Method Decoder

runtime/Log.cc:591–622

* Decoder constructor. * * Due to the large amount of memory needed to buffer log statements, the * decoder is intended to be constructed once and then re-used via open(). */

 * decoder is intended to be constructed once and then re-used via open().
 */
Log::Decoder::Decoder()
    : filename()
    , inputFd(nullptr)
    , logMsgsPrinted(0)
    , bufferFragment(nullptr)
    , good(false)
    , checkpoint()
    , freeBuffers()
    , fmtId2metadata()
    , fmtId2fmtString()
    , rawMetadata(nullptr)
    , endOfRawMetadata(nullptr)
    , numBufferFragmentsRead(0)
    , numCheckpointsRead(0)
{
    // Take advantage of virtual memory an allocate an insanely large (1GB)
    // buffer to store log metadata read from the logFile. Such a large buffer
    // is used so that we don't have to explicitly manage the buffer and instead
    // leave it up to the virtual memory system.
    rawMetadata = static_cast<char*>(malloc(1024*1024*1024));

    if (rawMetadata == nullptr) {
        fprintf(stderr, "Could not allocate an internal 1GB buffer to store log"
                " metadata");
        exit(-1);
    }

    endOfRawMetadata = rawMetadata;
    fmtId2metadata.reserve(1000);
    fmtId2fmtString.reserve(1000);
    bufferFragment = allocateBufferFragment();
}

/**
 * Reads the metadata necessary to decompress log messsages from a log file.