Implement Brotli support in fetch() (#7839)

* Implement Brotli support in fetch()

* Use @panic

* Update src/http.zig

Co-authored-by: Ciro Spaciari <ciro.spaciari@gmail.com>

* Update src/http.zig

Co-authored-by: Ciro Spaciari <ciro.spaciari@gmail.com>

* Fix redirect logic

* Allow extremely long redirect URLs

* Update fetch.test.ts

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>
Co-authored-by: Ciro Spaciari <ciro.spaciari@gmail.com>

misctools/compression.zig

@@ -0,0 +1,293 @@
+/// Demo app testing the macOS libcompression bindings.
+const std = @import("std");
+const CompressionFramework = struct {
+    var handle: ?*anyopaque = null;
+    pub fn load() !void {
+        handle = std.os.darwin.dlopen("libcompression.dylib", 1);
+
+        if (handle == null)
+            return error.@"failed to load Compression.framework";
+
+        compression_encode_scratch_buffer_size = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_encode_scratch_buffer_size").?));
+        compression_encode_buffer = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_encode_buffer").?));
+        compression_decode_scratch_buffer_size = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_decode_scratch_buffer_size").?));
+        compression_decode_buffer = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_decode_buffer").?));
+        compression_stream_init = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_stream_init").?));
+        compression_stream_process = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_stream_process").?));
+        compression_stream_destroy = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_stream_destroy").?));
+    }
+
+    pub const compression_algorithm = enum(c_uint) {
+        LZ4 = 256,
+        ZLIB = 0x205,
+        LZMA = 774,
+        LZ4_RAW = 257,
+        BROTLI = 2818,
+        LZFSE = 2049,
+        LZBITMAP = 1794,
+
+        pub fn fromName(name: []const u8) ?compression_algorithm {
+            if (std.mem.endsWith(u8, name, ".br")) {
+                return .BROTLI;
+            } else if (std.mem.endsWith(u8, name, ".lz4")) {
+                return .LZ4;
+            } else if (std.mem.endsWith(u8, name, ".lzma")) {
+                return .LZMA;
+            } else if (std.mem.endsWith(u8, name, ".lzfse")) {
+                return .LZFSE;
+            } else if (std.mem.endsWith(u8, name, ".zlib") or std.mem.endsWith(u8, name, ".gz")) {
+                return .ZLIB;
+            } else {
+                return null;
+            }
+        }
+    };
+    const compression_encode_scratch_buffer_size_type = fn (algorithm: compression_algorithm) callconv(.C) usize;
+    const compression_encode_buffer_type = fn (noalias dst_buffer: [*]u8, dst_size: usize, noalias src_buffer: ?[*]const u8, src_size: usize, noalias scratch_buffer: ?*anyopaque, algorithm: compression_algorithm) callconv(.C) usize;
+    const compression_decode_scratch_buffer_size_type = fn (algorithm: compression_algorithm) callconv(.C) usize;
+    const compression_decode_buffer_type = fn (noalias dst_buffer: [*]u8, dst_size: usize, noalias src_buffer: ?[*]const u8, src_size: usize, noalias scratch_buffer: ?*anyopaque, algorithm: compression_algorithm) callconv(.C) usize;
+
+    const compression_stream_init_type = fn (stream: *compression_stream, operation: compression_stream_operation, algorithm: compression_algorithm) callconv(.C) compression_status;
+    const compression_stream_process_type = fn (stream: *compression_stream, flags: c_int) callconv(.C) compression_status;
+    const compression_stream_destroy_type = fn (stream: *compression_stream) callconv(.C) compression_status;
+
+    var compression_encode_scratch_buffer_size: *const compression_encode_scratch_buffer_size_type = undefined;
+    var compression_encode_buffer: *const compression_encode_buffer_type = undefined;
+    var compression_decode_scratch_buffer_size: *const compression_decode_scratch_buffer_size_type = undefined;
+    var compression_decode_buffer: *const compression_decode_buffer_type = undefined;
+
+    var compression_stream_init: *const compression_stream_init_type = undefined;
+    var compression_stream_process: *const compression_stream_process_type = undefined;
+    var compression_stream_destroy: *const compression_stream_destroy_type = undefined;
+    pub const compression_stream = extern struct {
+        dst_ptr: ?[*]u8 = null,
+        dst_size: usize = 0,
+        src_ptr: ?[*]const u8 = null,
+        src_size: usize = 0,
+        state: ?*anyopaque = null,
+
+        pub fn init(src: []const u8, operation: compression_stream_operation, algorithm: compression_algorithm) !compression_stream {
+            var stream = compression_stream{
+                .src_ptr = src.ptr,
+                .src_size = src.len,
+                .dst_ptr = null,
+                .dst_size = 0,
+            };
+
+            switch (compression_stream_init(&stream, operation, algorithm)) {
+                .OK => {},
+                .ERROR => return error.@"failed to initialize compression stream",
+                .END => return error.@"compression stream init returned END",
+            }
+
+            return stream;
+        }
+
+        pub fn process(stream: *compression_stream, data: []const u8, is_done: bool, comptime Iterator: type, iter: *Iterator) !StreamResult {
+            stream.src_ptr = data.ptr;
+            stream.src_size = data.len;
+
+            const initial_dest = try iter.wrote(0);
+            stream.dst_ptr = initial_dest.ptr;
+            stream.dst_size = initial_dest.len;
+
+            var total_written: usize = 0;
+            while (true) {
+                var flags: c_int = 0;
+                if (stream.src_size == 0 and is_done) {
+                    flags = COMPRESSION_STREAM_FINALIZE;
+                } else if (stream.src_size == 0) {
+                    return .{
+                        .progress = .{
+                            .read = data.len - stream.src_size,
+                            .wrote = total_written,
+                        },
+                    };
+                }
+
+                const prev_size = stream.dst_size;
+                const rc = compression_stream_process(stream, flags);
+                const wrote = prev_size - stream.dst_size;
+                switch (rc) {
+                    .OK => {
+                        const new_buffer = try iter.wrote(wrote);
+                        stream.dst_ptr = new_buffer.ptr;
+                        stream.dst_size = new_buffer.len;
+                        total_written += wrote;
+                    },
+                    .END => {
+                        _ = try iter.wrote(wrote);
+                        total_written += wrote;
+
+                        return .{
+                            .done = .{
+                                .read = data.len - stream.src_size,
+                                .wrote = total_written,
+                            },
+                        };
+                    },
+                    .ERROR => {
+                        return .{
+                            .err = .{
+                                .err = error.@"failed to process compression stream",
+                                .read = data.len - stream.src_size,
+                                .wrote = total_written,
+                            },
+                        };
+                    },
+                }
+            }
+        }
+    };
+    pub const COMPRESSION_STREAM_ENCODE: c_int = 0;
+    pub const COMPRESSION_STREAM_DECODE: c_int = 1;
+    pub const compression_stream_operation = enum(c_uint) {
+        ENCODE = 0,
+        DECODE = 1,
+    };
+    pub const COMPRESSION_STREAM_FINALIZE: c_int = 1;
+    pub const compression_stream_flags = c_uint;
+    pub const compression_status = enum(c_int) {
+        OK = 0,
+        ERROR = -1,
+        END = 1,
+    };
+
+    const StreamResult = union(enum) {
+        done: struct {
+            read: usize = 0,
+            wrote: usize = 0,
+        },
+        err: struct {
+            read: usize = 0,
+            wrote: usize = 0,
+            err: anyerror,
+        },
+        progress: struct {
+            read: usize = 0,
+            wrote: usize = 0,
+        },
+    };
+
+    pub fn compress(data: []const u8, algorithm: compression_algorithm, is_done: bool, writer: anytype) !StreamResult {
+        var scratch_buffer: [64 * 1024]u8 = undefined;
+
+        const scratch_buffer_size = compression_encode_scratch_buffer_size(algorithm);
+        if (scratch_buffer_size >= scratch_buffer.len) {
+            std.debug.panic("scratch buffer size is too small {d}", .{scratch_buffer_size});
+        }
+
+        var stream = try compression_stream.init(data, .ENCODE, algorithm);
+
+        defer _ = compression_stream_destroy(&stream);
+        const Iterator = struct {
+            writer: @TypeOf(writer),
+            scratch_buffer: []u8,
+            pub fn wrote(this: *@This(), w: usize) ![]u8 {
+                try this.writer.writeAll(this.scratch_buffer[0..w]);
+                return this.scratch_buffer;
+            }
+        };
+
+        var iter = Iterator{
+            .writer = writer,
+            .scratch_buffer = &scratch_buffer,
+        };
+
+        return try stream.process(data, is_done, Iterator, &iter);
+    }
+
+    pub fn decompress(data: []const u8, algorithm: compression_algorithm, is_done: bool, writer: anytype) !StreamResult {
+        var scratch_buffer: [64 * 1024]u8 = undefined;
+
+        const scratch_buffer_size = compression_decode_scratch_buffer_size(algorithm);
+        if (scratch_buffer_size >= scratch_buffer.len) {
+            std.debug.panic("scratch buffer size is too small {d}", .{scratch_buffer_size});
+        }
+
+        var stream = try compression_stream.init(data, .DECODE, algorithm);
+        defer _ = compression_stream_destroy(&stream);
+
+        const Iterator = struct {
+            writer: @TypeOf(writer),
+            scratch_buffer: []u8,
+            pub fn wrote(this: *@This(), w: usize) ![]u8 {
+                try this.writer.writeAll(this.scratch_buffer[0..w]);
+                return this.scratch_buffer;
+            }
+        };
+
+        var iter = Iterator{
+            .writer = writer,
+            .scratch_buffer = &scratch_buffer,
+        };
+
+        return try stream.process(data, is_done, Iterator, &iter);
+    }
+};
+
+pub fn main() anyerror!void {
+    try CompressionFramework.load();
+
+    var args = std.process.args();
+    const argv0 = args.next() orelse "";
+
+    const first = args.next() orelse "";
+    const second = args.next() orelse "";
+    var algorithm: ?CompressionFramework.compression_algorithm = null;
+    var operation: ?CompressionFramework.compression_stream_operation = null;
+
+    if (CompressionFramework.compression_algorithm.fromName(first)) |a| {
+        algorithm = a;
+        operation = .DECODE;
+    } else if (CompressionFramework.compression_algorithm.fromName(second)) |o| {
+        algorithm = o;
+        operation = .ENCODE;
+    }
+
+    if (algorithm == null or operation == null) {
+        try std.io.getStdErr().writer().print("to compress: {s} ./file ./out.{{br,gz,lz4,lzfse}}\nto decompress: {s} ./out.{{br,gz,lz4,lzfse}} ./out\n", .{ argv0, argv0 });
+        std.os.exit(1);
+    }
+
+    var output_file: std.fs.File = undefined;
+    var input_file: std.fs.File = undefined;
+
+    if (second.len == 0) {
+        output_file = std.io.getStdOut();
+    } else {
+        output_file = try std.fs.cwd().createFile(second, .{
+            .truncate = true,
+        });
+    }
+
+    if (first.len == 0) {
+        input_file = std.io.getStdIn();
+    } else {
+        input_file = try std.fs.cwd().openFile(first, .{});
+    }
+
+    var writer = std.io.BufferedWriter(64 * 1024, @TypeOf(output_file.writer())){
+        .unbuffered_writer = output_file.writer(),
+    };
+
+    const input_bytes = try input_file.readToEndAlloc(std.heap.c_allocator, std.math.maxInt(usize));
+
+    if (operation == .ENCODE) {
+        switch (try CompressionFramework.compress(input_bytes, algorithm.?, true, writer.writer())) {
+            .err => |err| {
+                return err.err;
+            },
+            else => {},
+        }
+    } else {
+        switch (try CompressionFramework.decompress(input_bytes, algorithm.?, true, writer.writer())) {
+            .err => |err| {
+                return err.err;
+            },
+            else => {},
+        }
+    }
+
+    try writer.flush();
+}

