem.Allocator, rdr: *Reader, block_size: u32) !Inode {
        },
    };
 }
-pub fn readFromEntry(alloc: std.mem.Allocator, archive: Archive, entry: DirEntry) !Inode {
-    var rdr = try archive.fil.readerAt(archive.super.inode_start + entry.block_start, &[0]u8{});
-    var meta: MetadataReader = .init(alloc, &rdr.interface, archive.decomp);
-    try meta.interface.discardAll(entry.block_offset);
-    return read(alloc, &meta.interface, archive.super.block_size);
+pub fn copy(alloc: std.mem.Allocator, from: Inode) !Inode {
+    var new = from;
+    switch (from.data) {
+        .file => |f| {
+            new.data.file.block_sizes = try alloc.alloc(FileTypes.BlockSize, f.block_sizes.len);
+            @memcpy(new.data.file.block_sizes, f.block_sizes);
+        },
+        .ext_file => |f| {
+            new.data.ext_file.block_sizes = try alloc.alloc(FileTypes.BlockSize, f.block_sizes.len);
+            @memcpy(new.data.ext_file.block_sizes, f.block_sizes);
+        },
+        .symlink => |s| {
+            const new_target = try alloc.alloc(u8, s.target.len);
+            @memcpy(new_target, s.target);
+            new.data.symlink.target = new_target;
+        },
+        .ext_symlink => |s| {
+            const new_target = try alloc.alloc(u8, s.target.len);
+            @memcpy(new_target, s.target);
+            new.data.ext_symlink.target = new_target;
+        },
+        else => {},
+    }
+    return new;
 }
-
 pub fn deinit(self: Inode, alloc: std.mem.Allocator) void {
    switch (self.data) {
        .file => |f| alloc.free(f.block_sizes),
@@ -114,76 +137,298 @@ pub fn deinit(self: Inode, alloc: std.mem.Allocator) void {
    }
 }

-/// Get the data reader for a file inode.
-pub fn dataReader(self: Inode, alloc: std.mem.Allocator, archive: Archive, tables: *Tables) !DataReader {
-    return switch (self.hdr.inode_type) {
-        .file => readerFromData(alloc, archive, tables, self.data.file),
-        .ext_file => readerFromData(alloc, archive, tables, self.data.ext_file),
-        else => error.NotRegularFile,
-    };
-}
-fn readerFromData(alloc: std.mem.Allocator, archive: Archive, tables: *Tables, data: anytype) !DataReader {
-    var out: DataReader = .init(alloc, archive, data.block_sizes, data.block_start, data.size);
-    if (data.frag_idx != 0xFFFFFFFF)
-        out.addFragment(try tables.frag_table.get(data.frag_idx), data.frag_block_offset);
-    return out;
-}
-
-/// Get the directory entries for a directory inode.
-pub fn dirEntries(self: Inode, alloc: std.mem.Allocator, archive: Archive) ![]DirEntry {
-    return switch (self.hdr.inode_type) {
-        .dir => entriesFromData(alloc, archive, self.data.dir),
-        .ext_dir => entriesFromData(alloc, archive, self.data.ext_dir),
-        else => error.NotDirectory,
-    };
-}
-fn entriesFromData(alloc: std.mem.Allocator, archive: Archive, data: anytype) ![]DirEntry {
-    var rdr = try archive.fil.readerAt(archive.super.dir_start + data.block_start, &[0]u8{});
-    var meta: MetadataReader = .init(alloc, &rdr.interface, archive.decomp);
-    try meta.interface.discardAll(data.block_offset);
-    return DirEntry.readDir(alloc, &meta.interface, data.size);
-}
-
-/// Returns the xattr index for the given inode. If the inode isn't an extended variant or doesn't have any, the u32 max is returned (0xFFFFFFFF).
-pub fn xattrIdx(self: Inode) u32 {
+pub fn readDirectory(self: Inode, alloc: std.mem.Allocator, io: Io, cache: *DecompCache, dir_start: u64) ![]DirEntry {
    return switch (self.data) {
-        .ext_dir => |d| d.xattr_id,
+        .dir => |d| readDirectoryFromData(alloc, io, cache, dir_start, d),
+        .ext_dir => |d| readDirectoryFromData(alloc, io, cache, dir_start, d),
+        else => Error.NotDirectory,
+    };
+}
+fn readDirectoryFromData(alloc: std.mem.Allocator, io: Io, cache: *DecompCache, dir_start: u64, d: anytype) ![]DirEntry {
+    var meta: MetadataReader = .init(io, cache, dir_start + d.block_start);
+    defer meta.deinit();
+    try meta.interface.discardAll(d.block_offset);
+
+    return DirEntry.readEntries(alloc, &meta.interface, d.size);
+}
+
+// Extraction
+
+pub fn extract(
+    self: Inode,
+    alloc: std.mem.Allocator,
+    io: Io,
+    cache: *DecompCache,
+    dir_start: u64,
+    inode_start: u64,
+    frag_start: u64,
+    block_size: u32,
+    id_start: u64,
+    xattr_start: u64,
+    ext_loc: []const u8,
+    options: ExtractionOptions,
+) !void {
+    const path = std.mem.trimEnd(u8, ext_loc, "/");
+
+    var sel_val: std.atomic.Value(usize) = .init(1);
+
+    var sel_buf: [5]ExtractUnion = undefined;
+    var sel: Io.Select(ExtractUnion) = .init(io, &sel_buf);
+    defer sel.cancelDiscard();
+
+    var meta_loop = io.async(metadataLoop, .{ alloc, io, cache, id_start, xattr_start, &sel, &sel_val, options });
+    defer _ = meta_loop.cancel(io) catch {};
+
+    sel.async(.ret, extractReal, .{ self, alloc, io, cache, dir_start, inode_start, frag_start, block_size, &sel, &sel_val, path, true });
+
+    try meta_loop.await(io);
+}
+fn extractReal(
+    self: Inode,
+    alloc: std.mem.Allocator,
+    io: Io,
+    cache: *DecompCache,
+    dir_start: u64,
+    inode_start: u64,
+    frag_start: u64,
+    block_size: u32,
+    sel: *Io.Select(ExtractUnion),
+    sel_val: *std.atomic.Value(usize),
+    path: []const u8,
+    origin: bool,
+) ExtractionError!ExtractReturn {
+    errdefer if (!origin) {
+        self.deinit(alloc);
+        alloc.free(path);
+    };
+    switch (self.hdr.inode_type) {
+        .dir, .ext_dir => {
+            try Io.Dir.cwd().createDir(io, path, @enumFromInt(0o777));
+
+            const entries = self.readDirectory(alloc, io, cache, dir_start) catch |err| switch (err) {
+                error.NotDirectory => unreachable,
+                else => |e| return e,
+            };
+            defer {
+                for (entries) |entry|
+                    entry.deinit(alloc);
+                alloc.free(entries);
+            }
+
+            if (entries.len != 0) {
+                _ = sel_val.fetchAdd(entries.len, .acq_rel);
+
+                for (entries) |entry| {
+                    var meta: MetadataReader = .init(io, cache, inode_start + entry.block_start);
+                    defer meta.deinit();
+                    try meta.interface.discardAll(entry.block_offset);
+
+                    var new_inode: Inode = try .fromReader(alloc, &meta.interface, block_size);
+                    errdefer new_inode.deinit(alloc);
+
+                    const new_path = try std.mem.concat(alloc, u8, &.{ path, "/", entry.name });
+                    errdefer alloc.free(new_path);
+                    sel.async(
+                        .ret,
+                        extractReal,
+                        .{ new_inode, alloc, io, cache, dir_start, inode_start, frag_start, block_size, sel, sel_val, new_path, false },
+                    );
+                }
+            }
+        },
+        .file, .ext_file => {
+            std.debug.print("{s} {}\n", .{ path, self.data });
+            // var atomic = try Io.Dir.cwd().createFileAtomic(io, path, .{});
+            // defer atomic.deinit(io);
+
+            // var data: DataExtract = undefined;
+            // var frag_offset: ?u64 = null;
+            // switch (self.data) {
+            //     .file => |f| {
+            //         data = .init(cache.decomp, cache.map, block_size, f.block_start, f.size, f.block_sizes);
+            //         if (f.frag_idx != 0xFFFFFFFF) {
+            //             const entry: FragEntry = try LookupTable.lookup(FragEntry, io, cache, frag_start, f.frag_idx);
+            //             if (entry.size.uncompressed) {
+            //                 data.addFrag(cache.map.memory[entry.start..][0..entry.size.size], f.frag_offset);
+            //             } else {
+            //                 frag_offset = entry.start;
+            //                 const block = try cache.checkoutBlock(io, entry.start, entry.size.size, block_size);
+            //                 data.addFrag(block, f.frag_offset);
+            //             }
+            //         }
+            //     },
+            //     .ext_file => |f| {
+            //         data = .init(cache.decomp, cache.map, block_size, f.block_start, f.size, f.block_sizes);
+            //         if (f.frag_idx != 0xFFFFFFFF) {
+            //             const entry: FragEntry = try LookupTable.lookup(FragEntry, io, cache, frag_start, f.frag_idx);
+            //             if (entry.size.uncompressed) {
+            //                 data.addFrag(cache.map.memory[entry.start..][0..entry.size.size], f.frag_offset);
+            //             } else {
+            //                 frag_offset = entry.start;
+            //                 const block = try cache.checkoutBlock(io, entry.start, entry.size.size, block_size);
+            //                 data.addFrag(block, f.frag_offset);
+            //             }
+            //         }
+            //     },
+            //     else => unreachable,
+            // }
+            // defer if (frag_offset != null) cache.checkinBlock(io, frag_offset.?) catch {};
+            // try data.asyncExtract(alloc, io, atomic.file);
+
+            // try atomic.link(io);
+        },
+        .symlink, .ext_symlink => {
+            const target = switch (self.data) {
+                .symlink => |s| s.target,
+                .ext_symlink => |s| s.target,
+                else => unreachable,
+            };
+            try Io.Dir.cwd().symLink(io, target, path, .{});
+        },
+        else => {
+            var dev: u32 = 0;
+            var mode: u32 = undefined;
+
+            const DT = std.os.linux.DT;
+
+            switch (self.data) {
+                .block_dev => |d| {
+                    mode = DT.BLK;
+                    dev = d.dev;
+                },
+                .ext_block_dev => |d| {
+                    mode = DT.BLK;
+                    dev = d.dev;
+                },
+                .char_dev => |d| {
+                    mode = DT.CHR;
+                    dev = d.dev;
+                },
+                .ext_char_dev => |d| {
+                    mode = DT.CHR;
+                    dev = d.dev;
+                },
+                .fifo, .ext_fifo => mode = DT.FIFO,
+                .socket, .ext_socket => mode = DT.SOCK,
+                else => unreachable,
+            }
+
+            const sentinel_path = try std.mem.concatWithSentinel(alloc, u8, &.{path}, 0);
+            defer alloc.free(sentinel_path);
+            const res = std.os.linux.mknod(sentinel_path, mode, dev);
+            if (res != 0)
+                return ExtractionError.Mknod;
+        },
+    }
+
+    return .{
+        .path = path,
+        .inode = self,
+        .origin = origin,
+    };
+}
+
+const ExtractUnion = union { ret: ExtractionError!ExtractReturn };
+pub const ExtractionError = error{ SetXattr, Mknod, Canceled } || DirEntry.Error || Io.Dir.CreateFileAtomicError || DataExtract.Error || Io.File.Atomic.LinkError ||
+    Io.Dir.SymLinkError;
+
+const ExtractReturn = struct {
+    path: []const u8,
+    inode: Inode,
+    origin: bool,
+
+    fn deinit(self: ExtractReturn, alloc: std.mem.Allocator) void {
+        if (self.origin) return;
+        alloc.free(self.path);
+        self.inode.deinit(alloc);
+    }
+    fn setMetadata(self: ExtractReturn, alloc: std.mem.Allocator, io: Io, cache: *DecompCache, id_start: u64, xattr_start: u64, options: ExtractionOptions) !void {
+        if (options.ignore_permissions and options.ignore_xattr) return;
+
+        var fil = try Io.Dir.cwd().openFile(io, self.path, .{});
+        defer fil.close(io);
+
+        if (!options.ignore_permissions) {
+            try fil.setTimestamps(io, .{ .modify_timestamp = .{
+                .new = .{ .nanoseconds = @as(i96, @intCast(self.inode.hdr.mod_time)) * std.time.ns_per_s },
+            } });
+            try fil.setPermissions(io, @enumFromInt(self.inode.hdr.permissions));
+            try fil.setOwner(
+                io,
+                try LookupTable.lookup(u16, io, cache, id_start, self.inode.hdr.uid_idx),
+                try LookupTable.lookup(u16, io, cache, id_start, self.inode.hdr.gid_idx),
+            );
+        }
+        if (options.ignore_xattr) return;
+        const xattr_idx: u32 = switch (self.inode.data) {
+            .ext_dir => |d| d.xattr_idx,
            .ext_file => |f| f.xattr_idx,
            .ext_symlink => |s| s.xattr_idx,
            .ext_block_dev, .ext_char_dev => |d| d.xattr_idx,
            .ext_fifo, .ext_socket => |i| i.xattr_idx,
-        else => 0xFFFFFFFF,
+            else => return,
        };
+        if (xattr_idx == 0xFFFFFFFF) return;
+        const xattrs = try LookupTable.xattrLookup(alloc, io, cache, xattr_start, xattr_idx);
+        defer {
+            for (xattrs) |kv|
+                kv.deinit(alloc);
+            alloc.free(xattrs);
        }

