Finished an initial version of extraction

It works, but is very slow.

src/decomp/zstd.zig

@@ -1,4 +1,5 @@
 const std = @import("std");
+const Io = std.Io;
 const Reader = std.Io.Reader;
 const zstd = std.compress.zstd;
 const Node = std.SinglyLinkedList.Node;
@@ -6,33 +7,39 @@ const Node = std.SinglyLinkedList.Node;
 const Decompressor = @import("../util/decompressor.zig");
 const Error = Decompressor.Error;
 
-const Self = @This();
+const Queue = std.Io.Queue([]u8);
 
-const Buffer = struct {
+const Self = @This();
-    node: Node,
-    buf: []u8,
-};
 
 interface: Decompressor = .{ .decomp_fn = decomp },
 
 alloc: std.mem.Allocator,
+io: Io,
 
 block_size: u32,
-buffers: std.ArrayList(Buffer),
+buf: [][]u8,
-buffer_queue: std.SinglyLinkedList = .{},
+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.
+    var queue: Queue = .init(buf);
+    for (0..20) |_|
+        try queue.putOne(io, try alloc.alloc(u8, block_size + zstd.block_size_max));
 
-pub fn init(alloc: std.mem.Allocator, block_size: u32) !Self {
     return .{
         .alloc = alloc,
+        .io = io,
 
         .block_size = block_size,
-        .buffers = try .initCapacity(alloc, 5),
+        .buf = buf,
+        .buf_queue = queue,
     };
 }
 pub fn deinit(self: *Self) void {
-    for (self.buffers.items) |buf|
+    self.buf_queue.close(self.io);
-        self.alloc.free(buf.buf);
+    for (self.buf) |buf|
-    self.buffers.deinit(self.alloc);
+        self.alloc.free(buf);
+    self.alloc.free(self.buf);
 }
 
 fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
@@ -42,17 +49,11 @@ fn decomp(d: ?*const Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8
         return zstdDecomp(buf, in, out);
     }
     var self: *Self = @fieldParentPtr("interface", @constCast(d.?));
-    const buf_node = self.buffer_queue.popFirst();
+
-    var buf: *Buffer = undefined;
+    const buf = self.buf_queue.getOne(self.io) catch return Error.ReadFailed;
-    if (buf_node == null) {
+    defer self.buf_queue.putOne(self.io, buf) catch {};
-        const new_buf = try self.buffers.addOne(self.alloc);
+
-        new_buf.* = .{ .node = .{}, .buf = try self.alloc.alloc(u8, self.block_size + zstd.block_size_max) };
+    return zstdDecomp(buf, in, out);
-        buf = new_buf;
-    } else {
-        buf = @fieldParentPtr("node", buf_node.?);
-    }
-    defer self.buffer_queue.prepend(&buf.node);
-    return zstdDecomp(buf.buf, in, out);
 }
 
 inline fn zstdDecomp(buffer: []u8, in: []u8, out: []u8) !usize {

src/directory.zig

@@ -3,6 +3,8 @@ const Reader = std.Io.Reader;
 
 const Inode = @import("inode.zig");
 
+pub const Error = error{OutOfMemory} || Reader.Error;
+
 const DirEntry = @This();
 
 block_start: u32,
@@ -14,7 +16,7 @@ pub fn deinit(self: DirEntry, alloc: std.mem.Allocator) void {
     alloc.free(self.name);
 }
 
-pub fn readDirectory(alloc: std.mem.Allocator, rdr: *Reader, size: u32) ![]DirEntry {
+pub fn readDirectory(alloc: std.mem.Allocator, rdr: *Reader, size: u32) Error![]DirEntry {
     var hdr: Header = undefined;
     var raw: RawEntry = undefined;
     var out: std.ArrayList(DirEntry) = try .initCapacity(alloc, 30);

src/inode.zig

@@ -207,16 +207,16 @@ pub const Header = extern struct {
 
 // Extract
 
+const ExtractError = error{ MknodFailed, CannotSetXattr, ConcurrencyUnavailable } || DataExtractor.Error || Io.Dir.CreateFileAtomicError || LookupTable.Error ||
+    Io.File.Reader.SeekError || Io.File.Atomic.LinkError || Io.Dir.CreateDirError || Io.File.OpenError ||
+    Io.File.SetPermissionsError || Io.File.SetOwnerError || Io.Dir.SymLinkError || Io.Dir.CreateDirPathError;
 const PathRet = struct {
     path: []const u8,
-    permissions: u16,
+    inode: Inode,
-    uid_idx: u16,
-    gid_idx: u16,
     xattr_idx: ?u32 = null,
 };
 const ExtractReturnUnion = union(enum) {
-    path_ret: anyerror!PathRet, // TODO: convert to concrete error type instead of anyerror.
+    path_ret: ExtractError!PathRet,
-    void_ret: anyerror!void,
 };
 const Tables = struct {
     id: LookupTable.CachedTable(u16),
@@ -224,12 +224,24 @@ const Tables = struct {
     xattr: XattrTable,
 };
 