src/brotli.zig

@@ -0,0 +1,169 @@
+const bun = @import("root").bun;
+const std = @import("std");
+const c = @import("./deps/brotli_decoder.zig");
+const BrotliDecoder = c.BrotliDecoder;
+
+const mimalloc = bun.Mimalloc;
+
+pub fn hasBrotli() bool {
+    return BrotliDecoder.initializeBrotli();
+}
+
+const BrotliAllocator = struct {
+    pub fn alloc(_: ?*anyopaque, len: usize) callconv(.C) *anyopaque {
+        if (comptime bun.is_heap_breakdown_enabled) {
+            const zone = bun.HeapBreakdown.malloc_zone_t.get(BrotliAllocator);
+            return zone.malloc_zone_malloc(len).?;
+        }
+
+        return mimalloc.mi_malloc(len) orelse unreachable;
+    }
+
+    pub fn free(_: ?*anyopaque, data: *anyopaque) callconv(.C) void {
+        if (comptime bun.is_heap_breakdown_enabled) {
+            const zone = bun.HeapBreakdown.malloc_zone_t.get(BrotliAllocator);
+            zone.malloc_zone_free(data);
+            return;
+        }
+
+        mimalloc.mi_free(data);
+    }
+};
+
+pub const Options = struct {
+    pub const Params = std.enums.EnumFieldStruct(c.BrotliDecoderParameter, bool, false);
+
+    params: Params = Params{
+        .LARGE_WINDOW = true,
+        .DISABLE_RING_BUFFER_REALLOCATION = false,
+    },
+};
+
+pub const BrotliReaderArrayList = struct {
+    pub const State = enum {
+        Uninitialized,
+        Inflating,
+        End,
+        Error,
+    };
+
+    input: []const u8,
+    list: std.ArrayListUnmanaged(u8),
+    list_allocator: std.mem.Allocator,
+    list_ptr: *std.ArrayListUnmanaged(u8),
+    brotli: *BrotliDecoder,
+    state: State = State.Uninitialized,
+    total_out: usize = 0,
+    total_in: usize = 0,
+
+    pub usingnamespace bun.New(BrotliReaderArrayList);
+
+    pub fn initWithOptions(input: []const u8, list: *std.ArrayListUnmanaged(u8), allocator: std.mem.Allocator, options: Options) !*BrotliReaderArrayList {
+        if (!BrotliDecoder.initializeBrotli()) {
+            return error.BrotliFailedToLoad;
+        }
+
+        var brotli = BrotliDecoder.createInstance(&BrotliAllocator.alloc, &BrotliAllocator.free, null) orelse return error.BrotliFailedToCreateInstance;
+        if (options.params.LARGE_WINDOW)
+            _ = brotli.setParameter(c.BrotliDecoderParameter.LARGE_WINDOW, 1);
+        if (options.params.DISABLE_RING_BUFFER_REALLOCATION)
+            _ = brotli.setParameter(c.BrotliDecoderParameter.DISABLE_RING_BUFFER_REALLOCATION, 1);
+
+        std.debug.assert(list.items.ptr != input.ptr);
+
+        return BrotliReaderArrayList.new(
+            .{
+                .input = input,
+                .list_ptr = list,
+                .list = list.*,
+                .list_allocator = allocator,
+                .brotli = brotli,
+            },
+        );
+    }
+
+    pub fn end(this: *BrotliReaderArrayList) void {
+        this.state = .End;
+    }
+
+    pub fn readAll(this: *BrotliReaderArrayList, is_done: bool) !void {
+        defer {
+            this.list_ptr.* = this.list;
+        }
+
+        if (this.state == .End or this.state == .Error) {
+            return;
+        }
+
+        std.debug.assert(this.list.items.ptr != this.input.ptr);
+
+        while (this.state == State.Uninitialized or this.state == State.Inflating) {
+            var unused_capacity = this.list.unusedCapacitySlice();
+
+            if (unused_capacity.len < 4096) {
+                try this.list.ensureUnusedCapacity(this.list_allocator, 4096);
+                unused_capacity = this.list.unusedCapacitySlice();
+            }
+
+            std.debug.assert(unused_capacity.len > 0);
+
+            var next_in = this.input[this.total_in..];
+
+            var in_remaining = next_in.len;
+            var out_remaining = unused_capacity.len;
+
+            // https://github.com/google/brotli/blob/fef82ea10435abb1500b615b1b2c6175d429ec6c/go/cbrotli/reader.go#L15-L27
+            const result = this.brotli.decompressStream(
+                &in_remaining,
+                @ptrCast(&next_in),
+                &out_remaining,
+                @ptrCast(&unused_capacity.ptr),
+                null,
+            );
+
+            const bytes_written = unused_capacity.len -| out_remaining;
+            const bytes_read = next_in.len -| in_remaining;
+
+            this.list.items.len += bytes_written;
+            this.total_in += bytes_read;
+
+            switch (result) {
+                .success => {
+                    if (comptime bun.Environment.allow_assert) {
+                        std.debug.assert(this.brotli.isFinished());
+                    }
+
+                    this.end();
+                    return;
+                },
+                .err => {
+                    this.state = .Error;
+                    if (comptime bun.Environment.allow_assert) {
+                        const code = this.brotli.getErrorCode();
+                        bun.Output.debugWarn("Brotli error: {s} ({d})", .{ @tagName(code), @intFromEnum(code) });
+                    }
+
+                    return error.BrotliDecompressionError;
+                },
+
+                .needs_more_input => {
+                    this.state = .Inflating;
+                    if (is_done) {
+                        this.state = .Error;
+                    }
+
+                    return error.ShortRead;
+                },
+                .needs_more_output => {
+                    try this.list.ensureTotalCapacity(this.list_allocator, this.list.capacity + 4096);
+                    this.state = .Inflating;
+                },
+            }
+        }
+    }
+
+    pub fn deinit(this: *BrotliReaderArrayList) void {
+        this.brotli.destroyInstance();
+        this.destroy();
+    }
+};

src/bun.zig

@@ -2794,7 +2794,7 @@ pub noinline fn outOfMemory() noreturn {
 
 pub const is_heap_breakdown_enabled = Environment.allow_assert and Environment.isMac;
 
-const HeapBreakdown = if (is_heap_breakdown_enabled) @import("./heap_breakdown.zig") else struct {};
+pub const HeapBreakdown = if (is_heap_breakdown_enabled) @import("./heap_breakdown.zig") else struct {};
 
 /// Globally-allocate a value on the heap.
 ///
@@ -3010,3 +3010,9 @@ pub const S = if (Environment.isWindows) windows.libuv.S else std.os.S;
 
 /// Deprecated!
 pub const trait = @import("./trait.zig");
+
+pub const brotli = @import("./brotli.zig");
+
+/// macOS-only libcompression
+/// It supports brotli without needing to link to libbrotlidec
+pub const CompressionFramework = @import("./deps/libcompression.zig").CompressionFramework;

src/c.zig

@@ -380,7 +380,7 @@ const LazyStatus = enum {
     failed,
 };
 
-fn _dlsym(handle: ?*anyopaque, name: [:0]const u8) ?*anyopaque {
+pub fn _dlsym(handle: ?*anyopaque, name: [:0]const u8) ?*anyopaque {
     if (comptime Environment.isWindows) {
         return bun.windows.GetProcAddressA(handle, name);
     } else if (comptime Environment.isMac or Environment.isLinux) {