-/// Applies the Inode's metadata to the given File.
-/// Mod time is always set, but permissions and xattrs are set based on the given ExtractionOptions.
-pub fn setMetadata(self: Inode, alloc: std.mem.Allocator, tables: *Tables, fil: std.fs.File, options: ExtractionOptions) !void {
-    const time = @as(i128, self.hdr.mod_time) * 1000000000;
-    try fil.updateTimes(time, time);
-    if (!options.ignore_permissions) {
-        try fil.chmod(self.hdr.permissions);
-        try fil.chown(try tables.id_table.get(self.hdr.uid_idx), try tables.id_table.get(self.hdr.gid_idx));
-    }
-    if (!options.ignore_xattr) {
-        const idx = self.xattrIdx();
-        if (idx == 0xFFFFFFFF) return;
-        const xattrs = try tables.xattr_table.get(alloc, idx);
-        defer alloc.free(xattrs);
        for (xattrs) |kv| {
-            const res = std.os.linux.fsetxattr(fil.handle, kv.key, kv.value.ptr, kv.value.len, 0);
-            alloc.free(kv.key);
-            alloc.free(kv.value);
-            if (res != 0) {
-                if (options.verbose)
-                    options.verbose_writer.?.print("fsetxattr has result of: {}\n", .{res}) catch {};
-                return error.SetXattr;
+            const res = std.os.linux.fsetxattr(fil.handle, kv.key.ptr, kv.value.ptr, kv.value.len, 0);
+            if (res != 0)
+                return ExtractionError.SetXattr;
        }
    }
+};
+
+fn metadataLoop(
+    alloc: std.mem.Allocator,
+    io: Io,
+    cache: *DecompCache,
+    id_start: u64,
+    xattr_start: u64,
+    sel: *Io.Select(ExtractUnion),
+    sel_val: *std.atomic.Value(usize),
+    options: ExtractionOptions,
+) !void {
+    errdefer {
+        while (sel.group.token.load(.unordered) != null) {
+            const ret = sel.queue.getOne(io) catch break;
+
+            const res = ret.ret catch continue;
+            res.deinit(alloc);
+        }
+    }
+    var dir_queue: std.PriorityDequeue(ExtractReturn, void, dirReturnQueueOrder) = .empty;
+    defer {
+        while (dir_queue.popMax()) |ret|
+            ret.deinit(alloc);
+        dir_queue.deinit(alloc);
+    }
+
+    while (sel_val.load(.unordered) > 0) {
+        defer _ = sel_val.fetchSub(1, .acq_rel);
+        const ret = try sel.queue.getOne(io);
+
+        const res = try ret.ret;
+
+        if (res.inode.hdr.inode_type == .dir or res.inode.hdr.inode_type == .ext_dir) {
+            try dir_queue.push(alloc, res);
+        } else {
+            defer res.deinit(alloc);
+            try res.setMetadata(alloc, io, cache, id_start, xattr_start, options);
        }
    }

-/// Extract the inode to the given path.
-pub fn extractTo(self: Inode, alloc: std.mem.Allocator, archive: Archive, path: []const u8, options: ExtractionOptions) !void {
-    return InodeExtract.extractTo(alloc, self, archive, path, options);
+    while (dir_queue.popMax()) |res| {
+        defer res.deinit(alloc);
+        try res.setMetadata(alloc, io, cache, id_start, xattr_start, options);
+    }
+}
+
+fn dirReturnQueueOrder(_: void, a: ExtractReturn, b: ExtractReturn) std.math.Order {
+    return std.math.order(std.mem.count(u8, a.path, "/"), std.mem.count(u8, b.path, "/"));
 }
@@ -1,6 +1,6 @@
 const Reader = @import("std").Io.Reader;

-pub const Dir = packed struct {
+pub const Dir = extern struct {
    block_start: u32,
    hard_links: u32,
    size: u16,
@@ -14,19 +14,19 @@ pub const Dir = packed struct {
    }
 };

-pub const ExtDir = packed struct {
+pub const ExtDir = extern struct {
    hard_links: u32,
    size: u32,
    block_start: u32,
    parent_num: u32,
    idx_count: u16,
    block_offset: u16,
-    xattr_id: u32,
+    xattr_idx: u32,
    // index: []DirIndex

    pub fn read(rdr: *Reader) !ExtDir {
        var d: ExtDir = undefined;
-        try rdr.readSliceEndian(Dir, @ptrCast(&d), .little);
+        try rdr.readSliceEndian(ExtDir, @ptrCast(&d), .little);
        return d;
    }
 };
@@ -1,7 +1,7 @@
 const std = @import("std");
 const Reader = std.Io.Reader;

-pub const BlockSize = packed struct {
+pub const BlockSize = packed struct(u32) {
    size: u24,
    uncompressed: bool,
    _: u7,
@@ -10,25 +10,31 @@ pub const BlockSize = packed struct {
 pub const File = struct {
    block_start: u32, // bytes 0-3
    frag_idx: u32, // bytes 4-7
-    frag_block_offset: u32, // bytes 8-11
+    frag_offset: u32, // bytes 8-11
    size: u32, // bytes 12-15
    block_sizes: []BlockSize,

    pub fn read(alloc: std.mem.Allocator, rdr: *Reader, block_size: u32) !File {
-        var start: [16]u8 = undefined;
-        try rdr.readSliceAll(&start);
-        const frag_idx: u32 = std.mem.readInt(u32, start[4..8], .little);
-        const size: u32 = std.mem.readInt(u32, start[12..16], .little);
-        var num_blocks: u32 = size / block_size;
-        if (size % block_size != 0 and frag_idx == 0xFFFFFFFF) num_blocks += 1;
+        const raw_values = extern struct {
+            block_start: u32, // bytes 0-3
+            frag_idx: u32, // bytes 4-7
+            frag_offset: u32, // bytes 8-11
+            size: u32, // bytes 12-15
+        };
+        var values: raw_values = undefined;
+        try rdr.readSliceEndian(@TypeOf(values), @ptrCast(&values), .little);
+
+        var num_blocks: u32 = values.size / block_size;
+        if (values.size % block_size != 0 and values.frag_idx == 0xFFFFFFFF) num_blocks += 1;
        const sizes = try alloc.alloc(BlockSize, num_blocks);
        errdefer alloc.free(sizes);
        try rdr.readSliceEndian(BlockSize, sizes, .little);
+
        return .{
-            .block_start = std.mem.readInt(u32, start[0..4], .little),
-            .frag_idx = frag_idx,
-            .frag_block_offset = std.mem.readInt(u32, start[8..12], .little),
-            .size = size,
+            .block_start = values.block_start,
+            .frag_idx = values.frag_idx,
+            .frag_offset = values.frag_offset,
+            .size = values.size,
            .block_sizes = sizes,
        };
    }
@@ -44,28 +50,37 @@ pub const ExtFile = struct {
    sparse: u64, // bytes 16-23
    hard_links: u32, // bytes 24-27
    frag_idx: u32, // bytes 28-31
-    frag_block_offset: u32, // bytes 32-35
+    frag_offset: u32, // bytes 32-35
    xattr_idx: u32, // bytes 36-39
    block_sizes: []BlockSize,

    pub fn read(alloc: std.mem.Allocator, rdr: *Reader, block_size: u32) !ExtFile {
-        var start: [40]u8 = undefined;
-        try rdr.readSliceAll(&start);
-        const frag_idx: u32 = std.mem.readInt(u32, start[28..32], .little);
-        const size: u64 = std.mem.readInt(u64, start[8..16], .little);
-        var num_blocks: u32 = @truncate(size / block_size);
-        if (size % block_size != 0 and frag_idx == 0xFFFFFFFF) num_blocks += 1;
+        const raw_values = extern struct {
+            block_start: u64, // bytes 0-7
+            size: u64, // bytes 8-15
+            sparse: u64, // bytes 16-23
+            hard_links: u32, // bytes 24-27
+            frag_idx: u32, // bytes 28-31
+            frag_offset: u32, // bytes 32-35
+            xattr_idx: u32, // bytes 36-39
+        };
+        var values: raw_values = undefined;
+        try rdr.readSliceEndian(@TypeOf(values), @ptrCast(&values), .little);
+
+        var num_blocks: u32 = @truncate(values.size / block_size);
+        if (values.size % block_size != 0 and values.frag_idx == 0xFFFFFFFF) num_blocks += 1;
        const sizes = try alloc.alloc(BlockSize, num_blocks);
        errdefer alloc.free(sizes);
        try rdr.readSliceEndian(BlockSize, sizes, .little);
+
        return .{
-            .block_start = std.mem.readInt(u64, start[0..8], .little),
-            .size = size,
-            .sparse = std.mem.readInt(u64, start[16..24], .little),
-            .hard_links = std.mem.readInt(u32, start[24..28], .little),
-            .frag_idx = frag_idx,
-            .frag_block_offset = std.mem.readInt(u32, start[32..36], .little),
-            .xattr_idx = std.mem.readInt(u32, start[36..40], .little),
+            .block_start = values.block_start,
+            .size = values.size,
+            .sparse = values.sparse,
+            .hard_links = values.hard_links,
+            .frag_idx = values.frag_idx,
+            .frag_offset = values.frag_offset,
+            .xattr_idx = values.xattr_idx,
            .block_sizes = sizes,
        };
    }
@@ -50,7 +50,7 @@ pub const ExtSymlink = struct {
 };

 /// A block or character device.
-pub const Dev = packed struct {
+pub const Dev = extern struct {
    hard_links: u32,
    dev: u32,

@@ -62,7 +62,7 @@ pub const Dev = packed struct {
 };

 /// An extended block or character device.
-pub const ExtDev = packed struct {
+pub const ExtDev = extern struct {
    hard_links: u32,
    dev: u32,
    xattr_idx: u32,
@@ -75,7 +75,7 @@ pub const ExtDev = packed struct {
 };

 /// A socket or FIFO file.
-pub const IPC = packed struct {
+pub const IPC = extern struct {
    hard_links: u32,

    pub fn read(rdr: *Reader) !IPC {
@@ -86,7 +86,7 @@ pub const IPC = packed struct {
 };

 /// An extended socket or FIFO file.
-pub const ExtIPC = packed struct {
+pub const ExtIPC = extern struct {
    hard_links: u32,
    xattr_idx: u32,

