Function QuickLZCompress

library/cpp/par/compression.cpp:32–55

    }

    void QuickLZCompress(TVector<char>* dst) {
        if (!dst || dst->empty())
            return;
        TStringBuf srcdata{dst->data(), dst->size()};
        if (srcdata.size() > MIN_SIZE_TO_PACK || (srcdata.size() >= SIZEOF_SIGNATURE && *(int*)srcdata.data() == N_SIGNATURE)) {
            const ICodec* usedCodec = GetCodec();
            TVector<char> packed;
            packed.yresize(SIZEOF_SIGNATURE);
            *(int*)(packed.data()) = N_SIGNATURE;
            /* Blocking for data >2Gb as most codecs don't support such big data chunks.
               Stream format as follows:
               | signature 4 bytes | LengthOfBlock1 4 bytes | Block1 compressed data | LengthOfBlock2 4 bytes| Block2 compressed data | ... |
            */
            for (size_t i = 0; i < srcdata.size(); i += BLOCK_SIZE) {
                TStringBuf srcDataBlock{dst->data() + i, Min((size_t)(dst->size() - i), (size_t)BLOCK_SIZE)};
                size_t packedPreviousSize = packed.size();
                packed.yresize(packedPreviousSize + sizeof(TBlockLen) + usedCodec->MaxCompressedLength(srcDataBlock));
                TBlockLen packedBlockSize = usedCodec->Compress(srcDataBlock, (packed.data() + packedPreviousSize + sizeof(TBlockLen)));
                *(TBlockLen*)(packed.data() + packedPreviousSize) = packedBlockSize;
                packed.yresize(packedPreviousSize + sizeof(TBlockLen) + packedBlockSize);
            }
            dst->swap(packed);
        }
    }

    void QuickLZDecompress(TVector<char>* dst) {
        if (!dst) {