src/deps/brotli_decoder.zig

@@ -0,0 +1,322 @@
+const bun = @import("root").bun;
+const std = @import("std");
+
+pub const brotli_alloc_func = ?*const fn (?*anyopaque, usize) callconv(.C) ?*anyopaque;
+pub const brotli_free_func = ?*const fn (?*anyopaque, *anyopaque) callconv(.C) void;
+pub const struct_BrotliSharedDictionaryStruct = opaque {};
+pub const BrotliSharedDictionary = struct_BrotliSharedDictionaryStruct;
+pub const BROTLI_SHARED_DICTIONARY_RAW: c_int = 0;
+pub const BROTLI_SHARED_DICTIONARY_SERIALIZED: c_int = 1;
+pub const enum_BrotliSharedDictionaryType = c_uint;
+pub const BrotliSharedDictionaryType = enum_BrotliSharedDictionaryType;
+// pub extern fn BrotliSharedDictionaryCreateInstance(alloc_func: brotli_alloc_func, free_func: brotli_free_func, @"opaque": ?*anyopaque) ?*BrotliSharedDictionary;
+// pub extern fn BrotliSharedDictionaryDestroyInstance(dict: ?*BrotliSharedDictionary) void;
+// pub extern fn BrotliSharedDictionaryAttach(dict: ?*BrotliSharedDictionary, @"type": BrotliSharedDictionaryType, data_size: usize, data: [*]const u8) c_int;
+pub const BrotliDecoder = opaque {
+    const BrotliDecoderSetParameterFnType = fn (state: *BrotliDecoder, param: BrotliDecoderParameter, value: u32) callconv(.C) c_int;
+    const BrotliDecoderAttachDictionaryFnType = fn (state: *BrotliDecoder, @"type": BrotliSharedDictionaryType, data_size: usize, data: [*]const u8) callconv(.C) c_int;
+    const BrotliDecoderCreateInstanceFnType = fn (alloc_func: brotli_alloc_func, free_func: brotli_free_func, @"opaque": ?*anyopaque) callconv(.C) ?*BrotliDecoder;
+    const BrotliDecoderDestroyInstanceFnType = fn (state: *BrotliDecoder) callconv(.C) void;
+    const BrotliDecoderDecompressFnType = fn (encoded_size: usize, encoded_buffer: [*]const u8, decoded_size: *usize, decoded_buffer: [*]u8) callconv(.C) BrotliDecoderResult;
+    const BrotliDecoderDecompressStreamFnType = fn (state: *BrotliDecoder, available_in: *usize, next_in: *?[*]const u8, available_out: *usize, next_out: *?[*]u8, total_out: ?*usize) callconv(.C) BrotliDecoderResult;
+    const BrotliDecoderHasMoreOutputFnType = fn (state: *const BrotliDecoder) callconv(.C) c_int;
+    const BrotliDecoderTakeOutputFnType = fn (state: *BrotliDecoder, size: *usize) callconv(.C) ?[*]const u8;
+    const BrotliDecoderIsUsedFnType = fn (state: *const BrotliDecoder) callconv(.C) c_int;
+    const BrotliDecoderIsFinishedFnType = fn (state: *const BrotliDecoder) callconv(.C) c_int;
+    const BrotliDecoderGetErrorCodeFnType = fn (state: *const BrotliDecoder) callconv(.C) BrotliDecoderErrorCode;
+    const BrotliDecoderErrorStringFnType = fn (c: BrotliDecoderErrorCode) callconv(.C) ?[*:0]const u8;
+    const BrotliDecoderVersionFnType = fn () callconv(.C) u32;
+    const BrotliDecoderSetMetadataCallbacks = fn (state: *BrotliDecoder, start_func: brotli_decoder_metadata_start_func, chunk_func: brotli_decoder_metadata_chunk_func, @"opaque": ?*anyopaque) callconv(.C) void;
+    const brotli_decoder_metadata_start_func = ?*const fn (?*anyopaque, usize) callconv(.C) void;
+    const brotli_decoder_metadata_chunk_func = ?*const fn (?*anyopaque, [*]const u8, usize) callconv(.C) void;
+
+    var brotli_handle: ?*anyopaque = null;
+
+    fn loadBrotli() ?*anyopaque {
+        if (brotli_handle != null) {
+            return brotli_handle;
+        }
+
+        brotli_handle = bun.C.dlopen("brotlidec", 1) orelse brk: {
+            var arena = std.heap.ArenaAllocator.init(bun.default_allocator);
+            defer arena.deinit();
+            const output = std.ChildProcess.run(.{
+                .allocator = arena.allocator(),
+                .argv = &.{
+                    "pkg-config",
+                    "--libs",
+                    "libbrotlidec",
+                },
+                .max_output_bytes = 8192,
+            }) catch break :brk null;
+            if (!(output.term == .Exited and output.term.Exited == 0)) {
+                break :brk null;
+            }
+
+            if (!bun.strings.hasPrefixComptime(output.stdout, "-L")) {
+                break :brk null;
+            }
+
+            var lib_path = output.stdout[2..];
+            if (lib_path.len == 0) {
+                break :brk null;
+            }
+
+            if (bun.strings.indexOfChar(lib_path, ' ')) |i| {
+                lib_path = lib_path[0..i];
+            }
+
+            const absolute = std.fmt.allocPrintZ(
+                arena.allocator(),
+                "{s}" ++ std.fs.path.sep_str ++ "libbrotlidec." ++
+                    if (bun.Environment.isWindows)
+                    "dll"
+                else if (bun.Environment.isLinux)
+                    "so"
+                else
+                    "dylib",
+                .{
+                    bun.strings.withoutTrailingSlash(lib_path),
+                },
+            ) catch break :brk null;
+
+            break :brk bun.C.dlopen(absolute, 1);
+        };
+        return brotli_handle;
+    }
+
+    pub fn hasLoaded() bool {
+        return did_load_brotli orelse false;
+    }
+
+    var BrotliDecoderSetParameter: ?*const BrotliDecoderSetParameterFnType = null;
+    var BrotliDecoderAttachDictionary: ?*const BrotliDecoderAttachDictionaryFnType = null;
+    var BrotliDecoderCreateInstance: ?*const BrotliDecoderCreateInstanceFnType = null;
+    var BrotliDecoderDestroyInstance: ?*const BrotliDecoderDestroyInstanceFnType = null;
+    var BrotliDecoderDecompress: ?*const BrotliDecoderDecompressFnType = null;
+    var BrotliDecoderDecompressStream: ?*const BrotliDecoderDecompressStreamFnType = null;
+    var BrotliDecoderHasMoreOutput: ?*const BrotliDecoderHasMoreOutputFnType = null;
+    var BrotliDecoderTakeOutput: ?*const BrotliDecoderTakeOutputFnType = null;
+    var BrotliDecoderIsUsed: ?*const BrotliDecoderIsUsedFnType = null;
+    var BrotliDecoderIsFinished: ?*const BrotliDecoderIsFinishedFnType = null;
+    var BrotliDecoderGetErrorCode: ?*const BrotliDecoderGetErrorCodeFnType = null;
+    var BrotliDecoderErrorString: ?*const BrotliDecoderErrorStringFnType = null;
+    var BrotliDecoderVersion: ?*const BrotliDecoderVersionFnType = null;
+    var did_load_brotli: ?bool = null;
+
+    pub fn setParameter(state: *BrotliDecoder, param: BrotliDecoderParameter, value: u32) callconv(.C) c_int {
+        return BrotliDecoderSetParameter.?(state, param, value);
+    }
+
+    pub fn attachDictionary(state: *BrotliDecoder, @"type": BrotliSharedDictionaryType, data: []const u8) callconv(.C) c_int {
+        return BrotliDecoderAttachDictionary.?(state, @"type", data.len, data.ptr);
+    }
+
+    pub fn createInstance(alloc_func: brotli_alloc_func, free_func: brotli_free_func, @"opaque": ?*anyopaque) callconv(.C) ?*BrotliDecoder {
+        return BrotliDecoderCreateInstance.?(alloc_func, free_func, @"opaque");
+    }
+
+    pub fn destroyInstance(state: *BrotliDecoder) callconv(.C) void {
+        return BrotliDecoderDestroyInstance.?(state);
+    }
+
+    pub fn decompress(encoded: []const u8, decoded: *[]u8) callconv(.C) BrotliDecoderResult {
+        return BrotliDecoderDecompress.?(encoded.len, encoded.ptr, &decoded.len, decoded.ptr);
+    }
+
+    pub fn decompressStream(state: *BrotliDecoder, available_in: *usize, next_in: *?[*]const u8, available_out: *usize, next_out: *?[*]u8, total_out: ?*usize) callconv(.C) BrotliDecoderResult {
+        return BrotliDecoderDecompressStream.?(
+            state,
+            available_in,
+            next_in,
+            available_out,
+            next_out,
+            total_out,
