Started changes to Zig 0.16.0

Added xattr & cached uid/gid to Inode
Added stateless Xattr lookup
2026-04-29 02:20:46 -05:00 · 2026-04-24 05:52:31 -05:00 · 2026-04-24 04:16:22 -05:00 · 2026-04-08 02:33:58 -05:00 · 2026-04-07 15:41:30 -05:00 · 2026-04-04 18:48:57 -05:00
47 changed files with 2146 additions and 1756 deletions
@@ -1,18 +0,0 @@
-// 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"],
-			},
-		},
-	},
-}
@@ -1,118 +1,107 @@
 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;
-    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 use_zig_decomp = b.option(bool, "use_zig_decomp", "Use zig standard library for decompression.") orelse true;
+    // 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 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);

-    version_string = std.mem.trimStart(u8, version_string, "v");
-    const version = try std.SemanticVersion.parse(version_string);
+    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,
+        .valgrind = debug,
+        .error_tracing = debug,
+        .strip = if (debug == true) false else null,
+    });
+    mod.addOptions("config", zig_squashfs_options);
+    if (!use_zig_decomp) {
+        mod.link_libc = true;
+
+        const c_imports = b.addTranslateC(.{
+            .optimize = optimize,
+            .target = target,
+            .root_source_file = b.path("src/imports.c"),
+        });
+        mod.addImport("c", c_imports.createModule());
+
+        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..];
    const unsquashfs_options = b.addOptions();
    unsquashfs_options.addOption(
        std.SemanticVersion,
        "version",
-        version,
+        try std.SemanticVersion.parse(version),
    );

-    if (debug) optimize = .Debug;
-    if (optimize == .Debug) debug = true;
-
-    const c_import = b.addTranslateC(.{
-        .root_source_file = b.path("src/c.h"),
+    var exe_mod = b.createModule(.{
+        .root_source_file = b.path("src/bin/unsquashfs.zig"),
        .target = target,
-        .optimize = optimize,
+        .optimize = if (debug == true) .Debug else optimize,
+        .link_libc = !use_zig_decomp,
+        .imports = &.{
+            .{ .name = "zig_squashfs", .module = mod },
+        },
+        .valgrind = debug,
+        .error_tracing = debug,
+        .strip = if (debug == true) false else null,
    });
-    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);
-
+    exe_mod.addOptions("config", unsquashfs_options);
    const exe = b.addExecutable(.{
        .name = "unsquashfs",
-        .root_module = b.createModule(.{
-            .root_source_file = b.path("src/bin/unsquashfs.zig"),
-            .target = target,
-            .optimize = optimize,
-            .imports = &.{
-                .{ .name = "config", .module = unsquashfs_options.createModule() },
-                .{ .name = "squashfs", .module = lib.root_module },
-            },
-            .valgrind = debug,
-            .error_tracing = debug,
-            .strip = !debug,
-        }),
+        .root_module = exe_mod,
+        .use_llvm = debug,
+    });
+
+    const lib = b.addLibrary(.{
+        .name = "squashfs",
+        .root_module = mod,
        .use_llvm = debug,
-        .version = version,
    });

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

    const mod_tests = b.addTest(.{
-        .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
+        .root_module = mod,
+        .test_runner = .{
+            .mode = .simple,
+            .path = b.path("src/test.zig"),
+        },
    });
-
-    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);
@@ -120,54 +109,13 @@ pub fn build(b: *std.Build) !void {
    // zls build check steps
    const lib_check = b.addLibrary(.{
        .name = "squashfs",
-        .root_module = lib.root_module,
+        .root_module = mod,
    });
    const exe_check = b.addExecutable(.{
        .name = "unsquashfs",
-        .root_module = exe.root_module,
+        .root_module = exe_mod,
    });
    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);
+    check.dependOn(&lib_check.step);
 }
@@ -2,11 +2,12 @@
    .name = .squashfs,
    .version = "0.0.6",
    .fingerprint = 0x37ba29474b87f145, // Changing this has security and trust implications.
-    .minimum_zig_version = "0.16.1",
+    .minimum_zig_version = "0.16.0",
    .dependencies = .{
        .zlib_ng = .{
-            .url = "git+https://github.com/CalebQ42/zig-zlib-ng#5f2f02dfb28acca2517dacbbd09e9b987f57b133",
-            .hash = "zlib_ng-2.3.3-pre1-2HYS4ClFAABW8KlHMyBHtlNKE3V7kCS8wqfxawG7xeaa",
+            // .url = "git+https://github.com/CalebQ42/zig-zlib-ng#5f2f02dfb28acca2517dacbbd09e9b987f57b133",
+            // .hash = "zlib_ng-2.3.3-pre1-2HYS4ClFAABW8KlHMyBHtlNKE3V7kCS8wqfxawG7xeaa",
+            .path = "../zig-zlib-ng",
        },
        .zstd = .{
            .url = "git+https://github.com/allyourcodebase/zstd.git?ref=1.5.7-1#e1a501be57f42c541e8a5597e4b59a074dfd09a3",
@@ -17,13 +18,14 @@
            .hash = "lz4-1.10.0-6-ewyzw-4NAAAWDpY4xpiqr4LQhZQAC0x_rGnW2iPh6jk2",
        },
        .minilzo = .{
-            .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",
+            // .url = "git+https://github.com/CalebQ42/zig-minilzo.git#7cbae997b91a44d74b7cd6c073584dc9562a6c90",
+            // .hash = "minilzo-2.10.0-Ij7BO8wLAADeWI4Pe4jp8XTDsDaquZR14oZ7_9yKKDWP",
+            .path = "../zig-minilzo",
        },
+        // .fastlzma2 = .{
+        //     .url = "git+https://github.com/allyourcodebase/fast-lzma2#d7615e0c957a62fcd6691b3fe9519a091885bfa2",
+        //     .hash = "fastlzma2-0.0.0-gNWHgVeLAAD0Tlak3xhNcgpPSYcjyJppq0tlGmPKCC_V",
+        // },
    },
    .paths = .{
        "build.zig",
@@ -1,2 +0,0 @@
-[tools]
-zig = "0.16.0"
@@ -1,10 +0,0 @@
-#!/bin/sh
-
-zig test \
-	-lc \
-	-lz \
-	-llzma \
-	-lminilzo \
-	-llz4 \
-	-lzstd \
-		src/test.zig
@@ -1,100 +1,184 @@
 const std = @import("std");
 const Io = std.Io;
-const MemoryMap = Io.File.MemoryMap;
-
-const c = @import("c");
-const config = @import("config");

+const DecompTypes = @import("decomp/types.zig");
+const Decompressor = @import("decomp.zig");
 const ExtractionOptions = @import("options.zig");
 const File = @import("file.zig");
 const Inode = @import("inode.zig");
-const Superblock = @import("super.zig").Superblock;
-const DecompCache = @import("util/decomp_cache.zig");
-const CompressionType = @import("util/decompress.zig").CompressionType;
+const BlockSize = @import("inode/file.zig").BlockSize;
+const LookupTable = @import("lookup_table.zig");
+const MetadataReader = @import("util/metadata.zig");
+const OffsetFile = @import("util/offset_file.zig");
+const Utils = @import("util/utils.zig");
+
+pub const Error = error{
+    BadMagic,
+    BadBlockLog,
+    BadVersion,
+    BadCheck,
+};

 const Archive = @This();

-const CACHE_MIN = 16 * 1024 * 1024;
-const CACHE_MAX = 1 * 1024 * 1024 * 1024;
-
-cache: DecompCache,
+file: OffsetFile,

 super: Superblock,

-/// 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);
+stateless_decomp: Decompressor,

+/// Create an Archive from a File.
+pub fn init(io: Io, fil: Io.File, offset: u64) !Archive {
    var super: Superblock = undefined;
-    try rdr.interface.readSliceEndian(Superblock, @ptrCast(&super), .little);
+    var fil_rdr = fil.reader(io, &[0]u8{});
+    if (offset > 0)
+        try fil_rdr.seekTo(offset);
+    try fil_rdr.interface.readSliceEndian(Superblock, @ptrCast(&super), .little);
    try super.validate();

-    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 .{
-        .cache = try .init(
-            alloc,
-            try file.createMemoryMap(
-                io,
-                .{
-                    .offset = offset,
-                    .len = super.size,
-                    .protection = .{ .read = true },
-                },
-            ),
-            super.compression,
-            cache_size,
-        ),
-
+        .file = .{ .fil = fil, .offset = offset },
        .super = super,
+        .stateless_decomp = .{ .vtable = &.{ .stateless = try DecompTypes.getStatelessFn(super.compression) } },
    };
 }
-pub fn deinit(self: *Archive, io: Io) void {
-    self.cache.deinit(io);
+
+pub fn root(self: Archive, alloc: std.mem.Allocator) !File {
+    return .{
+        .file = self.file,
+        .super = self.super.toMinimal(),
+        .decomp = self.stateless_decomp.statelessCopy(alloc),
+
+        .inode = try Utils.readInode(
+            alloc,
+            &self.stateless_decomp,
+            self.file,
+            self.super.inode_start,
+            self.super.block_size,
+            self.super.root_ref.block_start,
+            self.super.root_ref.block_offset,
+        ),
+        .name = "",
+    };
 }
-
-pub fn root(self: *Archive, alloc: std.mem.Allocator, io: Io) !File {
-    return .fromRef(alloc, io, self, "", self.super.root_ref);
-}
-
-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;
+pub fn open(self: Archive, alloc: std.mem.Allocator, path: []const u8) !File {
+    if (Utils.pathIsSelf(path)) return self.root(alloc);
+    var root_file = self.root(alloc);
    defer root_file.deinit();
-
-    return root_file.open(alloc, io, path);
+    return root_file.open(alloc, path);
 }

-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(
+pub fn fragEntry(self: Archive, idx: u32) !FragEntry {
+    return LookupTable.stateless(FragEntry, self.fil, &self.stateless_decomp, self.super.frag_start, idx);
+}
+pub fn id(self: Archive, idx: u32) !u16 {
+    return LookupTable.stateless(u16, self.fil, &self.stateless_decomp, self.super.id_start, idx);
+}
+pub fn inode(self: Archive, alloc: std.mem.Allocator, inode_num: u32) !Inode {
+    const ref = try LookupTable.stateless(Inode.Ref, self.file, &self.stateless_decomp, self.super.export_start, inode_num - 1);
+    return Utils.readInode(
        alloc,
-        io,
-        &self.cache,
-        self.super.dir_start,
+        &self.stateless_decomp,
+        self.file,
        self.super.inode_start,
-        self.super.frag_start,
        self.super.block_size,
-        self.super.id_start,
-        self.super.xattr_start,
-        ext_dir,
-        options,
+        ref.block_start,
+        ref.block_offset,
    );
 }
+
+pub fn extract(self: Archive, alloc: std.mem.Allocator, path: []const u8, options: ExtractionOptions) !void {
+    _ = self;
+    _ = alloc;
+    _ = path;
+    _ = options;
+    return error.TODO;
+}
+
+// Superblock
+
+const SQUASHFS_MAGIC: u32 = std.mem.readInt(u32, "hsqs", .little);
+
+pub const Superblock = packed struct {
+    magic: u32,
+    inode_count: u32,
+    mod_time: u32,
+    block_size: u32,
+    frag_count: u32,
+    compression: DecompTypes.Enum,
+    block_log: u16,
+    flags: packed struct {
+        inode_uncompressed: bool,
+        data_uncompressed: bool,
+        check: bool,
+        frag_uncompressed: bool,
+        fragment_never: bool,
+        fragment_always: bool,
+        duplicates: bool,
+        exportable: bool,
+        xattr_uncompressed: bool,
+        xattr_never: bool,
+        compression_options: bool,
+        ids_uncompressed: bool,
+        _: u4,
+    },
+    id_count: u16,
+    ver_maj: u16,
+    ver_min: u16,
+    root_ref: Inode.Ref,
+    size: u64,
+    id_start: u64,
+    xattr_start: u64,
+    inode_start: u64,
+    dir_start: u64,
+    frag_start: u64,
+    export_start: u64,
+
+    /// Validate the Superblock. If an error is returned, it's likely the archive is corrupted or not a squashfs archive.
+    fn validate(self: Superblock) !void {
+        if (self.magic != SQUASHFS_MAGIC)
+            return Error.BadMagic;
+        if (self.flags.check)
+            return Error.BadCheck;
+        if (self.ver_maj != 4 or self.ver_min != 0)
+            return Error.BadVersion;
+        if (std.math.log2(self.block_size) != self.block_log)
+            return Error.BadBlockLog;
+    }
+
+    pub fn toMinimal(self: Superblock) MinimalSuperblock {
+        return .{
+            .inode_count = self.inode_count,
+            .block_size = self.block_size,
+            .frag_count = self.frag_count,
+            .id_count = self.id_count,
+            .id_start = self.id_start,
+            .xattr_start = self.xattr_start,
+            .inode_start = self.inode_start,
+            .dir_start = self.dir_start,
+            .frag_start = self.frag_start,
+            .export_start = self.export_start,
+        };
+    }
+};
+
+pub const MinimalSuperblock = struct {
+    inode_count: u32,
+    block_size: u32,
+    frag_count: u32,
+    id_count: u16,
+    id_start: u64,
+    xattr_start: u64,
+    inode_start: u64,
+    dir_start: u64,
+    frag_start: u64,
+    export_start: u64,
+};
+
+// Frag Entry
+
+pub const FragEntry = packed struct {
+    block_start: u64,
+    size: BlockSize,
+    _: u32,
+};
@@ -1,10 +1,10 @@
 const std = @import("std");
 const Io = std.Io;
-const Writer = std.Io.Writer;
+const Writer = Io.Writer;
 const builtin = @import("builtin");

