int LZ4_compress_fast_continue()

in lib/lz4/lz4.cc [1032:1082]

• 44 lines of code
• 12 McCabe index (conditional complexity)

int LZ4_compress_fast_continue(LZ4_stream_t *LZ4_stream, const char *source, char *dest, int inputSize,
                               int maxOutputSize, int acceleration) {
    LZ4_stream_t_internal *streamPtr = (LZ4_stream_t_internal *)LZ4_stream;
    const BYTE *const dictEnd = streamPtr->dictionary + streamPtr->dictSize;

    const BYTE *smallest = (const BYTE *)source;
    if (streamPtr->initCheck) return 0; /* Uninitialized structure detected */
    if ((streamPtr->dictSize > 0) && (smallest > dictEnd)) smallest = dictEnd;
    LZ4_renormDictT(streamPtr, smallest);
    if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;

    /* Check overlapping input/dictionary space */
    {
        const BYTE *sourceEnd = (const BYTE *)source + inputSize;
        if ((sourceEnd > streamPtr->dictionary) && (sourceEnd < dictEnd)) {
            streamPtr->dictSize = (U32)(dictEnd - sourceEnd);
            if (streamPtr->dictSize > 64 KB) streamPtr->dictSize = 64 KB;
            if (streamPtr->dictSize < 4) streamPtr->dictSize = 0;
            streamPtr->dictionary = dictEnd - streamPtr->dictSize;
        }
    }

    /* prefix mode : source data follows dictionary */
    if (dictEnd == (const BYTE *)source) {
        int result;
        if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
            result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limitedOutput,
                                          byU32, withPrefix64k, dictSmall, acceleration);
        else
            result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limitedOutput,
                                          byU32, withPrefix64k, noDictIssue, acceleration);
        streamPtr->dictSize += (U32)inputSize;
        streamPtr->currentOffset += (U32)inputSize;
        return result;
    }

    /* external dictionary mode */
    {
        int result;
        if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
            result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limitedOutput,
                                          byU32, usingExtDict, dictSmall, acceleration);
        else
            result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limitedOutput,
                                          byU32, usingExtDict, noDictIssue, acceleration);
        streamPtr->dictionary = (const BYTE *)source;
        streamPtr->dictSize = (U32)inputSize;
        streamPtr->currentOffset += (U32)inputSize;
        return result;
    }
}