Fixed missed merge text (oops)

Changed all *const Decompressor to *Decompressor
Changed all decompressors to only stateless (my queues are borked)

README.md

@@ -8,13 +8,15 @@ A library and application to decompress or view squashfs archives.
 
 Overall works, but currently is missing some features ([see below](#capabilities)) and has significantly slow performance compared to `unsquashfs` ([see below](#performance)).
 
-Currently things are still in flux after Zig 0.16's Io changes and the documentation below *might* not be up to date.
-
 ## Build options
 
-> `-Duse_c_libs=true`
+> `-Duse_zig_decomp=true`
 
-Instead of using Zig's standard library for decompression, use the system's C libraries. Has the benefit of being much faster and enabling LZO and LZ4 decompression.
+Instead of using C libraries for decompression, use Zig's standard library for decompression. If using this option LZO and LZ4 decomrpession types are unsupported and decompression times will be significantly longer.
+
+> `-Ddynamic=true`
+
+Dynamicly link C libraries (if they're used) instead of statically linking them.
 
 > `-Dallow_lzo=true`
 
@@ -37,22 +39,22 @@ Most features are present except for the following:
 
 ## Performance
 
-This is some basic observation's I've made about this library's performance when compared to `unsquashfs`. Unless otherwise stated, most observations were made when extracting my test archive (which is fairly small and uses zstd compression) and with `-Doptimize=ReleaseFast`.
+This is some basic observation's I've made about this library's performance when compared to `unsquashfs`. Unless otherwise stated, most observations were made when extracting my test archive which is fairly small and uses zstd compression with `-Doptimize=ReleaseFast`.
 
 Currently, my only performance checks are checking execution time, nothing deeper.
 
-* Currently, using my test archive, performance matches `unsquashfs`.
-* Using Zig decompression libraries *significantly* increases decompression time by 5x. Under ideal circumstances.
+* Currently, using my test archive, performance aproximately matches `unsquashfs` when multi-threaded, but significantly slower when single-threaded.
+* Using Zig decompression libraries *significantly* increases decompression time.
 * Performance improvements/regressions will be common. I'm still learning Zig.
 
 Example Times:
 
-* *unsquashfs, multi-threaded*: .12s
+* *unsquashfs, multi-threaded*: .11s
 * *unsquashfs, single-threaded*: .13s
-* *C-libs, single-threaded*: CURRENTLY UNTESTED
-* *C-libs, multi-threaded*: .16s
-* *Zig-libs, single-threaded*: CURRENTLY UNTESTED
-* *Zig-libs, multi-threaded*: .76s
+* *C-libs, multi-threaded*: .10s
+* *C-libs, single-threaded*: ..28s
+* *Zig-libs, single-threaded*: .74s
+* *Zig-libs, multi-threaded*: 2.70s
 
 ## Build considerations
 

benchmark.sh

@@ -5,4 +5,13 @@ ARCHIVE="testing/LinuxPATest.sfs"
 REF_EXT_LOC="testing/LinuxPAReference"
 PROG_EXT_LOC="testing/LinuxPABinTest"
 
+echo "Testing Multi-threaded Performance"
+echo ""
+
 hyperfine --warmup 5 --prepare "rm -rf $REF_EXT_LOC && rm -rf $PROG_EXT_LOC" "unsquashfs -d $REF_EXT_LOC $ARCHIVE" "zig-out/bin/unsquashfs -d $PROG_EXT_LOC $ARCHIVE"
+
+echo ""
+echo "Testing Single-threaded Performance"
+echo ""
+
+hyperfine --warmup 5 --prepare "rm -rf $REF_EXT_LOC && rm -rf $PROG_EXT_LOC" "unsquashfs -p 1 -d $REF_EXT_LOC $ARCHIVE" "zig-out/bin/unsquashfs -p 1 -d $PROG_EXT_LOC $ARCHIVE"

build.zig

@@ -3,6 +3,7 @@ const std = @import("std");
 pub fn build(b: *std.Build) !void {
     const use_zig_decomp = b.option(bool, "use_zig_decomp", "Use zig standard library for decompression.") orelse false;
     const allow_lzo = b.option(bool, "allow_lzo", "Compile with lzo support") orelse false;
+    const dynamic = b.option(bool, "dynamic", "Dynamicly link C decompression libraries") orelse false;
     var debug = b.option(bool, "debug", "Enable options to make debugging easier.");
     const version_string_option = b.option([]const u8, "version", "Version of the library/binary");
 
@@ -11,15 +12,12 @@ pub fn build(b: *std.Build) !void {
     zig_squashfs_options.addOption(bool, "allow_lzo", allow_lzo);
 
     const target = b.standardTargetOptions(.{});
-    const optimize = b.standardOptimizeOption(.{});
+    var optimize = b.standardOptimizeOption(.{});
 
-    if (optimize == .Debug) debug = true;
-
-    const c = b.addTranslateC(.{
-        .optimize = optimize,
-        .target = target,
-        .root_source_file = b.path("src/c.h"),
-    });
+    if (debug == true)
+        optimize = .Debug;
+    if (optimize == .Debug)
+        debug = true;
 
     const lib = b.addLibrary(.{
         .name = "squashfs",
@@ -28,29 +26,30 @@ pub fn build(b: *std.Build) !void {
             .target = target,
             .valgrind = debug,
             .root_source_file = b.path("src/root.zig"),
-            // .link_libc = true,
             .imports = &.{
                 .{ .name = "options", .module = zig_squashfs_options.createModule() },
-                .{ .name = "c", .module = c.createModule() },
             },
         }),
         .use_llvm = debug,
     });
 
-    const zstd = b.dependency("zstd", .{ .optimize = optimize, .target = target });
-    lib.root_module.linkLibrary(zstd.artifact("zstd"));
+    const deps = try dependencies(b, optimize, target, use_zig_decomp, allow_lzo, dynamic);
+    defer b.allocator.free(deps);
+    for (deps) |d|
+        lib.root_module.linkLibrary(d);
 
-    const zng = b.dependency("zlib_ng", .{ .optimize = optimize, .target = target });
-    lib.root_module.linkLibrary(zng.artifact("zng"));
+    if (!use_zig_decomp) {
+        const c = b.addTranslateC(.{
+            .optimize = optimize,
+            .target = target,
+            .root_source_file = b.path("src/c.h"),
+        });
+        if (allow_lzo) c.defineCMacro("ALLOW_LZO", null);
+        lib.root_module.addImport("c", c.createModule());
 
-    const xz = b.dependency("xz", .{ .optimize = optimize, .target = target });
-    lib.root_module.linkLibrary(xz.artifact("lzma"));
-
-    const minilzo = b.dependency("minilzo", .{ .optimize = optimize, .target = target });
-    lib.root_module.linkLibrary(minilzo.artifact("minilzo"));
-
-    const lz4 = b.dependency("lz4", .{ .optimize = optimize, .target = target });
-    lib.root_module.linkLibrary(lz4.artifact("lz4"));
+        if (dynamic)
+            dynamicLinkLibraries(c, allow_lzo);
+    }
 
     var version = version_string_option orelse "0.0.0-testing";
     if (version[0] == 'v') version = version[1..];
@@ -80,17 +79,32 @@ pub fn build(b: *std.Build) !void {
 
     const mod_tests = b.addTest(.{
         .root_module = b.createModule(.{
-            .optimize = .Debug,
+            .optimize = optimize,
             .target = target,
-            .root_source_file = b.path("src/test.zig"),
+            .root_source_file = b.path("src/root.zig"),
             .imports = &.{
-                .{ .name = "c", .module = c.createModule() },
+                .{ .name = "options", .module = zig_squashfs_options.createModule() },
             },
-            .valgrind = true,
+            .valgrind = debug,
         }),
-        .use_llvm = true,
+        .use_llvm = debug,
     });
-    mod_tests.root_module.linkLibrary(zstd.artifact("zstd"));
+
+    for (deps) |d|
+        mod_tests.root_module.linkLibrary(d);
+
+    if (!use_zig_decomp) {
+        const c = b.addTranslateC(.{
+            .optimize = optimize,
+            .target = target,
+            .root_source_file = b.path("src/c.h"),
+        });
+        mod_tests.root_module.addImport("c", c.createModule());
+        if (allow_lzo) c.defineCMacro("ALLOW_LZO", null);
+
+        if (dynamic)
+            dynamicLinkLibraries(c, allow_lzo);
+    }
 
     const run_mod_tests = b.addRunArtifact(mod_tests);
     const test_step = b.step("test", "Run tests");
@@ -109,3 +123,42 @@ pub fn build(b: *std.Build) !void {
     check.dependOn(&lib_check.step);
     check.dependOn(&exe_check.step);
 }
+
+pub fn dynamicLinkLibraries(mod: *std.Build.Step.TranslateC, allow_lzo: bool) void {
+    mod.linkSystemLibrary("zstd", .{});
+    mod.linkSystemLibrary("zlib-ng", .{});
+    mod.linkSystemLibrary("lzma", .{});
+    mod.linkSystemLibrary("lz4", .{});
+    if (allow_lzo)
+        mod.linkSystemLibrary("minilzo", .{});
+}
+fn dependencies(
+    b: *std.Build,
+    optimize: std.builtin.OptimizeMode,
+    target: std.Build.ResolvedTarget,
+    use_zig_decomp: bool,
+    allow_lzo: bool,
+    dynamic: bool,
+) ![]*std.Build.Step.Compile {
+    if (use_zig_decomp or dynamic) return &.{};
+
+    var list: std.ArrayList(*std.Build.Step.Compile) = .empty;
+
+    const zstd = b.dependency("zstd", .{ .optimize = optimize, .target = target });
+    try list.append(b.allocator, zstd.artifact("zstd"));
+
+    const zng = b.dependency("zlib_ng", .{ .optimize = optimize, .target = target });
+    try list.append(b.allocator, zng.artifact("zng"));
+
+    const xz = b.dependency("xz", .{ .optimize = optimize, .target = target });
+    try list.append(b.allocator, xz.artifact("lzma"));
+
+    const lz4 = b.dependency("lz4", .{ .optimize = optimize, .target = target });
+    try list.append(b.allocator, lz4.artifact("lz4"));
+
+    if (allow_lzo) {
+        const minilzo = b.dependency("minilzo", .{ .optimize = optimize, .target = target });
+        try list.append(b.allocator, minilzo.artifact("minilzo"));
+    }
+    return list.toOwnedSlice(b.allocator);
+}

src/archive.zig

@@ -16,13 +16,14 @@ const Archive = @This();
 file: OffsetFile,
 super: Superblock,
 
