Method doStreamingCompression

c++/src/Compression.cc:303–346

  }

  uint64_t ZlibCompressionStream::doStreamingCompression() {
    if (deflateReset(&strm_) != Z_OK) {
      throw CompressionError("Failed to reset inflate.");
    }

    // iterate through all blocks
    uint64_t blockId = 0;
    bool finish = false;

    do {
      if (blockId == rawInputBuffer.getBlockNumber()) {
        finish = true;
        strm_.avail_in = 0;
        strm_.next_in = nullptr;
      } else {
        auto block = rawInputBuffer.getBlock(blockId++);
        strm_.avail_in = static_cast<unsigned int>(block.size);
        strm_.next_in = reinterpret_cast<unsigned char*>(block.data);
      }

      do {
        if (outputPosition >= outputSize) {
          if (!BufferedOutputStream::Next(reinterpret_cast<void**>(&outputBuffer), &outputSize)) {
            throw CompressionError("Failed to get next output buffer from output stream.");
          }
          outputPosition = 0;
        }
        strm_.next_out = reinterpret_cast<unsigned char*>(outputBuffer + outputPosition);
        strm_.avail_out = static_cast<unsigned int>(outputSize - outputPosition);

        int ret = deflate(&strm_, finish ? Z_FINISH : Z_NO_FLUSH);
        outputPosition = outputSize - static_cast<int>(strm_.avail_out);

        if (ret == Z_STREAM_END) {
          break;
        } else if (ret == Z_OK) {
          // needs more buffer so will continue the loop
        } else {
          throw CompressionError("Failed to deflate input data.");
        }
      } while (strm_.avail_out == 0);
    } while (!finish);
    return strm_.total_out;
  }

  std::string ZlibCompressionStream::getName() const {
    return "ZlibCompressionStream";