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

 //TODO: Add more options
 const help_mgs =
@@ -43,23 +43,20 @@ pub fn main(init: std.process.Init) !void {
    const alloc = init.gpa;
    const io = init.io;

-    var stdout = Io.File.stdout();
+    var stdout = std.Io.File.stdout();
    var out = stdout.writer(io, &[0]u8{});
    defer out.interface.flush() catch {};
-
-    try handleArgs(&out.interface, init.minimal.args);
+    try handleArgs(init.minimal.args, &out.interface);
    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.Io.File = try Io.Dir.cwd().openFile(io, archive, .{}); //TODO: Handle error gracefully.
+    var fil: 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);
+    var arc: squashfs.Archive = try .init(io, fil, offset); //TODO: Handle error gracefully.
    const options: squashfs.ExtractionOptions = .{
-        .single_threaded = threads == 1,
+        .threads = if (threads == 0) try std.Thread.getCpuCount() else threads,
        .verbose = verbose,
        .verbose_writer = if (verbose) &out.interface else null,
        .ignore_xattr = ignore_xattrs,
@@ -67,11 +64,12 @@ pub fn main(init: std.process.Init) !void {
    };
    if (force)
        try Io.Dir.cwd().deleteTree(io, extLoc);
-    try arc.extract(alloc, io, extLoc, options); //TODO: Handle error gracefully.
+    try arc.extract(alloc, extLoc, options); //TODO: Handle error gracefully.
 }