-stateless_decomp: *const Decompressor,
+stateless_decomp: Decompressor,
 
 pub fn init(io: Io, file: std.Io.File, offset: u64) !Archive {
     var rdr = file.reader(io, &[0]u8{});
     try rdr.seekTo(offset);
     var super: Superblock = undefined;
     try rdr.interface.readSliceEndian(Superblock, @ptrCast(&super), .little);
+    try super.validate();
 
     return .{
         .file = try .init(io, file, super.size, offset),
@@ -31,26 +32,25 @@ pub fn init(io: Io, file: std.Io.File, offset: u64) !Archive {
         .stateless_decomp = try Decomp.StatelessDecomp(super.compression),
     };
 }
-pub fn deinit(self: Archive, io: Io) void {
+pub fn deinit(self: *Archive, io: Io) void {
     self.file.deinit(io);
 }
 
 /// The root folder of the Archive. Used to open other Files.
-pub fn root(self: Archive, alloc: std.mem.Allocator, io: Io) !File {
+pub fn root(self: *Archive, alloc: std.mem.Allocator) !File {
     const root_inode = try Utils.inodeFromRef(
         alloc,
-        io,
         self.file,
-        self.stateless_decomp,
+        &self.stateless_decomp,
         self.super.inode_start,
         self.super.block_size,
         self.super.root_ref,
     );
-    return .init(alloc, self, root_inode, "");
+    return .init(alloc, self.*, root_inode, "");
 }
 /// Opens a File within the archive.
-pub fn open(self: Archive, alloc: std.mem.Allocator, io: Io, filepath: []const u8) !File {
-    const root_file = try self.root(alloc, io);
+pub fn open(self: *Archive, alloc: std.mem.Allocator, io: Io, filepath: []const u8) !File {
+    var root_file = try self.root(alloc);
     const path = std.mem.trim(u8, filepath, "/");
     if (Utils.pathIsSelf(path))
         return root_file;
@@ -60,7 +60,7 @@ pub fn open(self: Archive, alloc: std.mem.Allocator, io: Io, filepath: []const u
 
 /// Returns the inode with the given inode number.
 /// Requires that the archive is exportable (has an export lookup table).
-pub fn inode(self: Archive, alloc: std.mem.Allocator, io: Io, num: u32) !Inode {
+pub fn inode(self: *Archive, alloc: std.mem.Allocator, io: Io, num: u32) !Inode {
     if (!self.super.flags.exportable)
         return error.NotExportable;
     const ref = try LookupTable.lookupValue(
@@ -83,7 +83,7 @@ pub fn inode(self: Archive, alloc: std.mem.Allocator, io: Io, num: u32) !Inode {
     );
 }
 /// Returns a value at the given index from the Archive's id (uid/gid) table.
-pub fn idTable(self: Archive, alloc: std.mem.Allocator, io: Io, idx: u32) !u16 {
+pub fn idTable(self: *Archive, alloc: std.mem.Allocator, io: Io, idx: u32) !u16 {
     return LookupTable.lookupValue(
         u16,
         alloc,
@@ -95,6 +95,19 @@ pub fn idTable(self: Archive, alloc: std.mem.Allocator, io: Io, idx: u32) !u16 {
     );
 }
 
+/// Extract the entire archive contents to the given directory.
+pub fn extract(self: *Archive, alloc: std.mem.Allocator, io: Io, extract_dir: []const u8, options: ExtractionOptions) !void {
+    const root_inode = try Utils.inodeFromRef(
+        alloc,
+        self.file,
+        &self.stateless_decomp,
+        self.super.inode_start,
+        self.super.block_size,
+        self.super.root_ref,
+    );
+    return root_inode.extract(alloc, io, self.file, self.super, extract_dir, options);
+}
+
 // Superblock
 
 const SQUASHFS_MAGIC: u32 = std.mem.readInt(u32, "hsqs", .little);
@@ -155,17 +168,121 @@ pub const Superblock = extern struct {
     }
 };
 
-// Extraction
+// Tests
 
-/// Extract the entire archive contents to the given directory.
-pub fn extract(self: Archive, alloc: std.mem.Allocator, io: Io, extract_dir: []const u8, options: ExtractionOptions) !void {
-    const root_inode = try Utils.inodeFromRef(
-        alloc,
-        self.file,
-        self.stateless_decomp,
-        self.super.inode_start,
-        self.super.block_size,
-        self.super.root_ref,
-    );
-    return root_inode.extract(alloc, io, self.file, self.super, extract_dir, options);
+const TestArchive = "testing/LinuxPATest.sfs";
+
+test "Basics" {
+    std.debug.print("Starting test: Basics...\n", .{});
+
+    const alloc = std.testing.allocator;
+    const io = std.testing.io;
+
+    var fil = try Io.Dir.cwd().openFile(io, TestArchive, .{});
+    defer fil.close(io);
+    var sfs: Archive = try .init(io, fil, 0);
+    defer sfs.deinit(io);
+    try std.testing.expectEqualDeep(sfs.super, LinuxPATestCorrectSuperblock);
+    const root_file = try sfs.root(alloc);
+    defer root_file.deinit();
 }
+
+const TestFile = "Start.exe";
+const TestFileExtractLocation = "testing/Start.exe";
+
+test "ExtractSingleFile" {
+    std.debug.print("Starting test: ExtractSingleFile...\n", .{});
+
+    const alloc = std.testing.allocator;
+    const io = std.testing.io;
+
+    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(io, fil, 0);
+    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 TestFullExtractLocation = "testing/TestExtract";
+
+test "ExtractCompleteArchive" {
+    std.debug.print("Starting test: ExtractCompleteArchive...\n", .{});
+
+    const alloc = std.testing.allocator;
+    const io = std.testing.io;
+
+    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(io, fil, 0);
+    defer sfs.deinit(io);
+    try sfs.extract(alloc, io, TestFullExtractLocation, .default);
+}
+
+test "ExtractCompleteArchiveSingleThreaded" {
+    std.debug.print("Starting test: ExtractCompleteArchive...\n", .{});
+
+    const alloc = std.testing.allocator;
+    const io = std.testing.io;
+
+    var fil = try Io.Dir.cwd().openFile(io, TestArchive, .{});
+    defer fil.close(io);
+    {
+        std.debug.print("First testing using Threaded.global_single_threaded...\n", .{});
+        Io.Dir.cwd().deleteTree(io, TestFullExtractLocation) catch {};
+        var sfs: Archive = try .init(Io.Threaded.global_single_threaded.io(), fil, 0);
+        defer sfs.deinit(Io.Threaded.global_single_threaded.io());
+        try sfs.extract(alloc, Io.Threaded.global_single_threaded.io(), TestFullExtractLocation, .default);
+    }
+    {
+        std.debug.print("Next testing using ExtractionOptions.single_threaded...\n", .{});
+        Io.Dir.cwd().deleteTree(io, TestFullExtractLocation) catch {};
+        var sfs: Archive = try .init(io, fil, 0);
+        defer sfs.deinit(io);
+        try sfs.extract(alloc, io, TestFullExtractLocation, .default_single_threaded);
+    }
+}
+
+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,
+};

src/bin/unsquashfs.zig

@@ -41,7 +41,10 @@ var force: bool = false;
 
 pub fn main(init: std.process.Init) !void {
     const alloc = init.gpa;
-    const io = init.io;
+    // const io = init.io;
+    var evented: Io.Evented = undefined;
+    try evented.init(alloc, .{});
+    const io = evented.io();
 
     var stdout = std.Io.File.stdout();
     defer stdout.close(io);
@@ -60,6 +63,7 @@ pub fn main(init: std.process.Init) !void {
 
     var arc: squashfs.Archive = try .init(io, fil, offset); //TODO: Handle error gracefully.
     const options: squashfs.ExtractionOptions = .{
+        .single_threaded = threads == 1,
         .verbose = verbose,
         .verbose_writer = if (verbose) &out.interface else null,
         .ignore_xattr = ignore_xattrs,
@@ -68,7 +72,16 @@ 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.
+    if (threads != 0) {
+        var limited_io = Io.Threaded.init(alloc, .{
+            .async_limit = .limited(threads - 1),
+            .concurrent_limit = .limited(threads - 1),
+            .argv0 = .init(init.minimal.args),
+            .environ = init.minimal.environ,
+        });
+        return arc.extract(alloc, limited_io.io(), extLoc, options); //TODO: Handle error gracefully.
+    }
+    return arc.extract(alloc, io, extLoc, options); //TODO: Handle error gracefully.
 }
 
 fn handleArgs(args: std.process.Args, out: *Writer) !void {

src/c.h

@@ -1,5 +1,7 @@
 #include <zstd.h>
 #include <zlib-ng.h>
-// #include <lzma.h>
+#include <lzma.h>
+#ifdef ALLOW_LZO
 #include <lzo/minilzo.h>
+#endif
 #include <lz4.h>

src/decomp.zig

@@ -1,13 +1,14 @@
 const std = @import("std");
+const Io = std.Io;
 
 const options = @import("options");
 