@@ -0,0 +1,124 @@
+const std = @import("std");
+const Io = std.Io;
+
+const Inode = @import("inode.zig");
+const DecompCache = @import("util/decomp_cache.zig");
+const MetadataReader = @import("util/metadata.zig");
+
+pub fn lookup(comptime T: anytype, io: Io, cache: *DecompCache, table_start: u64, idx: u32) !T {
+    const PER_BLOCK = 8192 / @sizeOf(T);
+
+    const block_idx = idx / PER_BLOCK;
+    const block_offset = idx % PER_BLOCK;
+
+    if (table_start + (block_idx * 8) > cache.map.memory.len) return error.ReadFailed;
+    const offset: u64 = std.mem.readInt(u64, cache.map.memory[table_start + (block_idx * 8) ..][0..8], .little);
+
+    var meta: MetadataReader = .init(io, cache, offset);
+    defer meta.deinit();
+    try meta.interface.discardAll(block_offset * @sizeOf(T));
+
+    var new: T = undefined;
+    try meta.interface.readSliceEndian(T, @ptrCast(&new), .little);
+    return new;
+}
+
+pub const XattrKV = struct {
+    key: [:0]u8,
+    value: []u8,
+
+    pub fn deinit(self: XattrKV, alloc: std.mem.Allocator) void {
+        alloc.free(self.key);
+        alloc.free(self.value);
+    }
+};
+
+const LookupValue = extern struct {
+    ref: Inode.Ref,
+    count: u32,
+    size: u32,
+};
+const KeyEntry = extern struct {
+    prefix: packed struct(u16) {
+        prefix: enum(u8) {
+            user,
+            trusted,
+            security,
+        },
+        out_of_line: bool,
+        _: u7,
+    },
+    name_size: u16,
+};
+
+pub fn xattrLookup(alloc: std.mem.Allocator, io: Io, cache: *DecompCache, xattr_start: u64, idx: u32) ![]XattrKV {
+    const table_start = std.mem.readInt(u64, cache.map.memory[xattr_start..][0..8], .little);
+
+    const val: LookupValue = try lookup(
+        LookupValue,
+        io,
+        cache,
+        xattr_start + 16,
+        idx,
+    );
+
+    const out = try alloc.alloc(XattrKV, val.count);
+    errdefer alloc.free(out);
+
+    var meta: MetadataReader = .init(io, cache, table_start + val.ref.block_start);
+    defer meta.deinit();
+    try meta.interface.discardAll(val.ref.block_offset);
+
+    for (out) |*kv| {
+        var key_entry: KeyEntry = undefined;
+        try meta.interface.readSliceEndian(KeyEntry, @ptrCast(&key_entry), .little);
+
+        const prefix_len: u16 = switch (key_entry.prefix.prefix) {
+            .user => 5,
+            .trusted => 8,
+            .security => 9,
+        };
+        var key_len = key_entry.name_size;
+        key_len += prefix_len;
+
+        kv.key = try alloc.allocSentinel(u8, key_len, 0);
+        errdefer alloc.free(kv.key);
+
+        try meta.interface.readSliceEndian(u8, kv.key[prefix_len..], .little);
+        switch (key_entry.prefix.prefix) {
+            .user => @memcpy(kv.key[0..prefix_len], "user."),
+            .trusted => @memcpy(kv.key[0..prefix_len], "trusted."),
+            .security => @memcpy(kv.key[0..prefix_len], "security."),
+        }
+
+        if (key_entry.prefix.out_of_line) {
+            try meta.interface.discardAll(8);
+
+            var ool_ref: Inode.Ref = undefined;
+            try meta.interface.readSliceEndian(Inode.Ref, @ptrCast(&ool_ref), .little);
+
+            var ool_meta: MetadataReader = .init(io, cache, table_start + ool_ref.block_start);
+            defer ool_meta.deinit();
+            try ool_meta.interface.discardAll(ool_ref.block_offset);
+
+            kv.value = try readValue(alloc, &ool_meta.interface);
+            errdefer alloc.free(kv.value);
+        } else {
+            kv.value = try readValue(alloc, &meta.interface);
+        }
+    }
+
+    return out;
+}
+
+fn readValue(alloc: std.mem.Allocator, rdr: *Io.Reader) ![]u8 {
+    var val_size: u32 = undefined;
+    try rdr.readSliceEndian(u32, @ptrCast(&val_size), .little);
+
+    const val = try alloc.alloc(u8, val_size);
+    errdefer alloc.free(val);
+
+    try rdr.readSliceEndian(u8, val, .little);
+
+    return val;
+}
@@ -5,25 +5,22 @@ const Writer = std.Io.Writer;

 const ExtractionOptions = @This();

-/// The number of threads used for extraction. 0 implies single threaded.
-threads: usize = 1,
-/// Don't set the file's owner & permissions after extraction
+/// Force single-threaded extraction. Io.Threaded.global_single_threaded also works.
+single_threaded: bool = false,
+/// Don't set the file's owner, permissions, & modify time after extraction.
 ignore_permissions: bool = false,
-/// Don't set xattr values. Currently xattrs are never set anyway.
+/// Don't set xattr values.
 ignore_xattr: bool = false,
-/// Replace symlinks with their target.
+/// Replace symlinks with their target. Currently doesn't do anything.
 dereference_symlinks: bool = false,
 /// Verbose logging. If true, verbose_writer must be set
 verbose: bool = false,
 /// Where to print verbose log.
 verbose_writer: ?*Writer = null,

-pub const SingleThreadedDefault: ExtractionOptions = .{};
-pub fn Default() !ExtractionOptions {
-    return .{
-        .threads = try std.Thread.getCpuCount(),
-    };
-}
+pub const defaultSingleThreaded: ExtractionOptions = .{ .single_threaded = true };
+pub const default: ExtractionOptions = .{};
+
 pub fn VerboseDefault(wrt: *Writer) !ExtractionOptions {
    return .{
        .verbose = true,
@@ -1,2 +1,7 @@
 pub const Archive = @import("archive.zig");
 pub const ExtractionOptions = @import("options.zig");
+const Test = @import("test.zig");
+
+test {
+    @import("std").testing.refAllDecls(Test);
+}
@@ -2,6 +2,7 @@ const std = @import("std");
 const math = std.math;

 const InodeRef = @import("inode.zig").Ref;
+const CompressionType = @import("util/decompress.zig").CompressionType;

 const SQUASHFS_MAGIC: u32 = std.mem.readInt(u32, "hsqs", .little);

@@ -13,22 +14,15 @@ const SuperblockError = error{
 };

 /// A squashfs Superblock
-pub const Superblock = packed struct {
+pub const Superblock = extern struct {
    magic: u32,
    inode_count: u32,
    mod_time: u32,
    block_size: u32,
    frag_count: u32,
-    compression: enum(u16) {
-        gzip = 1,
-        lzma,
-        lzo,
-        xz,
-        lz4,
-        zstd,
-    },
+    compression: CompressionType,
    block_log: u16,
-    flags: packed struct {
+    flags: packed struct(u16) {
        inode_uncompressed: bool,
        data_uncompressed: bool,
        check: bool,
@@ -1,107 +0,0 @@
-const std = @import("std");
-const Mutex = std.Thread.Mutex;
-
-const Archive = @import("archive.zig");
-const BlockSize = @import("inode_data/file.zig").BlockSize;
-const InodeRef = @import("inode.zig").Ref;
-const Superblock = @import("super.zig").Superblock;
-const MetadataReader = @import("util/metadata.zig");
-const OffsetFile = @import("util/offset_file.zig");
-const XattrTable = @import("xattr.zig");
-
-/// Information about a fragment section. Multiple fragments are contained in the block described by a single FragEntry.
-/// The offset into the block and fragment size is stored in the file's inode.
-pub const FragEntry = packed struct {
-    start: u64,
-    size: BlockSize,
-    _: u32,
-};
-
-const Tables = @This();
-
-frag_table: Table(FragEntry),
-id_table: Table(u16),
-export_table: Table(InodeRef),
-xattr_table: XattrTable,
-
-pub fn init(alloc: std.mem.Allocator, archive: Archive) !Tables {
-    return .{
-        .frag_table = try .init(alloc, archive.fil, archive.decomp, archive.super.frag_start, archive.super.frag_count),
-        .id_table = try .init(alloc, archive.fil, archive.decomp, archive.super.id_start, archive.super.id_count),
-        .export_table = try .init(alloc, archive.fil, archive.decomp, archive.super.export_start, archive.super.inode_count),
-        .xattr_table = try .init(alloc, archive.fil, archive.decomp, archive.super.xattr_start),
-    };
-}
-pub fn deinit(self: *Tables) void {
-    self.frag_table.deinit();
-    self.id_table.deinit();
-    self.export_table.deinit();
-    self.xattr_table.deinit();
-}
-
-/// A two-layer metadata table.
-pub fn Table(T: anytype) type {
-    return struct {
-        const Self = @This();
-
-        const VALS_PER_BLOCK = 8192 / @sizeOf(T);
-
-        alloc: std.mem.Allocator,
-        fil: OffsetFile,
-        decomp: DecompFn,
-        tab_start: u64,
-
-        tab: std.AutoHashMap(u32, []T),
-        values: u32,
-
-        mut: Mutex = .{},
-
-        pub fn init(alloc: std.mem.Allocator, fil: OffsetFile, decomp: DecompFn, tab_start: u64, values: u32) !Self {
-            return .{
-                .alloc = alloc,
-                .fil = fil,
-                .decomp = decomp,
-                .tab_start = tab_start,
-
-                .tab = .init(alloc),
-                .values = values,
-            };
-        }
-
-        pub fn deinit(self: *Self) void {
-            var iter = self.tab.valueIterator();
-            while (iter.next()) |s| {
-                self.alloc.free(s.*);
-            }
-            self.tab.deinit();
-        }
-
-        pub fn get(self: *Self, idx: u32) !T {
-            if (idx >= self.values) return error.InvalidIndex;
-            const block_num = idx / VALS_PER_BLOCK;
-            const idx_offset = idx - (block_num * VALS_PER_BLOCK);
-            if (self.tab.contains(block_num)) {
-                const block = self.tab.get(block_num).?;
-                return block[idx_offset];
-            }
-            self.mut.lock();
-            defer self.mut.unlock();
-            // Double check in case of race condition..
-            if (self.tab.contains(block_num)) {
-                const block = self.tab.get(block_num).?;
-                return block[idx_offset];
-            }
-            const is_last = (self.values - 1) / VALS_PER_BLOCK == block_num;
-            const slice_size = if (is_last) self.values - (block_num * VALS_PER_BLOCK) else VALS_PER_BLOCK;
-            const slice = try self.alloc.alloc(T, slice_size);
-            var rdr = try self.fil.readerAt(self.tab_start + (8 * block_num), &[0]u8{});
-            var offset: u64 = 0;
-            try rdr.interface.readSliceEndian(u64, @ptrCast(&offset), .little);
-            rdr = try self.fil.readerAt(offset, &[0]u8{});
-            var meta: MetadataReader = .init(self.alloc, &rdr.interface, self.decomp);
-            try meta.interface.readSliceEndian(T, @ptrCast(slice), .little);
-            try self.tab.put(block_num, slice);
-            return slice[idx_offset];
-        }
-    };
-}
@@ -1,4 +1,5 @@
 const std = @import("std");
+const Io = std.Io;
 const stuff = @import("builtin");

 const Archive = @import("archive.zig");
@@ -7,40 +8,64 @@ const Superblock = @import("super.zig").Superblock;
 const TestArchive = "testing/LinuxPATest.sfs";

 test "Basics" {
-    var fil = try std.fs.cwd().openFile(TestArchive, .{});
-    defer fil.close();
-    var sfs: Archive = try .init(std.testing.allocator, fil);
-    defer sfs.deinit();
-    if (sfs.super != LinuxPATestCorrectSuperblock) {
-        std.debug.print("Superblock wrong\nShould be: {}\n\nis: {}\n", .{ LinuxPATestCorrectSuperblock, sfs.super });
-        return error.BadSuperblock;
-    }
+    const io = std.testing.io;
+    const alloc = std.testing.allocator;
+
+    var fil = try Io.Dir.cwd().openFile(io, TestArchive, .{});
+    defer fil.close(io);
+    var sfs: Archive = try .init(alloc, io, fil);
+    defer sfs.deinit(io);
+    try std.testing.expectEqualDeep(sfs.super, LinuxPATestCorrectSuperblock);
 }