-fn handleArgs(out: *Writer, args: std.process.Args) !void {
+fn handleArgs(args: std.process.Args, out: *Writer) !void {
    var arg_iter = args.iterate();
+    defer arg_iter.deinit();
    _ = arg_iter.next(); // args[0] is the application launch command.
    while (arg_iter.next()) |arg| {
        if (std.mem.eql(u8, arg, "-o")) {
@@ -135,7 +133,3 @@ fn handleArgs(out: *Writer, args: std.process.Args) !void {
        archive = arg;
    }
 }
-
-test {
-    std.testing.refAllDecls(squashfs.Archive);
-}
@@ -0,0 +1,31 @@
+const std = @import("std");
+
+pub const StatelessDecomp = *const fn (std.mem.Allocator, in: []u8, out: []u8) Error!usize;
+
+pub const Error = error{
+    OutOfMemory,
+    EndOfStream,
+    ReadFailed,
+    WriteFailed,
+};
+
+const Decompressor = @This();
+
+alloc: std.mem.Allocator = std.heap.smp_allocator,
+vtable: *const struct {
+    decompress: *const fn (*const Decompressor, in: []u8, out: []u8) Error!usize = defaultDecompress,
+    stateless: StatelessDecomp,
+},
+
+/// Create a copy of the decompressor using it's stateless function and the new allocator.
+pub fn statelessCopy(self: Decompressor, alloc: std.mem.Allocator) Decompressor {
+    return &.{ .alloc = alloc, .vtable = &.{ .stateless = self.vtable.stateless } };
+}
+
+pub fn decompress(self: *const Decompressor, in: []u8, out: []u8) Error!usize {
+    return self.vtable.decompress(self, in, out);
+}
+
+fn defaultDecompress(self: *const Decompressor, in: []u8, out: []u8) Error!usize {
+    return self.vtable.stateless(self.alloc, in, out);
+}
@@ -0,0 +1,12 @@
+const std = @import("std");
+
+const c = @import("c");
+const Decompressor = @import("../../decomp.zig");
+
+interface: Decompressor = .{ .vtable = &.{ .stateless = stateless } },
+
+pub fn stateless(_: 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.ReadFailed; // TOOD: Find out what errors can be returned.
+}
@@ -0,0 +1,142 @@
+const std = @import("std");
+
+const c = @import("c");
+const Decompressor = @import("../../decomp.zig");
+
+const Lzma = @This();
+
+streams: std.AutoHashMap(std.Thread.Id, c.lzma_stream),
+
+interface: Decompressor,
+
+err: ?Error = null,
+
+pub fn init(alloc: std.mem.Allocator) !Lzma {
+    return .{
+        .streams = try .init(alloc),
+        .interface = &.{
+            .alloc = alloc,
+            .vtable = .{ .decompress = decompress, .stateless = stateless },
+        },
+    };
+}
+pub fn deinit(self: *Lzma) void {
+    var values = self.streams.valueIterator();
+    while (values.next()) |val| {
+        c.lzma_end(val);
+    }
+    self.streams.deinit();
+}
+
+fn getOrCreate(self: *Lzma) !*c.lzma_stream {
+    const res = try self.streams.getOrPut(std.Thread.getCurrentId());
+    if (res.found_existing) return res.value_ptr;
+    res.value_ptr.* = .{
+        .alloc = .{
+            .alloc = lzmaAlloc,
+            .free = lzmaFree,
+            .@"opaque" = &self.interface.alloc,
+        },
+    };
+    return res.value_ptr;
+}
+
+fn decompress(decomp: *const Decompressor, in: []u8, out: []u8) Decompressor.Error!usize {
+    var self: *Lzma = @fieldParentPtr("interface", decomp);
+
+    const stream = try self.getOrCreate();
+    stream.next_in = in.ptr;
+    stream.avail_in = in.len;
+    stream.next_out = out.ptr;
+    stream.avail_out = out.len;
+    var res = c.lzma_alone_decoder(stream, out.len);
+    decodeResult(res) catch |err| {
+        self.err = err;
+        return lzmaErrorToDecompError(err);
+    };
+    while (true) {
+        res = c.lzma_code(&stream, c.LZMA_RUN);
+        if (res == c.LZMA_OK) continue;
+        if (res == c.LZMA_STREAM_END) break;
+        decodeResult(res) catch |err| {
+            self.err = err;
+            return lzmaErrorToDecompError(err);
+        };
+    }
+    return stream.total_out;
+}
+pub fn stateless(alloc: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
+    var stream: c.lzma_stream = .{
+        .next_in = in.ptr,
+        .avail_in = in.len,
+        .next_out = out.ptr,
+        .avail_out = out.len,
+        .allocator = &.{
+            .alloc = lzmaAlloc,
+            .free = lzmaFree,
+            .@"opaque" = @ptrCast(@constCast(&alloc)),
+        },
+    };
+    var res = c.lzma_alone_decoder(&stream, out.len);
+    decodeResult(res) catch |err| return lzmaErrorToDecompError(err);
+    while (true) {
+        res = c.lzma_code(&stream, c.LZMA_RUN);
+        if (res == c.LZMA_OK) continue;
+        if (res == c.LZMA_STREAM_END) break;
+        decodeResult(res) catch |err| return lzmaErrorToDecompError(err);
+    }
+    return stream.total_out;
+}
+
+inline fn decodeResult(res: c_uint) Error!void {
+    return switch (res) {
+        c.LZMA_OK => {},
+        c.LZMA_STREAM_END => {},
+        c.LZMA_NO_CHECK => {},
+        c.LZMA_UNSUPPORTED_CHECK => Error.UnsupportedCheck,
+        c.LZMA_MEM_ERROR => Error.OutOfMemory,
+        c.LZMA_MEMLIMIT_ERROR => Error.OutOfMemory,
+        c.LZMA_FORMAT_ERROR => Error.Format,
+        c.LZMA_OPTIONS_ERROR => Error.Options,
+        c.LZMA_DATA_ERROR => Error.Data,
+        c.LZMA_BUF_ERROR => Error.BufferExhausted,
+        c.LZMA_PROG_ERROR => Error.Programming,
+        c.LZMA_SEEK_NEEDED => Error.SeekNeeded,
+        else => Error.Unknown,
+    };
+}
+fn lzmaErrorToDecompError(err: Error) Decompressor.Error {
+    switch (err) {
+        Error.OutOfMemory => return Decompressor.Error.OutOfMemory,
+        Error.UnsupportedCheck => return Decompressor.Error.ReadFailed,
+        Error.Format => return Decompressor.Error.ReadFailed,
+        Error.Options => return Decompressor.Error.ReadFailed,
+        Error.Data => return Decompressor.Error.ReadFailed,
+        Error.BufferExhausted => return Decompressor.Error.WriteFailed,
+        Error.Programming => return Decompressor.Error.ReadFailed,
+        Error.SeekNeeded => return Decompressor.Error.ReadFailed,
+        Error.Unknown => return Decompressor.Error.ReadFailed,
+    }
+}
+
+fn lzmaAlloc(ptr: ?*anyopaque, _: usize, size: usize) callconv(.c) ?*anyopaque {
+    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
+    return alloc.rawAlloc(size, .@"1", 0);
+}
+fn lzmaFree(ptr: ?*anyopaque, alloc_ptr: ?*anyopaque) callconv(.c) void {
+    if (alloc_ptr == null) return;
+    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
+    alloc.rawFree(@ptrCast(alloc_ptr), .@"1", 0);
+}
+
+pub const Error = error{
+    OutOfMemory,
+    UnsupportedCheck,
+    Format,
+    Options,
+    Data,
+    BufferExhausted,
+    Programming,
+    SeekNeeded,
+    Unknown,
+};
@@ -0,0 +1,28 @@
+const std = @import("std");
+
+const c = @import("c");
+const Decompressor = @import("../../decomp.zig");
+
+interface: Decompressor = .{ .vtable = &.{ .stateless = stateless } },
+
+pub fn stateless(_: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
+    var out_len = out.len;
+    const 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_ERROR => Decompressor.Error.ReadFailed,
+        c.LZO_E_OUT_OF_MEMORY => Decompressor.Error.OutOfMemory,
+        c.LZO_E_NOT_COMPRESSIBLE => Decompressor.Error.ReadFailed,
+        c.LZO_E_INPUT_OVERRUN => Decompressor.Error.ReadFailed,
+        c.LZO_E_OUTPUT_OVERRUN => Decompressor.Error.WriteFailed,
+        c.LZO_E_LOOKBEHIND_OVERRUN => Decompressor.Error.ReadFailed,
+        c.LZO_E_EOF_NOT_FOUND => Decompressor.Error.ReadFailed,
+        c.LZO_E_INPUT_NOT_CONSUMED => Decompressor.Error.ReadFailed,
+        c.LZO_E_NOT_YET_IMPLEMENTED => Decompressor.Error.ReadFailed,
+        c.LZO_E_INVALID_ARGUMENT => Decompressor.Error.ReadFailed,
+        c.LZO_E_INVALID_ALIGNMENT => Decompressor.Error.ReadFailed,
+        c.LZO_E_OUTPUT_NOT_CONSUMED => Decompressor.Error.WriteFailed,
+        c.LZO_E_INTERNAL_ERROR => Decompressor.Error.ReadFailed,
+        else => Decompressor.Error.ReadFailed,
+    };
+}
@@ -0,0 +1,142 @@
+const std = @import("std");
+
+const c = @import("c");
+const Decompressor = @import("../../decomp.zig");
+
+const Xz = @This();
+
+streams: std.AutoHashMap(std.Thread.Id, c.lzma_stream),
+
+interface: Decompressor,
+
+err: ?Error = null,
+
+pub fn init(alloc: std.mem.Allocator) !Xz {
+    return .{
+        .streams = try .init(alloc),
+        .interface = &.{
+            .alloc = alloc,
+            .vtable = .{ .decompress = decompress, .stateless = stateless },
+        },
+    };
+}
+pub fn deinit(self: *Xz) void {
+    var values = self.streams.valueIterator();
+    while (values.next()) |val| {
+        c.xz_end(val);
+    }
+    self.streams.deinit();
+}
+
+fn getOrCreate(self: *Xz) !*c.xz_stream {
+    const res = try self.streams.getOrPut(std.Thread.getCurrentId());
+    if (res.found_existing) return res.value_ptr;
+    res.value_ptr.* = .{
+        .alloc = .{
+            .alloc = lzmaAlloc,
+            .free = lzmaFree,
+            .@"opaque" = &self.interface.alloc,
+        },
+    };
+    return res.value_ptr;
+}
+
+fn decompress(decomp: *const Decompressor, in: []u8, out: []u8) Decompressor.Error!usize {
+    var self: *Xz = @fieldParentPtr("interface", decomp);
+
+    const stream = try self.getOrCreate();
+    stream.next_in = in.ptr;
+    stream.avail_in = in.len;
+    stream.next_out = out.ptr;
+    stream.avail_out = out.len;
+    var res = c.lzma_alone_decoder(stream, out.len);
+    decodeResult(res) catch |err| {
+        self.err = err;
+        return xzErrorToDecompError(err);
+    };
+    while (true) {
+        res = c.lzma_code(&stream, c.LZMA_RUN);
+        if (res == c.LZMA_OK) continue;
+        if (res == c.LZMA_STREAM_END) break;
+        decodeResult(res) catch |err| {
+            self.err = err;
+            return xzErrorToDecompError(err);
+        };
+    }
+    return stream.total_out;
+}
+pub fn stateless(alloc: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
+    var stream: c.lzma_stream = .{
+        .next_in = in.ptr,
+        .avail_in = in.len,
+        .next_out = out.ptr,
+        .avail_out = out.len,
+        .allocator = &.{
+            .alloc = lzmaAlloc,
+            .free = lzmaFree,
+            .@"opaque" = @ptrCast(@constCast(&alloc)),
+        },
+    };
+    var res = c.lzma_alone_decoder(&stream, out.len);
+    decodeResult(res) catch |err| return xzErrorToDecompError(err);
+    while (true) {
+        res = c.lzma_code(&stream, c.LZMA_RUN);
+        if (res == c.LZMA_OK) continue;
+        if (res == c.LZMA_STREAM_END) break;
+        decodeResult(res) catch |err| return xzErrorToDecompError(err);
+    }
+    return stream.total_out;
+}
+
+inline fn decodeResult(res: c_uint) Error!void {
+    return switch (res) {
+        c.LZMA_OK => {},
+        c.LZMA_STREAM_END => {},
+        c.LZMA_NO_CHECK => {},
+        c.LZMA_UNSUPPORTED_CHECK => Error.UnsupportedCheck,
+        c.LZMA_MEM_ERROR => Error.OutOfMemory,
+        c.LZMA_MEMLIMIT_ERROR => Error.OutOfMemory,
+        c.LZMA_FORMAT_ERROR => Error.Format,
+        c.LZMA_OPTIONS_ERROR => Error.Options,
+        c.LZMA_DATA_ERROR => Error.Data,
+        c.LZMA_BUF_ERROR => Error.BufferExhausted,
+        c.LZMA_PROG_ERROR => Error.Programming,
+        c.LZMA_SEEK_NEEDED => Error.SeekNeeded,
+        else => Error.Unknown,
+    };
+}
+fn xzErrorToDecompError(err: Error) Decompressor.Error {
+    switch (err) {
+        Error.OutOfMemory => return Decompressor.Error.OutOfMemory,
+        Error.UnsupportedCheck => return Decompressor.Error.ReadFailed,
+        Error.Format => return Decompressor.Error.ReadFailed,
+        Error.Options => return Decompressor.Error.ReadFailed,
+        Error.Data => return Decompressor.Error.ReadFailed,
+        Error.BufferExhausted => return Decompressor.Error.WriteFailed,
+        Error.Programming => return Decompressor.Error.ReadFailed,
+        Error.SeekNeeded => return Decompressor.Error.ReadFailed,
+        Error.Unknown => return Decompressor.Error.ReadFailed,
+    }
+}
+
+fn lzmaAlloc(ptr: ?*anyopaque, _: usize, size: usize) callconv(.c) ?*anyopaque {
+    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
+    return alloc.rawAlloc(size, .@"1", 0);
+}
+fn lzmaFree(ptr: ?*anyopaque, alloc_ptr: ?*anyopaque) callconv(.c) void {
+    if (alloc_ptr == null) return;
+    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
+    alloc.rawFree(@ptrCast(alloc_ptr), .@"1", 0);
+}
+
+pub const Error = error{
+    OutOfMemory,
+    UnsupportedCheck,
+    Format,
+    Options,
+    Data,
+    BufferExhausted,
+    Programming,
+    SeekNeeded,
+    Unknown,
+};
@@ -0,0 +1,106 @@
+const std = @import("std");
+
+const c = @import("c");
+const Decompressor = @import("../../decomp.zig");
+
+const Zlib = @This();
+
+streams: std.AutoHashMap(std.Thread.Id, c.zng_stream),
+
+interface: Decompressor,
+
+err: ?Error = null,
+
+pub fn init(alloc: std.mem.Allocator) !Zlib {
+    return .{
+        .streams = try .init(alloc),
+        .interface = &.{
+            .alloc = alloc,
+            .vtable = .{ .decompress = decompress, .stateless = stateless },
+        },
+    };
+}
+pub fn deinit(self: *Zlib) void {
+    var values = self.streams.valueIterator();
+    while (values.next()) |val| {
+        _ = c.zng_deflateEnd(val);
+    }
+    self.streams.deinit();
+}
+
+fn getOrCreate(self: *Zlib) !*c.zng_stream {
+    const res = try self.streams.getOrPut(std.Thread.getCurrentId());
+    if (res.found_existing) return res.value_ptr;
+    res.value_ptr.* = .{
+        .@"opaque" = self,
+        .zalloc = zalloc,
+        .zfree = zfree,
+    };
+    return res.value_ptr;
+}
+
+fn decompress(decomp: *const Decompressor, in: []u8, out: []u8) Decompressor.Error!usize {
+    var self: *Zlib = @fieldParentPtr("interface", decomp);
+
+    var stream = try self.getOrCreate();
+    stream.next_in = in.ptr;
+    stream.avail_in = in.len;
+    stream.next_out = out.ptr;
+    stream.avail_out = out.len;
+    var res = c.zng_inflateReset(stream);
+    decodeError(res) catch |err| {
+        self.err = err;
+        return Decompressor.Error.ReadFailed;
+    };
+    res = c.zng_inflate(stream, c.Z_FINISH);
+    decodeError(res) catch |err| {
+        self.err = err;
+        return switch (err) {
+            Error.OutOfMemory => err,
+            else => Decompressor.Error.ReadFailed,
+        };
+    };
+}
+
+pub fn stateless(alloc: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
+    _ = alloc;
+    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.WriteFailed,
+        else => Decompressor.Error.ReadFailed,
+    };
+}
+
+inline fn decodeError(res: i32) Error!void {
+    return switch (res) {
+        c.Z_OK => {},
+        c.Z_STREAM_ERROR => Error.Stream,
+        c.Z_BUF_ERROR => Error.Buffer,
+        c.Z_MEM_ERROR => Error.OutOfMemory,
+        c.Z_DATA_ERROR => Error.Data,
+        c.Z_VERSION_ERROR => Error.Version,
+        else => Error.Unknown,
+    };
+}
+
+fn zalloc(ptr: ?*anyopaque, items: c_uint, size: c_uint) callconv(.c) ?*anyopaque {
+    var self: *Zlib = @ptrCast(ptr);
+    return self.interface.alloc.rawAlloc(items * size, .@"1", 0);
+}
+
+fn zfree(ptr: ?*anyopaque, addr: ?*anyopaque) callconv(.c) void {
+    var self: *Zlib = @ptrCast(ptr);
+    self.interface.alloc.rawFree(@ptrCast(addr), .@"1", 0);
+}
+
+pub const Error = error{
+    OutOfMemory,
+    Stream,
+    Buffer,
+    Data,
+    Version,
+    Unknown,
+};
@@ -0,0 +1,172 @@
+const std = @import("std");
+
+const c = @import("c");
+const Decompressor = @import("../../decomp.zig");
+
+const Zstd = @This();
+
+context: std.AutoHashMap(std.Thread.Id, ?*c.ZSTD_DCtx),
+
+interface: Decompressor,
+
+err: ?Error = null,
+
+pub fn init(alloc: std.mem.Allocator) !Zstd {
+    return .{
+        .streams = try .init(alloc),
+        .interface = &.{
+            .alloc = alloc,
+            .vtable = .{ .decompress = decompress, .stateless = stateless },
+        },
+    };
+}
+pub fn deinit(self: *Zstd) void {
+    var values = self.context.valueIterator();
+    while (values.next()) |val| {
+        _ = c.ZSTD_freeDCtx(val.*);
+    }
+    self.context.deinit();
+}
+
+fn getOrCreate(self: *Zstd) !*c.ZSTD_DCtx {
+    const res = try self.context.getOrPut(std.Thread.getCurrentId());
+    if (res.found_existing) return res.value_ptr;
+    res.value_ptr.* = c.ZSTD_createDCtx();
+    if (res.value_ptr.* == null) return Error.OutOfMemory;
+    return res.value_ptr;
+}
+
+fn decompress(decomp: *const Decompressor, in: []u8, out: []u8) Decompressor.Error!usize {
+    var self: *Zstd = @fieldParentPtr("interface", decomp);
+
+    const ctx = self.getOrCreate();
+    const res = c.ZSTD_decompressDCtx(ctx, out.ptr, out.len, in.ptr, in.len);
+    decodeError(res) catch |err| {
+        self.err = err;
+        return ZstdErrorToDecompError(err);
+    };
+    return res;
+}
+pub fn stateless(alloc: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
+    _ = alloc;
+    const res = c.ZSTD_decompress(out.ptr, out.len, in.ptr, in.len);
+    decodeError(res) catch |err| return ZstdErrorToDecompError(err);
+    return res;
+}
+
+inline fn decodeError(res: usize) Error!void {
+    if (c.ZSTD_isError(res) == 0) return;
+    return switch (c.ZSTD_getErrorCode(res)) {
+        c.ZSTD_error_prefix_unknown => Error.PrefixUnknown,
+        c.ZSTD_error_version_unsupported => Error.VersionUnsupported,
+        c.ZSTD_error_frameParameter_unsupported => Error.FrameParameterUnsupported,
+        c.ZSTD_error_frameParameter_windowTooLarge => Error.FrameParameterWindowTooLarge,
+        c.ZSTD_error_corruption_detected => Error.CorruptionDetected,
+        c.ZSTD_error_checksum_wrong => Error.ChecksumWrong,
+        c.ZSTD_error_literals_headerWrong => Error.LiteralsHeaderWrong,
+        c.ZSTD_error_dictionary_corrupted => Error.DictionaryCorrupted,
+        c.ZSTD_error_dictionary_wrong => Error.DictionaryWrong,
+        c.ZSTD_error_dictionaryCreation_failed => Error.DictionaryCreationFailed,
+        c.ZSTD_error_parameter_unsupported => Error.ParameterUnsupported,
+        c.ZSTD_error_parameter_combination_unsupported => Error.ParameterCombinationUnsupported,
+        c.ZSTD_error_parameter_outOfBound => Error.ParameterOutOfBound,
+        c.ZSTD_error_tableLog_tooLarge => Error.TableLogTooLarge,
+        c.ZSTD_error_maxSymbolValue_tooLarge => Error.MaxSymbolValueTooLarge,
+        c.ZSTD_error_maxSymbolValue_tooSmall => Error.MaxSymbolValueTooSmall,
+        c.ZSTD_error_cannotProduce_uncompressedBlock => Error.CannotProduceUncompressedBlock,
+        c.ZSTD_error_stabilityCondition_notRespected => Error.StabilityConditionNotRespected,
+        c.ZSTD_error_stage_wrong => Error.StageWrong,
+        c.ZSTD_error_init_missing => Error.InitMissing,
+        c.ZSTD_error_memory_allocation => Error.MemoryAllocation,
+        c.ZSTD_error_workSpace_tooSmall => Error.WorkSpaceTooSmall,
+        c.ZSTD_error_dstSize_tooSmall => Error.DstSizeTooSmall,
+        c.ZSTD_error_srcSize_wrong => Error.SrcSizeWrong,
+        c.ZSTD_error_dstBuffer_null => Error.DstBufferNull,
+        c.ZSTD_error_noForwardProgress_destFull => Error.NoForwardProgressDestFull,
+        c.ZSTD_error_noForwardProgress_inputEmpty => Error.NoForwardProgressInputEmpty,
+        c.ZSTD_error_frameIndex_tooLarge => Error.FrameIndexTooLarge,
+        c.ZSTD_error_seekableIO => Error.SeekableIo,
+        c.ZSTD_error_dstBuffer_wrong => Error.DstBufferWrong,
+        c.ZSTD_error_srcBuffer_wrong => Error.SrcBufferWrong,
+        c.ZSTD_error_sequenceProducer_failed => Error.SequenceProducerFailed,
+        c.ZSTD_error_externalSequences_invalid => Error.ExternalSequencesInvalid,
+        else => Error.Generic,
+    };
+}
+inline fn ZstdErrorToDecompError(err: Error) Decompressor.Error {
+    return switch (err) {
+        Error.OutOfMemory => Decompressor.Error.OutOfMemory,
+        Error.Generic => Decompressor.Error.ReadFailed,
+        Error.PrefixUnknown => Decompressor.Error.ReadFailed,
+        Error.VersionUnsupported => Decompressor.Error.ReadFailed,
+        Error.FrameParameterUnsupported => Decompressor.Error.ReadFailed,
+        Error.FrameParameterWindowTooLarge => Decompressor.Error.ReadFailed,
+        Error.CorruptionDetected => Decompressor.Error.ReadFailed,
+        Error.ChecksumWrong => Decompressor.Error.ReadFailed,
+        Error.LiteralsHeaderWrong => Decompressor.Error.ReadFailed,
+        Error.DictionaryCorrupted => Decompressor.Error.ReadFailed,
+        Error.DictionaryWrong => Decompressor.Error.ReadFailed,
+        Error.DictionaryCreationFailed => Decompressor.Error.ReadFailed,
+        Error.ParameterUnsupported => Decompressor.Error.ReadFailed,
+        Error.ParameterCombinationUnsupported => Decompressor.Error.ReadFailed,
+        Error.ParameterOutOfBound => Decompressor.Error.ReadFailed,
+        Error.TableLogTooLarge => Decompressor.Error.ReadFailed,
+        Error.MaxSymbolValueTooLarge => Decompressor.Error.ReadFailed,
+        Error.MaxSymbolValueTooSmall => Decompressor.Error.ReadFailed,
+        Error.CannotProduceUncompressedBlock => Decompressor.Error.ReadFailed,
+        Error.StabilityConditionNotRespected => Decompressor.Error.ReadFailed,
+        Error.StageWrong => Decompressor.Error.ReadFailed,
+        Error.InitMissing => Decompressor.Error.ReadFailed,
+        Error.MemoryAllocation => Decompressor.Error.OutOfMemory,
+        Error.WorkSpaceTooSmall => Decompressor.Error.WriteFailed,
+        Error.DstSizeTooSmall => Decompressor.Error.WriteFailed,
+        Error.SrcSizeWrong => Decompressor.Error.ReadFailed,
+        Error.DstBufferNull => Decompressor.Error.WriteFailed,
+        Error.NoForwardProgressDestFull => Decompressor.Error.WriteFailed,
+        Error.NoForwardProgressInputEmpty => Decompressor.Error.ReadFailed,
+        Error.FrameIndexTooLarge => Decompressor.Error.ReadFailed,
+        Error.SeekableIo => Decompressor.Error.ReadFailed,
+        Error.DstBufferWrong => Decompressor.Error.WriteFailed,
+        Error.SrcBufferWrong => Decompressor.Error.ReadFailed,
+        Error.SequenceProducerFailed => Decompressor.Error.ReadFailed,
+        Error.ExternalSequencesInvalid => Decompressor.Error.ReadFailed,
+    };
+}
+
+pub const Error = 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,
+};
@@ -0,0 +1,64 @@
+const config = @import("config");
+
+const Decompressor = @import("../decomp.zig");
+
+pub fn getStatelessFn(decomp: Enum) !Decompressor.StatelessDecomp {
+    if (config.use_zig_decomp) {
+        return switch (decomp) {
+            .gzip => @import("zig/zlib.zig").stateless,
+            .lzma => @import("zig/lzma.zig").stateless,
+            .xz => @import("zig/xz.zig").stateless,
+            .zstd => @import("zig/zstd.zig").stateless,
+            .lz4 => error.ZigLz4Unsupported,
+            .lzo => error.ZigLzoUnsupported,
+        };
+    }
+    return switch (decomp) {
+        .gzip => @import("c/zlib.zig").stateless,
+        .lzma => @import("c/lzma.zig").stateless,
+        .lzo => @import("c/lzo.zig").stateless,
+        .xz => @import("c/xz.zig").stateless,
+        .lz4 => @import("c/lz4.zig").stateless,
+        .zstd => @import("c/zstd.zig").stateless,
+    };
+}
+
+pub const Enum = enum(u16) {
+    gzip = 1, // Though officially named gzip, it actually uses zlib.
+    lzma,
+    lzo,
+    xz,
+    lz4,
+    zstd,
+};
+
+pub const Decomp = if (config.use_zig_decomp)
+    union(enum) {
+        gzip: @import("zig/zlib.zig"),
+        lzma: @import("zig/lzma.zig"),
+        xz: @import("zig/xz.zig"),
+        zstd: @import("zig/zstd.zig"),
+
+        pub fn deinit(_: *Decomp) void {
+            return;
+        }
+    }
+else
+    union(enum) {
+        gzip: @import("c/zlib.zig"),
+        lzma: @import("c/lzma.zig"),
+        lzo: @import("c/lzo.zig"),
+        xz: @import("c/xz.zig"),
+        lz4: @import("c/lz4.zig"),
+        zstd: @import("c/zstd.zig"),
+
+        pub fn deinit(self: *Decomp) void {
+            switch (self) {
+                .gzip => self.gzip.deinit(),
+                .lzma => self.lzma.deinit(),
+                .xz => self.xz.deinit(),
+                .zstd => self.zstd.deinit(),
+                else => {},
+            }
+        }
+    };
@@ -0,0 +1,23 @@
+const std = @import("std");
+const lzma = std.compress.lzma;
+const Reader = std.Io.Reader;
+
+const Decompressor = @import("../../decomp.zig");
+
+interface: Decompressor = .{ .vtable = &.{ .stateless = stateless } },
+
+pub fn stateless(alloc: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
+    var rdr: Reader = .fixed(in);
+    const buf = try alloc.alloc(u8, in.len);
+    defer alloc.free(buf);
+
+    var decomp = lzma.Decompress.initOptions(&rdr, alloc, buf, .{}, out.len) catch |err|
+        return switch (err) {
+            error.Overflow => Decompressor.Error.ReadFailed,
+            error.CorruptInput => Decompressor.Error.ReadFailed,
+            error.InvalidRangeCode => Decompressor.Error.ReadFailed,
+            else => @errorCast(err),
+        };
+    defer decomp.deinit();
+    return decomp.reader.readSliceShort(out);
+}
@@ -0,0 +1,22 @@
+const std = @import("std");
+const xz = std.compress.xz;
+const Reader = std.Io.Reader;
+
+const Decompressor = @import("../../decomp.zig");
+
+interface: Decompressor = .{ .vtable = &.{ .stateless = stateless } },
+
+pub fn stateless(alloc: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
+    var rdr: Reader = .fixed(in);
+    const buf = try alloc.alloc(u8, in.len);
+    defer alloc.free(buf);
+
+    var decomp = xz.Decompress.init(&rdr, alloc, buf) catch |err|
+        return switch (err) {
+            error.WrongChecksum => Decompressor.Error.ReadFailed,
+            error.NotXzStream => Decompressor.Error.ReadFailed,
+            else => @errorCast(err),
+        };
+    defer decomp.deinit();
+    return decomp.reader.readSliceShort(out);
+}
@@ -0,0 +1,16 @@
+const std = @import("std");
+const flate = std.compress.flate;
+const Reader = std.Io.Reader;
+
+const Decompressor = @import("../../decomp.zig");
+
+interface: Decompressor = .{ .vtable = &.{ .stateless = stateless } },
+
+pub fn stateless(alloc: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
+    var rdr: Reader = .fixed(in);
+    const buf = try alloc.alloc(u8, out.len);
+    defer alloc.free(buf);
+
+    var decomp = flate.Decompress.init(&rdr, .zlib, buf);
+    return decomp.reader.readSliceShort(out);
+}
@@ -0,0 +1,16 @@
+const std = @import("std");
+const zstd = std.compress.zstd;
+const Reader = std.Io.Reader;
+
+const Decompressor = @import("../../decomp.zig");
+
+interface: Decompressor = .{ .vtable = &.{ .stateless = stateless } },
+
+pub fn stateless(alloc: std.mem.Allocator, in: []u8, out: []u8) Decompressor.Error!usize {
+    var rdr: Reader = .fixed(in);
+    const buf = try alloc.alloc(u8, out.len * 2);
+    defer alloc.free(buf);
+
+    var decomp = zstd.Decompress.init(&rdr, buf, .{ .window_len = @truncate(out.len) });
+    return decomp.reader.readSliceShort(out);
+}
@@ -1,67 +0,0 @@
-const std = @import("std");
-const Reader = std.Io.Reader;
-
-const Inode = @import("inode.zig");
-
-const Header = extern struct {
-    count: u32,
-    block_start: u32,
-    num: u32,
-};
-const Entry = extern struct {
-    block_offset: u16,
-    num_offset: i16,
-    inode_type: Inode.Type,
-    name_size: u16,
-};
-
-pub const Error = error{OutOfMemory} || std.Io.Reader.Error;
-
-const DirEntry = @This();
-
-inode_type: Inode.Type,
-name: []const u8,
-
-block_start: u32,
-block_offset: u32,
-num: u32,
-
-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);
-}
@@ -0,0 +1,63 @@
+const std = @import("std");
+const Reader = std.Io.Reader;
+
+const InodeType = @import("inode.zig").Type;
+
+pub fn readDirectory(alloc: std.mem.Allocator, rdr: *Reader, size: u32) []Entry {
+    var read: u32 = 3;
+    var hdr: Header = undefined;
+    var raw: RawEntry = undefined;
+    var out: std.ArrayList(Entry) = .initCapacity(alloc, 50);
+    errdefer {
+        for (out.items) |i|
+            alloc.free(i.name);
+        out.deinit(alloc);
+    }
+    while (read < size) {
+        try rdr.readSliceEndian(Header, @ptrCast(&hdr), .little);
+        try out.ensureUnusedCapacity(alloc, hdr.count + 1);
+        read += @sizeOf(Header);
+        for (0..hdr.count + 1) |_| {
+            try rdr.readSliceEndian(RawEntry, @ptrCast(&raw), .little);
+            read += @sizeOf(RawEntry) + raw.name_size + 1;
+            const new = out.addOneAssumeCapacity();
+            new.* = .{
+                .block_start = hdr.block_start,
+                .block_offset = raw.block_offset,
+                .num = @abs(hdr.num + raw.num_offset),
+                .inode_type = raw.inode_type,
+                .name = try alloc.alloc(u8, raw.name_size + 1),
+            };
+            try rdr.readSliceEndian(u8, new.name, .little);
+        }
+    }
+    return out.toOwnedSlice(alloc);
+}
+
+// Types
+
+pub const Entry = struct {
+    block_start: u32,
+    block_offset: u16,
+    num: u32,
+    inode_type: InodeType,
+    name: []u8,
+
+    pub fn deinit(self: Entry, alloc: std.mem.Allocator) void {
+        alloc.free(self.name);
+    }
+};
+
+// extern instead of packed due to alignment issues (packed will read it as 16 bytes instead of 12).
+const Header = extern struct {
+    count: u32,
+    block_start: u32,
+    num: u32,
+};
+
+const RawEntry = packed struct {
+    block_offset: u16,
+    num_offset: i16,
+    inode_type: InodeType,
+    name_size: u16,
+};
@@ -1,126 +1,118 @@
-//! A wrapper around an Inode to make common activities easier.
-
 const std = @import("std");
 const Io = std.Io;