-const lzma = @import("decomp/zig_lzma.zig");
-const xz = @import("decomp/zig_xz.zig");
 const Decompressor = @import("util/decompressor.zig");
 
 const zlib = if (options.use_zig_decomp) @import("decomp/zig_zlib.zig") else @import("decomp/c_zlib.zig");
+const lzma = if (options.use_zig_decomp) @import("decomp/zig_lzma.zig") else @import("decomp/c_lzma.zig");
 const lzo = if (options.use_zig_decomp or !options.allow_lzo) void else @import("decomp/c_lzo.zig");
+const xz = if (options.use_zig_decomp) @import("decomp/zig_xz.zig") else @import("decomp/c_xz.zig");
 const lz4 = if (options.use_zig_decomp) void else @import("decomp/c_lz4.zig");
 const zstd = if (options.use_zig_decomp) @import("decomp/zig_zstd.zig") else @import("decomp/c_zstd.zig");
 
@@ -20,20 +21,20 @@ pub const Enum = enum(u16) {
     zstd,
 };
 
-pub fn StatelessDecomp(val: Enum) !*const Decompressor {
+pub fn StatelessDecomp(val: Enum) !Decompressor {
     return switch (val) {
-        .gzip => &zlib.stateless_decompressor,
-        .lzma => &lzma.stateless_decompressor,
+        .gzip => zlib.stateless_decompressor,
+        .lzma => lzma.stateless_decompressor,
         .lzo => if (options.use_zig_decomp or !options.allow_lzo)
             error.LzoUnsupported
         else
-            &lzo.stateless_decompressor,
-        .xz => &xz.stateless_decompressor,
+            lzo.stateless_decompressor,
+        .xz => xz.stateless_decompressor,
         .lz4 => if (options.use_zig_decomp)
             error.Lz4Unsupported
         else
-            &lz4.stateless_decompressor,
-        .zstd => &zstd.stateless_decompressor,
+            lz4.stateless_decompressor,
+        .zstd => zstd.stateless_decompressor,
     };
 }
 
@@ -45,31 +46,41 @@ pub const Decomp = union(enum) {
     lz4: lz4,
     zstd: zstd,
 
-    pub fn init(val: Enum, alloc: std.mem.Allocator, io: std.Io, block_size: u32) !Decomp {
+    pub fn init(val: Enum, alloc: std.mem.Allocator, io: Io, block_size: u32) !Decomp {
         return switch (val) {
-            .gzip => .{ .gzip = zlib.init(alloc, io, block_size) },
-            .lzma => .{ .lzma = .{} },
-            .lzo => .{ .lzo = .{} },
-            .xz => .{ .xz = .{} },
-            .lz4 => .{ .lz4 = .{} },
-            .zstd => .{ .zstd = zstd.init(alloc, io, block_size) },
+            .gzip => .{ .gzip = if (options.use_zig_decomp) try zlib.init(alloc, io, block_size) else try zlib.init(alloc, io) },
+            .lzma => .{ .lzma = if (options.use_zig_decomp) try lzma.init(alloc, io, block_size) else .{} },
+            .lzo => if (options.use_zig_decomp or !options.allow_lzo) error.LzoUnsupported else .{ .lzo = .{} },
+            .xz => .{ .xz = if (options.use_zig_decomp) try xz.init(alloc, io, block_size) else .{} },
+            .lz4 => if (options.use_zig_decomp) error.Lz4Unsupported else .{ .lz4 = .{} },
+            .zstd => .{ .zstd = if (options.use_zig_decomp) try zstd.init(alloc, io, block_size) else try zstd.init(alloc, io) },
         };
     }
-    pub fn deinit(self: *Decomp) void {
-        switch (self.*) {
-            .gzip => self.gzip.deinit(),
-            .zstd => self.zstd.deinit(),
-            else => {},
+    pub fn deinit(self: *Decomp, alloc: std.mem.Allocator) void {
+        if (options.use_zig_decomp) {
+            switch (self.*) {
+                .gzip => self.gzip.deinit(),
+                .lzma => self.lzma.deinit(),
+                .xz => self.xz.deinit(),
+                .zstd => self.zstd.deinit(),
+                else => {},
+            }
+        } else {
+            switch (self.*) {
+                .gzip => self.gzip.deinit(alloc),
+                .zstd => self.zstd.deinit(alloc),
+                else => {},
+            }
         }
     }
 
-    pub fn decompressor(self: *Decomp) *const Decompressor {
+    pub fn decompressor(self: *Decomp) *Decompressor {
         return switch (self.*) {
             .gzip => &self.gzip.interface,
-            .lzma => &lzma.stateless_decompressor,
-            .lzo => &lzo.stateless_decompressor,
-            .xz => &xz.stateless_decompressor,
-            .lz4 => &lz4.stateless_decompressor,
+            .lzma => &self.lzma.interface,
+            .lzo => if (options.use_zig_decomp or !options.allow_lzo) unreachable else &self.lzo.interface,
+            .xz => &self.xz.interface,
+            .lz4 => if (options.use_zig_decomp) unreachable else &self.lz4.interface,
             .zstd => &self.zstd.interface,
         };
     }

src/decomp/c_lz4.zig

@@ -7,19 +7,11 @@ const Error = Decompressor.Error;
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, _: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
-    const res = c.LZ4_decompress_fast(in.ptr, out.ptr, @truncate(out.len));
+interface: Decompressor = .{ .decomp_fn = statelessDecomp },
+
+fn statelessDecomp(_: ?*Decompressor, _: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+    const out_len: c_int = @bitCast(@as(u32, @truncate(out.len)));
+    const res = c.LZ4_decompress_fast(in.ptr, out.ptr, out_len);
     if (res < 0) return Error.ReadFailed;
     return @abs(res);
 }
-
-// lzma_allocator
-
-fn lzmaAlloc(ptr: ?*anyopaque, size: usize, _: usize) callconv(.c) ?*anyopaque {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(@constCast(ptr)));
-    return alloc.rawAlloc(size, .@"1", 0);
-}
-fn lzmaFree(ptr: ?*anyopaque, mem_ptr: ?*anyopaque) callconv(.c) void {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(@constCast(ptr)));
-    alloc.rawFree(@ptrCast(mem_ptr), .@"1", 0);
-}

src/decomp/c_lzma.zig

@@ -15,13 +15,10 @@ const Self = @This();
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+interface: Decompressor = .{ .decomp_fn = statelessDecomp },
+
+fn statelessDecomp(_: ?*Decompressor, _: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     var stream: c.lzma_stream = .{
-        .allocator = &.{
-            .alloc = lzmaAlloc,
-            .free = lzmaFree,
-            .@"opaque" = @constCast(&alloc),
-        },
         .next_in = in.ptr,
         .avail_in = in.len,
         .next_out = out.ptr,
@@ -38,11 +35,12 @@ fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8,
 
 // lzma_allocator
 
-fn lzmaAlloc(ptr: ?*anyopaque, size: usize, _: usize) callconv(.c) ?*anyopaque {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(@constCast(ptr)));
-    return alloc.rawAlloc(size, .@"1", 0);
-}
-fn lzmaFree(ptr: ?*anyopaque, mem_ptr: ?*anyopaque) callconv(.c) void {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(@constCast(ptr)));
-    alloc.rawFree(@ptrCast(mem_ptr), .@"1", 0);
-}
+// fn lzmaAlloc(ptr: ?*anyopaque, size: usize, _: usize) callconv(.c) ?*anyopaque {
+//     var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
+//     return alloc.rawAlloc(size, .@"1", 0);
+// }
+// fn lzmaFree(ptr: ?*anyopaque, mem_ptr: ?*anyopaque) callconv(.c) void {
+//     if (mem_ptr == null) return;
+//     var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
+//     alloc.free(@as([*]u8, @ptrCast(mem_ptr.?)));
+// }

src/decomp/c_lzo.zig

@@ -15,21 +15,12 @@ const Self = @This();
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, _: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+interface: Decompressor = .{ .decomp_fn = statelessDecomp },
+
+fn statelessDecomp(_: ?*Decompressor, _: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     _ = c.lzo_init();
     var out_len = out.len;
     const res = c.lzo1x_decompress_safe(in.ptr, in.len, out.ptr, &out_len, null);
     if (res != c.LZO_E_OK) return Error.ReadFailed;
     return out_len;
 }
-
-// lzma_allocator
-
-fn lzmaAlloc(ptr: ?*anyopaque, size: usize, _: usize) callconv(.c) ?*anyopaque {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(@constCast(ptr)));
-    return alloc.rawAlloc(size, .@"1", 0);
-}
-fn lzmaFree(ptr: ?*anyopaque, mem_ptr: ?*anyopaque) callconv(.c) void {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(@constCast(ptr)));
-    alloc.rawFree(@ptrCast(mem_ptr), .@"1", 0);
-}

src/decomp/c_xz.zig

@@ -15,13 +15,10 @@ const Self = @This();
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+interface: Decompressor = .{ .decomp_fn = statelessDecomp },
+
+fn statelessDecomp(_: ?*Decompressor, _: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     var stream: c.lzma_stream = .{
-        .allocator = &.{
-            .alloc = lzmaAlloc,
-            .free = lzmaFree,
-            .@"opaque" = @constCast(&alloc),
-        },
         .next_in = in.ptr,
         .avail_in = in.len,
         .next_out = out.ptr,
@@ -38,11 +35,13 @@ fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8,
 