 const TestFile = "Start.exe";
 const TestFileExtractLocation = "testing/Start.exe";

 test "ExtractSingleFile" {
-    std.fs.cwd().deleteFile(TestFileExtractLocation) catch {};
-    var fil = try std.fs.cwd().openFile(TestArchive, .{});
-    defer fil.close();
-    var sfs: Archive = try .init(std.testing.allocator, fil);
-    defer sfs.deinit();
-    var test_fil = try sfs.open(TestFile);
+    const io = std.testing.io;
+    const alloc = std.testing.allocator;
+
+    Io.Dir.cwd().deleteFile(io, TestFileExtractLocation) catch {};
+    var fil = try Io.Dir.cwd().openFile(io, TestArchive, .{});
+    defer fil.close(io);
+    var sfs: Archive = try .init(alloc, io, fil);
+    defer sfs.deinit(io);
+    var test_fil = try sfs.open(alloc, io, TestFile);
    defer test_fil.deinit();
-    try test_fil.extract(TestFileExtractLocation, .Default);
+    try test_fil.extract(alloc, io, TestFileExtractLocation, .default);
+    //TODO: validate extracted file.
+}
+
+const TestDir = "Documents";
+const TestDirExtractLocation = "testing/Documents";
+
+test "ExtractSmallDir" {
+    const io = std.testing.io;
+    const alloc = std.testing.allocator;
+
+    Io.Dir.cwd().deleteTree(io, TestDirExtractLocation) catch {};
+    var fil = try Io.Dir.cwd().openFile(io, TestArchive, .{});
+    defer fil.close(io);
+    var sfs: Archive = try .init(alloc, io, fil);
+    defer sfs.deinit(io);
+    var test_fil = try sfs.open(alloc, io, TestDir);
+    defer test_fil.deinit();
+    try test_fil.extract(alloc, io, TestDirExtractLocation, .default);
    //TODO: validate extracted file.
 }

 const TestFullExtractLocation = "testing/TestExtract";

 test "ExtractCompleteArchive" {
-    std.fs.cwd().deleteTree(TestFullExtractLocation) catch {};
-    var fil = try std.fs.cwd().openFile(TestArchive, .{});
-    defer fil.close();
-    var sfs: Archive = try .init(std.testing.allocator, fil);
-    defer sfs.deinit();
-    try sfs.extract(TestFullExtractLocation, .Default);
+    const io = std.testing.io;
+    const alloc = std.testing.allocator;
+
+    Io.Dir.cwd().deleteTree(io, TestFullExtractLocation) catch {};
+    var fil = try Io.Dir.cwd().openFile(io, TestArchive, .{});
+    defer fil.close(io);
+    var sfs: Archive = try .init(alloc, io, fil);
+    defer sfs.deinit(io);
+    try sfs.extract(alloc, io, TestFullExtractLocation, .default);
 }