+        );
+    }
+
+    pub fn hasMoreOutput(state: *const BrotliDecoder) callconv(.C) bool {
+        return BrotliDecoderHasMoreOutput.?(state) != 0;
+    }
+
+    pub fn takeOutput(state: *BrotliDecoder) callconv(.C) []const u8 {
+        var max_size: usize = std.math.maxInt(usize);
+        const ptr = BrotliDecoderTakeOutput.?(state, &max_size) orelse return "";
+        return ptr[0..max_size];
+    }
+
+    pub fn isUsed(state: *const BrotliDecoder) callconv(.C) bool {
+        return BrotliDecoderIsUsed.?(state) != 0;
+    }
+
+    pub fn isFinished(state: *const BrotliDecoder) callconv(.C) bool {
+        return BrotliDecoderIsFinished.?(state) != 0;
+    }
+
+    pub fn getErrorCode(state: *const BrotliDecoder) callconv(.C) BrotliDecoderErrorCode {
+        return BrotliDecoderGetErrorCode.?(state);
+    }
+
+    pub fn errorString(c: BrotliDecoderErrorCode) callconv(.C) [:0]const u8 {
+        return bun.sliceTo(BrotliDecoderErrorString.?(c) orelse "", 0);
+    }
+
+    pub fn version() callconv(.C) u32 {
+        return BrotliDecoderVersion.?();
+    }
+
+    pub fn initializeBrotli() bool {
+        if (did_load_brotli) |did| {
+            return did;
+        }
+
+        defer {
+            if (comptime bun.Environment.isDebug) {
+                if (did_load_brotli) |did| {
+                    if (!did) {
+                        bun.Output.debugWarn("failed to load Brotli", .{});
+                    }
+                }
+            }
+        }
+
+        const handle = loadBrotli() orelse {
+            did_load_brotli = false;
+            return false;
+        };
+
+        BrotliDecoderSetParameter = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderSetParameter") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderAttachDictionary = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderAttachDictionary") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderCreateInstance = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderCreateInstance") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderDestroyInstance = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderDestroyInstance") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderDecompress = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderDecompress") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderDecompressStream = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderDecompressStream") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderHasMoreOutput = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderHasMoreOutput") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderTakeOutput = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderTakeOutput") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderIsUsed = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderIsUsed") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderIsFinished = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderIsFinished") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderGetErrorCode = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderGetErrorCode") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderErrorString = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderErrorString") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+        BrotliDecoderVersion = @alignCast(@ptrCast(bun.C._dlsym(handle, "BrotliDecoderVersion") orelse {
+            did_load_brotli = false;
+            return false;
+        }));
+
+        return true;
+    }
+};
+pub const BrotliDecoderResult = enum(c_uint) {
+    err = 0,
+    success = 1,
+    needs_more_input = 2,
+    needs_more_output = 3,
+};
+pub const BROTLI_DECODER_NO_ERROR: c_int = 0;
+pub const BROTLI_DECODER_SUCCESS: c_int = 1;
+pub const BROTLI_DECODER_NEEDS_MORE_INPUT: c_int = 2;
+pub const BROTLI_DECODER_NEEDS_MORE_OUTPUT: c_int = 3;
+pub const BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_NIBBLE: c_int = -1;
+pub const BROTLI_DECODER_ERROR_FORMAT_RESERVED: c_int = -2;
+pub const BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_META_NIBBLE: c_int = -3;
+pub const BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET: c_int = -4;
+pub const BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_SAME: c_int = -5;
+pub const BROTLI_DECODER_ERROR_FORMAT_CL_SPACE: c_int = -6;
+pub const BROTLI_DECODER_ERROR_FORMAT_HUFFMAN_SPACE: c_int = -7;
+pub const BROTLI_DECODER_ERROR_FORMAT_CONTEXT_MAP_REPEAT: c_int = -8;
+pub const BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_1: c_int = -9;
+pub const BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_2: c_int = -10;
+pub const BROTLI_DECODER_ERROR_FORMAT_TRANSFORM: c_int = -11;
+pub const BROTLI_DECODER_ERROR_FORMAT_DICTIONARY: c_int = -12;
+pub const BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS: c_int = -13;
+pub const BROTLI_DECODER_ERROR_FORMAT_PADDING_1: c_int = -14;
+pub const BROTLI_DECODER_ERROR_FORMAT_PADDING_2: c_int = -15;
+pub const BROTLI_DECODER_ERROR_FORMAT_DISTANCE: c_int = -16;
+pub const BROTLI_DECODER_ERROR_COMPOUND_DICTIONARY: c_int = -18;
+pub const BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET: c_int = -19;
+pub const BROTLI_DECODER_ERROR_INVALID_ARGUMENTS: c_int = -20;
+pub const BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MODES: c_int = -21;
+pub const BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS: c_int = -22;
+pub const BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MAP: c_int = -25;
+pub const BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_1: c_int = -26;
+pub const BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_2: c_int = -27;
+pub const BROTLI_DECODER_ERROR_ALLOC_BLOCK_TYPE_TREES: c_int = -30;
+pub const BROTLI_DECODER_ERROR_UNREACHABLE: c_int = -31;
+pub const BrotliDecoderErrorCode = enum(c_int) {
+    FORMAT_EXUBERANT_NIBBLE = -1,
+    FORMAT_RESERVED = -2,
+    FORMAT_EXUBERANT_META_NIBBLE = -3,
+    FORMAT_SIMPLE_HUFFMAN_ALPHABET = -4,
+    FORMAT_SIMPLE_HUFFMAN_SAME = -5,
+    FORMAT_CL_SPACE = -6,
+    FORMAT_HUFFMAN_SPACE = -7,
+    FORMAT_CONTEXT_MAP_REPEAT = -8,
+    FORMAT_BLOCK_LENGTH_1 = -9,
+    FORMAT_BLOCK_LENGTH_2 = -10,
+    FORMAT_TRANSFORM = -11,
+    FORMAT_DICTIONARY = -12,
+    FORMAT_WINDOW_BITS = -13,
+    FORMAT_PADDING_1 = -14,
+    FORMAT_PADDING_2 = -15,
+    FORMAT_DISTANCE = -16,
+    COMPOUND_DICTIONARY = -18,
+    DICTIONARY_NOT_SET = -19,
+    INVALID_ARGUMENTS = -20,
+    ALLOC_CONTEXT_MODES = -21,
+    ALLOC_TREE_GROUPS = -22,
+    ALLOC_CONTEXT_MAP = -25,
+    ALLOC_RING_BUFFER_1 = -26,
+    ALLOC_RING_BUFFER_2 = -27,
+    ALLOC_BLOCK_TYPE_TREES = -30,
+    UNREACHABLE = -31,
+};
+pub const BROTLI_DECODER_PARAM_DISABLE_RING_BUFFER_REALLOCATION: c_int = 0;
+pub const BROTLI_DECODER_PARAM_LARGE_WINDOW: c_int = 1;
+pub const BrotliDecoderParameter = enum(c_uint) {
+    DISABLE_RING_BUFFER_REALLOCATION = 0,
+    LARGE_WINDOW = 1,
+};
+
+pub const BROTLI_UINT32_MAX = ~@import("std").zig.c_translation.cast(u32, @as(c_int, 0));
+pub const BROTLI_SIZE_MAX = ~@import("std").zig.c_translation.cast(usize, @as(c_int, 0));
+pub const SHARED_BROTLI_MIN_DICTIONARY_WORD_LENGTH = @as(c_int, 4);
+pub const SHARED_BROTLI_MAX_DICTIONARY_WORD_LENGTH = @as(c_int, 31);
+pub const SHARED_BROTLI_NUM_DICTIONARY_CONTEXTS = @as(c_int, 64);
+pub const SHARED_BROTLI_MAX_COMPOUND_DICTS = @as(c_int, 15);
+pub const BROTLI_LAST_ERROR_CODE = BROTLI_DECODER_ERROR_UNREACHABLE;
+pub const BrotliSharedDictionaryStruct = struct_BrotliSharedDictionaryStruct;