 // lzma_allocator
 
-fn lzmaAlloc(ptr: ?*anyopaque, size: usize, _: usize) callconv(.c) ?*anyopaque {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(@constCast(ptr)));
-    return alloc.rawAlloc(size, .@"1", 0);
-}
-fn lzmaFree(ptr: ?*anyopaque, mem_ptr: ?*anyopaque) callconv(.c) void {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(@constCast(ptr)));
-    alloc.rawFree(@ptrCast(mem_ptr), .@"1", 0);
-}
+// fn lzmaAlloc(ptr: ?*anyopaque, size: usize, _: usize) callconv(.c) ?*anyopaque {
+//     var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
+//     const mem = alloc.alloc(u8, size) catch return null;
+//     return mem.ptr;
+// }
+// fn lzmaFree(ptr: ?*anyopaque, mem_ptr: ?*anyopaque) callconv(.c) void {
+//     if (mem_ptr == null) return;
+//     var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
+//     alloc.free(@as([*]u8, @ptrCast(mem_ptr.?)));
+// }

src/decomp/c_zlib.zig

@@ -20,20 +20,15 @@ io: Io,
 ctx: []c.zng_stream,
 ctx_queue: Queue,
 
-pub fn init(alloc: std.mem.Allocator, io: Io, block_size: u32) !Self {
+pub fn init(alloc: std.mem.Allocator, io: Io) !Self {
     const buf = try alloc.alloc(c.zng_stream, 20); // TODO: Choose a better number instead of a random one.
     var queue: Queue = .init(buf);
     for (0..20) |_|
-        try queue.putOne(io, .{
-            .zalloc = zalloc,
-            .zfree = zfree,
-        });
+        try queue.putOne(io, .{});
 
     return .{
-        .alloc = alloc,
         .io = io,
 
-        .block_size = block_size,
         .ctx = buf,
         .ctx_queue = queue,
     };
@@ -43,7 +38,7 @@ pub fn deinit(self: *Self, alloc: std.mem.Allocator) void {
     alloc.free(self.ctx);
 }
 
-fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn decomp(d: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     if (d == null) {
         return statelessDecomp(d, alloc, in, out);
     }
@@ -52,13 +47,12 @@ fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8
     var stream = self.ctx_queue.getOne(self.io) catch return Error.ReadFailed;
     defer self.ctx_queue.putOne(self.io, stream) catch {};
 
-    stream.@"opaque" = @constCast(&alloc);
     stream.next_in = in.ptr;
     stream.avail_in = @truncate(in.len);
     stream.next_out = out.ptr;
     stream.avail_out = @truncate(out.len);
 
-    try zlibDecomp(&stream, in, out);
+    try zlibDecomp(&stream);
 
     return stream.total_out;
 }
@@ -74,9 +68,8 @@ inline fn zlibDecomp(stream: *c.zng_stream) !void {
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn statelessDecomp(_: ?*Decompressor, _: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     var stream: c.zng_stream = .{
-        .@"opaque" = @constCast(&alloc),
         .next_in = in.ptr,
         .avail_in = @truncate(in.len),
         .next_out = out.ptr,
@@ -85,14 +78,3 @@ fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8,
     try zlibDecomp(&stream);
     return stream.total_out;
 }
-
-// zalloc
-
-fn zalloc(ptr: ?*anyopaque, size: c_uint, len: c_uint) callconv(.c) ?*anyopaque {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
-    return alloc.rawAlloc(size * len, .@"1", 0);
-}
-fn zfree(ptr: ?*anyopaque, mem_ptr: ?*anyopaque) callconv(.c) void {
-    var alloc: *std.mem.Allocator = @ptrCast(@alignCast(ptr));
-    alloc.rawFree(@ptrCast(mem_ptr), .@"1", 0);
-}

src/decomp/c_zstd.zig

@@ -20,17 +20,15 @@ io: Io,
 ctx: []?*c.ZSTD_DCtx,
 ctx_queue: Queue,
 
-pub fn init(alloc: std.mem.Allocator, io: Io, block_size: u32) !Self {
+pub fn init(alloc: std.mem.Allocator, io: Io) !Self {
     const buf = try alloc.alloc(?*c.ZSTD_DCtx, 20); // TODO: Choose a better number instead of a random one.
     var queue: Queue = .init(buf);
     for (0..20) |_|
         try queue.putOne(io, c.ZSTD_createDCtx());
 
     return .{
-        .alloc = alloc,
         .io = io,
 
-        .block_size = block_size,
         .ctx = buf,
         .ctx_queue = queue,
     };
@@ -38,11 +36,11 @@ pub fn init(alloc: std.mem.Allocator, io: Io, block_size: u32) !Self {
 pub fn deinit(self: *Self, alloc: std.mem.Allocator) void {
     self.ctx_queue.close(self.io);
     for (self.ctx) |ctx|
-        c.ZSTD_freeDCtx(ctx);
+        _ = c.ZSTD_freeDCtx(ctx);
     alloc.free(self.ctx);
 }
 
-fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn decomp(d: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     if (d == null) {
         return statelessDecomp(d, alloc, in, out);
     }
@@ -63,7 +61,7 @@ fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, _: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn statelessDecomp(_: ?*Decompressor, _: 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;

src/decomp/zig_lzma.zig

@@ -47,7 +47,7 @@ pub fn deinit(self: *Self) void {
     self.alloc.free(self.buf);
 }
 
-fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn decomp(d: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     if (d == null) {
         return statelessDecomp(d, alloc, in, out);
     }
@@ -74,7 +74,7 @@ inline fn lzmaDecomp(alloc: std.mem.Allocator, buffer: *[]u8, in: []u8, out: []u
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn statelessDecomp(_: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     var buf = try alloc.alloc(u8, in.len);
     defer alloc.free(buf);
     return lzmaDecomp(alloc, &buf, in, out) catch return Error.ReadFailed;

src/decomp/zig_xz.zig

@@ -47,7 +47,7 @@ pub fn deinit(self: *Self) void {
     self.alloc.free(self.buf);
 }
 
-fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn decomp(d: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     if (d == null) {
         return statelessDecomp(d, alloc, in, out);
     }
@@ -74,7 +74,7 @@ inline fn xzDecomp(alloc: std.mem.Allocator, buffer: *[]u8, in: []u8, out: []u8)
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn statelessDecomp(_: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     var buf = try alloc.alloc(u8, in.len);
     defer alloc.free(buf);
     return xzDecomp(alloc, &buf, in, out) catch return Error.ReadFailed;

src/decomp/zig_zlib.zig

@@ -47,7 +47,7 @@ pub fn deinit(self: *Self) void {
     self.alloc.free(self.buf);
 }
 
-fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn decomp(d: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     if (d == null) {
         return statelessDecomp(d, alloc, in, out);
     }
@@ -56,7 +56,7 @@ fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8
     const buf = self.buf_queue.getOne(self.io) catch return Error.ReadFailed;
     defer self.buf_queue.putOne(self.io, buf) catch {};
 
-    return zlibDecomp(buf.buf, in, out);
+    return zlibDecomp(buf, in, out);
 }
 
 inline fn zlibDecomp(buffer: []u8, in: []u8, out: []u8) !usize {
@@ -70,7 +70,7 @@ inline fn zlibDecomp(buffer: []u8, in: []u8, out: []u8) !usize {
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn statelessDecomp(_: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     const buf = try alloc.alloc(u8, out.len);
     defer alloc.free(buf);
     return zlibDecomp(buf, in, out);

src/decomp/zig_zstd.zig

@@ -20,9 +20,9 @@ buf: [][]u8,
 buf_queue: Queue,
 
 pub fn init(alloc: std.mem.Allocator, io: Io, block_size: u32) !Self {
-    const buf = try alloc.alloc([]u8, 20); // TODO: Choose a better number instead of a random one.
+    const buf = try alloc.alloc([]u8, 5); // TODO: Choose a better number instead of a random one.
     var queue: Queue = .init(buf);
-    for (0..20) |_|
+    for (buf) |_|
         try queue.putOne(io, try alloc.alloc(u8, block_size + zstd.block_size_max));
 
     return .{
@@ -41,7 +41,7 @@ pub fn deinit(self: *Self) void {
     self.alloc.free(self.buf);
 }
 
-fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn decomp(d: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     if (d == null) {
         const buf = try alloc.alloc(u8, in.len * 2);
         defer alloc.free(buf);
@@ -66,7 +66,7 @@ inline fn zstdDecomp(buffer: []u8, in: []u8, out: []u8) !usize {
 
 pub const stateless_decompressor: Decompressor = .{ .decomp_fn = statelessDecomp };
 
-fn statelessDecomp(_: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+fn statelessDecomp(_: ?*Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     const buf = try alloc.alloc(u8, out.len + zstd.block_size_max);
     defer alloc.free(buf);
     return zstdDecomp(buf, in, out);

src/file.zig

@@ -10,7 +10,6 @@ const Inode = @import("inode.zig");
 const DataExtractor = @import("util/data_extractor.zig");
 const Decompressor = @import("util/decompressor.zig");
 const MetadataReader = @import("util/metadata.zig");
-const SharedCache = @import("util/shared_cache.zig");
 
 const File = @This();
 
@@ -35,26 +34,25 @@ pub fn init(alloc: std.mem.Allocator, archive: Archive, in: Inode, name: []const
         .name = new_name,
     };
 }
-pub fn fromDirEntry(alloc: std.mem.Allocator, archive: Archive, ent: DirEntry) !File {
+pub fn fromDirEntry(alloc: std.mem.Allocator, archive: *Archive, ent: DirEntry) !File {
     var rdr = archive.file.readerAt(archive.super.inode_start + ent.block_start);
-    var meta: MetadataReader = .init(alloc, &rdr.interface, archive.stateless_decomp);
+    var meta: MetadataReader = .init(alloc, &rdr, &archive.stateless_decomp);
     try meta.interface.discardAll(ent.block_offset);
 
     var in: Inode = try .read(alloc, &meta.interface, archive.super.block_size);
     errdefer in.deinit(alloc);
-    return .init(alloc, archive, in, ent.name);
+    return .init(alloc, archive.*, in, ent.name);
 }
 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 {
+pub fn open(self: *File, alloc: std.mem.Allocator, io: Io, filepath: []const u8) !File {
     const entries = try self.inode.readDirectory(
         alloc,
-        io,
         self.archive.file,
-        self.archive.stateless_decomp,
+        &self.archive.stateless_decomp,
         self.archive.super.dir_start,
     );
     defer {
@@ -77,7 +75,7 @@ pub fn open(self: File, alloc: std.mem.Allocator, io: Io, filepath: []const u8)
         }
     } else return Error.FileNotFound;
 
-    const first_elem_file = try fromDirEntry(alloc, io, self.archive, search_slice[idx]);
+    var first_elem_file = try fromDirEntry(alloc, &self.archive, search_slice[idx]);
     if (first_element.len == path.len)
         return first_elem_file;
     defer first_elem_file.deinit();

src/frag.zig

@@ -17,7 +17,7 @@ pub const FragEntry = extern struct {
 
 alloc: std.mem.Allocator,
 fil: OffsetFile,
-decomp: *const Decompressor,
+decomp: *Decompressor,
 block_size: u32,
 
 entries: []FragEntry,
@@ -25,7 +25,7 @@ entries: []FragEntry,
 frag_cache: std.array_hash_map.Auto(u32, []u8),
 cache_mut: std.Io.RwLock = .init,
 
-pub fn init(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *const Decompressor, frag_start: u64, frag_num: u32, block_size: u32) !FragManager {
+pub fn init(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *Decompressor, frag_start: u64, frag_num: u32, block_size: u32) !FragManager {
     const first_offset: u64 = std.mem.readInt(u64, @ptrCast(fil.map.memory[frag_start .. frag_start + 8]), .little);
 
     var rdr = fil.readerAt(first_offset);

src/inode.zig

@@ -20,7 +20,6 @@ const DataReader = @import("util/data_reader.zig");
 const Decompressor = @import("util/decompressor.zig");
 const MetadataReader = @import("util/metadata.zig");
 const OffsetFile = @import("util/offset_file.zig");
-const SharedCache = @import("util/shared_cache.zig");
 const XattrTable = @import("xattr_table.zig");
 
 const Inode = @This();
@@ -64,14 +63,14 @@ pub fn deinit(self: Inode, alloc: std.mem.Allocator) void {
 // Utility Functions
 
 /// Read the directory entries
-pub fn readDirectory(self: Inode, alloc: std.mem.Allocator, fil: OffsetFile, decomp: *const Decompressor, dir_offset: u64) ![]DirEntry {
+pub fn readDirectory(self: Inode, alloc: std.mem.Allocator, fil: OffsetFile, decomp: *Decompressor, dir_offset: u64) ![]DirEntry {
     return switch (self.data) {
         .dir => |d| readDirFromData(alloc, fil, decomp, dir_offset, d),
         .ext_dir => |d| readDirFromData(alloc, fil, decomp, dir_offset, d),
         else => Error.NotDirectory,
     };
 }
-fn readDirFromData(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *const Decompressor, dir_offset: u64, d: anytype) ![]DirEntry {
+fn readDirFromData(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *Decompressor, dir_offset: u64, d: anytype) ![]DirEntry {
     var rdr = fil.readerAt(dir_offset + d.block_start);
     var meta: MetadataReader = .init(alloc, &rdr, decomp);
     try meta.interface.discardAll(d.block_offset);
@@ -79,34 +78,34 @@ fn readDirFromData(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *const Dec
     return DirEntry.readDirectory(alloc, &meta.interface, d.size);
 }
 /// Get a reader for a regular file's data.
-pub fn dataReader(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, cache: *SharedCache, decomp: *const Decompressor, block_size: u32) !DataReader {
+pub fn dataReader(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *Decompressor, block_size: u32, frag_block: ?[]u8) !DataReader {
     return switch (self.data) {
-        .file => |f| getReaderFromData(alloc, io, fil, cache, decomp, block_size, f),
-        .ext_file => |f| getReaderFromData(alloc, io, fil, cache, decomp, block_size, f),
+        .file => |f| getReaderFromData(alloc, io, fil, decomp, block_size, frag_block, f),
+        .ext_file => |f| getReaderFromData(alloc, io, fil, decomp, block_size, frag_block, f),
         else => Error.NotRegularFile,
     };
 }
-fn getReaderFromData(alloc: std.mem.Allocator, io: Io, fil: OffsetFile, cache: *SharedCache, decomp: *const Decompressor, block_size: u32, d: anytype) !DataReader {
-    const ext: DataReader = .init(alloc, io, fil, cache, decomp, block_size, d.size, d.block_start, d.blocks);
+fn getReaderFromData(alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *Decompressor, block_size: u32, frag_block: ?[]u8, d: anytype) !DataReader {
+    const ext: DataReader = .init(alloc, io, fil, decomp, block_size, d.size, d.block_start, d.blocks);
     if (d.frag_block_offset == 0xFFFFFFFF) {
-        // TODO:
-        return error.TODO;
+        if (frag_block == null) return error.FragBlockNotProvided;
+        ext.addFrag(d.frag_block_offset, frag_block.?);
     }
     return ext;
 }
 /// Get an extractor for a regular file's data.
-pub fn dataExtractor(self: Inode, fil: OffsetFile, cache: *SharedCache, decomp: *const Decompressor, block_size: u32) !DataExtractor {
+pub fn dataExtractor(self: Inode, fil: OffsetFile, decomp: *Decompressor, block_size: u32, frag_block: ?[]u8) !DataExtractor {
     return switch (self.data) {
-        .file => |f| getExtractorFromData(fil, cache, decomp, block_size, f),
-        .ext_file => |f| getExtractorFromData(fil, cache, decomp, block_size, f),
+        .file => |f| getExtractorFromData(fil, decomp, block_size, frag_block, f),
+        .ext_file => |f| getExtractorFromData(fil, decomp, block_size, frag_block, f),
         else => Error.NotRegularFile,
     };
 }
-fn getExtractorFromData(fil: OffsetFile, cache: *SharedCache, decomp: *const Decompressor, block_size: u32, d: anytype) !DataExtractor {
-    const ext: DataExtractor = .init(fil, cache, decomp, block_size, d.size, d.block_start, d.blocks);
+fn getExtractorFromData(fil: OffsetFile, decomp: *Decompressor, block_size: u32, frag_block: ?[]u8, d: anytype) !DataExtractor {
+    const ext: DataExtractor = .init(fil, decomp, block_size, d.size, d.block_start, d.blocks);
     if (d.frag_block_offset == 0xFFFFFFFF) {
-        // TODO:
-        return error.TODO;
+        if (frag_block == null) return error.FragBlockNotProvided;
+        ext.addFrag(d.frag_block_offset, frag_block.?);
     }
     return ext;
 }
@@ -119,11 +118,11 @@ pub fn symlinkTarget(self: Inode) ![]const u8 {
     };
 }
 /// Get inode's gid
-pub fn gid(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *const Decompressor, id_table_start: u64) !u16 {
+pub fn gid(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *Decompressor, id_table_start: u64) !u16 {
     return LookupTable.lookupValue(u16, alloc, io, decomp, fil, id_table_start, self.hdr.gid_idx);
 }
 /// Get inode's uid
-pub fn uid(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *const Decompressor, id_table_start: u64) !u16 {
+pub fn uid(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *Decompressor, id_table_start: u64) !u16 {
     return LookupTable.lookupValue(u16, alloc, io, decomp, fil, id_table_start, self.hdr.uid_idx);
 }
 /// Get the inode's xattr values as an index into the Archive's xattr table.
@@ -143,7 +142,7 @@ pub fn xattrIndex(self: Inode) !u32 {
     return idx;
 }
 // Get an inode's xattr values. If the inode does not have xattr values (including if the inode is not an extended type), an empty slice is returned.
-pub fn xattrValues(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *const Decompressor, xattr_table_start: u64) ![]XattrTable.XattrOwned {
+pub fn xattrValues(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *Decompressor, xattr_table_start: u64) ![]XattrTable.XattrOwned {
     const idx = self.xattrIndex() catch &[0]XattrTable.XattrOwned{};
     return XattrTable.statelessLookup(alloc, io, decomp, fil, xattr_table_start, idx);
 }
@@ -275,80 +274,32 @@ pub fn extract(
 ) !void {
     const path = std.mem.trimEnd(u8, filepath, "/");
 