 const LinuxPATestCorrectSuperblock: Superblock = .{
@@ -0,0 +1,61 @@
+const std = @import("std");
+
+const c = @import("c");
+
+const Error = @import("decompress.zig").Error;
+
+pub fn zlibDecompress(_: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    var strem: c.zng_stream = .{
+        .next_in = in.ptr,
+        .avail_in = @truncate(in.len),
+        .next_out = out.ptr,
+        .avail_out = @truncate(out.len),
+    };
+    var res = c.zng_inflateInit(&strem);
+    if (res != c.Z_OK) return Error.ReadFailed;
+    defer _ = c.zng_inflateEnd(&strem);
+
+    res = c.zng_inflate(&strem, c.Z_FULL_FLUSH);
+    if (res != c.Z_OK) return Error.ReadFailed;
+
+    return strem.total_out;
+}
+pub fn lzmaDecompress(_: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    var strem: c.lzma_stream = .{
+        .next_in = in.ptr,
+        .avail_in = in.len,
+        .next_out = out.ptr,
+        .avail_out = out.len,
+    };
+    var res = c.lzma_auto_decoder(&strem, out.len * 2, 0);
+    if (res != c.LZMA_OK) return Error.ReadFailed;
+    defer c.lzma_end(&strem);
+
+    while (res == c.LZMA_OK)
+        res = c.lzma_code(&strem, c.LZMA_RUN);
+    if (res != c.LZMA_FINISH) return Error.ReadFailed;
+
+    return strem.total_out;
+}
+pub fn lzoDecompress(_: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    var out_len = out.len;
+    const res = c.lzo1x_decompress(in.ptr, in.len, out.ptr, &out_len, null);
+    if (res != c.LZO_E_OK) return Error.ReadFailed;
+    return out_len;
+}
+pub fn lz4Decompress(_: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    const res = c.LZ4_decompress_safe(
+        in.ptr,
+        out.ptr,
+        @bitCast(@as(u32, @truncate(in.len))),
+        @bitCast(@as(u32, @truncate(out.len))),
+    );
+    if (res < 0) return Error.ReadFailed;
+    return @abs(res);
+}
+pub fn zstdDecompress(_: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    const res = c.ZSTD_decompress(out.ptr, out.len, in.ptr, in.len);
+    if (c.ZSTD_isError(res) != 0)
+        return Error.ReadFailed;
+    return res;
+}
@@ -1,174 +0,0 @@
-//! A reader for a regular file.
-
-const std = @import("std");
-const Reader = std.Io.Reader;
-const Writer = std.Io.Writer;
-const Limit = std.Io.Limit;
-
-const Archive = @import("../archive.zig");
-const DecompFn = @import("../decomp.zig").DecompFn;
-const BlockSize = @import("../inode_data/file.zig").BlockSize;
-const FragEntry = @import("../tables.zig").FragEntry;
-const OffsetFile = @import("offset_file.zig");
-
-const DataReader = @This();
-
-alloc: std.mem.Allocator,
-fil: OffsetFile,
-decomp: DecompFn,
-block_size: u32,
-
-blocks: []BlockSize,
-
-frag: ?FragEntry = null, // TODO: do something better?
-frag_offset: u32 = 0,
-size: u64,
-
-interface: Reader,
-
-cur_offset: u64,
-block_idx: u32 = 0,
-
-pub fn init(alloc: std.mem.Allocator, archive: Archive, blocks: []BlockSize, start: u64, size: u64) DataReader {
-    return .{
-        .alloc = alloc,
-        .fil = archive.fil,
-        .decomp = archive.decomp,
-        .block_size = archive.super.block_size,
-        .blocks = blocks,
-        .size = size,
-        .cur_offset = start,
-        .interface = .{
-            .end = 0,
-            .seek = 0,
-            .buffer = &[0]u8{},
-            .vtable = &.{
-                .stream = stream,
-                .discard = discard,
-                .readVec = readVec,
-            },
-        },
-    };
-}
-pub fn deinit(self: *DataReader) void {
-    self.alloc.free(self.interface.buffer);
-    self.interface.end = 0;
-    self.interface.seek = 0;
-}
-
-pub fn addFragment(self: *DataReader, entry: FragEntry, frag_offset: u32) void {
-    self.frag = entry;
-    self.frag_offset = frag_offset;
-}
-
-fn numBlocks(self: DataReader) usize {
-    var res = self.blocks.len;
-    if (self.frag != null) res += 1;
-    return res;
-}
-
-fn advance(self: *DataReader) !void {
-    if (self.block_idx > self.blocks.len or (self.block_idx == self.blocks.len and self.frag == null)) {
-        if (self.interface.buffer.len > 0) {
-            self.alloc.free(self.interface.buffer);
-            self.interface.buffer = &[0]u8{};
-            self.interface.end = 0;
-            self.interface.seek = 0;
-        }
-        return Reader.Error.EndOfStream;
-    }
-    defer self.block_idx += 1;
-    const cur_block_size = if (self.block_idx == self.numBlocks() - 1) self.size % self.block_size else self.block_size;
-    try self.resizeBuffer(cur_block_size);
-    self.interface.seek = 0;
-    self.interface.end = cur_block_size;
-    if (self.block_idx == self.blocks.len) { // fragment
-        var rdr = try self.fil.readerAt(self.frag.?.start, &[0]u8{});
-        if (self.frag.?.size.uncompressed) {
-            try rdr.interface.discardAll(self.frag_offset);
-            try rdr.interface.readSliceAll(self.interface.buffer);
-            return;
-        }
-        const tmp_buf = try self.alloc.alloc(u8, self.frag.?.size.size);
-        defer self.alloc.free(tmp_buf);
-        try rdr.interface.readSliceAll(tmp_buf);
-        const needed_block = try self.alloc.alloc(u8, self.block_size);
-        defer self.alloc.free(needed_block);
-        _ = try self.decomp(self.alloc, tmp_buf, needed_block);
-        @memcpy(self.interface.buffer, needed_block[self.frag_offset .. self.frag_offset + cur_block_size]);
-        return;
-    }
-    const block = self.blocks[self.block_idx];
-    if (block.size == 0) {
-        @memset(self.interface.buffer, 0);
-        return;
-    }
-    var rdr = try self.fil.readerAt(self.cur_offset, &[0]u8{});
-    self.cur_offset += block.size;
-    if (block.uncompressed) {
-        try rdr.interface.readSliceAll(self.interface.buffer);
-        return;
-    }
-    const tmp_buf = try self.alloc.alloc(u8, block.size);
-    defer self.alloc.free(tmp_buf);
-    try rdr.interface.readSliceAll(tmp_buf);
-    _ = try self.decomp(self.alloc, tmp_buf, self.interface.buffer);
-}
-/// Does not guarentee that data currently in the buffer is retained.
-fn resizeBuffer(self: *DataReader, size: usize) !void {
-    if (self.interface.buffer.len == size) return;
-    if (!self.alloc.resize(self.interface.buffer, size)) {
-        self.alloc.free(self.interface.buffer);
-        self.interface.buffer = self.alloc.alloc(u8, size) catch |err| {
-            self.interface.buffer = &[0]u8{};
-            return err;
-        };
-    } else {
-        self.interface.buffer.len = size;
-    }
-}
-
-fn stream(rdr: *Reader, wrt: *Writer, limit: Limit) Reader.StreamError!usize {
-    var self: *DataReader = @alignCast(@fieldParentPtr("interface", rdr));
-    if (rdr.seek >= rdr.end) self.advance() catch |err| {
-        if (err == error.EndOfStream) return error.EndOfStream;
-        std.log.err("Error advancing data reader: {}\n", .{err});
-        return Reader.Error.ReadFailed;
-    };
-    if (limit == .nothing) return 0;
-    const to_read = @min(rdr.end - rdr.seek, @intFromEnum(limit));
-    const res = try wrt.write(rdr.buffer[rdr.seek .. rdr.seek + to_read]);
-    rdr.seek += res;
-    return res;
-}
-
-fn discard(rdr: *Reader, limit: Limit) Reader.Error!usize {
-    var self: *DataReader = @alignCast(@fieldParentPtr("interface", rdr));
-    if (rdr.seek >= rdr.end) self.advance() catch |err| {
-        if (err == error.EndOfStream) return error.EndOfStream;
-        std.log.err("Error advancing data reader: {}\n", .{err});
-        return Reader.Error.ReadFailed;
-    };
-    if (limit == .nothing) return 0;
-    const to_adv = @min(rdr.end - rdr.seek, @intFromEnum(limit));
-    rdr.seek += to_adv;
-    return to_adv;
-}
-
-fn readVec(rdr: *Reader, vec: [][]u8) Reader.Error!usize {
-    var self: *DataReader = @alignCast(@fieldParentPtr("interface", rdr));
-    if (rdr.seek >= rdr.end) self.advance() catch |err| {
-        if (err == error.EndOfStream) return error.EndOfStream;
-        std.log.err("Error advancing data reader: {}\n", .{err});
-        return Reader.Error.ReadFailed;
-    };
-    var cur_red: usize = 0;
-    for (vec) |s| {
-        const to_copy: usize = @min(rdr.end - rdr.seek, s.len);
-        @memcpy(s[0..to_copy], rdr.buffer[rdr.seek .. rdr.seek + to_copy]);
-        rdr.seek += to_copy;
-        cur_red += to_copy;
-        if (rdr.end == rdr.seek) break;
-    }
-    return cur_red;
-}
@@ -0,0 +1,85 @@
+const std = @import("std");
+const Io = std.Io;
+
+const BlockSize = @import("../inode_data/file.zig").BlockSize;
+const Decompress = @import("decompress.zig");
+
+const DataExtract = @This();
+
+decomp: Decompress.Fn,
+map: Io.File.MemoryMap,
+
+block_size: u32,
+block_start: u64,
+size: u64,
+blocks: []BlockSize,
+
+frag_data: ?[]u8 = null,
+frag_offset: u32 = undefined,
+
+pub fn init(decomp: Decompress.Fn, map: Io.File.MemoryMap, block_size: u32, block_start: u64, size: u64, blocks: []BlockSize) DataExtract {
+    return .{
+        .decomp = decomp,
+        .map = map,
+
+        .block_size = block_size,
+        .block_start = block_start,
+        .size = size,
+        .blocks = blocks,
+    };
+}
+pub fn addFrag(self: *DataExtract, frag_block: []u8, frag_offset: u32) void {
+    self.frag_data = frag_block;
+    self.frag_offset = frag_offset;
+}
+
+pub const Error = error{} || Io.File.MemoryMap.CreateError || Io.File.WritePositionalError || Decompress.Error || Io.File.MemoryMap.SetLengthError;
+
+pub fn asyncExtract(self: DataExtract, alloc: std.mem.Allocator, io: Io, fil: Io.File) Error!void {
+    if (self.size == 0) return;
+
+    try fil.writePositionalAll(io, &.{0}, self.size - 1);
+    var map = try fil.createMemoryMap(io, .{ .len = self.size, .protection = .{ .write = true }, .undefined_contents = true });
+    defer map.destroy(io);
+
+    var group: Io.Group = .init;
+    defer group.cancel(io);
+
+    var ret_err: ?Error = null;
+
+    var offset: u64 = self.block_start;
+    for (0..self.blocks.len) |i| {
+        group.async(io, blockThread, .{ self, alloc, map, offset, i, &ret_err });
+        offset += self.blocks[i].size;
+    }
+    if (self.frag_data != null)
+        group.async(io, fragThread, .{ self, map });
+
+    try group.await(io);
+    if (ret_err != null) return ret_err.?;
+    return map.write(io);
+}
+fn blockThread(self: DataExtract, alloc: std.mem.Allocator, map: Io.File.MemoryMap, read_offset: u64, idx: usize, ret_err: *?Error) error{Canceled}!void {
+    const block = self.blocks[idx];
+    const write_offset = idx * self.block_size;
+
+    const size = if (self.frag_data == null and idx == self.blocks.len - 1)
+        self.size % self.block_size
+    else
+        self.block_size;
+
+    if (block.size == 0) {
+        @memset(map.memory[write_offset..][0..size], 0);
+        return;
+    } else if (block.uncompressed) {
+        @memcpy(map.memory[write_offset..][0..size], self.map.memory[read_offset..][0..block.size]);
+    }
+    _ = self.decomp(alloc, self.map.memory[read_offset..][0..block.size], map.memory[write_offset..][0..size]) catch |err| {
+        ret_err.* = err;
+        return error.Canceled;
+    };
+}
+fn fragThread(self: DataExtract, map: Io.File.MemoryMap) error{Canceled}!void {
+    const size = self.size % self.block_size;
+    @memcpy(map.memory[self.blocks.len * self.block_size ..][0..size], self.frag_data.?[self.frag_offset..][0..size]);
+}
@@ -1,207 +0,0 @@
-//! Similiar to DataReader, but set-up for threaded writing to files.
-
-const std = @import("std");
-const Reader = std.Io.Reader;
-const Writer = std.Io.Writer;
-const Limit = std.Io.Limit;
-const WaitGroup = std.Thread.WaitGroup;
-const Pool = std.Thread.Pool;
-
-const Archive = @import("../archive.zig");
-const DecompFn = @import("../decomp.zig").DecompFn;
-const BlockSize = @import("../inode_data/file.zig").BlockSize;
-const FragEntry = @import("../tables.zig").FragEntry;
-const InodeFinish = @import("inode_finish.zig");
-const OffsetFile = @import("offset_file.zig");
-
-const ThreadedDataReader = @This();
-
-alloc: std.mem.Allocator,
-fil: OffsetFile,
-decomp: DecompFn,
-block_size: u32,
-
-blocks: []BlockSize,
-
-frag: ?FragEntry = null, // TODO: do something better?
-frag_offset: u32 = 0,
-size: u64,
-num_blocks: usize,
-
-start_offset: u64,
-
-pub fn init(alloc: std.mem.Allocator, archive: Archive, blocks: []BlockSize, start: u64, size: u64) ThreadedDataReader {
-    return .{
-        .alloc = alloc,
-        .fil = archive.fil,
-        .decomp = archive.decomp,
-        .block_size = archive.super.block_size,
-
-        .blocks = blocks,
-
-        .size = size,
-        .num_blocks = blocks.len,
-
-        .start_offset = start,
-    };
-}
-
-pub fn addFragment(self: *ThreadedDataReader, entry: FragEntry, frag_offset: u32) void {
-    self.frag = entry;
-    self.frag_offset = frag_offset;
-    self.num_blocks = self.blocks.len + 1;
-}
-
-/// Extract the data to the file threadedly, using pool to spawn threads.
-/// If errors occur, they are set to finish.out_err.
-pub fn extractThreaded(self: ThreadedDataReader, file: std.fs.File, pool: *Pool, finish: *InodeFinish) void {
-    var cur_write_offset: u64 = 0;
-    var cur_read_offset: u64 = self.start_offset;
-    for (0..self.blocks.len) |i| {
-        const cur_block_size = if (i == self.num_blocks - 1) self.size % self.block_size else self.block_size;
-        pool.spawn(workThreadBlocks, .{ self, file, cur_write_offset, cur_read_offset, self.blocks[i], cur_block_size, finish }) catch |res_err| {
-            finish.logError("Can't spawn pool task: {}", .{res_err});
-            finish.out_err.* = res_err;
-            finish.finish();
-        };
-        cur_write_offset += cur_block_size;
-        cur_read_offset += self.blocks[i].size;
-    }
-    if (self.frag != null)
-        pool.spawn(workThreadFragment, .{ self, file, cur_write_offset, finish }) catch |res_err| {
-            finish.logError("Can't spawn pool task: {}", .{res_err});
-            finish.out_err.* = res_err;
-            finish.finish();
-        };
-}
-
-fn workThreadBlocks(
-    self: ThreadedDataReader,
-    fil: std.fs.File,
-    write_offset: u64,
-    read_offset: u64,
-    block: BlockSize,
-    cur_block_size: u64,
-    finish: *InodeFinish,
-) void {
-    defer finish.finish();
-    var wrt = fil.writer(&[0]u8{});
-    wrt.seekTo(write_offset) catch |err| {
-        finish.logError("Error seeking file writer: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    defer wrt.interface.flush() catch |err| {
-        finish.logError("Error flushing file writer: {}", .{err});
-        finish.out_err.* = err;
-    };
-    if (block.size == 0) {
-        wrt.interface.splatByteAll(0, cur_block_size) catch |err| {
-            finish.logError("Error writing zeroes: {}", .{err});
-            finish.out_err.* = err;
-            return;
-        };
-        return;
-    }
-    var rdr = self.fil.readerAt(read_offset, &[0]u8{}) catch |err| {
-        finish.logError("Error creating file reader: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    if (block.uncompressed) {
-        rdr.interface.streamExact(&wrt.interface, block.size) catch |err| {
-            finish.logError("Error streaming data: {}", .{err});
-            finish.out_err.* = err;
-            return;
-        };
-        return;
-    }
-    // TODO: shared buffers
-    const read_buf = self.alloc.alloc(u8, block.size) catch |err| {
-        finish.logError("Error creating reader buffer: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    defer self.alloc.free(read_buf);
-    rdr.interface.readSliceAll(read_buf) catch |err| {
-        finish.logError("Error reading data into reader buffer: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    // TODO: shared buffers
-    const res_buf = self.alloc.alloc(u8, cur_block_size) catch |err| {
-        finish.logError("Error creating result buffer: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    defer self.alloc.free(res_buf);
-    _ = self.decomp(self.alloc, read_buf, res_buf) catch |err| {
-        finish.logError("Error decompressing data block: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    wrt.interface.writeAll(res_buf) catch |err| {
-        finish.logError("Error writing to file: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-}
-fn workThreadFragment(self: ThreadedDataReader, fil: std.fs.File, write_offset: u64, finish: *InodeFinish) void {
-    defer finish.finish();
-
-    var wrt = fil.writer(&[0]u8{});
-    wrt.seekTo(write_offset) catch |err| {
-        finish.logError("Error seeking file writer for file fragment: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    defer wrt.interface.flush() catch |err| {
-        finish.out_err.* = err;
-    };
-
-    var rdr = self.fil.readerAt(self.frag.?.start, &[0]u8{}) catch |err| {
-        finish.logError("Error creating file reader for file fragment: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    if (self.frag.?.size.uncompressed) {
-        rdr.interface.discardAll(self.frag_offset) catch |err| {
-            finish.logError("Error discarding useless fragment data: {}", .{err});
-            finish.out_err.* = err;
-            return;
-        };
-        rdr.interface.streamExact(&wrt.interface, self.size % self.block_size) catch |err| {
-            finish.logError("Error streaming fragment data: {}", .{err});
-            finish.out_err.* = err;
-            return;
-        };
-        return;
-    }
-    const tmp_buf = self.alloc.alloc(u8, self.frag.?.size.size) catch |err| {
-        finish.logError("Error creating a temporary buffer for a file fragment: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    defer self.alloc.free(tmp_buf);
-    rdr.interface.readSliceAll(tmp_buf) catch |err| {
-        finish.logError("Error reading data into fragment buffer: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    const needed_block = self.alloc.alloc(u8, self.block_size) catch |err| {
-        finish.logError("Error allocating fragment decompression results: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    defer self.alloc.free(needed_block);
-    _ = self.decomp(self.alloc, tmp_buf, needed_block) catch |err| {
-        finish.logError("Error decompressing fragment: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-    wrt.interface.writeAll(needed_block[self.frag_offset .. self.frag_offset + (self.size % self.block_size)]) catch |err| {
-        finish.logError("Error writing fragment: {}", .{err});
-        finish.out_err.* = err;
-        return;
-    };
-}
@@ -0,0 +1,112 @@
+const std = @import("std");
+const Io = std.Io;
+const ArrayHashMap = std.array_hash_map.Auto;
+const Atomic = std.atomic.Value;
+
+const Decompress = @import("decompress.zig");
+const Fn = Decompress.Fn;
+const DecompressType = Decompress.CompressionType;
+
+const DecompCache = @This();
+
+const Cache = struct {
+    cache: []u8,
+    usage: Atomic(u32),
+};
+
+arena: std.heap.ArenaAllocator,
+decomp: Fn,
+
+map: Io.File.MemoryMap,
+
+cache: ArrayHashMap(u64, Cache),
+mut: Io.RwLock = .init,
+cond: Io.Condition = .init,
+
+max_size: u64,
+cur_size: u64 = 0,
+
+pub fn init(alloc: std.mem.Allocator, map: Io.File.MemoryMap, decomp_type: DecompressType, max_size: u64) !DecompCache {
+    return .{
+        .arena = .init(alloc),
+        .decomp = try Decompress.getDecompressFn(decomp_type),
+
+        .map = map,
+
+        .cache = .empty,
+
+        .max_size = max_size,
+    };
+}
+pub fn deinit(self: *DecompCache, io: Io) void {
+    self.mut.lockUncancelable(io);
+    self.cache.deinit(self.arena.child_allocator);
+    self.arena.deinit();
+    self.map.destroy(io);
+}
+
+fn makeRoom(self: *DecompCache, io: Io, size: u32) !void {
+    if (size + self.cur_size < self.max_size) return;
+    var iter = self.cache.iterator();
+    while (iter.next()) |ent| {
+        const val = ent.value_ptr;
+        if (val.usage.load(.unordered) == 0) {
+            self.cur_size -= val.cache.len;
