XZ Compression API

xz.zig provides single-call heap allocating compression, zero-allocation caller-buffer operations, and incremental streaming compressors.

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1. xz.compress

pub fn compress(allocator: std.mem.Allocator, src: []const u8, options: CompressOptions) ![]u8

Compresses the input byte slice src into a complete XZ container file.

• Parameters:
  • allocator: Memory allocator used to allocate the output buffer.
  • src: Input slice to compress.
  • options: Compression options (check, enable_bcj_x86, delta_distance, lzma2_options).
• Returns: An allocated slice containing the valid XZ stream. The caller owns this memory and must free it with allocator.free().
• Errors: OutOfMemory, InvalidOptions.

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2. xz.compressInto

pub fn compressInto(dst: []u8, src: []const u8, options: CompressOptions) !usize

Compresses src into caller-provided buffer dst with zero dynamic heap allocations.

• Parameters:
  • dst: Pre-allocated buffer provided by the caller.
  • src: Input data to compress.
  • options: Compression options.
• Returns: Number of bytes written to dst.
• Errors: OutputTooSmall.

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3. xz.compressStream

pub fn compressStream(reader: anytype, writer: anytype, options: CompressOptions) !void

Streams uncompressed data from any reader supporting .read(buf) and writes XZ container blocks to any writer supporting .writeAll(bytes).

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4. xz.StreamingCompressor

Stateful incremental block compressor for feeding blocks sequentially:

pub const StreamingCompressor = struct {
    allocator: std.mem.Allocator,
    options: CompressOptions,

    pub fn init(allocator: std.mem.Allocator, options: CompressOptions) StreamingCompressor;
    pub fn startStream(self: *StreamingCompressor, writer: anytype) !void;
    pub fn writeBlock(self: *StreamingCompressor, writer: anytype, data: []const u8) !void;
    pub fn finishStream(self: *StreamingCompressor, writer: anytype) !void;
    pub fn deinit(self: *StreamingCompressor) void;
};