 const Archive = @import("archive.zig");
-const DirEntry = @import("dir_entry.zig");
+const Decompressor = @import("decomp.zig");
+const Directory = @import("directory.zig");
 const ExtractionOptions = @import("options.zig");
 const Inode = @import("inode.zig");
-const LookupTable = @import("lookup_table.zig");
+const DataReader = @import("util/data_reader.zig");
+const FileIter = @import("util/iter.zig");
 const MetadataReader = @import("util/metadata.zig");
+const OffsetFile = @import("util/offset_file.zig");
+const Utils = @import("util/utils.zig");

 pub const Error = error{
-    NotFound,
+    NotDirectory,
+    NotRegularFile,
 };

 const File = @This();

-alloc: std.mem.Allocator,
-archive: *Archive,
+file: OffsetFile,
+super: Archive.MinimalSuperblock,
+decomp: Decompressor,

 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);
-
+pub fn init(alloc: std.mem.Allocator, archive: Archive, entry: Directory.Entry) !File {
    const new_name = try alloc.alloc(u8, entry.name.len);
    errdefer alloc.free(new_name);
    @memcpy(new_name, entry.name);
-
    return .{
-        .alloc = alloc,
-        .archive = archive,
-
+        .file = archive.file,
+        .super = archive.super,
+        .decomp = archive.stateless_decomp.statelessCopy(alloc),
        .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(
+        .inode = try Utils.readInode(
            alloc,
-            io,
-            &archive.cache,
+            &archive.decomp,
+            archive.file,
            archive.super.inode_start,
            archive.super.block_size,
-            ref,
+            entry.block_start,
+            entry.block_offset,
        ),
    };
 }
-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);
+pub fn deinit(self: File) void {
+    self.decomp.alloc.free(self.name);
+    self.inode.deinit(self.decomp.alloc);
+}

-    return .{
-        .alloc = alloc,
-        .archive = from.archive,
+// Directory functions

-        .inode = try .copy(alloc, from.inode),
-        .name = new_name,
+pub fn isDir(self: File) bool {
+    return switch (self.inode.hdr.inode_type) {
+        .dir, .ext_dir => true,
+        else => false,
    };
 }
-pub fn deinit(self: File) void {
-    self.alloc.free(self.name);
-    self.inode.deinit(self.alloc);
-}
-
-pub fn open(self: File, alloc: std.mem.Allocator, io: Io, filepath: []const u8) !File {
-    const path = std.mem.trim(u8, filepath, "/");
-
-    if (path.len == 0 or std.mem.eql(u8, path, ".")) return .copy(alloc, self);
-
-    const first_element = std.mem.sliceTo(path, '/');
-
-    const entries = try self.inode.readDirectory(alloc, io, &self.archive.cache, self.archive.super.dir_start);
-    defer {
-        for (entries) |entry|
-            entry.deinit(alloc);
-        alloc.free(entries);
-    }
-
-    // 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, io, filepath[first_element.len..]);
-}
-
-pub fn extract(self: File, alloc: std.mem.Allocator, io: Io, path: []const u8, options: ExtractionOptions) !void {
-    return self.inode.extract(
+/// Opens a sub-file. If the given path is "" or "." (after trimming /) a copy of the File is returned.
+pub fn open(self: File, alloc: std.mem.Allocator, filepath: []const u8) !File {
+    var res = try self.inode.findInode(
        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,
+        &self.decomp,
+        self.file,
+        self.super.dir_start,
+        self.super.inode_start,
+        self.super.block_size,
+        filepath,
+    );
+    if (res.name.len == 0) {
+        res.name = try alloc.alloc(u8, self.name.len);
+        @memcpy(res.name, self.name);
+    }
+    return .{
+        .file = self.file,
+        .super = self.super,
+        .decomp = self.decomp.statelessCopy(alloc),
+        .name = res.name,
+        .inode = res.inode,
+    };
+}
+pub fn iter(self: File, alloc: std.mem.Allocator) !FileIter {
+    return .{
+        .alloc = alloc,
+        .entries = try self.inode.readDirectory(alloc, &self.decomp, self.file, self.super.dir_start),
+    };
+}
+
+// Regular file functions
+
+pub fn isRegularFile(self: File) bool {
+    return switch (self.inode.hdr.inode_type) {
+        .file, .ext_file => true,
+        else => false,
+    };
+}
+// a std.Io.Reader compatible reader that reads a regular file's data.
+pub fn dataReader(self: File, alloc: std.mem.Allocator) !DataReader {
+    return self.inode.dataReader(
+        &self.decomp.statelessCopy(alloc),
+        self.file,
+        self.super.frag_start,
+        self.super.block_size,
    );
 }
+
+// Universal functions
+
+pub fn extract(self: File, alloc: std.mem.Allocator, path: []const u8, options: ExtractionOptions) !void {
+    _ = self;
+    _ = alloc;
+    _ = path;
+    _ = options;
+    return error.TODO;
+}
@@ -1,7 +0,0 @@
-const BlockSize = @import("inode_data/file.zig").BlockSize;
-
-pub const FragEntry = extern struct {
-    start: u64,
-    size: BlockSize,
-    _: u32,
-};
@@ -1,7 +1,5 @@
-#ifdef ALLOW_LZO
-#include <lzo/minilzo.h>
-#endif
 #include <zlib-ng.h>
-#include <zstd.h>
+#include <lzo/minilzo.h>
 #include <lz4.h>
+#include <zstd.h>
 #include <lzma.h>
@@ -1,132 +1,51 @@
-//! A file-system object. Represents a File or directory.
+//! This is the raw squashfs representation of a file/directory.
+//! Most of the time using File is a better experience and using Inodes directory
+//! is only required for more technical use cases.

