[HADOOP-9665] BlockDecompressorStream#decompress will throw EOFException instead of return -1 when EOF

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.1.2, 2.1.0-beta, 2.3.0
• Fix Version/s: 1-win, 2.1.0-beta, 1.2.1
• Assignee: Zhijie Shen
• Reporter: Zhijie Shen
• Created: 21/Jun/13 20:43
• Updated: 28/Jan/14 23:36
• Resolved: 28/Jun/13 21:41

Description

BlockDecompressorStream#decompress ultimately calls rawReadInt, which will throw EOFException instead of return -1 when encountering end of a stream. Then, decompress will be called by read. However, InputStream#read is supposed to return -1 instead of throwing EOFException to indicate the end of a stream. This explains why in LineReader,

      if (bufferPosn >= bufferLength) {
        startPosn = bufferPosn = 0;
        if (prevCharCR)
          ++bytesConsumed; //account for CR from previous read
        bufferLength = in.read(buffer);
        if (bufferLength <= 0)
          break; // EOF
      }

-1 is checked instead of catching EOFException.

Now the problem will occur with SnappyCodec. If an input file is compressed with SnappyCodec, it needs to be decompressed through BlockDecompressorStream when it is read. Then, if it empty, EOFException will been thrown from rawReadInt and break LineReader.

Issue Links

• is related to: HADOOP-9658 SnappyCodec#checkNativeCodeLoaded may unexpectedly fail when native code is not loaded