-    var decomp_base: Decomp = try .init(super.compression, alloc, io, super.block_size);
-    const decomp = decomp_base.decompressor();
+    var decomp_base: Decompressor = try @import("decomp.zig").StatelessDecomp(super.compression); // TODO: Replace with actual Decomp value to share states & caches for efficiency.
+    const decomp = &decomp_base;
 
     var frag_mgr: FragManager = try .init(alloc, fil, decomp, super.frag_start, super.frag_count, super.block_size);
     defer frag_mgr.deinit(io);
 
+    if (options.single_threaded)
+        return self.extractSinglethreaded(alloc, io, fil, super, path, options, decomp, &frag_mgr);
+
     var sel_buf: [10]ExtractReturnUnion = undefined;
     var sel: Io.Select(ExtractReturnUnion) = .init(io, &sel_buf);
     defer sel.cancelDiscard();
 
-    sel.async(.path_ret, extractReal, .{ self, alloc, io, fil, super, decomp, &sel, &frag_mgr, path, true });
+    var loop = io.async(finishLoop, .{ alloc, io, fil, decomp, super, options, &sel });
 
-    var id_table: CachedTable(u16) = .init(alloc, fil, decomp, super.id_start, super.id_count);
-    defer id_table.deinit(io);
+    sel.async(.path_ret, extractRealAsync, .{ self, alloc, io, fil, super, decomp, &sel, &frag_mgr, path, true });
 
-    var xattr_table: ?XattrTable = if (super.flags.xattr_never or options.ignore_xattr or !@hasField(std.os, "linux"))
-        null
-    else
-        try .init(alloc, fil, decomp, super.xattr_start);
-    defer if (xattr_table != null) xattr_table.?.deinit(io);
-
-    var dir_queue: std.PriorityDequeue(PathRet, void, DirCompare) = .empty;
-    defer dir_queue.deinit(alloc);
-
-    while (true) {
-        if (sel.group.token.load(.unordered) == null) break;
-
-        const ret = try sel.await();
-        const path_ret = try ret.path_ret;
-
-        if (options.ignore_permissions and xattr_table == null) {
-            path_ret.deinit(alloc);
-            continue;
-        }
-
-        if (path_ret.inode.hdr.inode_type == .dir or path_ret.inode.hdr.inode_type == .ext_dir) {
-            try dir_queue.push(alloc, path_ret);
-            continue;
-        }
-
-        defer path_ret.deinit(alloc);
-        try path_ret.setMetadata(alloc, io, &id_table, if (xattr_table == null) null else &xattr_table.?, options);
-    }
-
-    while (sel.cancel()) |ret| {
-        const path_ret = try ret.path_ret;
-
-        if (options.ignore_permissions and xattr_table == null) {
-            path_ret.deinit(alloc);
-            continue;
-        }
-
-        if (path_ret.inode.hdr.inode_type == .dir or path_ret.inode.hdr.inode_type == .ext_dir) {
-            try dir_queue.push(alloc, path_ret);
-            continue;
-        }
-
-        defer path_ret.deinit(alloc);
-        try path_ret.setMetadata(alloc, io, &id_table, if (xattr_table == null) null else &xattr_table.?, options);
-    }
-
-    var iter = dir_queue.iterator();
-    while (iter.next()) |path_ret| {
-        defer path_ret.deinit(alloc);
-        try path_ret.setMetadata(alloc, io, &id_table, if (xattr_table == null) null else &xattr_table.?, options);
-    }
+    try loop.await(io);
 }
-pub fn extractReal(
+fn extractRealAsync(
     self: Inode,
     alloc: std.mem.Allocator,
     io: Io,
     fil: OffsetFile,
     super: Archive.Superblock,
-    decomp: *const Decompressor,
+    decomp: *Decompressor,
     sel: *Io.Select(ExtractReturnUnion),
     frag_mgr: *FragManager,
     path: []const u8,
@@ -385,7 +336,7 @@ pub fn extractReal(
                 const new_inode = try read(alloc, &meta.interface, super.block_size);
                 errdefer new_inode.deinit(alloc);
 