 const std = @import("std");
-const Io = std.Io;
-const Reader = Io.Reader;
+const Reader = std.Io.Reader;

-const DirEntry = @import("dir_entry.zig");
-const ExtractionOptions = @import("options.zig");
-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 Decompressor = @import("decomp.zig");
+const Directory = @import("directory.zig");
+const FragEntry = @import("archive.zig").FragEntry;
+const Dir = @import("inode/dir.zig");
+const File = @import("inode/file.zig");
+const Misc = @import("inode/misc.zig");
+const Sym = @import("inode/sym.zig");
 const LookupTable = @import("lookup_table.zig");
-const DataExtract = @import("util/data_extract.zig");
-const DecompCache = @import("util/decomp_cache.zig");
+const MinimalSuperblock = @import("archive.zig").MinimalSuperblock;
+const DataReader = @import("util/data_reader.zig");
 const MetadataReader = @import("util/metadata.zig");
-
-pub const Ref = packed struct(u64) {
-    block_offset: u16,
-    block_start: u32,
-    _: u16,
-};
-
-pub const Type = enum(u16) {
-    dir = 1,
-    file,
-    symlink,
-    block_dev,
-    char_dev,
-    fifo,
-    socket,
-    ext_dir,
-    ext_file,
-    ext_symlink,
-    ext_block_dev,
-    ext_char_dev,
-    ext_fifo,
-    ext_socket,
-};
-
-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: Type,
-    permissions: u16,
-    uid_idx: u16,
-    gid_idx: u16,
-    mod_time: u32,
-    num: u32,
-};
-
-pub const Error = error{
-    NotDirectory,
-};
+const OffsetFile = @import("util/offset_file.zig");

 const Inode = @This();

 hdr: Header,
 data: Data,

-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 {
+pub fn read(alloc: std.mem.Allocator, rdr: *Reader, block_size: u32) !Inode {
    var hdr: Header = undefined;
    try rdr.readSliceEndian(Header, @ptrCast(&hdr), .little);
    return .{
        .hdr = hdr,
        .data = switch (hdr.inode_type) {
-            .dir => .{ .dir = try .read(rdr) },
-            .file => .{ .file = try .read(alloc, rdr, block_size) },
-            .symlink => .{ .symlink = try .read(alloc, rdr) },
-            .block_dev => .{ .block_dev = try .read(rdr) },
-            .char_dev => .{ .char_dev = try .read(rdr) },
-            .fifo => .{ .fifo = try .read(rdr) },
-            .socket => .{ .socket = try .read(rdr) },
-            .ext_dir => .{ .ext_dir = try .read(rdr) },
-            .ext_file => .{ .ext_file = try .read(alloc, rdr, block_size) },
-            .ext_symlink => .{ .ext_symlink = try .read(alloc, rdr) },
-            .ext_block_dev => .{ .ext_block_dev = try .read(rdr) },
-            .ext_char_dev => .{ .ext_char_dev = try .read(rdr) },
-            .ext_fifo => .{ .ext_fifo = try .read(rdr) },
-            .ext_socket => .{ .ext_socket = try .read(rdr) },
+            .dir => .{ .dir = .read(rdr) },
+            .file => .{ .file = .read(alloc, rdr, block_size) },
+            .symlink => .{ .symlink = .read(alloc, rdr) },
+            .block => .{ .block = .read(rdr) },
+            .char => .{ .char = .read(rdr) },
+            .fifo => .{ .fifo = .read(rdr) },
+            .sock => .{ .sock = .read(rdr) },
+            .ext_dir => .{ .ext_dir = .read(rdr) },
+            .ext_file => .{ .ext_file = .read(alloc, rdr, block_size) },
+            .ext_symlink => .{ .ext_symlink = .read(alloc, rdr) },
+            .ext_block => .{ .ext_block = .read(rdr) },
+            .ext_char => .{ .ext_char = .read(rdr) },
+            .ext_fifo => .{ .ext_fifo = .read(rdr) },
+            .ext_sock => .{ .ext_sock = .read(rdr) },
        },
    };
 }
-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),
@@ -136,299 +55,301 @@ pub fn deinit(self: Inode, alloc: std.mem.Allocator) void {
        else => {},
    }
 }
+pub fn copy(self: Inode, alloc: std.mem.Allocator) !Inode {
+    switch (self.data) {
+        .dir,
+        .ext_dir,
+        .block,
+        .ext_block,
+        .char,
+        .ext_char,
+        .fifo,
+        .ext_fifo,
+        .sock,
+        .ext_sock,
+        => return self,
+        .file => |f| {
+            const new_sizes = try alloc.alloc(File.BlockSize, f.block_sizes.len);
+            @memcpy(new_sizes, f.block_sizes);
+            return .{
+                .hdr = self.hdr,
+                .data = .{ .file = .{
+                    .block_start = f.block_start,
+                    .frag_idx = f.frag_idx,
+                    .block_offset = f.block_offset,
+                    .size = f.size,
+                    .block_sizes = new_sizes,
+                } },
+            };
+        },
+        .ext_file => |f| {
+            const new_sizes = try alloc.alloc(File.BlockSize, f.block_sizes.len);
+            @memcpy(new_sizes, f.block_sizes);
+            return .{
+                .hdr = self.hdr,
+                .data = .{ .ext_file = .{
+                    .block_start = self.block_start,
+                    .size = self.size,
+                    .sparse = self.sparse,
+                    .hard_links = self.hard_links,
+                    .frag_idx = self.frag_idx,
+                    .block_offset = self.block_offset,
+                    .xattr_idx = self.xattr_idx,
+                    .block_sizes = new_sizes,
+                } },
+            };
+        },
+        .symlink => |s| {
+            const new_target = try alloc.alloc(u8, s.target.len);
+            @memcpy(new_target, s.target);
+            return .{
+                .hdr = self.hdr,
+                .data = .{ .symlink = .{
+                    .hard_links = s.hard_links,
+                    .target = new_target,
+                } },
+            };
+        },
+        .ext_symlink => |s| {
+            const new_target = try alloc.alloc(u8, s.target.len);
+            @memcpy(new_target, s.target);
+            return .{
+                .hdr = self.hdr,
+                .data = .{ .ext_symlink = .{
+                    .hard_links = s.hard_links,
+                    .xattr_idx = s.xattr_idx,
+                    .target = new_target,
+                } },
+            };
+        },
+    }
+}

-pub fn readDirectory(self: Inode, alloc: std.mem.Allocator, io: Io, cache: *DecompCache, dir_start: u64) ![]DirEntry {
-    return switch (self.data) {
-        .dir => |d| readDirectoryFromData(alloc, io, cache, dir_start, d),
-        .ext_dir => |d| readDirectoryFromData(alloc, io, cache, dir_start, d),
+// Types
+
+pub const Ref = packed struct {
+    block_offset: u16,
+    block_start: u32,
+    _: u16,
+};
+
+pub const Type = enum(u16) {
+    dir = 1,
+    file,
+    symlink,
+    block,
+    char,
+    fifo,
+    sock,
+    ext_dir,
+    ext_file,
+    ext_symlink,
+    ext_block,
+    ext_char,
+    ext_fifo,
+    ext_sock,
+};
+
+const Header = packed struct {
+    inode_type: Type,
+    permission: u16,
+    uid_idx: u16,
+    gid_idx: u16,
+    mod_time: u32,
+    num: u32,
+};
+
+pub const Data = union(Type) {
+    dir: Dir.Dir,
+    file: File.File,
+    symlink: Sym.Symlink,
+    block: Misc.Device,
+    char: Misc.Device,
+    fifo: Misc.Ipc,
+    sock: Misc.Ipc,
+    ext_dir: Dir.ExtDir,
+    ext_file: File.ExtFile,
+    ext_symlink: Sym.ExtSymlink,
+    ext_block: Misc.ExtDevice,
+    ext_char: Misc.ExtDevice,
+    ext_fifo: Misc.ExtIpc,
+    ext_sock: Misc.ExtIpc,
+};
+
+// Errors
+
+pub const Error = error{
+    NotDirectory,
+    NotFound,
+    NotRegularFile,
+};
+
+// Utils functions
+
+// Universal
+
+pub fn uid(self: Inode, decomp: *const Decompressor, fil: OffsetFile, id_start: u64) !u16 {
+    return LookupTable.stateless(u16, fil, decomp, id_start, self.hdr.uid_idx);
+}
+pub fn uidCached(self: Inode, table: LookupTable.CachedTable(u16)) !u16 {
+    return table.get(self.hdr.uid_idx);
+}
+pub fn gid(self: Inode, decomp: *const Decompressor, fil: OffsetFile, id_start: u64) !u16 {
+    return LookupTable.stateless(u16, fil, decomp, id_start, self.hdr.gid_idx);
+}
+pub fn gidCached(self: Inode, table: LookupTable.CachedTable(u16)) !u16 {
+    return table.get(self.hdr.gid_idx);
+}
+pub fn xattr(self: Inode, alloc: std.mem.Allocator, decomp: *const Decompressor, fil: OffsetFile, xattr_start: u64) !?LookupTable.XattrValues {
+    if (@intFromEnum(self.hdr.inode_type) < 8) return null;
+    const idx: u32 = switch (self.data) {
+        .ext_dir => |d| d.xattr_idx,
+        .ext_file => |f| f.xattr_idx,
+        .ext_symlink => |s| s.xattr_idx,
+        .ext_block, .ext_char => |d| d.xattr_idx,
+        .ext_fifo, .ext_sock => |d| d.xattr_idx,
+        else => unreachable,
+    };
+    if (idx == 0xFFFFFFFF) return null;
+    return LookupTable.statelessXattr(alloc, fil, decomp, xattr_start, idx);
+}
+
+// Dir inodes
+
+/// For directory inodes, tries to find the inode at the given path. Returns both the inode, and it's file name.
+/// If the path is empty or "." then a copy of this inode is returned with no name ("").
+pub fn findInode(
+    inode: Inode,
+    alloc: std.mem.Allocator,
+    decomp: *const Decompressor,
+    fil: OffsetFile,
+    dir_start: u64,
+    inode_start: u64,
+    block_size: u32,
+    filepath: []const u8,
+) !struct { inode: Inode, name: []const u8 } {
+    switch (inode.data) {
+        .dir => |d| {
+            const path: []const u8 = std.mem.trim(u8, filepath, "/");
+            if (path.len == 0 or (path.len == 1 and path[0] == '.'))
+                return .{ .inode = inode.copy(alloc), .name = "" };
+            return findInodeRaw(
+                alloc,
+                decomp,
+                fil,
+                dir_start,
+                inode_start,
+                block_size,
+                path,
+                d,
+            );
+        },
+        .ext_dir => |d| {
+            const path: []const u8 = std.mem.trim(u8, filepath, "/");
+            if (path.len == 0 or (path.len == 1 and path[0] == '.'))
+                return .{ .inode = inode.copy(alloc), .name = "" };
+            return findInodeRaw(
+                alloc,
+                decomp,
+                fil,
+                dir_start,
+                inode_start,
+                block_size,
+                path,
+                d,
+            );
+        },
+        else => return Error.NotDirectory,
+    }
+}
+inline fn findInodeRaw(
+    inode: Inode,
+    alloc: std.mem.Allocator,
+    decomp: *const Decompressor,
+    fil: OffsetFile,
+    dir_start: u64,
+    inode_start: u64,
+    block_size: u32,
+    path: []const u8,
+    dat: anytype,
+) !struct { inode: Inode, name: []const u8 } {
+    const first_element: []const u8 = std.mem.sliceTo(path, '/');
+
+    const dirs = try readDirRaw(alloc, decomp, fil, dir_start, dat);
+    defer {
+        for (dirs) |dir|
+            dir.deinit(alloc);
+        alloc.free(dirs);
+    }
+
+    // Directories are stored ASCIIbetically, so we can use binary search.
+    var cur_slice = dirs;
+    var idx: usize = 0;
+    while (cur_slice.len > 0) {
+        idx = cur_slice.len / 2;
+        const mid_name = cur_slice[idx].name;
+        switch (std.mem.order(u8, first_element, mid_name)) {
+            .gt => {
+                cur_slice = cur_slice[idx + 1 ..];
+                continue;
+            },
+            .lt => {
+                cur_slice = cur_slice[0..idx];
+                continue;
+            },
+            .eq => break,
+        }
+    } else return Error.NotFound;
+    const entry = cur_slice[idx];
+    var rdr = try fil.readerAt(inode_start + entry.block_start, &[0]u8{});
+    var meta_rdr: MetadataReader = .init(&rdr.interface, decomp);
+    try meta_rdr.interface.discardAll(entry.block_offset);
+    const ret_inode: Inode = try .read(alloc, &meta_rdr.interface, block_size);
+    if (first_element.len == path.len) {
+        const name_copy = try alloc.alloc(u8, entry.name.len);
+        @memcpy(name_copy, entry.name.len);
+        return .{ .inode = ret_inode, .name = name_copy };
+    }
+    return inode.findInode(alloc, decomp, fil, dir_start, inode_start, block_size, path[first_element.len..]);
+}
+
+/// Get the directory entries for a directory inode.
+pub fn readDirectory(inode: Inode, alloc: std.mem.Allocator, decomp: *const Decompressor, fil: OffsetFile, dir_start: u64) ![]Directory.Entry {
+    return switch (inode.data) {
+        .dir => |d| readDirRaw(alloc, decomp, fil, dir_start, d),
+        .ext_dir => |d| readDirRaw(alloc, decomp, fil, 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);
+inline fn readDirRaw(alloc: std.mem.Allocator, decomp: *const Decompressor, fil: OffsetFile, dir_start: u64, dat: anytype) ![]Directory.Entry {
+    var rdr = try fil.readerAt(dir_start + dat.block_start, &[0]u8{});
+    var meta_rdr: MetadataReader = .init(&rdr.interface, decomp);
+    try meta_rdr.interface.discardAll(dat.block_offset);
+    return Directory.readDirectory(alloc, meta_rdr, dat.size);
 }