+            _ = self.cache.orderedRemove(ent.key_ptr.*);
+        }
+        if (size + self.cur_size < self.max_size) return;
+    }
+    try self.cond.wait(io, &self.mut.mutex);
+    return self.makeRoom(io, size);
+}
+
+pub fn checkinBlock(self: *DecompCache, io: Io, offset: u64) !void {
+    self.mut.lockSharedUncancelable(io);
+    defer self.mut.unlockShared(io);
+
+    const get = self.cache.getPtr(offset);
+    if (get == null) return error.NotACachedBlock;
+    const res = get.?.usage.fetchSub(1, .acq_rel);
+    if (res == 0) self.cond.broadcast(io);
+}
+pub fn checkoutBlock(self: *DecompCache, io: Io, offset: u64, data_size: u32, max_result_size: u32) ![]u8 {
+    {
+        try self.mut.lockShared(io);
+        defer self.mut.unlockShared(io);
+
+        const get = self.cache.getPtr(offset);
+        if (get != null) {
+            _ = get.?.usage.fetchAdd(1, .acq_rel);
+            return get.?.cache;
+        }
+    }
+    try self.mut.lock(io);
+    defer self.mut.unlock(io);
+
+    try self.makeRoom(io, max_result_size);
+
+    var alloc = self.arena.allocator();
+    const buf_alloc = self.arena.child_allocator;
+
+    var out = try alloc.alloc(u8, max_result_size);
+    errdefer alloc.free(out);
+
+    const out_size = try self.decomp(buf_alloc, self.map.memory[offset..][0..data_size], out);
+    if (out_size != max_result_size) {
+        if (alloc.resize(out, out_size)) {
+            out.len = out_size;
+        } else {
+            const new_out = try alloc.alloc(u8, out_size);
+            @memcpy(new_out, out[0..out_size]);
+            alloc.free(out);
+            out = new_out;
+        }
+    }
+
+    try self.cache.put(buf_alloc, offset, .{
+        .cache = out,
+        .usage = .init(1),
+    });
+
+    return out;
+}
@@ -0,0 +1,38 @@
+const std = @import("std");
+const Io = std.Io;
+
+const config = @import("config");
+
+const c_decomp = @import("c_decomp.zig");
+const zig_decomp = @import("zig_decomp.zig");
+
+pub const Error = Io.Reader.Error || std.mem.Allocator.Error;
+
+pub const Fn = *const fn (alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize;
+
+pub const CompressionType = enum(u16) {
+    gzip = 1,
+    lzma,
+    lzo,
+    xz,
+    lz4,
+    zstd,
+};
+
+pub fn getDecompressFn(t: CompressionType) !Fn {
+    return if (config.use_zig_decomp) switch (t) {
+        .lzo => error.LzoUnsupported,
+        .lz4 => error.Lz4Unsupported,
+        .gzip => zig_decomp.zlibDecompress,
+        .lzma => zig_decomp.lzmaDecompress,
+        .xz => zig_decomp.xzDecompress,
+        .zstd => zig_decomp.zstdDecompress,
+    } else switch (t) {
+        .gzip => c_decomp.zlibDecompress,
+        .lzma => c_decomp.lzmaDecompress,
+        .lzo => if (config.allow_lzo) c_decomp.lzoDecompress else error.LzoUnsupported,
+        .xz => c_decomp.lzmaDecompress,
+        .lz4 => c_decomp.lz4Decompress,
+        .zstd => c_decomp.zstdDecompress,
+    };
+}
@@ -1,353 +0,0 @@
-const std = @import("std");
-const Allocator = std.mem.Allocator;
-const Pool = std.Thread.Pool;
-const WaitGroup = std.Thread.WaitGroup;
-
-const Archive = @import("../archive.zig");
-const DirEntry = @import("../dir_entry.zig");
-const Inode = @import("../inode.zig");
-const ExtractionOptions = @import("../options.zig");
-const Tables = @import("../tables.zig");
-const InodeFinish = @import("inode_finish.zig");
-const FinishUnion = InodeFinish.FinishUnion;
-const ThreadedDataReader = @import("data_threaded.zig");
-
-// 1 MB
-const STACK_ALLOC_SIZE = 1024 * 1024;
-
-pub fn extractTo(
-    allocator: Allocator,
-    inode: Inode,
-    archive: Archive,
-    path: []const u8,
-    options: ExtractionOptions,
-) !void {
-    if (path[path.len - 1] == '/')
-        return extractTo(allocator, inode, archive, path[0 .. path.len - 2], options);
-
-    var stack_alloc = std.heap.stackFallback(STACK_ALLOC_SIZE, allocator);
-    var arena: std.heap.ArenaAllocator = .init(stack_alloc.get());
-    defer arena.deinit();
-    if (options.threads <= 1) {
-        const alloc = arena.allocator();
-        var tables: Tables = try .init(alloc, archive);
-        return extractSingleThread(arena.allocator(), inode, archive, &tables, path, options);
-    }
-
-    var thread_alloc = std.heap.ThreadSafeAllocator{ .child_allocator = arena.allocator() };
-    const alloc = thread_alloc.allocator();
-    var tables: Tables = try .init(alloc, archive);
-
-    var pool_alloc = std.heap.stackFallback(10 * 1024, alloc);
-    var pool: Pool = undefined;
-    try pool.init(.{ .allocator = pool_alloc.get(), .n_jobs = options.threads - 1 });
-
-    var wg: WaitGroup = .{};
-    var err: ?anyerror = null;
-    wg.start();
-    try pool.spawn(extractMultiThread, .{
-        alloc,
-        inode,
-        archive,
-        &tables,
-        path,
-        options,
-        &pool,
-        FinishUnion{ .wg = &wg },
-        &err,
-    });
-    pool.waitAndWork(&wg);
-    if (err != null) return err.?;
-}
-
-fn extractSingleThread(
-    alloc: Allocator,
-    inode: Inode,
-    archive: Archive,
-    tables: *Tables,
-    path: []const u8,
-    options: ExtractionOptions,
-) !void {
-    switch (inode.hdr.inode_type) {
-        .dir, .ext_dir => {
-            _ = std.fs.cwd().makeDir(path) catch |err| switch (err) {
-                std.fs.Dir.MakeError.PathAlreadyExists => {},
-                else => return err,
-            };
-
-            // Currently we are ignoring any deinit or free calls since we know we are under an ArenaAllocator.
-            // Possibly in the future, do some simple math to see if it would be safe to ONLY deinit via Arena,
-            // otherwise be more conscientious about freeing memory.
-            // For now, this is good enough.
-
-            const entries = try inode.dirEntries(alloc, archive);
-            for (entries) |ent| {
-                const sub_inode: Inode = try .readFromEntry(alloc, archive, ent);
-                const new_path = try std.mem.concat(alloc, u8, &[_][]const u8{ path, "/", ent.name });
-                try extractSingleThread(alloc, sub_inode, archive, tables, new_path, options);
-            }
-
-            const fil = try std.fs.cwd().openFile(path, .{});
-            defer fil.close();
-            try inode.setMetadata(alloc, tables, fil, options);
-        },
-        .file, .ext_file => {
-            var fil = try std.fs.cwd().createFile(path, .{ .exclusive = true });
-            defer fil.close();
-            var wrt = fil.writer(&[0]u8{});
-            var dat_rdr = try inode.dataReader(alloc, archive, tables);
-            defer dat_rdr.deinit();
-            _ = try dat_rdr.interface.streamRemaining(&wrt.interface);
-            try wrt.interface.flush();
-
-            try inode.setMetadata(alloc, tables, fil, options);
-        },
-        .symlink, .ext_symlink => return extractSymlink(inode, path),
-        else => return extractDeviceAndIPC(inode, alloc, tables, path, options),
-    }
-}
-
-fn extractMultiThread(
-    alloc: Allocator,
-    inode: Inode,
-    archive: Archive,
-    tables: *Tables,
-    path: []const u8,
-    options: ExtractionOptions,
-    pool: *Pool,
-    fin: FinishUnion,
-    err: *?anyerror,
-) void {
-    if (err.* != null) {
-        fin.finish();
-        return;
-    }
-    switch (inode.hdr.inode_type) {
-        .dir, .ext_dir => {
-            _ = std.fs.cwd().makeDir(path) catch |res_err| switch (res_err) {
-                std.fs.Dir.MakeError.PathAlreadyExists => {},
-                else => {
-                    err.* = res_err;
-                    fin.finish();
-                    return;
-                },
-            };
-
-            // Currently we are ignoring any deinit or free calls since we know we are under an ArenaAllocator.
-            // Possibly in the future, do some simple math to see if it would be safe to ONLY deinit via Arena,
-            // otherwise be more conscientious about freeing memory.
-            // For now, this is good enough.
-
-            const entries = inode.dirEntries(alloc, archive) catch |res_err| {
-                err.* = res_err;
-                fin.finish();
-                return;
-            };
-
-            if (entries.len == 0) {
-                fin.finish();
-                return;
-            }
-
-            var dir_fin = InodeFinish.create(
-                alloc,
-                inode,
-                path,
-                tables,
-                options,
-                fin,
-                err,
-                null,
-                entries.len,
-            ) catch |res_err| {
-                err.* = res_err;
-                fin.finish();
-                return;
-            };
-
-            for (entries) |ent| {
-                if (ent.inode_type == .dir) {
-                    extractEntry(
-                        alloc,
-                        ent,
-                        archive,
-                        tables,
-                        path,
-                        options,
-                        pool,
-                        .{ .fin = dir_fin },
-                        err,
-                    );
-                    continue;
-                }
-
-                pool.spawn(
-                    extractEntry,
-                    .{ alloc, ent, archive, tables, path, options, pool, FinishUnion{ .fin = dir_fin }, err },
-                ) catch |res_err| {
-                    err.* = res_err;
-                    dir_fin.finish();
-                    return;
-                };
-            }
-        },
-        .file, .ext_file => {
-            const fil = std.fs.cwd().createFile(path, .{ .exclusive = true }) catch |res_err| {
-                if (options.verbose)
-                    options.verbose_writer.?.print("Can't create file at {s}: {}\n", .{ path, res_err }) catch {};
-                err.* = res_err;
-                fin.finish();
-                return;
-            };
-
-            var data_rdr = threadedDataReader(inode, alloc, archive, tables) catch |res_err| {
-                if (options.verbose)
-                    options.verbose_writer.?.print("Can't create data reader for inode #{} (extracting to {s}): {}\n", .{ inode.hdr.num, path, res_err }) catch {};
-                err.* = res_err;
-                fin.finish();
-                return;
-            };
-            if (data_rdr == null) {
-                inode.setMetadata(alloc, tables, fil, options) catch |res_err| {
-                    if (options.verbose)
-                        options.verbose_writer.?.print("Can't set metadata to {s}: {}\n", .{ path, res_err }) catch {};
-                    err.* = res_err;
-                };
-                fin.finish();
-                return;
-            }
-            const file_fin = InodeFinish.create(
-                alloc,
-                inode,
-                path,
-                tables,
-                options,
-                fin,
-                err,
-                fil,
-                data_rdr.?.num_blocks,
-            ) catch |res_err| {
-                if (options.verbose)
-                    options.verbose_writer.?.print("Can't create callback for inode #{} (extracting to {s}): {}\n", .{ inode.hdr.num, path, res_err }) catch {};
-                err.* = res_err;
-                fin.finish();
-                return;
-            };
-
-            data_rdr.?.extractThreaded(fil, pool, file_fin);
-        },
-        .symlink, .ext_symlink => {
-            extractSymlink(inode, path) catch |res_err| {
-                err.* = res_err;
-            };
-            fin.finish();
-        },
-        else => {
-            extractDeviceAndIPC(inode, alloc, tables, path, options) catch |res_err| {
-                err.* = res_err;
-            };
-            fin.finish();
-        },
-    }
-}
-
-fn extractEntry(
-    alloc: Allocator,
-    ent: DirEntry,
-    archive: Archive,
-    tables: *Tables,
-    path: []const u8,
-    options: ExtractionOptions,
-    pool: *Pool,
-    fin: FinishUnion,
-    err: *?anyerror,
-) void {
-    const new_path = std.mem.concat(alloc, u8, &[_][]const u8{ path, "/", ent.name }) catch |res_err| {
-        err.* = res_err;
-        fin.finish();
-        return;
-    };
-
-    const inode = Inode.readFromEntry(alloc, archive, ent) catch |res_err| {
-        err.* = res_err;
-        fin.finish();
-        return;
-    };
-    extractMultiThread(alloc, inode, archive, tables, new_path, options, pool, fin, err);
-}
-
-/// Get a threaded data reader for a file inode.
-fn threadedDataReader(self: Inode, alloc: std.mem.Allocator, archive: Archive, tables: *Tables) !?ThreadedDataReader {
-    return switch (self.hdr.inode_type) {
-        .file => threadedReaderFromData(alloc, archive, tables, self.data.file),
-        .ext_file => threadedReaderFromData(alloc, archive, tables, self.data.ext_file),
-        else => error.NotRegularFile,
-    };
-}
-fn threadedReaderFromData(alloc: std.mem.Allocator, archive: Archive, tables: *Tables, data: anytype) !?ThreadedDataReader {
-    if (data.block_sizes.len == 0 and data.frag_idx == 0xFFFFFFFF) return null;
-    var out: ThreadedDataReader = .init(alloc, archive, data.block_sizes, data.block_start, data.size);
-    if (data.frag_idx != 0xFFFFFFFF)
-        out.addFragment(try tables.frag_table.get(data.frag_idx), data.frag_block_offset);
-    return out;
-}
-
-/// Creates the symlink described by the inode.
-/// Sets metadata.
-fn extractSymlink(self: Inode, path: []const u8) !void {
-    const target = switch (self.data) {
-        .symlink => |s| s.target,
-        .ext_symlink => |s| s.target,
-        else => unreachable,
-    };
-    try std.fs.cwd().symLink(target, path, .{});
-}
-/// Creates the device described by the inode.
-/// Sets metadata.
-fn extractDeviceAndIPC(self: Inode, alloc: std.mem.Allocator, tables: *Tables, path: []const u8, options: ExtractionOptions) !void {
-    var mode: u32 = undefined;
-    var dev: u32 = 0;
-    switch (self.data) {
-        .char_dev => |d| {
-            mode = std.posix.S.IFCHR;
-            dev = d.dev;
-        },
-        .ext_char_dev => |d| {
-            mode = std.posix.S.IFCHR;
-            dev = d.dev;
-        },
-        .block_dev => |d| {
-            mode = std.posix.S.IFBLK;
-            dev = d.dev;
-        },
-        .ext_block_dev => |d| {
-            mode = std.posix.S.IFBLK;
-            dev = d.dev;
-        },
-        .fifo, .ext_fifo => mode = std.posix.S.IFIFO,
-        .socket, .ext_socket => mode = std.posix.S.IFSOCK,
-        else => unreachable,
-    }
-    const res: std.os.linux.E = @enumFromInt(std.os.linux.mknod(@ptrCast(path), mode, dev));
-    switch (res) {
-        .SUCCESS => {},
-        .ACCES => return std.fs.Dir.MakeError.AccessDenied,
-        .DQUOT => return std.fs.Dir.MakeError.DiskQuota,
-        .EXIST => return std.fs.Dir.MakeError.PathAlreadyExists,
-        .FAULT, .NOENT => return std.fs.Dir.MakeError.BadPathName,
-        .LOOP => return std.fs.Dir.MakeError.SymLinkLoop,
-        .NAMETOOLONG => return std.fs.Dir.MakeError.NameTooLong,
-        .NOMEM => return std.fs.Dir.MakeError.SystemResources,
-        .NOSPC => return std.fs.Dir.MakeError.NoSpaceLeft,
-        .NOTDIR => return std.fs.Dir.MakeError.NotDir,
-        .PERM => return std.fs.Dir.MakeError.PermissionDenied,
-        .ROFS => return std.fs.Dir.MakeError.ReadOnlyFileSystem,
-        else => return blk: {
-            std.debug.print("unhandled mknod result: {}\n", .{res});
-            break :blk std.fs.Dir.MakeError.Unexpected;
-        },
-    }
-    var fil = try std.fs.cwd().openFile(path, .{});
-    defer fil.close();
-    try self.setMetadata(alloc, tables, fil, options);
-}
@@ -1,101 +0,0 @@
-const std = @import("std");
-const WaitGroup = std.Thread.WaitGroup;
-const Mutex = std.Thread.Mutex;
-
-const Archive = @import("../archive.zig");
-const Inode = @import("../inode.zig");
-const ExtractionOptions = @import("../options.zig");
-const Tables = @import("../tables.zig");
-
-const InodeFinish = @This();
-
-const FinishEnum = enum {
-    wg,
-    fin,
-};
-pub const FinishUnion = union(FinishEnum) {
-    wg: *WaitGroup,
-    fin: *InodeFinish,
-
-    pub fn finish(self: FinishUnion) void {
-        switch (self) {
-            .wg => |wg| wg.finish(),
-            .fin => |fin| fin.finish(),
-        }
-    }
-};
-
-alloc: std.mem.Allocator,
-
-inode: Inode,
-path: []const u8,
-tables: *Tables,
-options: ExtractionOptions,
-parent_finish: FinishUnion,
-fil: ?std.fs.File,
-out_err: *?anyerror,
-
-wg: WaitGroup = .{},
-mut: Mutex = .{},
-
-pub fn create(
-    alloc: std.mem.Allocator,
-    inode: Inode,
-    path: []const u8,
-    tables: *Tables,
-    options: ExtractionOptions,
-    parent_finish: FinishUnion,
-    out_err: *?anyerror,
-    fil: ?std.fs.File,
-    work_size: usize,
-) !*InodeFinish {
-    if (work_size == 0)
-        return error.InvalidWorkSize;
-    const out = try alloc.create(InodeFinish);
-    errdefer alloc.destroy(out);
-    out.* = .{
-        .alloc = alloc,
-
-        .inode = inode,
-        .path = path,
-        .tables = tables,
-        .options = options,
-        .parent_finish = parent_finish,
-        .out_err = out_err,
-        .fil = fil,
-    };
-    out.wg.startMany(work_size);
-    return out;
-}
-
-pub fn logError(self: *InodeFinish, comptime fmt: []const u8, args: anytype) void {
-    if (self.options.verbose)
-        self.options.verbose_writer.?.print(fmt, args) catch {};
-}
-
-pub fn finish(self: *InodeFinish) void {
-    self.mut.lock();
-    {
-        defer self.mut.unlock();
-        self.wg.finish();
-        if (!self.wg.isDone()) return;
-    }
-    defer {
-        self.parent_finish.finish();
-        self.alloc.destroy(self);
-    }
-    if (self.fil == null)
-        self.fil = std.fs.cwd().openFile(self.path, .{}) catch |err| {
-            if (self.options.verbose)
-                self.options.verbose_writer.?.print("Error opening {s} to set metadata: {}\n", .{ self.path, err }) catch {};
-            self.out_err.* = err;
-            return;
-        };
-    defer self.fil.?.close();
-    self.inode.setMetadata(self.alloc, self.tables, self.fil.?, self.options) catch |err| {
-        if (self.options.verbose)
-            self.options.verbose_writer.?.print("Error setting metadata to {s}: {}\n", .{ self.path, err }) catch {};
-        self.out_err.* = err;
-        return;
-    };
-}
@@ -1,41 +0,0 @@
-const std = @import("std");
-
-const OffsetFile = @import("offset_file.zig");
-
-const MetadataCache = @This();
-
-alloc: std.mem.Allocator,
-
-buf: []u8,
-fixed_alloc: std.heap.FixedBufferAllocator,
-
-cache: std.AutoArrayHashMap(u64, [8192]u8),
-
-mut: std.Thread.Mutex = .{},
-cache_mut: std.AutoArrayHashMap(u64, std.Thread.Mutex),
-
-fil: OffsetFile,
-
-pub fn init(alloc: std.mem.Allocator, cache_size: u64) !MetadataCache {}
-pub fn deinit(self: *MetadataCache) void {
-    self.mut.lock();
-    defer self.mut.unlock();
-    self.cache.deinit();
-    self.cache_mut.deinit();
-    self.alloc.free(self.buf);
-}
-
-pub fn getChunk(self: *MetadataCache, offset: u64) ![8192]u8 {
-    var res = self.cache.get(offset);
-    if (res != null) return res.?;
-    var offset_mut = blk: {
-        self.mut.lock();
-        defer self.mut.unlock();
-        const mut = try self.cache_mut.getOrPut(offset);
-        if (!mut.found_existing)
-            mut.value_ptr.* = .{};
-        break :blk mut.value_ptr;
-    };
-    offset_mut.lock();
-    defer offset_mut.unlock();
-}
@@ -1,33 +1,30 @@
+//! A cache for decompressed blocks. Used for Metadata & fragments.
+
 const std = @import("std");
-const Reader = std.Io.Reader;
-const Writer = std.Io.Writer;
-const Limit = std.Io.Limit;
-const StreamError = std.Io.Reader.StreamError;
+const Io = std.Io;
+const Reader = Io.Reader;
+const Writer = Io.Writer;
+const Limit = Io.Limit;

