Function checkAndWriteHeader

programs/compressor/Compressor.cpp:52–70

Outputs method, sizes of uncompressed and compressed blocks for compressed file.

/// Outputs method, sizes of uncompressed and compressed blocks for compressed file.
void checkAndWriteHeader(DB::ReadBuffer & in, DB::WriteBuffer & out)
{
    while (!in.eof())
    {
        UInt32 size_compressed = {};
        UInt32 size_decompressed = {};
        auto codec = DB::getCompressionCodecForFile(in, size_compressed, size_decompressed, true /* skip_to_next_block */);

        if (size_compressed > DBMS_MAX_COMPRESSED_SIZE)
            throw DB::Exception(DB::ErrorCodes::TOO_LARGE_SIZE_COMPRESSED, "Too large size_compressed. Most likely corrupted data.");

        DB::writeText(codec->getFullCodecDesc()->formatWithSecretsOneLine(), out);
        DB::writeChar('\t', out);
        DB::writeText(size_decompressed, out);
        DB::writeChar('\t', out);
        DB::writeText(size_compressed, out);
        DB::writeChar('\n', out);
    }
}

}