src/deps/libcompression.zig

@@ -0,0 +1,400 @@
+const std = @import("std");
+const bun = @import("root").bun;
+
+fn macOSOnly() noreturn {
+    @panic("CompressionFramework is only available on macOS. This code should not be reachable.");
+}
+
+/// https://developer.apple.com/documentation/compression?language=objc
+/// We only use this for Brotli on macOS, to avoid linking in libbrotli.
+///
+/// Note: this doesn't seem to work for gzip.
+pub const CompressionFramework = struct {
+    var handle: ?*anyopaque = null;
+
+    pub fn isAvailable() bool {
+        if (comptime !bun.Environment.isMac) {
+            return false;
+        }
+        const cached_value = struct {
+            pub var value: ?bool = null;
+        };
+
+        if (cached_value.value == null) {
+            if (bun.getenvZ("BUN_DISABLE_COMPRESSION_FRAMEWORK") != null) {
+                cached_value.value = false;
+                return false;
+            }
+
+            cached_value.value = CompressionFramework.load();
+        }
+
+        return cached_value.value.?;
+    }
+
+    pub fn load() bool {
+        if (comptime !bun.Environment.isMac) {
+            return false;
+        }
+        if (handle != null) {
+            return true;
+        }
+        handle = std.os.darwin.dlopen("libcompression.dylib", 1);
+
+        if (handle == null)
+            return false;
+
+        compression_encode_scratch_buffer_size = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_encode_scratch_buffer_size") orelse return false));
+        compression_encode_buffer = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_encode_buffer") orelse return false));
+        compression_decode_scratch_buffer_size = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_decode_scratch_buffer_size") orelse return false));
+        compression_decode_buffer = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_decode_buffer") orelse return false));
+        compression_stream_init = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_stream_init") orelse return false));
+        compression_stream_process = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_stream_process") orelse return false));
+        compression_stream_destroy = @alignCast(@ptrCast(std.c.dlsym(handle, "compression_stream_destroy") orelse return false));
+
+        return true;
+    }
+
+    pub const compression_algorithm = enum(c_uint) {
+        LZ4 = 256,
+        ZLIB = 0x205,
+        LZMA = 774,
+        LZ4_RAW = 257,
+        BROTLI = 2818,
+        LZFSE = 2049,
+        LZBITMAP = 1794,
+
+        pub fn fromName(name: []const u8) ?compression_algorithm {
+            if (std.mem.endsWith(u8, name, ".br")) {
+                return .BROTLI;
+            } else if (std.mem.endsWith(u8, name, ".lz4")) {
+                return .LZ4;
+            } else if (std.mem.endsWith(u8, name, ".lzma")) {
+                return .LZMA;
+            } else if (std.mem.endsWith(u8, name, ".lzfse")) {
+                return .LZFSE;
+            } else if (std.mem.endsWith(u8, name, ".zlib") or std.mem.endsWith(u8, name, ".gz")) {
+                return .ZLIB;
+            } else {
+                return null;
+            }
+        }
+    };
+    const compression_encode_scratch_buffer_size_type = fn (algorithm: compression_algorithm) callconv(.C) usize;
+    const compression_encode_buffer_type = fn (noalias dst_buffer: [*]u8, dst_size: usize, noalias src_buffer: ?[*]const u8, src_size: usize, noalias scratch_buffer: ?*anyopaque, algorithm: compression_algorithm) callconv(.C) usize;
+    const compression_decode_scratch_buffer_size_type = fn (algorithm: compression_algorithm) callconv(.C) usize;
+    const compression_decode_buffer_type = fn (noalias dst_buffer: [*]u8, dst_size: usize, noalias src_buffer: ?[*]const u8, src_size: usize, noalias scratch_buffer: ?*anyopaque, algorithm: compression_algorithm) callconv(.C) usize;
+
+    const compression_stream_init_type = fn (stream: *compression_stream, operation: compression_stream_operation, algorithm: compression_algorithm) callconv(.C) compression_status;
+    const compression_stream_process_type = fn (stream: *compression_stream, flags: c_int) callconv(.C) compression_status;
+    const compression_stream_destroy_type = fn (stream: *compression_stream) callconv(.C) compression_status;
+
+    var compression_encode_scratch_buffer_size: *const compression_encode_scratch_buffer_size_type = undefined;
+    var compression_encode_buffer: *const compression_encode_buffer_type = undefined;
+    var compression_decode_scratch_buffer_size: *const compression_decode_scratch_buffer_size_type = undefined;
+    var compression_decode_buffer: *const compression_decode_buffer_type = undefined;
+
+    var compression_stream_init: *const compression_stream_init_type = undefined;
+    var compression_stream_process: *const compression_stream_process_type = undefined;
+    var compression_stream_destroy: *const compression_stream_destroy_type = undefined;
+    pub const compression_stream = extern struct {
+        dst_ptr: ?[*]u8 = null,
+        dst_size: usize = 0,
+        src_ptr: ?[*]const u8 = null,
+        src_size: usize = 0,
+        state: ?*anyopaque = null,
+
+        pub fn init(src: []const u8, operation: compression_stream_operation, algorithm: compression_algorithm) !compression_stream {
+            var stream = compression_stream{
+                .src_ptr = src.ptr,
+                .src_size = src.len,
+                .dst_ptr = null,
+                .dst_size = 0,
+            };
+
+            switch (compression_stream_init(&stream, operation, algorithm)) {
+                .OK => {},
+                .ERROR => return error.@"failed to initialize compression stream",
+                .END => return error.@"compression stream init returned END",
+            }
+
+            return stream;
+        }
+
+        pub fn deinit(this: *compression_stream) void {
+            if (comptime !bun.Environment.isMac) {
+                macOSOnly();
+            }
+
+            _ = compression_stream_destroy(this);
+        }
+
+        pub fn process(stream: *compression_stream, data: []const u8, is_done: bool, comptime Iterator: type, iter: *Iterator) !StreamResult {
+            if (comptime !bun.Environment.isMac) {
+                macOSOnly();
+            }
+            stream.src_ptr = data.ptr;
+            stream.src_size = data.len;
+
+            const initial_dest = try iter.wrote(0);
+            stream.dst_ptr = initial_dest.ptr;
+            stream.dst_size = initial_dest.len;
+
+            var total_written: usize = 0;
+            while (true) {
+                var flags: c_int = 0;
+                if (stream.src_size == 0 and is_done) {
+                    flags = COMPRESSION_STREAM_FINALIZE;
+                } else if (stream.src_size == 0) {
+                    return .{
+                        .progress = .{
+                            .read = data.len - stream.src_size,
+                            .wrote = total_written,
+                        },
+                    };
+                }
+
+                const prev_size = stream.dst_size;
+                const rc = compression_stream_process(stream, flags);
+                const wrote = prev_size - stream.dst_size;
+                switch (rc) {
+                    .OK => {
+                        const new_buffer = try iter.wrote(wrote);
+                        stream.dst_ptr = new_buffer.ptr;
+                        stream.dst_size = new_buffer.len;
+                        total_written += wrote;
+                    },
+                    .END => {
+                        _ = try iter.wrote(wrote);
+                        total_written += wrote;
+
+                        return .{
+                            .done = .{
+                                .read = data.len - stream.src_size,
+                                .wrote = total_written,
+                            },
+                        };
+                    },
+                    .ERROR => {
+                        return .{
+                            .err = .{
+                                .err = error.@"failed to process compression stream",
+                                .read = data.len - stream.src_size,
+                                .wrote = total_written,
+                            },
+                        };
+                    },
+                }
+            }
+        }
+    };
+    pub const COMPRESSION_STREAM_ENCODE: c_int = 0;
+    pub const COMPRESSION_STREAM_DECODE: c_int = 1;
+    pub const compression_stream_operation = enum(c_uint) {
+        ENCODE = 0,
+        DECODE = 1,
+    };
+    pub const COMPRESSION_STREAM_FINALIZE: c_int = 1;
+    pub const compression_stream_flags = c_uint;
+    pub const compression_status = enum(c_int) {
+        OK = 0,
+        ERROR = -1,
+        END = 1,
+    };
+
+    const StreamResult = union(enum) {
+        done: struct {
+            read: usize = 0,
+            wrote: usize = 0,
+        },
+        err: struct {
+            read: usize = 0,
+            wrote: usize = 0,
+            err: anyerror,
+        },
+        progress: struct {
+            read: usize = 0,
+            wrote: usize = 0,
+        },
+    };
+
+    pub fn compress(data: []const u8, algorithm: compression_algorithm, is_done: bool, writer: anytype) !StreamResult {
+        if (comptime !bun.Environment.isMac) {
+            macOSOnly();
+        }
+
+        var scratch_buffer: [64 * 1024]u8 = undefined;
+
+        const scratch_buffer_size = compression_encode_scratch_buffer_size(algorithm);
+        if (scratch_buffer_size >= scratch_buffer.len) {
+            std.debug.panic("scratch buffer size is too small {d}", .{scratch_buffer_size});
+        }
+
+        var stream = try compression_stream.init(data, .ENCODE, algorithm);
+
+        defer _ = compression_stream_destroy(&stream);
+        const Iterator = struct {
+            writer: @TypeOf(writer),
+            scratch_buffer: []u8,
+            pub fn wrote(this: *@This(), w: usize) ![]u8 {
+                try this.writer.writeAll(this.scratch_buffer[0..w]);
+                return this.scratch_buffer;
+            }
+        };
+
+        var iter = Iterator{
+            .writer = writer,
+            .scratch_buffer = &scratch_buffer,
+        };
+
+        return try stream.process(data, is_done, Iterator, &iter);
+    }
+
+    pub fn decompress(data: []const u8, algorithm: compression_algorithm, is_done: bool, writer: anytype) !StreamResult {
+        if (comptime !bun.Environment.isMac) {
+            macOSOnly();
+        }
+
+        var scratch_buffer: [64 * 1024]u8 = undefined;
+
+        const scratch_buffer_size = compression_decode_scratch_buffer_size(algorithm);
+        if (scratch_buffer_size >= scratch_buffer.len) {
+            std.debug.panic("scratch buffer size is too small {d}", .{scratch_buffer_size});
+        }
+
+        var stream = try compression_stream.init(data, .DECODE, algorithm);
+        defer _ = compression_stream_destroy(&stream);
+
+        const Iterator = struct {
+            writer: @TypeOf(writer),
+            scratch_buffer: []u8,
+            pub fn wrote(this: *@This(), w: usize) ![]u8 {
+                try this.writer.writeAll(this.scratch_buffer[0..w]);
+                return this.scratch_buffer;
+            }
+        };
+
+        var iter = Iterator{
+            .writer = writer,
+            .scratch_buffer = &scratch_buffer,
+        };
+
+        return try stream.process(data, is_done, Iterator, &iter);
+    }
+
+    pub const DecompressionArrayList = struct {
+        pub const State = enum {
+            Uninitialized,
+            Inflating,
+            End,
+            Error,
+        };
+
+        input: []const u8,
+        list: std.ArrayListUnmanaged(u8),
+        list_allocator: std.mem.Allocator,
+        list_ptr: *std.ArrayListUnmanaged(u8),
+        stream: CompressionFramework.compression_stream,
+        state: State = State.Uninitialized,
+        total_out: usize = 0,
+        total_in: usize = 0,
+        total_read: usize = 0,
+
+        pub usingnamespace bun.New(DecompressionArrayList);
+
+        pub fn initWithOptions(input: []const u8, list: *std.ArrayListUnmanaged(u8), allocator: std.mem.Allocator, algorithm: CompressionFramework.compression_algorithm) !*DecompressionArrayList {
+            if (comptime !bun.Environment.isMac) {
+                macOSOnly();
+            }
+
+            if (!CompressionFramework.load()) {
+                return error.CompressionFrameworkFailedToLoad;
+            }
+
+            const stream = try CompressionFramework.compression_stream.init(input, .DECODE, algorithm);
+            std.debug.assert(list.items.ptr != input.ptr);
+
+            return DecompressionArrayList.new(
+                .{
+                    .input = input,
+                    .list_ptr = list,
+                    .list = list.*,
+                    .list_allocator = allocator,
+                    .stream = stream,
+                },
+            );
+        }
+
+        pub fn deinit(this: *DecompressionArrayList) void {
+            this.stream.deinit();
+            this.destroy();
+        }
+
+        pub fn readAll(this: *DecompressionArrayList, is_done: bool) !void {
+            if (this.state == State.End or this.state == State.Error or this.input.len == 0) {
+                return;
+            }
+            defer this.list_ptr.* = this.list;
+
+            var scratch_buffer = this.list.unusedCapacitySlice();
+
+            if (scratch_buffer.len < 4096) {
+                try this.list.ensureUnusedCapacity(this.list_allocator, 4096);
+                scratch_buffer = this.list.unusedCapacitySlice();
+            }
+
+            const Iterator = struct {
+                list: *std.ArrayListUnmanaged(u8),
+                scratch_buffer: []u8,
+                list_allocator: std.mem.Allocator,
+                pub fn wrote(i: *@This(), w: usize) ![]u8 {
+                    i.list.items.len += w;
+                    i.scratch_buffer = i.list.unusedCapacitySlice();
+
+                    if (i.scratch_buffer.len < 4096) {
+                        try i.list.ensureUnusedCapacity(i.list_allocator, 4096);
+                    }
+
+                    i.scratch_buffer = i.list.unusedCapacitySlice();
+
+                    return i.scratch_buffer;
+                }
+            };
+
+            var iter = Iterator{
+                .list = &this.list,
+                .list_allocator = this.list_allocator,
+                .scratch_buffer = scratch_buffer,
+            };
+
+            const result = try CompressionFramework.compression_stream.process(&this.stream, this.input, is_done, Iterator, &iter);
+            switch (result) {
+                .done => |done| {
+                    this.total_out += done.wrote;
+                    this.total_in += done.read;
+
+                    this.state = State.End;
+                    return;
+                },
+                .err => |*err| {
+                    this.state = State.Error;
+                    this.total_out += err.wrote;
+                    this.total_in += err.read;
+
+                    return err.err;
+                },
+                .progress => |*progress| {
+                    this.total_out += progress.wrote;
+                    this.total_in += progress.read;
+                    this.total_read += progress.read;
+
+                    if (progress.read < this.input.len) {
+                        return error.ShortRead;
+                    }
+
+                    return;
+                },
+            }
+        }
+    };
+};

src/heap_breakdown.zig

@@ -3,27 +3,10 @@ const std = @import("std");
 const HeapBreakdown = @This();
 
 pub fn allocator(comptime T: type) std.mem.Allocator {
-    const Holder = struct {
-        pub var zone_t: std.atomic.Value(?*malloc_zone_t) = std.atomic.Value(?*malloc_zone_t).init(null);
-        pub var zone_t_lock: bun.Lock = bun.Lock.init();
-    };
-    const zone = Holder.zone_t.load(.Monotonic) orelse brk: {
-        Holder.zone_t_lock.lock();
-        defer Holder.zone_t_lock.unlock();
-
-        if (Holder.zone_t.load(.Monotonic)) |z| {
-            break :brk z;
-        }
-
-        const z = malloc_zone_t.create(T);
-        Holder.zone_t.store(z, .Monotonic);
-        break :brk z;
-    };
-
-    return zone.getAllocator();
+    return malloc_zone_t.get(T).getAllocator();
 }
 
-const malloc_zone_t = opaque {
+pub const malloc_zone_t = opaque {
     const Allocator = std.mem.Allocator;
     const vm_size_t = usize;
 
