void queueReadAhead()

in src/main/java/com/microsoft/azure/datalake/store/ReadBufferManager.java [102:126]

• 24 lines of code
• 6 McCabe index (conditional complexity)

    void queueReadAhead(ADLFileInputStream file, long requestedOffset, int requestedLength) {
        if (log.isTraceEnabled())
            log.trace("Start Queueing readAhead for " + file.getFilename() + " offset " + requestedOffset + " length " + requestedLength);
        ReadBuffer buffer;
        synchronized (this) {
            if (isAlreadyQueued(file, requestedOffset)) return; // already queued, do not queue again
            if (freeList.size() == 0 && !tryEvict()) return; // no buffers available, cannot queue anything

            buffer = new ReadBuffer();
            buffer.file = file;
            buffer.offset = requestedOffset;
            buffer.length = 0;
            buffer.requestedLength = requestedLength;
            buffer.status = ReadBufferStatus.NOT_AVAILABLE;
            buffer.latch = new CountDownLatch(1);
            Integer bufferIndex = freeList.pop();  // will return a value, since we have checked size > 0 already
            buffer.buffer = buffers[bufferIndex];
            buffer.bufferindex = bufferIndex;
            readAheadQueue.add(buffer);
            notifyAll();
        }
        if (log.isTraceEnabled()) {
            log.trace("Done q-ing readAhead for file " + file.getFilename() + " offset " + requestedOffset + " buffer idx " + buffer.bufferindex);
        }
    }