Function init [src]

XZ uses a series of LZMA2 blocks which each specify a dictionary size anywhere from 4K to 4G. Thus, this API dynamically allocates the dictionary as-needed.

Prototype

pub fn init( input: *Reader, gpa: Allocator, buffer: []u8, ) !Decompress

Parameters

input: *Readergpa: Allocator

buffer: []u8Decompress takes ownership of this buffer and resizes it with gpa.

Source

  pub fn init(
    input: *Reader,
    gpa: Allocator,
    /// Decompress takes ownership of this buffer and resizes it with `gpa`.
    buffer: []u8,
) !Decompress {
    const magic = try input.takeArray(6);
    if (!std.mem.eql(u8, magic, &.{ 0xFD, '7', 'z', 'X', 'Z', 0x00 }))
        return error.NotXzStream;

    const computed_checksum = Crc32.hash(try input.peek(@sizeOf(StreamFlags)));
    const stream_flags = input.takeStruct(StreamFlags, .little) catch unreachable;
    const stored_hash = try input.takeInt(u32, .little);
    if (computed_checksum != stored_hash) return error.WrongChecksum;

    return .{
        .input = input,
        .reader = .{
            .vtable = &.{
                .stream = stream,
                .readVec = readVec,
                .discard = discard,
            },
            .buffer = buffer,
            .seek = 0,
            .end = 0,
        },
        .gpa = gpa,
        .check = stream_flags.check,
        .block_count = 0,
        .err = null,
    };
}  