@@ -48,6 +31,25 @@ const malloc_zone_t = opaque {
     pub extern fn malloc_get_zone_name(zone: *malloc_zone_t) ?[*:0]const u8;
     pub extern fn malloc_zone_pressure_relief(zone: *malloc_zone_t, goal: usize) usize;
 
+    pub fn get(comptime T: type) *malloc_zone_t {
+        const Holder = struct {
+            pub var zone_t: std.atomic.Value(?*malloc_zone_t) = std.atomic.Value(?*malloc_zone_t).init(null);
+            pub var zone_t_lock: bun.Lock = bun.Lock.init();
+        };
+        return Holder.zone_t.load(.Monotonic) orelse brk: {
+            Holder.zone_t_lock.lock();
+            defer Holder.zone_t_lock.unlock();
+
+            if (Holder.zone_t.load(.Monotonic)) |z| {
+                break :brk z;
+            }
+
+            const z = malloc_zone_t.create(T);
+            Holder.zone_t.store(z, .Monotonic);
+            break :brk z;
+        };
+    }
+
     fn alignedAlloc(zone: *malloc_zone_t, len: usize, alignment: usize) ?[*]u8 {
         // The posix_memalign only accepts alignment values that are a
         // multiple of the pointer size

src/http.zig

@@ -21,6 +21,7 @@ const Api = @import("./api/schema.zig").Api;
 const Lock = @import("./lock.zig").Lock;
 const HTTPClient = @This();
 const Zlib = @import("./zlib.zig");
+const Brotli = bun.brotli;
 const StringBuilder = @import("./string_builder.zig");
 const ThreadPool = bun.ThreadPool;
 const ObjectPool = @import("./pool.zig").ObjectPool;
@@ -45,7 +46,7 @@ var dead_socket = @as(*DeadSocket, @ptrFromInt(1));
 //TODO: this needs to be freed when Worker Threads are implemented
 var socket_async_http_abort_tracker = std.AutoArrayHashMap(u32, *uws.Socket).init(bun.default_allocator);
 var async_http_id: std.atomic.Value(u32) = std.atomic.Value(u32).init(0);
-
+const MAX_REDIRECT_URL_LENGTH = 128 * 1024;
 const print_every = 0;
 var print_every_i: usize = 0;
 
@@ -114,6 +115,16 @@ pub const HTTPRequestBody = union(enum) {
     }
 };
 
+pub fn canUseBrotli() bool {
+    if (Environment.isMac) {
+        if (bun.CompressionFramework.isAvailable()) {
+            return true;
+        }
+    }
+
+    return bun.brotli.hasBrotli();
+}
+
 pub const Sendfile = struct {
     fd: bun.FileDescriptor,
     remain: usize = 0,
@@ -1194,6 +1205,130 @@ pub const CertificateInfo = struct {
     }
 };
 
+const Decompressor = union(enum) {
+    zlib: *Zlib.ZlibReaderArrayList,
+    brotli: *Brotli.BrotliReaderArrayList,
+    CompressionFramework: *bun.CompressionFramework.DecompressionArrayList,
+    none: void,
+
+    pub fn deinit(this: *Decompressor) void {
+        switch (this.*) {
+            inline .brotli, .CompressionFramework, .zlib => |that| {
+                that.deinit();
+                this.* = .{ .none = {} };
+            },
+            .none => {},
+        }
+    }
+
+    pub fn updateBuffers(this: *Decompressor, encoding: Encoding, buffer: []const u8, body_out_str: *MutableString) !void {
+        if (!encoding.isCompressed()) {
+            return;
+        }
+
+        if (this.* == .none) {
+            switch (encoding) {
+                .gzip, .deflate => {
+                    this.* = .{
+                        .zlib = try Zlib.ZlibReaderArrayList.initWithOptionsAndListAllocator(
+                            buffer,
+                            &body_out_str.list,
+                            body_out_str.allocator,
+                            default_allocator,
+                            .{
+                                // zlib.MAX_WBITS = 15
+                                // to (de-)compress deflate format, use wbits = -zlib.MAX_WBITS
+                                // to (de-)compress deflate format with headers we use wbits = 0 (we can detect the first byte using 120)
+                                // to (de-)compress gzip format, use wbits = zlib.MAX_WBITS | 16
+                                .windowBits = if (encoding == Encoding.gzip) Zlib.MAX_WBITS | 16 else (if (buffer.len > 1 and buffer[0] == 120) 0 else -Zlib.MAX_WBITS),
+                            },
+                        ),
+                    };
+                    return;
+                },
+                .brotli => {
+                    if (bun.CompressionFramework.isAvailable()) {
+                        this.* = .{
+                            .CompressionFramework = try bun.CompressionFramework.DecompressionArrayList.initWithOptions(
+                                buffer,
+                                &body_out_str.list,
+                                body_out_str.allocator,
+                                .BROTLI,
+                            ),
+                        };
+                    } else {
+                        this.* = .{
+                            .brotli = try Brotli.BrotliReaderArrayList.initWithOptions(
+                                buffer,
+                                &body_out_str.list,
+                                body_out_str.allocator,
+                                .{},
+                            ),
+                        };
+                    }
+
+                    return;
+                },
+                else => @panic("Invalid encoding. This code should not be reachable"),
+            }
+        }
+
+        switch (this.*) {
+            .zlib => |reader| {
+                std.debug.assert(reader.zlib.avail_in == 0);
+                reader.zlib.next_in = buffer.ptr;
+                reader.zlib.avail_in = @as(u32, @truncate(buffer.len));
+
+                const initial = body_out_str.list.items.len;
+                body_out_str.list.expandToCapacity();
+                if (body_out_str.list.capacity == initial) {
+                    try body_out_str.list.ensureUnusedCapacity(body_out_str.allocator, 4096);
+                    body_out_str.list.expandToCapacity();
+                }
+                reader.list = body_out_str.list;
+                reader.zlib.next_out = @ptrCast(&body_out_str.list.items[initial]);
+                reader.zlib.avail_out = @as(u32, @truncate(body_out_str.list.capacity - initial));
+                // we reset the total out so we can track how much we decompressed this time
+                reader.zlib.total_out = @truncate(initial);
+            },
+            .brotli => |reader| {
+                reader.input = buffer;
+                reader.total_in = @as(u32, @truncate(buffer.len));
+
+                const initial = body_out_str.list.items.len;
+                reader.list = body_out_str.list;
+                reader.total_out = @truncate(initial);
+            },
+            .CompressionFramework => |reader| {
+                if (comptime !Environment.isMac) {
+                    @panic("CompressionFramework is not supported on this platform. This code should not be reachable");
+                }
+
+                reader.input = buffer;
+                reader.total_in = @as(u32, @truncate(buffer.len));
+
+                const initial = body_out_str.list.items.len;
+
+                reader.list = body_out_str.list;
+                reader.total_out = @truncate(initial);
+            },
+            else => @panic("Invalid encoding. This code should not be reachable"),
+        }
+    }
+
+    pub fn readAll(this: *Decompressor, is_done: bool) !void {
+        switch (this.*) {
+            .zlib => |zlib| try zlib.readAll(),
+            .brotli => |brotli| try brotli.readAll(is_done),
+            .CompressionFramework => |framework| if (!bun.Environment.isMac)
+                unreachable
+            else
+                try framework.readAll(is_done),
+            .none => {},
+        }
+    }
+};
+
 pub const InternalState = struct {
     response_message_buffer: MutableString = undefined,
     /// pending response is the temporary storage for the response headers, url and status code
@@ -1214,7 +1349,7 @@ pub const InternalState = struct {
     encoding: Encoding = Encoding.identity,
     content_encoding_i: u8 = std.math.maxInt(u8),
     chunked_decoder: picohttp.phr_chunked_decoder = .{},
-    zlib_reader: ?*Zlib.ZlibReaderArrayList = null,
+    decompressor: Decompressor = .{ .none = {} },
     stage: Stage = Stage.pending,
     /// This is owned by the user and should not be freed here
     body_out_str: ?*MutableString = null,
@@ -1251,10 +1386,7 @@ pub const InternalState = struct {
 
         const body_msg = this.body_out_str;
         if (body_msg) |body| body.reset();
-        if (this.zlib_reader) |reader| {
-            this.zlib_reader = null;
-            reader.deinit();
-        }
+        this.decompressor.deinit();
 
         // just in case we check and free to avoid leaks
         if (this.cloned_metadata != null) {
@@ -1279,14 +1411,11 @@ pub const InternalState = struct {
     }
 
     pub fn getBodyBuffer(this: *InternalState) *MutableString {
-        switch (this.encoding) {
-            Encoding.gzip, Encoding.deflate => {
-                return &this.compressed_body;
-            },
-            else => {
-                return this.body_out_str.?;
-            },
+        if (this.encoding.isCompressed()) {
+            return &this.compressed_body;
         }
+
+        return this.body_out_str.?;
     }
 
     fn isDone(this: *InternalState) bool {
@@ -1302,54 +1431,19 @@ pub const InternalState = struct {
         return this.received_last_chunk;
     }
 
-    fn decompressConst(this: *InternalState, buffer: []const u8, body_out_str: *MutableString) !void {
+    fn decompressBytes(this: *InternalState, buffer: []const u8, body_out_str: *MutableString) !void {
         log("Decompressing {d} bytes\n", .{buffer.len});
-        std.debug.assert(!body_out_str.owns(buffer));
+
         defer this.compressed_body.reset();
         var gzip_timer: std.time.Timer = undefined;
 
         if (extremely_verbose)
             gzip_timer = std.time.Timer.start() catch @panic("Timer failure");
 