-// Extraction
+// file inodes

-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,
+/// Gets the data reader for a file inode.
+pub fn dataReader(inode: Inode, decomp: *const Decompressor, fil: OffsetFile, frag_start: u64, block_size: u32) !DataReader {
+    return switch (inode.data) {
+        .file => |f| dataReaderRaw(decomp, fil, frag_start, block_size, f),
+        .ext_file => |f| dataReaderRaw(decomp, fil, frag_start, block_size, f),
+        else => Error.NotRegularFile,
    };
 }
-
-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 => 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);
-        }
-
-        for (xattrs) |kv| {
-            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);
-        }
-    }
-
-    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, "/"));
+inline fn dataReaderRaw(decomp: *const Decompressor, fil: OffsetFile, frag_start: u64, block_size: u32, dat: anytype) !DataReader {
+    return .init(
+        decomp,
+        fil,
+        block_size,
+        dat.block_sizes,
+        dat.size,
+        dat.block_start,
+        if (dat.frag_idx != 0xFFFFFFFF)
+            try LookupTable.stateless(FragEntry, fil, decomp, frag_start, dat.frag_idx)
+        else
+            null,
+        dat.frag_offset,
+    );
 }
@@ -0,0 +1,35 @@
+const Reader = @import("std").Io.Reader;
+
+pub const Dir = packed struct {
+    block_start: u32,
+    hard_links: u32,
+    size: u16,
+    block_offset: u16,
+    parent_num: u32,
+
+    const Self = @This();
+
+    pub fn read(rdr: *Reader) !Self {
+        var new: Self = undefined;
+        try rdr.readSliceEndian(Self, @ptrCast(&new), .little);
+        return new;
+    }
+};
+
+pub const ExtDir = packed struct {
+    hard_links: u32,
+    size: u32,
+    block_start: u32,
+    parent_num: u32,
+    idx_count: u16,
+    block_offset: u16,
+    xattr_idx: u32,
+
+    const Self = @This();
+
+    pub fn read(rdr: *Reader) !Self {
+        var new: Self = undefined;
+        try rdr.readSliceEndian(Self, @ptrCast(&new), .little);
+        return new;
+    }
+};
@@ -0,0 +1,69 @@
+const std = @import("std");
+const Reader = std.Io.Reader;
+
+pub const BlockSize = packed struct {
+    size: u31,
+    uncompressed: bool,
+};
+
+pub const File = struct {
+    block_start: u32,
+    frag_idx: u32,
+    frag_offset: u32,
+    size: u32,
+    block_sizes: []BlockSize,
+
+    pub fn read(alloc: std.mem.Allocator, rdr: *Reader, block_size: u32) !File {
+        var buf: [16]u8 = undefined;
+        try rdr.readSliceAll(&buf);
+        const frag_idx = std.mem.readVarInt(u32, buf[4..8], .little);
+        const size = std.mem.readVarInt(u32, buf[12..], .little);
+        const sizes_len = size / block_size;
+        if (frag_idx != 0xFFFFFFFF and size % block_size > 0)
+            sizes_len += 1;
+        const sizes = try alloc.alloc(BlockSize, sizes_len);
+        errdefer alloc.free(sizes);
+        try rdr.readSliceEndian(BlockSize, sizes, .little);
+        return .{
+            .block_start = std.mem.readVarInt(u32, buf[0..4], .little),
+            .frag_idx = frag_idx,
+            .frag_offset = std.mem.readVarInt(u32, buf[8..12], .little),
+            .size = size,
+            .block_sizes = sizes,
+        };
+    }
+};
+
+pub const ExtFile = struct {
+    block_start: u64,
+    size: u64,
+    sparse: u64,
+    hard_links: u32,
+    frag_idx: u32,
+    frag_offset: u32,
+    xattr_idx: u32,
+    block_sizes: []BlockSize,
+
+    pub fn read(alloc: std.mem.Allocator, rdr: *Reader, block_size: u32) !File {
+        var buf: [40]u8 = undefined;
+        try rdr.readSliceAll(&buf);
+        const frag_idx = std.mem.readVarInt(u32, buf[28..32], .little);
+        const size = std.mem.readVarInt(u64, buf[8..16], .little);
+        const sizes_len = size / block_size;
+        if (frag_idx != 0xFFFFFFFF and size % block_size > 0)
+            sizes_len += 1;
+        const sizes = try alloc.alloc(BlockSize, sizes_len);
+        errdefer alloc.free(sizes);
+        try rdr.readSliceEndian(BlockSize, sizes, .little);
+        return .{
+            .block_start = std.mem.readVarInt(u64, buf[0..8], .little),
+            .size = size,
+            .sparse = std.mem.readVarInt(u64, buf[16..24], .little),
+            .hard_links = std.mem.readVarInt(u32, buf[24..28], .little),
+            .frag_idx = frag_idx,
+            .frag_offset = std.mem.readVarInt(u32, buf[32..36], .little),
+            .xattr_idx = std.mem.readVarInt(u32, buf[36..40], .little),
+            .block_sizes = sizes,
+        };
+    }
+};
@@ -0,0 +1,53 @@
+const Reader = @import("std").Io.Reader;
+
+pub const Device = packed struct {
+    hard_links: u32,
+    device: u32,
+
+    const Self = @This();
+
+    pub fn read(rdr: *Reader) !Self {
+        var new: Self = undefined;
+        try rdr.readSliceEndian(Self, @ptrCast(&new), .little);
+        return new;
+    }
+};
+
+pub const ExtDevice = packed struct {
+    hard_links: u32,
+    device: u32,
+    xattr_idx: u32,
+
+    const Self = @This();
+
+    pub fn read(rdr: *Reader) !Self {
+        var new: Self = undefined;
+        try rdr.readSliceEndian(Self, @ptrCast(&new), .little);
+        return new;
+    }
+};
+
+pub const Ipc = packed struct {
+    hard_links: u32,
+
+    const Self = @This();
+
+    pub fn read(rdr: *Reader) !Self {
+        var new: Self = undefined;
+        try rdr.readSliceEndian(Self, @ptrCast(&new), .little);
+        return new;
+    }
+};
+
+pub const ExtIpc = packed struct {
+    hard_links: u32,
+    xattr_idx: u32,
+
+    const Self = @This();
+
+    pub fn read(rdr: *Reader) !Self {
+        var new: Self = undefined;
+        try rdr.readSliceEndian(Self, @ptrCast(&new), .little);
+        return new;
+    }
+};
@@ -0,0 +1,42 @@
+const std = @import("std");
+const Reader = std.Io.Reader;
+
+pub const Symlink = struct {
+    hard_links: u32,
+    target: []const u8,
+
+    pub fn read(alloc: std.mem.Allocator, rdr: *Reader) !Symlink {
+        var buf: [8]u8 = undefined;
+        try rdr.readSliceAll(&buf);
+        const size = std.mem.readVarInt(u32, buf[4..], .little);
+        const target = try alloc.alloc(u8, size);
+        errdefer alloc.free(target);
+        try rdr.readSliceEndian(u8, target, .little);
+        return .{
+            .hard_links = std.mem.readVarInt(u32, buf[0..4], .little),
+            .target = target,
+        };
+    }
+};
+
+pub const ExtSymlink = struct {
+    hard_links: u32,
+    xattr_idx: u32,
+    target: []const u8,
+
+    pub fn read(alloc: std.mem.Allocator, rdr: *Reader) !ExtSymlink {
+        var buf: [8]u8 = undefined;
+        try rdr.readSliceAll(&buf);
+        const size = std.mem.readVarInt(u32, buf[4..], .little);
+        const target = try alloc.alloc(u8, size);
+        errdefer alloc.free(target);
+        try rdr.readSliceEndian(u8, target, .little);
+        var xattr_idx: u32 = undefined;
+        try rdr.readSliceEndian(u32, @ptrCast(&xattr_idx), .little);
+        return .{
+            .hard_links = std.mem.readVarInt(u32, buf[0..4], .little),
+            .target = target,
+            .xattr_idx = xattr_idx,
+        };
+    }
+};
@@ -1,32 +0,0 @@
-const Reader = @import("std").Io.Reader;
-
-pub const Dir = extern struct {
-    block_start: u32,
-    hard_links: u32,
-    size: u16,
-    block_offset: u16,
-    parent_num: u32,
-
-    pub fn read(rdr: *Reader) !Dir {
-        var d: Dir = undefined;
-        try rdr.readSliceEndian(Dir, @ptrCast(&d), .little);
-        return d;
-    }
-};
-
-pub const ExtDir = extern struct {
-    hard_links: u32,
-    size: u32,
-    block_start: u32,
-    parent_num: u32,
-    idx_count: u16,
-    block_offset: u16,
-    xattr_idx: u32,
-    // index: []DirIndex
-
-    pub fn read(rdr: *Reader) !ExtDir {
-        var d: ExtDir = undefined;
-        try rdr.readSliceEndian(ExtDir, @ptrCast(&d), .little);
-        return d;
-    }
-};
@@ -1,91 +0,0 @@
-const std = @import("std");
-const Reader = std.Io.Reader;
-
-pub const BlockSize = packed struct(u32) {
-    size: u24,
-    uncompressed: bool,
-    _: u7,
-};
-
-pub const File = struct {
-    block_start: u32, // bytes 0-3
-    frag_idx: u32, // bytes 4-7
-    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 {
-        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 = values.block_start,
-            .frag_idx = values.frag_idx,
-            .frag_offset = values.frag_offset,
-            .size = values.size,
-            .block_sizes = sizes,
-        };
-    }
-
-    pub fn deinit(self: File, alloc: std.mem.Allocator) void {
-        alloc.free(self.block_sizes);
-    }
-};
-
-pub const ExtFile = 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
-    block_sizes: []BlockSize,
-
-    pub fn read(alloc: std.mem.Allocator, rdr: *Reader, block_size: u32) !ExtFile {
-        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 = 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,
-        };
-    }
-
-    pub fn deinit(self: ExtFile, alloc: std.mem.Allocator) void {
-        alloc.free(self.block_sizes);
-    }
-};
@@ -1,98 +0,0 @@
-const std = @import("std");
-const Reader = std.Io.Reader;
-
-pub const Symlink = struct {
-    hard_links: u32,
-    target: []const u8,
-
-    pub fn read(alloc: std.mem.Allocator, rdr: *Reader) !Symlink {
-        var start: [8]u8 = undefined;
-        try rdr.readSliceAll(&start);
-        const target_size = std.mem.readInt(u32, start[4..8], .little);
-        const target = try alloc.alloc(u8, target_size + 1);
-        errdefer alloc.free(target);
-        try rdr.readSliceEndian(u8, target, .little);
-        return .{
-            .hard_links = std.mem.readInt(u32, start[0..4], .little),
-            .target = target,
-        };
-    }
-
-    pub fn deinit(self: Symlink, alloc: std.mem.Allocator) void {
-        alloc.free(self.target);
-    }
-};
-
-pub const ExtSymlink = struct {
-    hard_links: u32,
-    target: []const u8,
-    xattr_idx: u32,
-
-    pub fn read(alloc: std.mem.Allocator, rdr: *Reader) !ExtSymlink {
-        var start: [8]u8 = undefined;
-        try rdr.readSliceAll(&start);
-        const target_size = std.mem.readInt(u32, start[4..8], .little);
-        const target = try alloc.alloc(u8, target_size + 1);
-        errdefer alloc.free(target);
-        try rdr.readSliceEndian(u8, target, .little);
-        var xattr_idx: u32 = undefined;
-        try rdr.readSliceEndian(u32, @ptrCast(&xattr_idx), .little);
-        return .{
-            .hard_links = std.mem.readInt(u32, start[0..4], .little),
-            .target = target,
-            .xattr_idx = xattr_idx,
-        };
-    }
-
-    pub fn deinit(self: ExtSymlink, alloc: std.mem.Allocator) void {
-        alloc.free(self.target);
-    }
-};
-
-/// A block or character device.
-pub const Dev = extern struct {
-    hard_links: u32,
-    dev: u32,
-
-    pub fn read(rdr: *Reader) !Dev {
-        var d: Dev = undefined;
-        try rdr.readSliceEndian(Dev, @ptrCast(&d), .little);
-        return d;
-    }
-};
-
-/// An extended block or character device.
-pub const ExtDev = extern struct {
-    hard_links: u32,
-    dev: u32,
-    xattr_idx: u32,
-
-    pub fn read(rdr: *Reader) !ExtDev {
-        var d: ExtDev = undefined;
-        try rdr.readSliceEndian(ExtDev, @ptrCast(&d), .little);
-        return d;
-    }
-};
-
-/// A socket or FIFO file.
-pub const IPC = extern struct {
-    hard_links: u32,
-
-    pub fn read(rdr: *Reader) !IPC {
-        var d: IPC = undefined;
-        try rdr.readSliceEndian(IPC, @ptrCast(&d), .little);
-        return d;
-    }
-};
-
-/// An extended socket or FIFO file.
-pub const ExtIPC = extern struct {
-    hard_links: u32,
-    xattr_idx: u32,
-
-    pub fn read(rdr: *Reader) !ExtIPC {
-        var d: ExtIPC = undefined;
-        try rdr.readSliceEndian(ExtIPC, @ptrCast(&d), .little);
-        return d;
-    }
-};
@@ -1,124 +1,168 @@
 const std = @import("std");
-const Io = std.Io;

