protected void flushBuffer()

in src/main/java/org/mariadb/jdbc/internal/io/output/CompressPacketOutputStream.java [147:442]


  protected void flushBuffer(boolean commandEnd) throws IOException {
    if (pos > 0) {
      if (pos + remainingData.length > MIN_COMPRESSION_SIZE) {

        byte[] compressedBytes;
        int uncompressSize = Math.min(MAX_PACKET_LENGTH, remainingData.length + 4 + pos);
        checkMaxAllowedLength(uncompressSize);

        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
          try (DeflaterOutputStream deflater = new DeflaterOutputStream(baos)) {
            if (remainingData.length != 0) {
              deflater.write(remainingData);
            }
            subHeader[0] = (byte) pos;
            subHeader[1] = (byte) (pos >>> 8);
            subHeader[2] = (byte) (pos >>> 16);
            subHeader[3] = (byte) this.seqNo++;
            deflater.write(subHeader, 0, 4);
            deflater.write(buf, 0, uncompressSize - (remainingData.length + 4));
            deflater.finish();
          }

          compressedBytes = baos.toByteArray();

          if (compressedBytes.length < (int) (MIN_COMPRESSION_RATIO * pos)) {
            int compressedLength = compressedBytes.length;

            header[0] = (byte) compressedLength;
            header[1] = (byte) (compressedLength >>> 8);
            header[2] = (byte) (compressedLength >>> 16);
            header[3] = (byte) this.compressSeqNo++;
            header[4] = (byte) uncompressSize;
            header[5] = (byte) (uncompressSize >>> 8);
            header[6] = (byte) (uncompressSize >>> 16);
            out.write(header, 0, 7);
            out.write(compressedBytes, 0, compressedLength);
            cmdLength += uncompressSize;

            if (traceCache != null) {
              // trace last packets
              if (remainingData.length != 0) {
                traceCache.put(
                    new TraceObject(
                        true,
                        COMPRESSED_PROTOCOL_COMPRESSED_PACKET,
                        threadId,
                        Arrays.copyOfRange(header, 0, 7),
                        Arrays.copyOfRange(remainingData, 0, remainingData.length),
                        Arrays.copyOfRange(subHeader, 0, 4),
                        Arrays.copyOfRange(
                            buf,
                            0,
                            (uncompressSize > 1000 ? 1000 : uncompressSize)
                                - (remainingData.length + 4))));
              } else {
                traceCache.put(
                    new TraceObject(
                        true,
                        COMPRESSED_PROTOCOL_COMPRESSED_PACKET,
                        threadId,
                        Arrays.copyOfRange(header, 0, 7),
                        Arrays.copyOfRange(subHeader, 0, 4),
                        Arrays.copyOfRange(
                            buf,
                            0,
                            (uncompressSize > 1000 ? 1000 : uncompressSize)
                                - (remainingData.length + 4))));
              }
            }

            if (logger.isTraceEnabled()) {
              if (remainingData.length != 0) {
                logger.trace(
                    "send compress: {}{}",
                    serverThreadLog,
                    Utils.hexdump(
                        maxQuerySizeToLog - (remainingData.length + 11),
                        0,
                        compressedLength,
                        header,
                        remainingData,
                        subHeader,
                        buf));
              } else {
                logger.trace(
                    "send compress: {}{}",
                    serverThreadLog,
                    Utils.hexdump(
                        maxQuerySizeToLog - 11, 0, compressedLength, header, subHeader, buf));
              }
            }
            if (pos + remainingData.length + 4 - uncompressSize > 0) {
              remainingData =
                  Arrays.copyOfRange(buf, uncompressSize - (remainingData.length + 4), pos);
            } else {
              remainingData = EMPTY_ARRAY;
            }

            // if last packet fill the max size, must send an empty packet to indicate command end.
            lastPacketExactMaxPacketLength = pos == MAX_PACKET_LENGTH;
            if (commandEnd && lastPacketExactMaxPacketLength) {
              writeEmptyPacket();
            }
            pos = 0;
            return;
          }
        }
      }

      int uncompressSize = Math.min(MAX_PACKET_LENGTH, remainingData.length + 4 + pos);
      checkMaxAllowedLength(uncompressSize);
      cmdLength += uncompressSize;

      // send packet without compression
      header[0] = (byte) uncompressSize;
      header[1] = (byte) (uncompressSize >>> 8);
      header[2] = (byte) (uncompressSize >>> 16);
      header[3] = (byte) this.compressSeqNo++;
      header[4] = (byte) 0x00;
      header[5] = (byte) 0x00;
      header[6] = (byte) 0x00;
      out.write(header, 0, 7);

      cmdLength += uncompressSize;

      if (remainingData.length != 0) {
        out.write(remainingData);
      }
      subHeader[0] = (byte) pos;
      subHeader[1] = (byte) (pos >>> 8);
      subHeader[2] = (byte) (pos >>> 16);
      subHeader[3] = (byte) this.seqNo++;
      out.write(subHeader, 0, 4);
      out.write(buf, 0, uncompressSize - (remainingData.length + 4));
      cmdLength += remainingData.length;

