Function decodeLiteralsSection [src]

Decode a LiteralsSection from src, incrementing consumed_count by the number of bytes the section uses. See decodeLiterasSectionSlice().

Prototype

pub fn decodeLiteralsSection( source: anytype, buffer: []u8, ) !LiteralsSection

Parameters

buffer: []u8

Source

  pub fn decodeLiteralsSection(
    source: anytype,
    buffer: []u8,
) !LiteralsSection {
    const header = try decodeLiteralsHeader(source);
    switch (header.block_type) {
        .raw => {
            try source.readNoEof(buffer[0..header.regenerated_size]);
            return LiteralsSection{
                .header = header,
                .huffman_tree = null,
                .streams = .{ .one = buffer },
            };
        },
        .rle => {
            buffer[0] = try source.readByte();
            return LiteralsSection{
                .header = header,
                .huffman_tree = null,
                .streams = .{ .one = buffer[0..1] },
            };
        },
        .compressed, .treeless => {
            var counting_reader = std.io.countingReader(source);
            const huffman_tree = if (header.block_type == .compressed)
                try huffman.decodeHuffmanTree(counting_reader.reader(), buffer)
            else
                null;
            const huffman_tree_size = @as(usize, @intCast(counting_reader.bytes_read));
            const total_streams_size = std.math.sub(usize, header.compressed_size.?, huffman_tree_size) catch
                return error.MalformedLiteralsSection;

            if (total_streams_size > buffer.len) return error.LiteralsBufferTooSmall;
            try source.readNoEof(buffer[0..total_streams_size]);
            const stream_data = buffer[0..total_streams_size];

            const streams = try decodeStreams(header.size_format, stream_data);
            return LiteralsSection{
                .header = header,
                .huffman_tree = huffman_tree,
                .streams = streams,
            };
        },
    }
}  