-pub fn extract(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, super: Archive.Superblock, path: []const u8, options: ExtractionOptions) !void {
+/// 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.
+pub fn extract(
+    self: Inode,
+    alloc: std.mem.Allocator,
+    io: Io,
+    fil: OffsetFile,
+    super: Archive.Superblock,
+    filepath: []const u8,
+    options: ExtractionOptions,
+) !void {
+    const path = std.mem.trimEnd(u8, filepath, "/");
+
     var decomp_base: Decomp = switch (super.compression) {
         .gzip => .{ .gzip = try .init(alloc, super.block_size) },
         .lzma => .{ .lzma = try .init(alloc, super.block_size) },
         .xz => .{ .xz = try .init(alloc, super.block_size) },
-        .zstd => .{ .zstd = try .init(alloc, super.block_size) },
+        .zstd => .{ .zstd = try .init(alloc, io, super.block_size) },
         else => unreachable,
     };
     defer decomp_base.deinit();
@@ -237,14 +249,29 @@ pub fn extract(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, s
 
     var frag_table: CachedTable(FragEntry) = .init(alloc, fil, decomp, super.frag_start, super.frag_count);
     defer if (!options.ignore_permissions) frag_table.deinit(io);
+    try frag_table.fill(io);
+
+    var arena: std.heap.ArenaAllocator = .init(alloc);
+    defer arena.deinit();
 
     var sel_buf = [1]ExtractReturnUnion{undefined} ** 10;
     var sel: Io.Select(ExtractReturnUnion) = .init(io, &sel_buf);
     defer sel.cancelDiscard();
 
     switch (self.hdr.inode_type) {
-        .file, .ext_file => sel.async(.path_ret, extractFile, .{ self, alloc, io, fil, decomp, &frag_table, super.block_size, path }),
+        .dir, .ext_dir => try sel.concurrent(
-        else => return error.TODO,
+            .path_ret,
+            extractDir,
+            .{ self, alloc, io, fil, decomp, &sel, &arena, super.dir_start, super.inode_start, &frag_table, super.block_size, path },
+        ),
+        .file, .ext_file => try sel.concurrent(
+            .path_ret,
+            extractFile,
+            .{ self, alloc, io, fil, decomp, &frag_table, super.block_size, path },
+        ),
+        .symlink, .ext_symlink => try sel.concurrent(.path_ret, extractSymlink, .{ self, io, path }),
+        else => if (@hasField(std.os, "linux"))
+            try sel.concurrent(.path_ret, extractDevOrIPC, .{ self, alloc, path }),
     }
 
     var xattr_table: ?XattrTable = if (!options.ignore_xattr)
@@ -252,26 +279,24 @@ pub fn extract(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, s
     else
         null;
     defer if (!options.ignore_xattr) xattr_table.?.deinit(io);
+    if (xattr_table != null) try xattr_table.?.table.fill(io);
 
     var id_table: ?CachedTable(u16) = if (!options.ignore_xattr)
         .init(alloc, fil, decomp, super.id_start, super.id_count)
     else
         null;
     defer if (!options.ignore_xattr) id_table.?.deinit(io);
+    if (id_table != null) try id_table.?.fill(io);
 
     while (true) {
-        if (sel.group.token.load(.unordered) == null) break;
+        const group_token = sel.group.token.load(.acquire);
+        if (group_token == null) break;
+        // std.debug.print("{any}\n", .{sel.group.state});
 