      if (traceCache != null) {
        // trace last packets
        if (remainingData.length != 0) {
          traceCache.put(
              new TraceObject(
                  true,
                  COMPRESSED_PROTOCOL_NOT_COMPRESSED_PACKET,
                  threadId,
                  Arrays.copyOfRange(header, 0, 7),
                  Arrays.copyOfRange(remainingData, 0, remainingData.length),
                  Arrays.copyOfRange(subHeader, 0, 4),
                  Arrays.copyOfRange(
                      buf,
                      0,
                      (uncompressSize > 1000 ? 1000 : uncompressSize)
                          - (remainingData.length + 4))));
        } else {
          traceCache.put(
              new TraceObject(
                  true,
                  COMPRESSED_PROTOCOL_NOT_COMPRESSED_PACKET,
                  threadId,
                  Arrays.copyOfRange(header, 0, 7),
                  Arrays.copyOfRange(subHeader, 0, 4),
                  Arrays.copyOfRange(
                      buf,
                      0,
                      (uncompressSize > 1000 ? 1000 : uncompressSize)
                          - (remainingData.length + 4))));
        }
      }

      if (logger.isTraceEnabled()) {
        if (remainingData.length != 0) {
          logger.trace(
              "send uncompress: {}{}",
              serverThreadLog,
              Utils.hexdump(
                  maxQuerySizeToLog - (remainingData.length + 11),
                  0,
                  pos,
                  header,
                  remainingData,
                  subHeader,
                  buf));
        } else {
          logger.trace(
              "send uncompress: {}{}",
              serverThreadLog,
              Utils.hexdump(maxQuerySizeToLog - 11, 0, pos, header, subHeader, buf));
        }
      }

      if (pos + remainingData.length + 4 - uncompressSize > 0) {
        remainingData = Arrays.copyOfRange(buf, uncompressSize - (remainingData.length + 4), pos);
      } else {
        remainingData = EMPTY_ARRAY;
      }

      // if last packet fill the max size, must send an empty packet to indicate command end.
      lastPacketExactMaxPacketLength = pos == MAX_PACKET_LENGTH;
      pos = 0;
    }

    if (remainingData.length > 0) {
      if (remainingData.length > MIN_COMPRESSION_SIZE) {

        byte[] compressedBytes;
        int uncompressSize = Math.min(MAX_PACKET_LENGTH, remainingData.length);
        checkMaxAllowedLength(uncompressSize);
        cmdLength += uncompressSize;
        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
          try (DeflaterOutputStream deflater = new DeflaterOutputStream(baos)) {
            deflater.write(remainingData);
            deflater.finish();
          }
          compressedBytes = baos.toByteArray();
          remainingData = EMPTY_ARRAY;
        }

        if (compressedBytes.length < (int) (MIN_COMPRESSION_RATIO * pos)) {
          int compressedLength = compressedBytes.length;

          header[0] = (byte) compressedLength;
          header[1] = (byte) (compressedLength >>> 8);
          header[2] = (byte) (compressedLength >>> 16);
          header[3] = (byte) this.compressSeqNo++;
          header[4] = (byte) uncompressSize;
          header[5] = (byte) (uncompressSize >>> 8);
          header[6] = (byte) (uncompressSize >>> 16);
          out.write(header, 0, 7);
          out.write(compressedBytes, 0, compressedLength);

          if (traceCache != null) {
            traceCache.put(
                new TraceObject(
                    true,
                    COMPRESSED_PROTOCOL_COMPRESSED_PACKET,
                    threadId,
                    Arrays.copyOfRange(header, 0, 7),
                    Arrays.copyOfRange(
                        remainingData, 0, (uncompressSize > 1000 ? 1000 : uncompressSize))));
          }

          if (logger.isTraceEnabled()) {
            logger.trace(
                "send compress: {}{}",
                serverThreadLog,
                Utils.hexdump(maxQuerySizeToLog - 7, 0, uncompressSize, header, remainingData));
          }

          // if last packet fill the max size, must send an empty packet to indicate command end.
          if (commandEnd && lastPacketExactMaxPacketLength) {
            writeEmptyPacket();
          }
          return;
        }
      }

      int uncompressSize = Math.min(MAX_PACKET_LENGTH, remainingData.length);
      checkMaxAllowedLength(uncompressSize);
      cmdLength += uncompressSize;

      // send packet without compression
      header[0] = (byte) uncompressSize;
      header[1] = (byte) (uncompressSize >>> 8);
      header[2] = (byte) (uncompressSize >>> 16);
      header[3] = (byte) this.compressSeqNo++;
      header[4] = (byte) 0x00;
      header[5] = (byte) 0x00;
      header[6] = (byte) 0x00;
      out.write(header, 0, 7);

      out.write(remainingData);
      remainingData = EMPTY_ARRAY;

      if (traceCache != null) {
        traceCache.put(
            new TraceObject(
                true,
                COMPRESSED_PROTOCOL_NOT_COMPRESSED_PACKET,
                threadId,
                Arrays.copyOfRange(header, 0, 7),
                Arrays.copyOfRange(
                    remainingData,
                    0,
                    (remainingData.length > 1000 ? 1000 : remainingData.length))));
      }

      if (logger.isTraceEnabled()) {
        logger.trace(
            "send uncompress: {}{}",
            serverThreadLog,
            Utils.hexdump(maxQuerySizeToLog - 7, 0, remainingData.length, header, remainingData));
      }
      if (commandEnd && lastPacketExactMaxPacketLength) {
        writeEmptyPacket();
      }
    }
  }