-const DecompFn = @import("../decomp.zig").DecompFn;
+const DecompCache = @import("decomp_cache.zig");

-const BlockHeader = packed struct {
+const MetadataReader = @This();
+
+const BlockHeader = packed struct(u16) {
    size: u15,
    uncompressed: bool,
 };

-const This = @This();
+io: Io,

-alloc: std.mem.Allocator,
-rdr: *Reader,
-decomp: DecompFn,
+cur_offset: u64 = 0,
+next_offset: u64,

-buf: [8192]u8 = undefined,
+cache: *DecompCache,

-interface: Reader,
-err: ?anyerror = null,
+buf_uncompress: bool = false,

-pub fn init(alloc: std.mem.Allocator, rdr: *Reader, decomp: DecompFn) This {
-    return .{
-        .alloc = alloc,
-        .rdr = rdr,
-        .decomp = decomp,
-        .interface = .{
+interface: Reader = .{
    .buffer = &[0]u8{},
    .end = 0,
    .seek = 0,
@@ -37,61 +34,77 @@ pub fn init(alloc: std.mem.Allocator, rdr: *Reader, decomp: DecompFn) This {
        .readVec = readVec,
    },
 },
+
+pub fn init(io: Io, cache: *DecompCache, offset: u64) MetadataReader {
+    return .{
+        .io = io,
+
+        .next_offset = offset,
+
+        .cache = cache,
    };
 }
+pub fn deinit(self: *MetadataReader) void {
+    if (self.cur_offset != 0 and !self.buf_uncompress)
+        self.cache.checkinBlock(self.io, self.cur_offset) catch {};
+}