-        const ret = try sel.queue.getOne(io);
+        // std.debug.print("Waiting for return...", .{});
-        switch (ret) {
+        const ret = try sel.await();
-            .void_ret => {
+        // std.debug.print("Got One...\n", .{});
-                try ret.void_ret;
-                continue;
-            },
-            else => {},
-        }
         const path_ret = try ret.path_ret;
-        defer if (path_ret.path.len != path.len) alloc.free(path_ret.path);
 
         if (options.ignore_permissions and options.ignore_xattr) continue;
         if (options.ignore_permissions and path_ret.xattr_idx == null) continue;
@@ -280,10 +305,14 @@ pub fn extract(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, s
         defer ret_file.close(io);
 
         if (!options.ignore_permissions) {
-            try ret_file.setPermissions(io, @enumFromInt(path_ret.permissions));
+            try ret_file.setPermissions(io, @enumFromInt(path_ret.inode.hdr.permissions));
-            try ret_file.setOwner(io, try id_table.?.get(io, path_ret.uid_idx), try id_table.?.get(io, path_ret.gid_idx));
+            try ret_file.setOwner(
+                io,
+                try id_table.?.get(io, path_ret.inode.hdr.uid_idx),
+                try id_table.?.get(io, path_ret.inode.hdr.gid_idx),
+            );
         }
-        if (!options.ignore_xattr and path_ret.xattr_idx != null) {
+        if (@hasField(std.os, "linux") and !options.ignore_xattr and path_ret.xattr_idx != null) {
             const xattrs = try xattr_table.?.get(alloc, io, path_ret.xattr_idx.?);
             defer {
                 for (xattrs) |x|
@@ -299,14 +328,95 @@ pub fn extract(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, s
         }
     }
 }
-pub fn extractFile(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFile, decomp: *const Decompressor, frag: *CachedTable(FragEntry), block_size: u32, path: []const u8) anyerror!PathRet {
+fn extractDir(
+    self: Inode,
+    alloc: std.mem.Allocator,
+    io: Io,
+    fil: OffsetFile,
+    decomp: *const Decompressor,
+    parent_select: *Io.Select(ExtractReturnUnion),
+    arena: *std.heap.ArenaAllocator,
+    dir_start: u64,
+    inode_start: u64,
+    frag: *CachedTable(FragEntry),
+    block_size: u32,
+    path: []const u8,
+) ExtractError!PathRet {
+    try Io.Dir.cwd().createDirPath(io, path);
+
+    var sel_buf = [1]ExtractReturnUnion{undefined} ** 10;
+    var sel: Io.Select(ExtractReturnUnion) = .init(io, &sel_buf);
+    defer sel.cancelDiscard();
+
+    var num: usize = 0;
+    {
+        const dir_entries = self.readDirectory(alloc, io, fil, decomp, dir_start) catch |err| switch (err) {
+            Error.NotDirectory => unreachable,
+            else => return @errorCast(err),
+        };
+        num = dir_entries.len;
+        defer {
+            for (dir_entries) |d|
+                d.deinit(alloc);
+            alloc.free(dir_entries);
+        }
+
+        for (dir_entries) |d| {
+            var rdr = try fil.readerAt(io, d.block_start + inode_start, &[0]u8{});
+            var meta_rdr: MetadataReader = .init(alloc, &rdr.interface, decomp);
+            try meta_rdr.interface.discardAll(d.block_offset);
+            const inode = try read(arena.allocator(), &meta_rdr.interface, block_size);
+            errdefer inode.deinit(arena.allocator());
+
+            const new_path = try std.mem.concat(arena.allocator(), u8, &[_][]const u8{ path, "/", d.name });
+            errdefer arena.allocator().free(new_path);
+
+            switch (d.type) {
+                .dir => try sel.concurrent(
+                    .path_ret,
+                    extractDir,
+                    .{ inode, alloc, io, fil, decomp, parent_select, arena, dir_start, inode_start, frag, block_size, new_path },
+                ),
+                .file => try sel.concurrent(
+                    .path_ret,
+                    extractFile,
+                    .{ inode, alloc, io, fil, decomp, frag, block_size, new_path },
+                ),
+                .symlink => try sel.concurrent(.path_ret, extractSymlink, .{ inode, io, new_path }),
+                else => try sel.concurrent(.path_ret, extractDevOrIPC, .{ inode, alloc, new_path }),
+            }
+        }
+    }
+
+    while (num > 0) {
+        const ret = sel.await() catch break;
+        num -= 1;
+
+        parent_select.queue.putOne(io, ret) catch |err| switch (err) {
+            error.Canceled => return error.Canceled,
+            else => break,
+        };
+    }
+    return .{
+        .path = path,
+        .inode = self,
+    };
+}
+fn extractFile(
+    self: Inode,
+    alloc: std.mem.Allocator,
+    io: Io,
+    fil: OffsetFile,
+    decomp: *const Decompressor,
+    frag: *CachedTable(FragEntry),
+    block_size: u32,
+    path: []const u8,
+) ExtractError!PathRet {
     var atomic = try Io.Dir.cwd().createFileAtomic(io, path, .{});
     defer atomic.deinit(io);
 