-        var reader: *Zlib.ZlibReaderArrayList = undefined;
-        if (this.zlib_reader) |current_reader| {
-            std.debug.assert(current_reader.zlib.avail_in == 0);
-            reader = current_reader;
-            reader.zlib.next_in = buffer.ptr;
-            reader.zlib.avail_in = @as(u32, @truncate(buffer.len));
-
-            const initial = body_out_str.list.items.len;
-            body_out_str.list.expandToCapacity();
-            if (body_out_str.list.capacity == initial) {
-                try body_out_str.list.ensureUnusedCapacity(body_out_str.allocator, 4096);
-                body_out_str.list.expandToCapacity();
-            }
-            reader.list = body_out_str.list;
-            reader.zlib.next_out = @ptrCast(&body_out_str.list.items[initial]);
-            reader.zlib.avail_out = @as(u32, @truncate(body_out_str.list.capacity - initial));
-            // we reset the total out so we can track how much we decompressed this time
-            reader.zlib.total_out = @truncate(initial);
-        } else {
-            reader = try Zlib.ZlibReaderArrayList.initWithOptionsAndListAllocator(
-                buffer,
-                &body_out_str.list,
-                body_out_str.allocator,
-                default_allocator,
-                .{
-                    // TODO: add br support today we support gzip and deflate only
-                    // zlib.MAX_WBITS = 15
-                    // to (de-)compress deflate format, use wbits = -zlib.MAX_WBITS
-                    // to (de-)compress deflate format with headers we use wbits = 0 (we can detect the first byte using 120)
-                    // to (de-)compress gzip format, use wbits = zlib.MAX_WBITS | 16
-                    .windowBits = if (this.encoding == Encoding.gzip) Zlib.MAX_WBITS | 16 else (if (buffer.len > 1 and buffer[0] == 120) 0 else -Zlib.MAX_WBITS),
-                },
-            );
-            this.zlib_reader = reader;
-        }
-
-        reader.readAll() catch |err| {
+        try this.decompressor.updateBuffers(this.encoding, buffer, body_out_str);
+        this.decompressor.readAll(this.isDone()) catch |err| {
             if (this.isDone() or error.ShortRead != err) {
-                Output.prettyErrorln("<r><red>Zlib error: {s}<r>", .{bun.asByteSlice(@errorName(err))});
+                Output.prettyErrorln("<r><red>Decompression error: {s}<r>", .{bun.asByteSlice(@errorName(err))});
                 Output.flush();
                 return err;
             }
@@ -1360,14 +1454,14 @@ pub const InternalState = struct {
     }
 
     fn decompress(this: *InternalState, buffer: MutableString, body_out_str: *MutableString) !void {
-        try this.decompressConst(buffer.list.items, body_out_str);
+        try this.decompressBytes(buffer.list.items, body_out_str);
     }
 
     pub fn processBodyBuffer(this: *InternalState, buffer: MutableString) !usize {
         var body_out_str = this.body_out_str.?;
 
         switch (this.encoding) {
-            Encoding.gzip, Encoding.deflate => {
+            Encoding.brotli, Encoding.gzip, Encoding.deflate => {
                 try this.decompress(buffer, body_out_str);
             },
             else => {
@@ -1397,7 +1491,7 @@ verbose: bool = Environment.isTest,
 remaining_redirect_count: i8 = default_redirect_count,
 allow_retry: bool = false,
 redirect_type: FetchRedirect = FetchRedirect.follow,
-redirect: ?*URLBufferPool.Node = null,
+redirect: []u8 = &.{},
 timeout: usize = 0,
 progress_node: ?*std.Progress.Node = null,
 received_keep_alive: bool = false,
@@ -1445,9 +1539,9 @@ pub fn init(
 }
 
 pub fn deinit(this: *HTTPClient) void {
-    if (this.redirect) |redirect| {
-        redirect.release();
-        this.redirect = null;
+    if (this.redirect.len > 0) {
+        bun.default_allocator.free(this.redirect);
+        this.redirect = &.{};
     }
     if (this.proxy_authorization) |auth| {
         this.allocator.free(auth);
@@ -1522,8 +1616,7 @@ pub const Encoding = enum {
 
     pub fn isCompressed(this: Encoding) bool {
         return switch (this) {
-            // we don't support brotli yet
-            .gzip, .deflate => true,
+            .brotli, .gzip, .deflate => true,
             else => false,
         };
     }
@@ -1536,8 +1629,10 @@ const connection_closing_header = picohttp.Header{ .name = "Connection", .value
 const accept_header = picohttp.Header{ .name = "Accept", .value = "*/*" };
 
 const accept_encoding_no_compression = "identity";
-const accept_encoding_compression = "gzip, deflate";
+const accept_encoding_compression = "gzip, deflate, br";
+const accept_encoding_compression_no_brotli = "gzip, deflate";
 const accept_encoding_header_compression = picohttp.Header{ .name = "Accept-Encoding", .value = accept_encoding_compression };
+const accept_encoding_header_compression_no_brotli = picohttp.Header{ .name = "Accept-Encoding", .value = accept_encoding_compression_no_brotli };
 const accept_encoding_header_no_compression = picohttp.Header{ .name = "Accept-Encoding", .value = accept_encoding_no_compression };
 
 const accept_encoding_header = if (FeatureFlags.disable_compression_in_http_client)
@@ -2052,7 +2147,12 @@ pub fn buildRequest(this: *HTTPClient, body_len: usize) picohttp.Request {
     }
 
     if (!override_accept_encoding and !this.disable_decompression) {
-        request_headers_buf[header_count] = accept_encoding_header;
+        if (canUseBrotli()) {
+            request_headers_buf[header_count] = accept_encoding_header;
+        } else {
+            request_headers_buf[header_count] = accept_encoding_header_compression_no_brotli;
+        }
+
         header_count += 1;
     }
 
@@ -2573,15 +2673,8 @@ pub fn onData(this: *HTTPClient, comptime is_ssl: bool, incoming_data: []const u
                 return;
             }
 
-            var deferred_redirect: ?*URLBufferPool.Node = null;
             const should_continue = this.handleResponseMetadata(
                 &response,
-                // If there are multiple consecutive redirects
-                // and the redirect differs in hostname
-                // the new URL buffer may point to invalid memory after
-                // this function is called
-                // That matters because for Keep Alive, the hostname must point to valid memory
-                &deferred_redirect,
             ) catch |err| {
                 if (err == error.Redirect) {
                     this.state.response_message_buffer.deinit();
@@ -2601,11 +2694,6 @@ pub fn onData(this: *HTTPClient, comptime is_ssl: bool, incoming_data: []const u
                         socket.close(0, null);
                     }
 
-                    if (deferred_redirect) |redirect| {
-                        std.debug.assert(redirect != this.redirect);
-                        // connected_url no longer points to valid memory
-                        redirect.release();
-                    }
                     this.connected_url = URL{};
                     this.doRedirect();
                     return;
@@ -3041,7 +3129,8 @@ fn handleResponseBodyFromSinglePacket(this: *HTTPClient, incoming_data: []const
             try body_buffer.growBy(@max(@as(usize, @intFromFloat(min)), 32));
         }
 
-        try this.state.decompressConst(incoming_data, body_buffer);
+        // std.debug.assert(!body_buffer.owns(b));
+        try this.state.decompressBytes(incoming_data, body_buffer);
     } else {
         try this.state.getBodyBuffer().appendSliceExact(incoming_data);
     }
@@ -3269,7 +3358,6 @@ const ShouldContinue = enum {
 pub fn handleResponseMetadata(
     this: *HTTPClient,
     response: *picohttp.Response,
-    deferred_redirect: *?*URLBufferPool.Node,
 ) !ShouldContinue {
     var location: string = "";
     var pretend_304 = false;
@@ -3298,6 +3386,9 @@ pub fn handleResponseMetadata(
                     } else if (strings.eqlComptime(header.value, "deflate")) {
                         this.state.encoding = Encoding.deflate;
                         this.state.content_encoding_i = @as(u8, @truncate(header_i));
+                    } else if (strings.eqlComptime(header.value, "br")) {
+                        this.state.encoding = Encoding.brotli;
+                        this.state.content_encoding_i = @as(u8, @truncate(header_i));
                     }
                 }
             },
@@ -3310,6 +3401,10 @@ pub fn handleResponseMetadata(
                     if (!this.disable_decompression) {
                         this.state.transfer_encoding = Encoding.deflate;
                     }
+                } else if (strings.eqlComptime(header.value, "br")) {
+                    if (!this.disable_decompression) {
+                        this.state.transfer_encoding = Encoding.brotli;
+                    }
                 } else if (strings.eqlComptime(header.value, "identity")) {
                     this.state.transfer_encoding = Encoding.identity;
                 } else if (strings.eqlComptime(header.value, "chunked")) {
@@ -3391,89 +3486,118 @@ pub fn handleResponseMetadata(
                 302, 301, 307, 308, 303 => {
                     var is_same_origin = true;
 
-                    if (strings.indexOf(location, "://")) |i| {
-                        var url_buf = URLBufferPool.get(default_allocator);
+                    {
+                        var url_arena = std.heap.ArenaAllocator.init(bun.default_allocator);
+                        defer url_arena.deinit();
+                        var fba = std.heap.stackFallback(4096, url_arena.allocator());
+                        const url_allocator = fba.get();
+                        if (strings.indexOf(location, "://")) |i| {
+                            var string_builder = bun.StringBuilder{};
 
