Class CompressedEntry

runtime/Log.h:242–255

* Marks the beginning of a compressed log message and after this structure * comes the compressed arguments. The exact layout of the compressed * arguments is generated at compile-time (see the Python preprocessor), * but what comes immediately after this header are: * (1-4 bytes) pack()-ed FormatId * (1-8 bytes) pack()-ed rdtsc() timestamp * (0-n bytes

     *      (0-n bytes) arguments (determined by preprocessor)
     */
    struct CompressedEntry {
        // Byte representation of an EntryType::LOG_MSGS_OR_DIC to identify this
        // as a CompressedRecordEntry.
        uint8_t entryType:2;

        // Value returned by pack(formatId), subtracted by 1 to save space.
        // i.e. if pack() returned 2 this value is 1.
        // TODO(syang0) this is an abstraction failure; it's not treating
        // the value returned by pack() as a black box.
        uint8_t additionalFmtIdBytes:2;

        // Value returned by pack(timestamp)
        uint8_t additionalTimestampBytes:4;
    } __attribute__((packed));

    /**
     * Marker in the compressed log that indicates to which StagingBuffer/thread