-                sel.async(.path_ret, extractReal, .{ new_inode, alloc, io, fil, super, decomp, sel, frag_mgr, new_path, false });
+                sel.async(.path_ret, extractRealAsync, .{ new_inode, alloc, io, fil, super, decomp, sel, frag_mgr, new_path, false });
             }
         },
         .file, .ext_file => {
@@ -454,3 +405,229 @@ pub fn extractReal(
         .origin = origin,
     };
 }
+fn finishLoop(alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *Decompressor, super: Archive.Superblock, options: ExtractionOptions, sel: *Io.Select(ExtractReturnUnion)) !void {
+    var id_table: CachedTable(u16) = .init(alloc, fil, decomp, super.id_start, super.id_count);
+    defer id_table.deinit(io);
+
+    var xattr_table: ?XattrTable = if (super.flags.xattr_never or options.ignore_xattr or !@hasField(std.os, "linux"))
+        null
+    else
+        try .init(alloc, fil, decomp, super.xattr_start);
+    defer if (xattr_table != null) xattr_table.?.deinit(io);
+
+    var dir_queue: std.PriorityDequeue(PathRet, void, DirCompare) = .empty;
+    defer dir_queue.deinit(alloc);
+
+    while (true) {
+        if (sel.group.token.load(.unordered) == null) break;
+
+        const ret = try sel.await();
+        const path_ret = try ret.path_ret;
+
+        if (options.ignore_permissions and xattr_table == null) {
+            path_ret.deinit(alloc);
+            continue;
+        }
+
+        if (path_ret.inode.hdr.inode_type == .dir or path_ret.inode.hdr.inode_type == .ext_dir) {
+            try dir_queue.push(alloc, path_ret);
+            continue;
+        }
+        defer path_ret.deinit(alloc);
+
+        try path_ret.setMetadata(alloc, io, &id_table, if (xattr_table == null) null else &xattr_table.?, options);
+    }
+
+    while (sel.cancel()) |ret| {
+        const path_ret = try ret.path_ret;
+
+        if (options.ignore_permissions and xattr_table == null) {
+            path_ret.deinit(alloc);
+            continue;
+        }
+
+        if (path_ret.inode.hdr.inode_type == .dir or path_ret.inode.hdr.inode_type == .ext_dir) {
+            try dir_queue.push(alloc, path_ret);
+            continue;
+        }
+
+        defer path_ret.deinit(alloc);
+        try path_ret.setMetadata(alloc, io, &id_table, if (xattr_table == null) null else &xattr_table.?, options);
+    }
+
+    var iter = dir_queue.iterator();
+    while (iter.next()) |path_ret| {
+        defer path_ret.deinit(alloc);
+        try path_ret.setMetadata(alloc, io, &id_table, if (xattr_table == null) null else &xattr_table.?, options);
+    }
+}
+/// Extracts the given inode to the given path. If the inode not a directory, the given path must not exist.
+/// If the inode is a directory the path must not exist or be a directory.
+fn extractSinglethreaded(
+    self: Inode,
+    alloc: std.mem.Allocator,
+    io: Io,
+    fil: OffsetFile,
+    super: Archive.Superblock,
+    path: []const u8,
+    options: ExtractionOptions,
+    decomp: *Decompressor,
+    frag: *FragManager,
+) !void {
+    var id_table: CachedTable(u16) = .init(alloc, fil, decomp, super.id_start, super.id_count);
+    defer id_table.deinit(io);
+
+    var xattr_table: ?XattrTable = if (super.flags.xattr_never or options.ignore_xattr or !@hasField(std.os, "linux"))
+        null
+    else
+        try .init(alloc, fil, decomp, super.xattr_start);
+    defer if (xattr_table != null) xattr_table.?.deinit(io);
+
+    return self.extractReal(
+        alloc,
+        io,
+        fil,
+        super,
+        decomp,
+        frag,
+        &id_table,
+        if (xattr_table == null) null else &xattr_table.?,
+        path,
+        options,
+    );
+}
+fn extractReal(
+    self: Inode,
+    alloc: std.mem.Allocator,
+    io: Io,
+    fil: OffsetFile,
+    super: Archive.Superblock,
+    decomp: *Decompressor,
+    frag_mgr: *FragManager,
+    id_table: *CachedTable(u16),
+    xattr_table: ?*XattrTable,
+    path: []const u8,
+    options: ExtractionOptions,
+) !void {
+    switch (self.hdr.inode_type) {
+        .dir, .ext_dir => {
+            try Io.Dir.cwd().createDir(io, path, @enumFromInt(0o777));
+
+            const entries = self.readDirectory(alloc, fil, decomp, super.dir_start) catch |err| switch (err) {
+                Error.NotDirectory, Error.NotExtended, Error.NotRegularFile, Error.NotSymlink => unreachable,
+                else => |e| return e,
+            };
+            defer {
+                for (entries) |e|
+                    e.deinit(alloc);
+                alloc.free(entries);
+            }
+
+            for (entries) |e| {
+                const new_path = try std.mem.concat(alloc, u8, &[_][]const u8{ path, "/", e.name });
+                defer alloc.free(new_path);
+
+                var rdr = fil.readerAt(super.inode_start + e.block_start);
+                var meta: MetadataReader = .init(alloc, &rdr, decomp);
+                try meta.interface.discardAll(e.block_offset);
+
+                const new_inode = try read(alloc, &meta.interface, super.block_size);
+                defer new_inode.deinit(alloc);
+
+                try new_inode.extractReal(alloc, io, fil, super, decomp, frag_mgr, id_table, xattr_table, new_path, options);
+            }
+        },
+        .file, .ext_file => {
+            var atomic = try Io.Dir.cwd().createFileAtomic(io, path, .{ .make_path = true });
+            defer atomic.deinit(io);
+
+            var rdr: DataReader = switch (self.data) {
+                .file => |f| blk: {
+                    var ext: DataReader = try .init(alloc, io, fil, decomp, super.block_size, f.size, f.block_start, f.block_sizes);
+                    if (f.frag_idx != 0xFFFFFFFF)
+                        ext.addFrag(f.frag_block_offset, try frag_mgr.get(io, f.frag_idx));
+                    break :blk ext;
+                },
+                .ext_file => |f| blk: {
+                    var ext: DataReader = try .init(alloc, io, fil, decomp, super.block_size, f.size, f.block_start, f.block_sizes);
+                    if (f.frag_idx != 0xFFFFFFFF)
+                        ext.addFrag(f.frag_block_offset, try frag_mgr.get(io, f.frag_idx));
+                    break :blk ext;
+                },
+                else => unreachable,
+            };
+            defer rdr.deinit();
+
+            var buf: [512 * 1024]u8 = undefined;
+            var wrt = atomic.file.writer(io, &buf);
+
+            _ = try rdr.interface.streamRemaining(&wrt.interface);
+
+            try wrt.flush();
+
+            try atomic.link(io);
+        },
+        .symlink, .ext_symlink => try Io.Dir.cwd().symLink(io, self.symlinkTarget() catch unreachable, path, .{}),
+        else => {
+            var mode: u32 = undefined;
+            var dev: u32 = 0;
+
+            const DT = std.posix.DT;
+
+            switch (self.data) {
+                .char_dev => |d| {
+                    dev = d.dev;
+                    mode = DT.CHR;
+                },
+                .ext_char_dev => |d| {
+                    dev = d.dev;
+                    mode = DT.CHR;
+                },
+                .block_dev => |d| {
+                    dev = d.dev;
+                    mode = DT.BLK;
+                },
+                .ext_block_dev => |d| {
+                    dev = d.dev;
+                    mode = DT.BLK;
+                },
+                .fifo, .ext_fifo => mode = DT.FIFO,
+                .socket, .ext_socket => mode = DT.SOCK,
+                else => unreachable,
+            }
+
+            const sentinel_path = try std.mem.concatWithSentinel(alloc, u8, &[_][]const u8{path}, 0);
+            const res = std.os.linux.mknod(sentinel_path, mode, dev);
+            alloc.free(sentinel_path);
+            if (res != 0)
+                return ExtractError.MknodFailed;
+        },
+    }
+    if (options.ignore_permissions and options.ignore_xattr) return;
+
+    var f = try Io.Dir.cwd().openFile(io, path, .{});
+    defer f.close(io);
+
+    if (!options.ignore_permissions) {
+        try f.setPermissions(io, @enumFromInt(self.hdr.permissions));
+        try f.setOwner(io, try id_table.get(io, self.hdr.uid_idx), try id_table.get(io, self.hdr.gid_idx));
+    }
+    if (xattr_table != null) {
+        const idx = self.xattrIndex() catch return;
+
+        const xattrs = try xattr_table.?.get(alloc, io, idx);
+        defer {
+            for (xattrs) |x|
+                x.deinit(alloc);
+            alloc.free(xattrs);
+        }
+
+        const sentinel_path = try std.mem.concatWithSentinel(alloc, u8, &[_][]const u8{path}, 0);
+        defer alloc.free(sentinel_path);
+        for (xattrs) |x| {
+            const xattr_ret = std.os.linux.fsetxattr(f.handle, x.key, x.value.ptr, x.value.len, 0);
+            if (xattr_ret != 0)
+                return ExtractError.CannotSetXattr;
+        }
+    }
+}

src/lookup_table.zig

@@ -5,7 +5,7 @@ const Decompressor = @import("util/decompressor.zig");
 const MetadataReader = @import("util/metadata.zig");
 const OffsetFile = @import("util/offset_file.zig");
 
-pub fn lookupValue(comptime T: anytype, alloc: std.mem.Allocator, decomp: *const Decompressor, file: OffsetFile, table_start: u64, idx: u32) !T {
+pub fn lookupValue(comptime T: anytype, alloc: std.mem.Allocator, decomp: *Decompressor, file: OffsetFile, table_start: u64, idx: u32) !T {
     const T_PER_BLOCK: u16 = 8192 / @sizeOf(T);
 
     const block = idx / T_PER_BLOCK;
@@ -33,7 +33,7 @@ pub fn CachedTable(comptime T: anytype) type {
 
         alloc: std.mem.Allocator,
         fil: OffsetFile,
-        decomp: *const Decompressor,
+        decomp: *Decompressor,
 
         table_start: u64,
         total_num: u32,
@@ -42,7 +42,7 @@ pub fn CachedTable(comptime T: anytype) type {
 
         mut: Io.RwLock = .init,
 
-        pub fn init(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *const Decompressor, offset: u64, total_num: u32) Table {
+        pub fn init(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *Decompressor, offset: u64, total_num: u32) Table {
             return .{
                 .alloc = alloc,
                 .fil = fil,

src/options.zig

@@ -5,8 +5,10 @@ const Writer = std.Io.Writer;
 
 const ExtractionOptions = @This();
 
-// /// The number of threads used for extraction. 0 implies single threaded.
-// threads: usize = 1, // As of Zig 0.16 this should no longer be necessary, instead this should be set by the io instance used.
+/// Extract single-threaded only.
+/// Though not necessary if using Threaded.single_threaded,
+/// setting single_threaded is more efficient.
+single_threaded: bool = false,
 /// Don't set the file's owner & permissions after extraction
 ignore_permissions: bool = false,
 /// Don't set xattr values. Currently xattrs are never set anyway.
@@ -18,16 +20,12 @@ verbose: bool = false,
 /// Where to print verbose log.
 verbose_writer: ?*Writer = null,
 
-pub const SingleThreadedDefault: ExtractionOptions = .{};
-pub fn Default() !ExtractionOptions {
-    return .{
-        .threads = try std.Thread.getCpuCount(),
-    };
-}
+pub const default: ExtractionOptions = .{};
+pub const default_single_threaded: ExtractionOptions = .{ .single_threaded = true };
+
 pub fn VerboseDefault(wrt: *Writer) !ExtractionOptions {
     return .{
         .verbose = true,
         .verbose_writer = wrt,
-        .threads = try std.Thread.getCpuCount(),
     };
 }

src/root.zig

@@ -1,2 +1,6 @@
 pub const Archive = @import("archive.zig");
 pub const ExtractionOptions = @import("options.zig");
+
+test {
+    @import("std").testing.refAllDecls(@This());
+}

src/test.zig

@@ -1,92 +0,0 @@
-const std = @import("std");
-const Io = std.Io;
-const io = std.testing.io;
-const alloc = std.testing.allocator;
-const stuff = @import("builtin");
-
-const Archive = @import("archive.zig");
-const Superblock = Archive.Superblock;
-
-const TestArchive = "testing/LinuxPATest.sfs";
-
-test "Basics" {
-    std.debug.print("Starting test: Basics...\n", .{});
-
-    var fil = try Io.Dir.cwd().openFile(io, TestArchive, .{});
-    defer fil.close(io);
-    var sfs: Archive = try .init(io, fil, 0);
-    defer sfs.deinit(io);
-    try std.testing.expectEqualDeep(sfs.super, LinuxPATestCorrectSuperblock);
-    const root_file = try sfs.root(alloc, io);
-    defer root_file.deinit();
-}
-
-const TestFile = "Start.exe";
-const TestFileExtractLocation = "testing/Start.exe";
-
-test "ExtractSingleFile" {
-    std.debug.print("Starting test: ExtractSingleFile...\n", .{});
-
-    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(io, fil, 0);
-    defer sfs.deinit(io);
-    var test_fil = try sfs.open(alloc, io, TestFile);
-    defer test_fil.deinit();
-    try test_fil.extract(alloc, io, TestFileExtractLocation, try .Default());
-    //TODO: validate extracted file.
-}
-
-const TestFullExtractLocation = "testing/TestExtract";
-
-test "ExtractCompleteArchive" {
-    std.debug.print("Starting test: ExtractCompleteArchive...\n", .{});
-
-    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(io, fil, 0);
-    defer sfs.deinit(io);
-    try sfs.extract(alloc, io, TestFullExtractLocation, try .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,
-};