-const Inode = @import("inode.zig");
-const DecompCache = @import("util/decomp_cache.zig");
+const Decompressor = @import("decomp.zig");
 const MetadataReader = @import("util/metadata.zig");
+const OffsetFile = @import("util/offset_file.zig");

-pub fn lookup(comptime T: anytype, io: Io, cache: *DecompCache, table_start: u64, idx: u32) !T {
-    const PER_BLOCK = 8192 / @sizeOf(T);
+pub fn stateless(comptime T: anytype, fil: OffsetFile, decomp: *const Decompressor, table_start: u64, idx: u32) !T {
+    const VALS_PER_BLOCK = 8192 / @sizeOf(T);
+    const block = idx / VALS_PER_BLOCK;
+    const block_idx = idx % VALS_PER_BLOCK;

-    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);
-        }
-    }
+    const offset = try fil.valueAt(u64, table_start + (8 * block));
+    var buf: [8192]u8 = undefined;
+    var rdr = try fil.readerAt(offset, &buf);
+    var meta_rdr: MetadataReader = .init(&rdr.interface, decomp);
+    try meta_rdr.interface.discardAll(@sizeOf(T) * block_idx);

+    var out: T = undefined;
+    try meta_rdr.interface.readSliceEndian(T, @ptrCast(&out), .little);
    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 InodeRef = @import("inode.zig").Ref;

-    const val = try alloc.alloc(u8, val_size);
-    errdefer alloc.free(val);
+const XattrLookup = packed struct {
+    // This isn't actuall an inode ref, but is stored that exact same way.
+    ref: InodeRef,
+    kv_count: u32,
+    size: u32,
+};

-    try rdr.readSliceEndian(u8, val, .little);
+const XattrKey = packed struct {
+    type: enum(u2) {
+        user,
+        trusted,
+        security,
+    },
+    out_of_line: bool,
+    _: u13,
+    name_size: u16,
+};

-    return val;
+pub const XattrValues = std.AutoHashMap([:0]u8, []u8);
+
+pub fn statelessXattr(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *const Decompressor, table_start: u64, idx: u32) !XattrValues {
+    const xattr_start = try fil.valueAt(u64, table_start);
+    const block = idx / 512;
+    const block_idx = idx % 512;
+
+    const block_start = try fil.valueAt(u64, table_start + 8 + (block * 8));
+    var rdr = try fil.readerAt(block_start, &[0]u8{});
+    var meta_rdr: MetadataReader = .init(&rdr.interface, decomp);
+    try meta_rdr.interface.discardAll(16 * block_idx);
+
+    var lookup: XattrLookup = undefined;
+    try meta_rdr.interface.readSliceEndian(XattrLookup, @ptrCast(&lookup), .little);
+
+    rdr = try fil.readerAt(xattr_start + lookup.ref.block_start, &[0]u8{});
+    meta_rdr = .init(&rdr.interface, decomp);
+    try meta_rdr.interface.discardAll(lookup.ref.block_offset);
+
+    var out: XattrValues = try .init(alloc);
+    for (0..lookup.kv_count) |_| {
+        var key: XattrKey = undefined;
+        try meta_rdr.interface.readSliceEndian(XattrKey, @ptrCast(&key), .little);
+        const prefix_size = switch (key.type) {
+            .user => 4,
+            .trusted => 7,
+            .security => 8,
+        };
+        const name: [:0]u8 = try alloc.alloc(u8, prefix_size + key.name_size + 1);
+        name[prefix_size + key.name_size] = 0;
+        try meta_rdr.interface.readSliceEndian(u8, name[prefix_size .. prefix_size + key.name_size], .little);
+        switch (key.type) {
+            .user => @memcpy(name[0..4], "user"),
+            .trusted => @memcpy(name[0..7], "trusted"),
+            .security => @memcpy(name[0..8], "security"),
+        }
+        if (key.out_of_line) {
+            try meta_rdr.interface.discardAll(4);
+            var value_offset: InodeRef = undefined;
+            try meta_rdr.interface.readSliceEndian(InodeRef, @ptrCast(&value_offset), .little);
+
+            var value_rdr = try fil.readerAt(xattr_start + value_offset.block_start, &[0]u8{});
+            var value_meta: MetadataReader = .init(&value_rdr.interface, decomp);
+            try value_meta.interface.discardAll(value_offset.block_offset);
+
+            var val_size: u32 = undefined;
+            try value_meta.interface.readSliceEndian(u32, @ptrCast(&val_size), .little);
+            const value = try alloc.alloc(u8, val_size);
+            try value_meta.interface.readSliceEndian(u8, value, .little);
+            try out.put(name, value);
+        } else {
+            var val_size: u32 = undefined;
+            try meta_rdr.interface.readSliceEndian(u32, @ptrCast(&val_size), .little);
+            const value = try alloc.alloc(u8, val_size);
+            try meta_rdr.interface.readSliceEndian(u8, value, .little);
+            try out.put(name, value);
+        }
+    }
+    return out;
+}
+
+pub fn CachedTable(comptime T: anytype) type {
+    return struct {
+        const Self = @This();
+
+        const VALS_PER_BLOCK = 8192 / @sizeOf(T);
+
+        alloc: std.mem.Allocator,
+        decomp: *const Decompressor,
+
+        fil: OffsetFile,
+        table_start: u64,
+        num: u32,
+
+        cache: std.AutoHashMap(u32, []T),
+        cache_mut: std.Thread.Mutex = .{},
+
+        pub fn init(alloc: std.mem.Allocator, decomp: *const Decompressor, fil: OffsetFile, table_offset: u64, num: u32) !Self {
+            return .{
+                .alloc = alloc,
+                .decomp = decomp,
+
+                .fil = fil,
+                .table_start = table_offset,
+                .num = num,
+
+                .cache = .init(alloc),
+            };
+        }
+        pub fn deinit(self: *Self) void {
+            var values = self.cache.valueIterator();
+            while (values.next()) |val|
+                self.alloc.free(val);
+            self.cache.deinit();
+        }
+
+        pub fn get(self: *Self, idx: u32) !T {
+            const block = idx / VALS_PER_BLOCK;
+            const block_idx = idx % VALS_PER_BLOCK;
+
+            if (self.cache.get(block)) |val|
+                return val[block_idx];
+
+            self.cache_mut.lock();
+            defer self.cache_mut.unlock();
+
+            // Double check in case another thread was doing your work.
+            if (self.cache.get(block)) |val|
+                return val[block_idx];
+
+            const offset = try self.fil.valueAt(u64, self.table_start + (8 * block));
+            var buf: [8192]u8 = undefined;
+            var rdr = try self.fil.readerAt(offset, &buf);
+            var meta_rdr: MetadataReader = .init(&rdr.interface, self.decomp);
+            const block_size = if (block == (self.num - 1) / VALS_PER_BLOCK)
+                self.num % VALS_PER_BLOCK
+            else
+                VALS_PER_BLOCK;
+            const new_block = try self.alloc.alloc(T, block_size);
+            errdefer self.alloc.free(new_block);
+            try meta_rdr.interface.readSliceEndian(T, new_block, .little);
+            try self.cache.put(block, new_block);
+            return new_block[block_idx];
+        }
+    };
 }
@@ -5,22 +5,25 @@ const Writer = std.Io.Writer;

 const ExtractionOptions = @This();

-/// 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.
+/// The number of threads used for extraction. 0 implies single threaded.
+threads: usize = 1,
+/// Don't set the file's owner & permissions after extraction
 ignore_permissions: bool = false,
-/// Don't set xattr values.
+/// Don't set xattr values. Currently xattrs are never set anyway.
 ignore_xattr: bool = false,
-/// Replace symlinks with their target. Currently doesn't do anything.
+/// Replace symlinks with their target.
 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 defaultSingleThreaded: ExtractionOptions = .{ .single_threaded = true };
-pub const default: ExtractionOptions = .{};
-
+pub const SingleThreadedDefault: ExtractionOptions = .{};
+pub fn Default() !ExtractionOptions {
+    return .{
+        .threads = try std.Thread.getCpuCount(),
+    };
+}
 pub fn VerboseDefault(wrt: *Writer) !ExtractionOptions {
    return .{
        .verbose = true,
@@ -1,7 +1,3 @@
 pub const Archive = @import("archive.zig");
-pub const ExtractionOptions = @import("options.zig");
-const Test = @import("test.zig");

