private void flush()

in src/main/java/com/microsoft/azure/datalake/store/ADLFileOutputStream.java [140:201]
53 lines of code
19 McCabe index (conditional complexity)

    private void flush(SyncFlag syncFlag) throws IOException {
        if (log.isTraceEnabled()) {
            log.trace("flush() with data size {} at offset {} for client {} for file {}", cursor, remoteCursor, client.getClientId(), filename);
        }
        // Ignoring this, because HBase actually calls flush after close() <sigh>
        if (streamClosed) return;
        if (cursor == 0 && (syncFlag==SyncFlag.DATA)) return;  // nothing to flush
        if (cursor == 0 && lastFlushUpdatedMetadata && syncFlag == SyncFlag.METADATA) return; // do not send a
                                                   // flush if the last flush updated metadata and there is no data
        if (cursor == 0 && syncFlag == SyncFlag.CLOSE) // For no data and syncflag.close just do close and return
        {
            closehandle();
            return;
        }
        if (buffer == null) buffer = new byte[blocksize];
        SyncFlag origsyncFlag = syncFlag;
        if(syncFlag==SyncFlag.CLOSE) // syncflag close- we will do a close separately
        {
            syncFlag = SyncFlag.DATA;
            origsyncFlag=SyncFlag.CLOSE;
        }
        RequestOptions opts = new RequestOptions();
        opts.retryPolicy = client.makeExponentialBackoffPolicy();
        opts.timeout = client.timeout + (1000 + (buffer.length / 1000 / 1000)); // 1 second grace per MB to upload
        OperationResponse resp = new OperationResponse();
        Core.append(filename, remoteCursor, buffer, 0, cursor, leaseId,
                leaseId, syncFlag, client, opts, resp);
        if (!resp.successful) {
            if (resp.numRetries > 0 && resp.httpResponseCode == 400 && "BadOffsetException".equals(resp.remoteExceptionName)) {
                // if this was a retry and we get bad offset, then this might be because we got a transient
                // failure on first try, but request succeeded on back-end. In that case, the retry would fail
                // with bad offset. To detect that, we check if there was a retry done, and if the current error we
                // have is bad offset.
                // If so, do a zero-length append at the current expected Offset, and if that succeeds,
                // then the file length must be good - swallow the error. If this append fails, then the last append
                // did not succeed and we have some other offset on server - bubble up the error.
                long expectedRemoteLength = remoteCursor + cursor;
                boolean append0Succeeded =  doZeroLengthAppend(expectedRemoteLength);
                if (append0Succeeded) {
                    log.debug("zero-length append succeeded at expected offset (" + expectedRemoteLength + "), " +
                            " ignoring BadOffsetException for session: " + leaseId + ", file: " + filename);
                    remoteCursor += cursor;
                    cursor = 0;
                    lastFlushUpdatedMetadata = false;
                    if(origsyncFlag == SyncFlag.CLOSE){
                        closehandle();
                    }
                    return;
                } else {
                    log.debug("Append failed at expected offset(" + expectedRemoteLength +
                            "). Bubbling exception up for session: " + leaseId + ", file: " + filename);
                }
            }
            throw client.getExceptionFromResponse(resp, "Error appending to file " + filename);
        }
        remoteCursor += cursor;
        cursor = 0;
        lastFlushUpdatedMetadata = (syncFlag != SyncFlag.DATA);
        if(origsyncFlag == SyncFlag.CLOSE){
            closehandle();
        }
    }