src/util/data_extractor.zig

@@ -15,7 +15,7 @@ pub const Error = Decompressor.Error || Io.File.MemoryMap.CreateError || Io.File
 const DataExtractor = @This();
 
 fil: OffsetFile,
-decomp: *const Decompressor,
+decomp: *Decompressor,
 block_size: u32,
 
 file_size: u64,
@@ -27,7 +27,7 @@ frag_block: ?[]u8 = null,
 
 err: ?Error = null,
 
-pub fn init(fil: OffsetFile, decomp: *const Decompressor, block_size: u32, file_size: u64, data_start: u64, blocks: []BlockSize) DataExtractor {
+pub fn init(fil: OffsetFile, decomp: *Decompressor, block_size: u32, file_size: u64, data_start: u64, blocks: []BlockSize) DataExtractor {
     return .{
         .fil = fil,
         .decomp = decomp,
@@ -49,6 +49,23 @@ fn numBlocks(self: DataExtractor) usize {
     return num;
 }
 
+/// Starts extracting the data using the given group to spawn async tasks.
+pub fn extractConcurrent(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil: Io.File) (Error || Io.ConcurrentError)!void {
+    var group: Io.Group = .init;
+    defer group.cancel(io);
+    var err: ?Error = null;
+
+    var read_offset: u64 = self.start;
+    for (0..self.blocks.len) |idx| {
+        try group.concurrent(io, blockThread, .{ self, alloc, io, fil, read_offset, idx, &err });
+        read_offset += self.blocks[idx].size;
+    }
+    if (self.frag_block != null)
+        try group.concurrent(io, fragThread, .{ self, io, fil, &err });
+
+    group.await(io) catch |cancel| return err orelse cancel;
+}
+
 /// Starts extracting the data using the given group to spawn async tasks.
 pub fn extractAsync(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil: Io.File) Error!void {
     var group: Io.Group = .init;

src/util/data_reader.zig

@@ -18,7 +18,7 @@ alloc: std.mem.Allocator,
 
 fil: OffsetFile,
 io: Io,
-decomp: *const Decompressor,
+decomp: *Decompressor,
 block_size: u32,
 
 file_size: u64,
@@ -33,7 +33,7 @@ sparse_block: bool = false,
 
 interface: Io.Reader,
 
-pub fn init(alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *const Decompressor, block_size: u32, file_size: u64, data_start: u64, blocks: []BlockSize) !DataReader {
+pub fn init(alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *Decompressor, block_size: u32, file_size: u64, data_start: u64, blocks: []BlockSize) !DataReader {
     return .{
         .alloc = alloc,
 

src/util/decompressor.zig

@@ -8,8 +8,8 @@ pub const Error = std.Io.Reader.StreamError || std.mem.Allocator.Error;
 
 /// The actual decompression function.
 /// If the given decompressor is null, then the decompression should be done "stateless" without lasting allocations.
-decomp_fn: *const fn (?*const Decompressor, std.mem.Allocator, in: []u8, out: []u8) Error!usize,
+decomp_fn: *const fn (?*Decompressor, std.mem.Allocator, in: []u8, out: []u8) Error!usize,
 
-pub fn Decompress(self: *const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+pub fn Decompress(self: *Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
     return self.decomp_fn(self, alloc, in, out);
 }

src/util/metadata.zig

@@ -15,7 +15,7 @@ const This = @This();
 
 alloc: std.mem.Allocator,
 rdr: *Reader,
-decomp: *const Decompressor,
+decomp: *Decompressor,
 
 cur_block_start: u32 = 0,
 next_start_start: u32 = 0,
@@ -34,7 +34,7 @@ interface: Reader = .{
     },
 },
 
-pub fn init(alloc: std.mem.Allocator, rdr: *Reader, decomp: *const Decompressor) This {
+pub fn init(alloc: std.mem.Allocator, rdr: *Reader, decomp: *Decompressor) This {
     return .{
         .alloc = alloc,
         .rdr = rdr,

src/util/misc.zig

@@ -16,7 +16,7 @@ pub fn pathIsSelf(path: []const u8) bool {
     return path[0] == '.';
 }
 /// Creates an Inode from an Inode.Ref.
-pub fn inodeFromRef(alloc: std.mem.Allocator, file: OffsetFile, decomp: *const Decompressor, inode_start: u64, block_size: u32, ref: Inode.Ref) !Inode {
+pub fn inodeFromRef(alloc: std.mem.Allocator, file: OffsetFile, decomp: *Decompressor, inode_start: u64, block_size: u32, ref: Inode.Ref) !Inode {
     var rdr = file.readerAt(inode_start + ref.block_start);
     var meta: MetadataReader = .init(alloc, &rdr, decomp);
     try meta.interface.discardAll(ref.block_offset);

src/util/offset_file.zig

@@ -18,7 +18,7 @@ pub fn init(io: Io, fil: File, archive_size: u64, init_offset: u64) !OffsetFile
         }),
     };
 }
-pub fn deinit(self: @This(), io: Io) void {
+pub fn deinit(self: *OffsetFile, io: Io) void {
     self.map.destroy(io);
 }
 

src/util/shared_cache.zig

@@ -1,52 +0,0 @@
-const std = @import("std");
-const Io = std.Io;
-const Node = std.SinglyLinkedList.Node;
-
-const SharedCache = @This();
-
-pub const CACHE_SIZE = 1024 * 1024;
-
-pub const BufferNode = struct {
-    node: Node,
-    cache: [CACHE_SIZE]u8,
-};
-
-alloc: std.mem.Allocator,
-
-caches: std.ArrayList(BufferNode),
-cache_queue: std.SinglyLinkedList,
-queue_mut: Io.Mutex,
-
-pub fn init(alloc: std.mem.Allocator, init_cache_size: u32) !SharedCache {
-    const caches: std.ArrayList(BufferNode) = try .initCapacity(alloc, init_cache_size);
-    var queue: std.SinglyLinkedList = .{};
-    for (caches.items) |item|
-        queue.prepend(&item.node);
-    return .{
-        .alloc = alloc,
-
-        .caches = caches,
-        .cache_queue = queue,
-    };
-}
-pub fn deinit(self: *SharedCache) void {
-    self.caches.deinit(self.alloc);
-}
-
-pub fn getCache(self: *SharedCache, io: Io) !*BufferNode {
-    self.queue_mut.lock(io);
-    const nxt = self.cache_queue.popFirst();
-    self.queue_mut.unlock(io);
-    if (nxt == null) {
-        const new = try self.caches.addOne(self.alloc);
-        new.* = .{
-            .node = .{},
-            .cache = undefined,
-        };
-        return new;
-    }
-    return @fieldParentPtr("node", nxt.?);
-}
-pub fn returnCache(self: *SharedCache, buf: *BufferNode) void {
-    self.cache_queue.prepend(buf);
-}

src/xattr_table.zig

@@ -12,7 +12,7 @@ const XattrCachedTable = @This();
 alloc: std.mem.Allocator,
 
 fil: OffsetFile,
-decomp: *const Decompressor,
+decomp: *Decompressor,
 
 kv_start: u64,
 
@@ -20,7 +20,7 @@ table: LookupTable.CachedTable(TableValue),
 value_cache: std.AutoHashMap(InodeRef, []const u8),
 value_mut: Io.RwLock = .init,
 
-pub fn init(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *const Decompressor, xattr_start: u64) !XattrCachedTable {
+pub fn init(alloc: std.mem.Allocator, fil: OffsetFile, decomp: *Decompressor, xattr_start: u64) !XattrCachedTable {
     const start: u64 = std.mem.readInt(u64, @ptrCast(fil.map.memory[xattr_start .. xattr_start + 8]), .little);
     const num: u64 = std.mem.readInt(u64, @ptrCast(fil.map.memory[xattr_start + 8 .. xattr_start + 16]), .little);
 
@@ -212,7 +212,7 @@ const XattrPrefix = packed struct(u16) {
 
 // Stateless
 
-pub fn statelessLookup(alloc: std.mem.Allocator, io: Io, decomp: *const Decompressor, fil: OffsetFile, table_start: u64, idx: u16) ![]XattrOwned {
+pub fn statelessLookup(alloc: std.mem.Allocator, io: Io, decomp: *Decompressor, fil: OffsetFile, table_start: u64, idx: u16) ![]XattrOwned {
     const kv_start: u64 = std.mem.readInt(u64, @ptrCast(fil.map.memory[table_start .. table_start + 8]), .little);
 
     const lookup = try LookupTable.lookupValue(TableValue, alloc, io, decomp, fil, table_start + 16, idx);