     var ret: PathRet = .{
-        .gid_idx = self.hdr.gid_idx,
+        .inode = self,
-        .uid_idx = self.hdr.uid_idx,
-        .permissions = self.hdr.permissions,
         .path = path,
     };
     const data: DataExtractor = blk: {
@@ -335,3 +445,68 @@ pub fn extractFile(self: Inode, alloc: std.mem.Allocator, io: Io, fil: OffsetFil
 
     return ret;
 }
+fn extractSymlink(self: Inode, io: Io, path: []const u8) ExtractError!PathRet {
+    const target = switch (self.data) {
+        .symlink => |s| s.target,
+        .ext_symlink => |s| s.target,
+        else => unreachable,
+    };
+
+    try Io.Dir.cwd().symLink(io, target, path, .{});
+
+    return .{
+        .path = path,
+        .inode = self,
+    };
+}
+fn extractDevOrIPC(self: Inode, alloc: std.mem.Allocator, path: []const u8) ExtractError!PathRet {
+    var dev_num: u32 = 0;
+    var mode: u32 = 0;
+
+    const DT = std.posix.DT;
+
+    var ret: PathRet = .{
+        .inode = self,
+        .path = path,
+    };
+
+    switch (self.data) {
+        .block_dev => |d| {
+            dev_num = d.dev;
+            mode = DT.BLK;
+        },
+        .ext_block_dev => |d| {
+            dev_num = d.dev;
+            mode = DT.BLK;
+            if (d.xattr_idx != 0xFFFFFFFF) ret.xattr_idx = d.xattr_idx;
+        },
+        .char_dev => |d| {
+            dev_num = d.dev;
+            mode = DT.CHR;
+        },
+        .ext_char_dev => |d| {
+            dev_num = d.dev;
+            mode = DT.CHR;
+            if (d.xattr_idx != 0xFFFFFFFF) ret.xattr_idx = d.xattr_idx;
+        },
+        .fifo => mode = DT.FIFO,
+        .ext_fifo => |f| {
+            mode = DT.FIFO;
+            if (f.xattr_idx != 0xFFFFFFFF) ret.xattr_idx = f.xattr_idx;
+        },
+        .socket => mode = DT.SOCK,
+        .ext_socket => |s| {
+            mode = DT.SOCK;
+            if (s.xattr_idx != 0xFFFFFFFF) ret.xattr_idx = s.xattr_idx;
+        },
+        else => unreachable,
+    }
+
+    const sentinel_path = try std.mem.concatWithSentinel(alloc, u8, &[_][]const u8{path}, 0);
+    defer alloc.free(sentinel_path);
+
+    const res = std.os.linux.mknod(sentinel_path, mode, dev_num);
+    if (res != 0) return ExtractError.MknodFailed;
+
+    return ret;
+}

src/lookup_table.zig

@@ -24,6 +24,8 @@ pub fn lookupValue(comptime T: anytype, alloc: std.mem.Allocator, io: Io, decomp
     return out;
 }
 
+pub const Error = Io.Cancelable || Io.File.Reader.SeekError || Io.Reader.ReadAllocError;
+
 pub fn CachedTable(comptime T: anytype) type {
     return struct {
         const T_PER_BLOCK: u16 = 8192 / @sizeOf(T);
@@ -55,10 +57,39 @@ pub fn CachedTable(comptime T: anytype) type {
         }
         pub fn deinit(self: *Table, io: Io) void {
             self.mut.lockUncancelable(io);
+            var iter = self.table.valueIterator();
+            while (iter.next()) |val|
+                self.alloc.free(val.*);
             self.table.deinit();
         }
 
-        pub fn get(self: *Table, io: Io, idx: u32) !T {
+        pub fn fill(self: *Table, io: Io) Error!void {
+            try self.mut.lock(io);
+            defer self.mut.unlock(io);
+
+            var num_blocks = self.total_num / T_PER_BLOCK;
+            if (self.total_num % T_PER_BLOCK > 0)
+                num_blocks += 1;
+
+            for (0..num_blocks) |block| {
+                var rdr = try self.fil.readerAt(io, self.table_start + (8 * block), &[0]u8{});
+                var offset: u64 = undefined;
+                try rdr.interface.readSliceEndian(u64, @ptrCast(&offset), .little);
+
+                const len: u16 = if (self.total_num % T_PER_BLOCK != 0 and block == (self.total_num - 1) / T_PER_BLOCK)
+                    @truncate(self.total_num % T_PER_BLOCK)
+                else
+                    T_PER_BLOCK;
+
+                rdr = try self.fil.readerAt(io, offset, &[0]u8{});
+                var meta: MetadataReader = .init(self.alloc, &rdr.interface, self.decomp);
+
+                const slice = try meta.interface.readSliceEndianAlloc(self.alloc, T, len, .little);
+                try self.table.put(@truncate(block), slice);
+            }
+        }
+
+        pub fn get(self: *Table, io: Io, idx: u32) Error!T {
             const block = idx / T_PER_BLOCK;
             const block_offset = idx % T_PER_BLOCK;
             if (self.table.contains(block))