-fn advance(self: *This) !void {
-    self.interface.seek = 0;
-    var hdr: BlockHeader = undefined;
-    try self.rdr.readSliceEndian(BlockHeader, @ptrCast(&hdr), .little);
+fn advance(self: *MetadataReader) !void {
+    if (self.interface.buffer.len > 0 and !self.buf_uncompress)
+        self.cache.checkinBlock(self.io, self.cur_offset) catch |err| {
+            std.debug.print("UH OH! {}\n", .{err});
+            return error.ReadFailed;
+        };
+    const hdr: BlockHeader = @bitCast(std.mem.readInt(u16, self.cache.map.memory[self.next_offset..][0..2], .little));
+    self.cur_offset = self.next_offset + 2;
+    self.next_offset = self.cur_offset + hdr.size;
+
+    self.buf_uncompress = hdr.uncompressed;
    if (hdr.uncompressed) {
-        try self.rdr.readSliceEndian(u8, self.buf[0..hdr.size], .little);
+        self.interface.buffer = self.cache.map.memory[self.cur_offset..][0..hdr.size];
        self.interface.end = hdr.size;
-        self.interface.buffer = self.buf[0..hdr.size];
+        self.interface.seek = 0;
        return;
    }
-    var tmp_buf: [8192]u8 = undefined;
-    try self.rdr.readSliceAll(tmp_buf[0..hdr.size]);
-    self.interface.end = try self.decomp(self.alloc, tmp_buf[0..hdr.size], &self.buf);
-    self.interface.buffer = self.buf[0..self.interface.end];
+    self.interface.buffer = try self.cache.checkoutBlock(self.io, self.cur_offset, hdr.size, 8192);
+    self.interface.end = self.interface.buffer.len;
+    self.interface.seek = 0;
 }

-fn stream(rdr: *Reader, wrt: *Writer, limit: Limit) StreamError!usize {
-    const self: *This = @fieldParentPtr("interface", rdr);
-    if (rdr.end == rdr.seek) self.advance() catch |err| {
-        self.err = err;
-        return StreamError.ReadFailed;
-    };
-    if (@intFromEnum(limit) == 0) return 0;
-    const to_write = @min(rdr.end - rdr.seek, @intFromEnum(limit));
-    const wrote = try wrt.write(self.buf[rdr.seek .. rdr.seek + to_write]);
-    self.interface.seek += wrote;
+fn stream(r: *Reader, w: *Writer, limit: Limit) Reader.StreamError!usize {
+    if (r.seek == r.end) {
+        var self: *MetadataReader = @fieldParentPtr("interface", r);
+        self.advance() catch return Reader.Error.ReadFailed;
+    }
+    if (limit == .nothing) return 0;
+    const to_write = @min(r.end - r.seek, @intFromEnum(limit));
+    const wrote = try w.write(r.buffer[r.seek..][0..to_write]);
+    r.seek += wrote;
    return wrote;
 }
-fn discard(rdr: *Reader, limit: Limit) error{ EndOfStream, ReadFailed }!usize {
-    const self: *This = @fieldParentPtr("interface", rdr);
-    if (rdr.end == rdr.seek) self.advance() catch |err| {
-        self.err = err;
-        return StreamError.ReadFailed;
-    };
-    if (@intFromEnum(limit) == 0) return 0;
-    const to_skip = @min(rdr.end - rdr.seek, @intFromEnum(limit));
-    rdr.seek += to_skip;
+fn discard(r: *Reader, limit: Limit) Reader.Error!usize {
+    if (r.seek == r.end) {
+        var self: *MetadataReader = @fieldParentPtr("interface", r);
+        self.advance() catch return Reader.Error.ReadFailed;
+    }
+    if (limit == .nothing) return 0;
+    const to_skip = @min(r.end - r.seek, @intFromEnum(limit));
+    r.seek += to_skip;
    return to_skip;
 }
-fn readVec(rdr: *Reader, vec: [][]u8) error{ EndOfStream, ReadFailed }!usize {
-    const self: *This = @fieldParentPtr("interface", rdr);
-    if (rdr.end == rdr.seek) self.advance() catch |err| {
-        self.err = err;
-        return StreamError.ReadFailed;
-    };
-    var cur_red: usize = 0;
-    for (vec) |s| {
-        const to_copy: usize = @min(rdr.end - rdr.seek, s.len);
-        @memcpy(s[0..to_copy], self.buf[rdr.seek .. rdr.seek + to_copy]);
-        rdr.seek += to_copy;
-        cur_red += to_copy;
-        if (rdr.end == rdr.seek) break;
+fn readVec(r: *Reader, vec: [][]u8) Reader.Error!usize {
+    if (r.seek == r.end) {
+        var self: *MetadataReader = @fieldParentPtr("interface", r);
+        self.advance() catch return Reader.Error.ReadFailed;
    }
-    return cur_red;
+    if (vec.len == 0) return 0;
+    var total_copied: usize = 0;
+    for (vec) |v| {
+        const to_cpy = @min(r.end - r.seek, v.len);
+        @memcpy(v[0..to_cpy], r.buffer[r.seek..][0..to_cpy]);
+        r.seek += to_cpy;
+        total_copied += to_cpy;
+        if (r.seek == r.end) break;
+    }
+    return total_copied;
 }
@@ -1,20 +0,0 @@
-//! A File where it's meaningful (to us) content starts at a given offset.
-
-const std = @import("std");
-const File = std.fs.File;
-const Reader = std.fs.File.Reader;
-
-const OffsetFile = @This();
-
-fil: File,
-offset: u64,
-
-pub fn init(fil: File, init_offset: u64) OffsetFile {
-    return .{ .fil = fil, .offset = init_offset };
-}
-
-pub fn readerAt(self: OffsetFile, offset: u64, buffer: []u8) !Reader {
-    var rdr = self.fil.reader(buffer);
-    try rdr.seekTo(self.offset + offset);
-    return rdr;
-}
@@ -0,0 +1,40 @@
+const std = @import("std");
+const Reader = std.Io.Reader;
+const flate = std.compress.flate;
+const zstd = std.compress.zstd;
+const xz = std.compress.xz;
+const lzma = std.compress.lzma;
+
+const Error = @import("decompress.zig").Error;
+
+pub fn zlibDecompress(_: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    var buf: [flate.max_window_len]u8 = undefined;
+
+    var rdr: Reader = .fixed(in);
+    var decomp: flate.Decompress = .init(&rdr, .zlib, &buf);
+
+    return decomp.reader.readSliceShort(out);
+}
+pub fn zstdDecompress(alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    const buf = try alloc.alloc(u8, in.len + zstd.block_size_max);
+    defer alloc.free(buf);
+
+    var rdr: Reader = .fixed(in);
+    var decomp: zstd.Decompress = .init(&rdr, buf, .{ .window_len = in.len });
+
+    return decomp.reader.readSliceShort(out);
+}
+pub fn lzmaDecompress(alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    var rdr: Reader = .fixed(in);
+    var decomp: lzma.Decompress = .initOptions(&rdr, alloc, &[0]u8{}, .{}, 2 * out.len);
+    defer decomp.deinit();
+
+    return decomp.reader.readSliceShort(out);
+}
+pub fn xzDecompress(alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    var rdr: Reader = .fixed(in);
+    var decomp: xz.Decompress = .init(&rdr, alloc, &[0]u8{});
+    defer decomp.deinit();
+
+    return decomp.reader.readSliceShort(out);
+}
@@ -1,117 +0,0 @@
-const std = @import("std");
-
-const DecompFn = @import("decomp.zig").DecompFn;
-const Table = @import("tables.zig").Table;
-const MetadataReader = @import("util/metadata.zig");
-const OffsetFile = @import("util/offset_file.zig");
-
-const Ref = packed struct {
-    block_offset: u16,
-    block_start: u32,
-    _: u16,
-};
-const Entry = packed struct {
-    ref: Ref,
-    count: u32,
-    size: u32,
-};
-const KeyPrefix = enum(u8) {
-    user,
-    trusted,
-    security,
-};
-const KeyRaw = packed struct {
-    type: packed struct {
-        prefix: KeyPrefix,
-        out_of_line: bool,
-        _: u7,
-    },
-    name_size: u16,
-};
-
-pub const KeyValue = struct {
-    key: [:0]u8,
-    value: []u8,
-};
-
-const XattrTable = @This();
-
-alloc: std.mem.Allocator,
-fil: OffsetFile,
-decomp: DecompFn,
-
-count: u32,
-start: u64,
-
-table: Table(Entry),
-
-pub fn init(alloc: std.mem.Allocator, fil: OffsetFile, decomp: DecompFn, table_start: u64) !XattrTable {
-    var info = packed struct {
-        start: u64 = undefined,
-        count: u32 = undefined,
-        _: u32 = undefined,
-    }{};
-    var rdr = try fil.readerAt(table_start, &[0]u8{});
-    try rdr.interface.readSliceEndian(@TypeOf(info), @ptrCast(&info), .little);
-    return .{
-        .alloc = alloc,
-        .fil = fil,
-        .decomp = decomp,
-        .count = info.count,
-        .start = info.start,
-        .table = try .init(alloc, fil, decomp, table_start + 16, info.count),
-    };
-}
-pub fn deinit(self: *XattrTable) void {
-    self.table.deinit();
-}
-
-pub fn get(self: *XattrTable, alloc: std.mem.Allocator, idx: u32) ![]KeyValue {
-    const entry: Entry = try self.table.get(idx);
-    const out = try alloc.alloc(KeyValue, entry.count);
-
-    for (out) |*kv| {
-        var rdr = try self.fil.readerAt(self.start + entry.ref.block_start, &[0]u8{});
-        var meta: MetadataReader = .init(alloc, &rdr.interface, self.decomp);
-        try meta.interface.discardAll(entry.ref.block_offset);
-
-        var key_raw: KeyRaw = undefined;
-        try meta.interface.readSliceEndian(KeyRaw, @ptrCast(&key_raw), .little);
-
-        switch (key_raw.type.prefix) {
-            .user => {
-                kv.key = @ptrCast(try alloc.alloc(u8, key_raw.name_size + 5 + 1));
-                @memcpy(kv.key[0..5], "user.");
-                try meta.interface.readSliceAll(kv.key[5 .. kv.key.len - 1]);
-                kv.key[kv.key.len - 1] = 0;
-            },
-            .security => {
-                kv.key = @ptrCast(try alloc.alloc(u8, key_raw.name_size + 9 + 1));
-                @memcpy(kv.key[0..9], "security.");
-                try meta.interface.readSliceAll(kv.key[9 .. kv.key.len - 1]);
-                kv.key[kv.key.len - 1] = 0;
-            },
-            .trusted => {
-                kv.key = @ptrCast(try alloc.alloc(u8, key_raw.name_size + 8 + 1));
-                @memcpy(kv.key[0..8], "trusted.");
-                try meta.interface.readSliceAll(kv.key[8 .. kv.key.len - 1]);
-                kv.key[kv.key.len - 1] = 0;
-            },
-        }
-        if (key_raw.type.out_of_line) {
-            try meta.interface.discardAll(4);
-            var ref: Ref = undefined;
-            try meta.interface.readSliceEndian(Ref, @ptrCast(&ref), .little);
-
-            rdr = try self.fil.readerAt(self.start + ref.block_start, &[0]u8{});
-            meta = .init(alloc, &rdr.interface, self.decomp);
-            try meta.interface.discardAll(ref.block_offset);
-        }
-        var value_size: u32 = undefined;
-        try meta.interface.readSliceEndian(u32, @ptrCast(&value_size), .little);
-        kv.value = try alloc.alloc(u8, value_size);
-        try meta.interface.readSliceAll(kv.value);
-    }
-
-    return out;
-}
Author	SHA1	Message	Date
Caleb Gardner	c2a3eb420f	Fixed some bugs. Caused some bugs	2026-05-28 03:56:43 -05:00
Caleb Gardner	eb1b940854	(Mostly) Finished extraction (currently infinitely hanging) Added DataExtract Added LookupTable	2026-05-27 19:17:17 -05:00
Caleb Gardner	ba2f069a4a	More work on re-implementing everything Finished MetadataReader Finished DirEntry Started work on File Added most important things to Inode Fixed test.zig Fixed some build issues causing SEGV	2026-05-27 11:59:47 -05:00
Caleb Gardner	7c4089f826	Re-set & re-write of several things Implemented new decompression cache to prevent decompressing the same block multiple times	2026-05-27 06:03:54 -05:00
Caleb J. Gardner	4b2b7021c7	Moved & organized decompression Fully implemented Decompressor vtable	2026-04-02 06:27:34 -05:00