-                        const is_protocol_relative = i == 0;
-                        const protocol_name = if (is_protocol_relative) this.url.displayProtocol() else location[0..i];
-                        const is_http = strings.eqlComptime(protocol_name, "http");
-                        if (is_http or strings.eqlComptime(protocol_name, "https")) {} else {
-                            return error.UnsupportedRedirectProtocol;
-                        }
-
-                        if ((protocol_name.len * @as(usize, @intFromBool(is_protocol_relative))) + location.len > url_buf.data.len) {
-                            return error.RedirectURLTooLong;
-                        }
-
-                        deferred_redirect.* = this.redirect;
-                        var url_buf_len = location.len;
-                        if (is_protocol_relative) {
-                            if (is_http) {
-                                url_buf.data[0.."http".len].* = "http".*;
-                                bun.copy(u8, url_buf.data["http".len..], location);
-                                url_buf_len += "http".len;
-                            } else {
-                                url_buf.data[0.."https".len].* = "https".*;
-                                bun.copy(u8, url_buf.data["https".len..], location);
-                                url_buf_len += "https".len;
+                            const is_protocol_relative = i == 0;
+                            const protocol_name = if (is_protocol_relative) this.url.displayProtocol() else location[0..i];
+                            const is_http = strings.eqlComptime(protocol_name, "http");
+                            if (is_http or strings.eqlComptime(protocol_name, "https")) {} else {
+                                return error.UnsupportedRedirectProtocol;
                             }
+
+                            if ((protocol_name.len * @as(usize, @intFromBool(is_protocol_relative))) + location.len > MAX_REDIRECT_URL_LENGTH) {
+                                return error.RedirectURLTooLong;
+                            }
+
+                            string_builder.count(location);
+
+                            if (is_protocol_relative) {
+                                if (is_http) {
+                                    string_builder.count("http");
+                                } else {
+                                    string_builder.count("https");
+                                }
+                            }
+
+                            try string_builder.allocate(url_allocator);
+
+                            if (is_protocol_relative) {
+                                if (is_http) {
+                                    _ = string_builder.append("http");
+                                } else {
+                                    _ = string_builder.append("https");
+                                }
+                            }
+
+                            _ = string_builder.append(location);
+
+                            if (comptime Environment.allow_assert)
+                                std.debug.assert(string_builder.cap == string_builder.len);
+
+                            const normalized_url = JSC.URL.hrefFromString(bun.String.fromBytes(string_builder.allocatedSlice()));
+                            defer normalized_url.deref();
+                            const normalized_url_str = try normalized_url.toOwnedSlice(bun.default_allocator);
+
+                            const new_url = URL.parse(normalized_url_str);
+                            is_same_origin = strings.eqlCaseInsensitiveASCII(strings.withoutTrailingSlash(new_url.origin), strings.withoutTrailingSlash(this.url.origin), true);
+                            this.url = new_url;
+                            this.redirect = normalized_url_str;
+                        } else if (strings.hasPrefixComptime(location, "//")) {
+                            var string_builder = bun.StringBuilder{};
+
+                            const protocol_name = this.url.displayProtocol();
+
+                            if (protocol_name.len + 1 + location.len > MAX_REDIRECT_URL_LENGTH) {
+                                return error.RedirectURLTooLong;
+                            }
+
+                            const is_http = strings.eqlComptime(protocol_name, "http");
+
+                            if (is_http) {
+                                string_builder.count("http:");
+                            } else {
+                                string_builder.count("https:");
+                            }
+
+                            string_builder.count(location);
+
+                            try string_builder.allocate(url_allocator);
+
+                            if (is_http) {
+                                _ = string_builder.append("http:");
+                            } else {
+                                _ = string_builder.append("https:");
+                            }
+
+                            _ = string_builder.append(location);
+
+                            if (comptime Environment.allow_assert)
+                                std.debug.assert(string_builder.cap == string_builder.len);
+
+                            const normalized_url = JSC.URL.hrefFromString(bun.String.fromBytes(string_builder.allocatedSlice()));
+                            defer normalized_url.deref();
+                            const normalized_url_str = try normalized_url.toOwnedSlice(bun.default_allocator);
+
+                            const new_url = URL.parse(normalized_url_str);
+                            is_same_origin = strings.eqlCaseInsensitiveASCII(strings.withoutTrailingSlash(new_url.origin), strings.withoutTrailingSlash(this.url.origin), true);
+                            this.url = new_url;
+                            this.redirect = normalized_url_str;
                         } else {
-                            bun.copy(u8, &url_buf.data, location);
+                            const original_url = this.url;
+
+                            const new_url_ = bun.JSC.URL.join(
+                                bun.String.fromBytes(original_url.href),
+                                bun.String.fromBytes(location),
+                            );
+                            defer new_url_.deref();
+
+                            if (new_url_.isEmpty()) {
+                                return error.InvalidRedirectURL;
+                            }
+
+                            const new_url = new_url_.toOwnedSlice(bun.default_allocator) catch {
+                                return error.RedirectURLTooLong;
+                            };
+                            this.url = URL.parse(new_url);
+                            is_same_origin = strings.eqlCaseInsensitiveASCII(strings.withoutTrailingSlash(this.url.origin), strings.withoutTrailingSlash(original_url.origin), true);
+                            this.redirect = new_url;
                         }
-
-                        const new_url = URL.parse(url_buf.data[0..url_buf_len]);
-                        is_same_origin = strings.eqlCaseInsensitiveASCII(strings.withoutTrailingSlash(new_url.origin), strings.withoutTrailingSlash(this.url.origin), true);
-                        this.url = new_url;
-                        this.redirect = url_buf;
-                    } else if (strings.hasPrefixComptime(location, "//")) {
-                        var url_buf = URLBufferPool.get(default_allocator);
-
-                        const protocol_name = this.url.displayProtocol();
-
-                        if (protocol_name.len + 1 + location.len > url_buf.data.len) {
-                            return error.RedirectURLTooLong;
-                        }
-
-                        deferred_redirect.* = this.redirect;
-                        var url_buf_len = location.len;
-
-                        if (strings.eqlComptime(protocol_name, "http")) {
-                            url_buf.data[0.."http:".len].* = "http:".*;
-                            bun.copy(u8, url_buf.data["http:".len..], location);
-                            url_buf_len += "http:".len;
-                        } else {
-                            url_buf.data[0.."https:".len].* = "https:".*;
-                            bun.copy(u8, url_buf.data["https:".len..], location);
-                            url_buf_len += "https:".len;
-                        }
-
-                        const new_url = URL.parse(url_buf.data[0..url_buf_len]);
-                        is_same_origin = strings.eqlCaseInsensitiveASCII(strings.withoutTrailingSlash(new_url.origin), strings.withoutTrailingSlash(this.url.origin), true);
-                        this.url = new_url;
-                        this.redirect = url_buf;
-                    } else {
-                        var url_buf = URLBufferPool.get(default_allocator);
-                        var fba = std.heap.FixedBufferAllocator.init(&url_buf.data);
-                        const original_url = this.url;
-
-                        const new_url_ = bun.JSC.URL.join(
-                            bun.String.fromUTF8(original_url.href),
-                            bun.String.fromUTF8(location),
-                        );
-                        defer new_url_.deref();
-
-                        if (new_url_.isEmpty()) {
-                            return error.InvalidRedirectURL;
-                        }
-
-                        const new_url = new_url_.toOwnedSlice(fba.allocator()) catch {
-                            return error.RedirectURLTooLong;
-                        };
-                        this.url = URL.parse(new_url);
-
-                        is_same_origin = strings.eqlCaseInsensitiveASCII(strings.withoutTrailingSlash(this.url.origin), strings.withoutTrailingSlash(original_url.origin), true);
-                        deferred_redirect.* = this.redirect;
-                        this.redirect = url_buf;
                     }
 
                     // If one of the following is true

src/output.zig

@@ -733,8 +733,10 @@ pub inline fn warn(comptime fmt: []const u8, args: anytype) void {
 
 /// Print a yellow warning message, only in debug mode
 pub inline fn debugWarn(comptime fmt: []const u8, args: anytype) void {
-    if (Environment.isDebug)
+    if (Environment.isDebug) {
         prettyErrorln("<yellow>debug warn<r><d>:<r> " ++ fmt, args);
+        flush();
+    }
 }
 
 /// Print a red error message. The first argument takes an `error_name` value, which can be either

src/zlib.zig

@@ -316,6 +316,27 @@ pub const ZlibError = error{
     ShortRead,
 };
 
+const ZlibAllocator = struct {
+    pub fn alloc(_: *anyopaque, items: uInt, len: uInt) callconv(.C) *anyopaque {
+        if (comptime bun.is_heap_breakdown_enabled) {
+            const zone = bun.HeapBreakdown.malloc_zone_t.get(ZlibAllocator);
+            return zone.malloc_zone_calloc(items, len).?;
+        }
+
+        return mimalloc.mi_calloc(items, len) orelse unreachable;
+    }
+
+    pub fn free(_: *anyopaque, data: *anyopaque) callconv(.C) void {
+        if (comptime bun.is_heap_breakdown_enabled) {
+            const zone = bun.HeapBreakdown.malloc_zone_t.get(ZlibAllocator);
+            zone.malloc_zone_free(data);
+            return;
+        }
+
+        mimalloc.mi_free(data);
+    }
+};
+
 pub const ZlibReaderArrayList = struct {
     const ZlibReader = ZlibReaderArrayList;
 
@@ -334,14 +355,6 @@ pub const ZlibReaderArrayList = struct {
     allocator: std.mem.Allocator,
     state: State = State.Uninitialized,
 
-    pub fn alloc(_: *anyopaque, items: uInt, len: uInt) callconv(.C) *anyopaque {
-        return mimalloc.mi_malloc(items * len) orelse unreachable;
-    }
-
-    pub fn free(_: *anyopaque, data: *anyopaque) callconv(.C) void {
-        mimalloc.mi_free(data);
-    }
-
     pub fn deinit(this: *ZlibReader) void {
         var allocator = this.allocator;
         this.end();
@@ -393,8 +406,8 @@ pub const ZlibReaderArrayList = struct {
             .total_out = @truncate(zlib_reader.list.items.len),
 
             .err_msg = null,
-            .alloc_func = ZlibReader.alloc,
-            .free_func = ZlibReader.free,
+            .alloc_func = ZlibAllocator.alloc,
+            .free_func = ZlibAllocator.free,
 
             .internal_state = null,
             .user_data = zlib_reader,

test/js/web/fetch/fetch.test.ts

@@ -1747,7 +1747,8 @@ describe("should handle relative location in the redirect, issue#5635", () => {
   });
 });
 
-it("should throw RedirectURLTooLong when location is too long", async () => {
+it("should allow very long redirect URLS", async () => {
+  const Location = "/" + "B".repeat(32 * 1024);
   const server = Bun.serve({
     port: 0,
     async fetch(request: Request) {
@@ -1756,7 +1757,7 @@ it("should throw RedirectURLTooLong when location is too long", async () => {
       if (url.pathname == "/redirect") {
         return new Response("redirecting", {
           headers: {
-            "Location": "B".repeat(8193),
+            Location,
           },
           status: 302,
         });
@@ -1767,17 +1768,10 @@ it("should throw RedirectURLTooLong when location is too long", async () => {
     },
   });
 
-  let err = undefined;
-  try {
-    gc();
-    const resp = await fetch(`http://${server.hostname}:${server.port}/redirect`);
-  } catch (error) {
-    gc();
-    err = error;
-  }
-  expect(err).not.toBeUndefined();
-  expect(err).toBeInstanceOf(Error);
-  expect(err.code).toStrictEqual("RedirectURLTooLong");
+  const { url, status } = await fetch(`http://${server.hostname}:${server.port}/redirect`);
+
+  expect(url).toBe(`http://${server.hostname}:${server.port}${Location}`);
+  expect(status).toBe(404);
   server.stop(true);
 });