src/test.zig

@@ -10,6 +10,8 @@ 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);
@@ -22,6 +24,8 @@ 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);
@@ -35,6 +39,8 @@ test "ExtractSingleFile" {
 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);

src/util/data_extractor.zig

@@ -10,6 +10,8 @@ const OffsetFile = @import("offset_file.zig");
 
 // const SharedCache = @import("shared_cache.zig");
 
+pub const Error = error{OutOfMemory} || Io.File.Reader.SeekError || Io.Writer.Error;
+
 const DataExtractor = @This();
 
 fil: OffsetFile,
@@ -23,7 +25,7 @@ blocks: []BlockSize,
 frag_offset: u32 = 0,
 frag_entry: ?FragEntry = null,
 
-err: ?anyerror = null,
+err: ?Error = null,
 
 pub fn init(fil: OffsetFile, decomp: *const Decompressor, block_size: u32, file_size: u64, data_start: u64, blocks: []BlockSize) DataExtractor {
     return .{
@@ -48,10 +50,10 @@ fn numBlocks(self: DataExtractor) usize {
 }
 
 /// 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) !void {
+pub fn extractAsync(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil: Io.File) Error!void {
     var group: Io.Group = .init;
     defer group.cancel(io);
-    var err: ?anyerror = null;
+    var err: ?Error = null;
 
     var read_offset: u64 = self.start;
     for (0..self.blocks.len) |idx| {
@@ -64,7 +66,7 @@ pub fn extractAsync(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil:
     group.await(io) catch |cancel| return err orelse cancel;
 }
 
-fn blockThread(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil: Io.File, read_offset: u64, idx: usize, ret_err: *?anyerror) Io.Cancelable!void {
+fn blockThread(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil: Io.File, read_offset: u64, idx: usize, ret_err: *?Error) Io.Cancelable!void {
     const block = self.blocks[idx];
 
     const cur_block_size = if (idx == self.numBlocks() - 1)
@@ -124,7 +126,7 @@ fn blockThread(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil: Io.Fi
         };
     }
 }
-fn fragThread(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil: Io.File, ret_err: *?anyerror) Io.Cancelable!void {
+fn fragThread(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil: Io.File, ret_err: *?Error) Io.Cancelable!void {
     const frag = self.frag_entry.?;
     const cur_block_size = self.file_size % self.block_size;
 
@@ -169,7 +171,7 @@ fn fragThread(self: DataExtractor, alloc: std.mem.Allocator, io: Io, fil: Io.Fil
             if (err == error.Canceled) io.recancel();
             return Io.Cancelable.Canceled;
         };
-        wrt.interface.writeAll(tmp[0..cur_block_size]) catch |err| {
+        wrt.interface.writeAll(tmp[self.frag_offset .. self.frag_offset + cur_block_size]) catch |err| {
             ret_err.* = err;
             if (err == error.Canceled) io.recancel();
             return Io.Cancelable.Canceled;

src/util/offset_file.zig

@@ -14,16 +14,11 @@ pub fn init(fil: File, init_offset: u64) OffsetFile {
     return .{ .fil = fil, .offset = init_offset };
 }
 
-pub fn readerAt(self: OffsetFile, io: Io, offset: u64, buffer: []u8) !Reader {
+pub fn readerAt(self: OffsetFile, io: Io, offset: u64, buffer: []u8) Reader.SeekError!Reader {
     var rdr = self.fil.reader(io, buffer);
     try rdr.seekTo(self.offset + offset);
     return rdr;
 }
-pub fn readAt(self: OffsetFile, io: Io, offset: u64, buf: []u8) !void {
+pub fn readAt(self: OffsetFile, io: Io, offset: u64, buf: []u8) File.ReadPositionalError!void {
     _ = try self.fil.readPositionalAll(io, buf, self.offset + offset);
 }
-pub fn readValueAt(self: OffsetFile, comptime T: anytype, io: Io, offset: u64) !void {
-    //TODO: check for endianess and decode accordingly.
-    var new: T = undefined;
-    _ = try self.fil.readPositionalAll(io, @ptrCast(&new), self.offset + offset);
-}