-test {
-    @import("std").testing.refAllDecls(Test);
-}
+pub const ExtractionOptions = @import("options.zig");
@@ -1,63 +0,0 @@
-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);
-
-const SuperblockError = error{
-    InvalidMagic,
-    InvalidBlockLog,
-    InvalidVersion,
-    InvalidCheck,
-};
-
-/// A squashfs Superblock
-pub const Superblock = extern struct {
-    magic: u32,
-    inode_count: u32,
-    mod_time: u32,
-    block_size: u32,
-    frag_count: u32,
-    compression: CompressionType,
-    block_log: u16,
-    flags: packed struct(u16) {
-        inode_uncompressed: bool,
-        data_uncompressed: bool,
-        check: bool,
-        frag_uncompressed: bool,
-        fragment_never: bool,
-        fragment_always: bool,
-        duplicates: bool,
-        exportable: bool,
-        xattr_uncompressed: bool,
-        xattr_never: bool,
-        compression_options: bool,
-        ids_uncompressed: bool,
-        _: u4,
-    },
-    id_count: u16,
-    ver_maj: u16,
-    ver_min: u16,
-    root_ref: InodeRef,
-    size: u64,
-    id_start: u64,
-    xattr_start: u64,
-    inode_start: u64,
-    dir_start: u64,
-    frag_start: u64,
-    export_start: u64,
-
-    /// Validate the Superblock. If an error is returned, it's likely the archive is corrupted or not a squashfs archive.
-    pub fn validate(self: Superblock) !void {
-        if (self.magic != SQUASHFS_MAGIC)
-            return SuperblockError.InvalidMagic;
-        if (self.flags.check)
-            return SuperblockError.InvalidCheck;
-        if (self.ver_maj != 4 or self.ver_min != 0)
-            return SuperblockError.InvalidVersion;
-        if (math.log2(self.block_size) != self.block_log)
-            return SuperblockError.InvalidBlockLog;
-    }
-};
@@ -1,109 +0,0 @@
-const std = @import("std");
-const Io = std.Io;
-const stuff = @import("builtin");
-
-const Archive = @import("archive.zig");
-const Superblock = @import("super.zig").Superblock;
-
-const TestArchive = "testing/LinuxPATest.sfs";
-
-test "Basics" {
-    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" {
-    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(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" {
-    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 = .{
-    .magic = std.mem.readInt(u32, "hsqs", .little),
-    .inode_count = 2974,
-    .mod_time = 1632696724,
-    .block_size = 131072,
-    .frag_count = 264,
-    .compression = .zstd,
-    .block_log = 17,
-    .flags = .{
-        .inode_uncompressed = false,
-        .data_uncompressed = false,
-        .check = false,
-        .frag_uncompressed = false,
-        .fragment_never = false,
-        .fragment_always = false,
-        .duplicates = true,
-        .exportable = true,
-        .xattr_uncompressed = false,
-        .xattr_never = false,
-        .compression_options = false,
-        .ids_uncompressed = false,
-        ._ = 0,
-    },
-    .id_count = 1,
-    .ver_maj = 4,
-    .ver_min = 0,
-    .root_ref = .{
-        .block_offset = 1363,
-        .block_start = 29237,
-        ._ = 0,
-    },
-    .size = 106841744,
-    .id_start = 106841632,
-    .xattr_start = 106841720,
-    .inode_start = 106778274,
-    .dir_start = 106807998,
-    .frag_start = 106837747,
-    .export_start = 106841602,
-};
@@ -1,61 +0,0 @@
-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;
-}
@@ -1,85 +0,0 @@
-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]);
-}
@@ -0,0 +1,138 @@
+const std = @import("std");
+const Reader = std.Io.Reader;
+const Writer = std.Io.Writer;
+const Limit = std.Io.Limit;
+
+const FragEntry = @import("../archive.zig").FragEntry;
+const Decompressor = @import("../decomp.zig");
+const BlockSize = @import("../inode/file.zig").BlockSize;
+const OffsetFile = @import("offset_file.zig");
+
+const DataReader = @This();
+
+decomp: *const Decompressor,
+file: OffsetFile,
+block_size: u32,
+blocks: []BlockSize,
+size: u64,
+frag: ?FragEntry,
+frag_offset: u32,
+
+offset: u64,
+idx: usize = 0,
+sparse: bool = false,
+
+interface: Reader,
+
+pub fn init(decomp: *const Decompressor, file: OffsetFile, block_size: u32, blocks: []BlockSize, size: u64, init_offset: u64, frag: ?FragEntry, frag_offset: u32) DataReader {
+    return .{
+        .decomp = decomp,
+        .file = file,
+        .block_size = block_size,
+        .blocks = blocks,
+        .size = size,
+        .frag = frag,
+        .frag_offset = frag_offset,
+
+        .offset = init_offset,
+
+        .interface = .{
+            .buffer = &[1]u8{undefined} ** (1024 * 1024),
+            .end = 0,
+            .seek = 0,
+            .vtable = &.{ .stream = stream, .discard = discard, .readVec = readVec },
+        },
+    };
+}
+
+fn numBlocks(self: *DataReader) usize {
+    return if (self.frag == null)
+        self.blocks.len
+    else
+        self.blocks.len + 1;
+}
+fn advanceBuffer(self: *DataReader) Reader.Error!void {
+    if (self.idx >= self.numBlocks()) return Reader.Error.EndOfStream;
+    defer self.idx += 1;
+    self.sparse = false;
+    self.interface.end = 0; // If we error out and the error is ignored, we'll stil end up back here to error again.
+    self.interface.seek = 0;
+    if (self.idx == self.blocks.len) { // Fragment
+        var rdr = self.file.readerAt(self.frag.?.block_start, &[0]u8{}) catch return Reader.Error.ReadFailed;
+        const size = self.size % self.block_size;
+        if (self.frag.?.size.uncompressed) {
+            try rdr.interface.discardAll(self.frag_offset);
+            try rdr.interface.readSliceAll(self.interface.buffer[0..size]);
+            self.interface.end = size;
+            return;
+        }
+        const raw_loc = self.interface.buffer.len - self.frag.?.size.size;
+        try rdr.interface.readSliceAll(self.interface.buffer[raw_loc..]);
+        _ = self.decomp.decompress(self.interface.buffer[raw_loc..], self.interface.buffer) catch
+            return Reader.Error.ReadFailed;
+        @memmove(self.interface.buffer[0..size], self.interface.buffer[self.frag_offset .. self.frag_offset + size]);
+        self.interface.end = size;
+        return;
+    }
+    const block = self.blocks[self.idx];
+    if (block.size == 0) {
+        self.interface.end = if (self.idx == self.numBlocks() - 1)
+            self.size % self.block_size
+        else
+            self.block_size;
+        self.sparse = true;
+        return;
+    }
+    defer self.offset += block.size;
+    var rdr = try self.file.readerAt(self.offset, &[0]u8{});
+    if (block.uncompressed) {
+        try rdr.interface.readSliceAll(self.interface.buffer[0..block.size]);
+        self.interface.end = block.size;
+        return;
+    }
+    const raw_loc = self.interface.buffer.len - block.size;
+    try rdr.interface.readSliceAll(self.interface.buffer[raw_loc..]);
+    self.interface.end = self.decomp.decompress(self.interface.buffer[raw_loc..], self.interface.buffer) catch
+        return Reader.Error.ReadFailed;
+}
+
+fn stream(r: *Reader, wrt: *Writer, limit: Limit) Reader.StreamError!usize {
+    var self: *DataReader = @fieldParentPtr("interface", r);
+    if (r.seek == r.end) try self.advanceBuffer();
+    if (limit == .nothing) return 0;
+
+    const to_write = @min(r.end - r.seek, @intFromEnum(limit));
+    const wrote = if (self.sparse)
+        try wrt.splatByte(0, to_write)
+    else
+        try wrt.write(r.buffer[r.seek .. r.seek + to_write]);
+    r.seek += wrote;
+    return wrote;
+}
+fn discard(r: *Reader, limit: Limit) Reader.Error!usize {
+    var self: *DataReader = @fieldParentPtr("interface", r);
+    if (r.seek == r.end) try self.advanceBuffer();
+    if (limit == .nothing) return 0;
+
+    const adv = @min(r.end - r.seek, @intFromEnum(limit));
+    r.seek += adv;
+    return adv;
+}
+fn readVec(r: *Reader, vec: [][]u8) Reader.Error!usize {
+    var self: *DataReader = @fieldParentPtr("interface", r);
+    if (r.seek == r.end) try self.advanceBuffer();
+
+    var wrote: usize = 0;
+    for (vec) |slice| {
+        if (r.seek == r.end) break;
+        const to_copy = @min(r.end - r.seek, slice.len);
+        if (self.sparse) {
+            @memset(slice[0..to_copy], 0);
+        } else {
+            @memcpy(slice[0..to_copy], r.buffer[r.seek .. r.seek + to_copy]);
+        }
+        r.seek += to_copy;
+        wrote += to_copy;
+    }
+    return wrote;
+}
@@ -1,112 +0,0 @@
-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;
-}
@@ -1,38 +0,0 @@
-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,
-    };
-}
@@ -0,0 +1,54 @@
+const std = @import("std");
+
+const MinimalSuperblock = @import("../archive.zig").MinimalSuperblock;
+const Decompressor = @import("../decomp.zig");
+const DirEntry = @import("../directory.zig").Entry;
+const File = @import("../file.zig");
+const Inode = @import("../inode.zig");
+const MetadataReader = @import("metadata.zig");
+const OffsetFile = @import("offset_file.zig");
+const Utils = @import("utils.zig");
+
+const Iter = @This();
+
+file: OffsetFile,
+super: MinimalSuperblock,
+decomp: Decompressor,
+
+entries: []DirEntry,
+idx: usize = 0,
+
+pub fn deinit(self: Iter) void {
+    for (self.entries) |ent|
+        ent.deinit(self.decomp.alloc);
+    self.decomp.alloc.free(self.entries);
+}
+
+pub fn next(self: *Iter) !?File {
+    if (self.idx >= self.entries.len) return null;
+    defer self.idx += 1;
+
+    const entry = self.entries[self.idx];
+
+    const new_name = try self.decomp.alloc.alloc(u8, entry.name.len);
+    @memcpy(new_name, entry.name);
+    return .{
+        .file = self.file,
+        .super = self.super,
+        .decomp = self.decomp,
+
+        .name = new_name,
+        .inode = Utils.readInode(
+            self.decomp.alloc,
+            &self.decomp,
+            self.file,
+            self.super.inode_start,
+            self.super.block_size,
+            entry.block_start,
+            entry.block_offset,
+        ),
+    };
+}
+pub fn reset(self: *Iter) void {
+    self.idx = 0;
+}
@@ -1,31 +1,23 @@
-//! A cache for decompressed blocks. Used for Metadata & fragments.
-
 const std = @import("std");
-const Io = std.Io;
-const Reader = Io.Reader;
-const Writer = Io.Writer;
-const Limit = Io.Limit;
+const Reader = std.Io.Reader;
+const Writer = std.Io.Writer;
+const Limit = std.Io.Limit;

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

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

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

-cur_offset: u64 = 0,
-next_offset: u64,
-
-cache: *DecompCache,
-
-buf_uncompress: bool = false,
+rdr: *Reader,
+decomp: *const Decompressor,

+read_buf: [8192]u8 = undefined,
 interface: Reader = .{
-    .buffer = &[0]u8{},
+    .buffer = &([1]u8{undefined} ** 8192),
    .end = 0,
    .seek = 0,
    .vtable = &.{
@@ -35,76 +27,51 @@ interface: Reader = .{
    },
 },

-pub fn init(io: Io, cache: *DecompCache, offset: u64) MetadataReader {
-    return .{
-        .io = io,
-
-        .next_offset = offset,
-
-        .cache = cache,
-    };
+pub fn init(rdr: *Reader, decomp: *const Decompressor) MetadataReader {
+    return .{ .rdr = rdr, .decomp = decomp };
 }
-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: *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;
+fn advanceBuffer(self: *MetadataReader) Reader.Error!void {
+    self.interface.seek = 0;
+    var hdr: Header = undefined;
+    try self.rdr.readSliceEndian(Header, @ptrCast(&hdr), .little);
+    try self.rdr.readSliceAll(self.read_buf[0..hdr.size]);
    if (hdr.uncompressed) {
-        self.interface.buffer = self.cache.map.memory[self.cur_offset..][0..hdr.size];
+        @memcpy(self.interface.buffer[0..hdr.size], self.read_buf[0..hdr.size]);
        self.interface.end = hdr.size;
-        self.interface.seek = 0;
        return;
    }
-    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;
+    self.interface.end = self.decomp.decompress(self.read_buf[0..hdr.size], self.interface.buffer) catch |err|
+        return switch (err) {
+            error.OutOfMemory => error.ReadFailed,
+            else => err,
+        };
 }

-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;
+fn stream(rdr: *Reader, wrt: *Writer, limit: Limit) Reader.StreamError!usize {
+    var self: *MetadataReader = @fieldParentPtr("interface", rdr);
+    if (rdr.seek == rdr.end) try self.advanceBuffer();
+    const to_write = @min(@intFromEnum(limit), rdr.end - rdr.seek);
+    const wrote = try wrt.write(rdr.buffer[rdr.seek .. rdr.seek + to_write]);
+    rdr.seek += wrote;
    return wrote;
 }
-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 discard(rdr: *Reader, limit: Limit) Reader.Error!usize {
+    var self: *MetadataReader = @fieldParentPtr("interface", rdr);
+    if (rdr.seek == rdr.end) try self.advanceBuffer();
+    const to_adv = @min(@intFromEnum(limit), rdr.end - rdr.seek);
+    rdr.seek += to_adv;
+    return to_adv;
 }
-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;
-    }
-    if (vec.len == 0) return 0;
-    var total_copied: usize = 0;
+fn readVec(rdr: *Reader, vec: [][]u8) Reader.Error!usize {
+    var self: *MetadataReader = @fieldParentPtr("interface", rdr);
+    if (rdr.seek == rdr.end) try self.advanceBuffer();
+    var wrote = 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;
+        if (rdr.seek == rdr.end) break;
+        const to_write = @min(v.len, rdr.end - rdr.seek);
+        @memcpy(v[0..to_write], rdr.buffer[rdr.seek .. rdr.seek + to_write]);
+        wrote += to_write;
+        rdr.seek += to_write;
    }
-    return total_copied;
+    return wrote;
 }
@@ -0,0 +1,21 @@
+const std = @import("std");
+const Io = std.Io;
+const FileReader = Io.File.Reader;
+
+const OffsetFile = @This();
+
+fil: Io.File,
+offset: u64 = 0,
+
+pub fn readerAt(self: OffsetFile, io: Io, offset: u64, buf: []u8) !FileReader {
+    var rdr = self.fil.reader(io, buf);
+    try rdr.seekTo(self.offset + offset);
+    return rdr;
+}
+pub fn valueAt(self: OffsetFile, comptime T: type, io: Io, offset: u64) !T {
+    var rdr = self.fil.reader(io, &[0]u8{});
+    try rdr.seekTo(self.offset + offset);
+    var new: T = undefined;
+    try rdr.interface.readSliceEndian(T, @ptrCast(&new), .little);
+    return new;
+}
@@ -0,0 +1,25 @@
+const std = @import("std");
+
+const Decompressor = @import("../decomp.zig");
+const DirEntry = @import("../directory.zig").Entry;
+const Inode = @import("../inode.zig");
+const MetadataReader = @import("metadata.zig");
+const OffsetFile = @import("offset_file.zig");
+
+pub fn pathIsSelf(path: []const u8) bool {
+    if (path.len == 0) return true;
+    if (path.len == 1) {
+        return switch (path[0]) {
+            '.', '/' => true,
+            else => false,
+        };
+    }
+    return std.mem.eql(u8, path, "./");
+}
+
+pub fn readInode(alloc: std.mem.Allocator, decomp: *const Decompressor, fil: OffsetFile, inode_start: u64, block_size: u32, block_start: u32, block_offset: u16) !Inode {
+    var rdr = try fil.readerAt(inode_start + block_start, &[0]u8{});
+    var meta: MetadataReader = .init(&rdr.interface, decomp);
+    try meta.interface.discardAll(block_offset);
+    return .read(alloc, &meta.interface, block_size);
+}
@@ -1,40 +0,0 @@
-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);
-}
Author	SHA1	Message	Date
Caleb Gardner	21f1a304ca	Started changes to Zig 0.16.0	2026-04-29 02:20:46 -05:00
Caleb Gardner	cfc0e58905	Added xattr & cached uid/gid to Inode	2026-04-24 05:52:31 -05:00
Caleb Gardner	0d5b727919	Added stateless Xattr lookup	2026-04-24 04:16:22 -05:00
Caleb J. Gardner	b111859c4d	DataReader!	2026-04-08 02:33:58 -05:00
Caleb J. Gardner	3e97aabe53	Fleshing out more of the library. Mainly adding functions to File	2026-04-07 15:41:30 -05:00
Caleb J. Gardner	eec468ff17	File stuff	2026-04-04 18:48:57 -05:00
Caleb J. Gardner	c7c44029c9	Started working on Archive functions Started working on File	2026-04-04 14:17:50 -05:00
Caleb J. Gardner	e07f11d195	Lookup tables!	2026-04-04 01:37:36 -05:00
Caleb J. Gardner	d0787a5200	Fixed a couple decompressor issues. Re-added ExtractionOptions	2026-04-03 22:27:40 -05:00
Caleb J. Gardner	4ee15b036a	Finished(?) decompression stuff	2026-04-03 21:25:13 -05:00
Caleb J. Gardner	c01caba69b	More decompressor work	2026-04-02 01:42:43 -05:00
Caleb J. Gardner	3093994ac1	Started work on actual decompression implementations	2026-03-29 03:36:43 -05:00
Caleb J. Gardner	ad8222911f	Further implementing everthing again. Added Decompressor vtable interface. Directory table parsing Inode reading Metadata Reader	2026-03-27 02:39:07 -05:00
Caleb J. Gardner	a8c067e933	Some initial work Some basic Inode stuff Some basic Archive stuff	2026-03-26 22:30:15 -05:00
Caleb J. Gardner	30755f7d5c	Reseting. Again.	2026-03-26 21:46:01 -05:00