Java Future.map方法代码示例

import com.twitter.util.Future; //导入方法依赖的package包/类
@Override
protected Future<WriteResponse> executeOp(AsyncLogWriter writer,
                                          Sequencer sequencer,
                                          Object txnLock) {
    // write a control record if heartbeat is the first request of the recovered log segment.
    if (writeControlRecord) {
        long txnId;
        Future<DLSN> writeResult;
        synchronized (txnLock) {
            txnId = sequencer.nextId();
            writeResult = ((BKAsyncLogWriter) writer).writeControlRecord(new LogRecord(txnId, HEARTBEAT_DATA));
        }
        return writeResult.map(new AbstractFunction1<DLSN, WriteResponse>() {
            @Override
            public WriteResponse apply(DLSN value) {
                return ResponseUtils.writeSuccess().setDlsn(value.serialize(dlsnVersion));
            }
        });
    } else {
        return Future.value(ResponseUtils.writeSuccess());
    }
}
 

import com.twitter.util.Future; //导入方法依赖的package包/类
@Benchmark
public String mapConstN() throws Exception {
  Future<String> f = constFuture;
  for (int i = 0; i < N.n; i++)
    f = f.map(mapF);
  return Await.result(f);
}
 

import com.twitter.util.Future; //导入方法依赖的package包/类
@Benchmark
public String mapPromiseN() throws Exception {
  Promise<String> p = new Promise<String>();
  Future<String> f = p;
  for (int i = 0; i < N.n; i++)
    f = f.map(mapF);
  p.setValue(string);
  return Await.result(f);
}
 

import com.twitter.util.Future; //导入方法依赖的package包/类
@Benchmark
public String setValueN() throws Exception {
  Promise<String> p = new Promise<String>();
  Future<String> f = p;
  for (int i = 0; i < N.n; i++)
    f = f.map(mapF);
  p.setValue(string);
  return Await.result(f);
}
 

import com.twitter.util.Future; //导入方法依赖的package包/类
synchronized protected Future<BKLogSegmentWriter> rollLogSegmentIfNecessary(
        final BKLogSegmentWriter segmentWriter,
        long startTxId,
        boolean bestEffort,
        boolean allowMaxTxID) {
    final BKLogWriteHandler writeHandler;
    try {
        writeHandler = getWriteHandler();
    } catch (IOException e) {
        return Future.exception(e);
    }
    Future<BKLogSegmentWriter> rollPromise;
    if (null != segmentWriter && (writeHandler.shouldStartNewSegment(segmentWriter) || forceRolling)) {
        rollPromise = closeOldLogSegmentAndStartNewOneWithPermit(
                segmentWriter, writeHandler, startTxId, bestEffort, allowMaxTxID);
    } else if (null == segmentWriter) {
        rollPromise = asyncStartNewLogSegment(writeHandler, startTxId, allowMaxTxID);
    } else {
        rollPromise = Future.value(segmentWriter);
    }
    return rollPromise.map(new AbstractFunction1<BKLogSegmentWriter, BKLogSegmentWriter>() {
        @Override
        public BKLogSegmentWriter apply(BKLogSegmentWriter newSegmentWriter) {
            if (segmentWriter == newSegmentWriter) {
                return newSegmentWriter;
            }
            truncateLogSegmentsIfNecessary(writeHandler);
            return newSegmentWriter;
        }
    });
}
 

import com.twitter.util.Future; //导入方法依赖的package包/类
@Override
protected Future<WriteResponse> executeOp(AsyncLogWriter writer,
                                          Sequencer sequencer,
                                          Object txnLock) {
  Future<Void> result = streamManager.createStreamAsync(streamName());
  return result.map(new AbstractFunction1<Void, WriteResponse>() {
    @Override
    public WriteResponse apply(Void value) {
      return ResponseUtils.writeSuccess();
    }
  });
}
 

import com.twitter.util.Future; //导入方法依赖的package包/类
@Override
protected Future<WriteResponse> executeOp(AsyncLogWriter writer,
                                          Sequencer sequencer,
                                          Object txnLock) {
    Future<Void> result = streamManager.deleteAndRemoveAsync(streamName());
    return result.map(new AbstractFunction1<Void, WriteResponse>() {
        @Override
        public WriteResponse apply(Void value) {
            return ResponseUtils.writeSuccess();
        }
    });
}
 

import com.twitter.util.Future; //导入方法依赖的package包/类
@Override
protected Future<WriteResponse> executeOp(AsyncLogWriter writer,
                                          Sequencer sequencer,
                                          Object txnLock) {
    if (!stream.equals(writer.getStreamName())) {
        logger.error("Write: Stream Name Mismatch in the Stream Map {}, {}", stream, writer.getStreamName());
        return Future.exception(new IllegalStateException("The stream mapping is incorrect, fail the request"));
    }

    long txnId;
    Future<DLSN> writeResult;
    synchronized (txnLock) {
        txnId = sequencer.nextId();
        LogRecord record = new LogRecord(txnId, payload);
        if (isRecordSet) {
            record.setRecordSet();
        }
        writeResult = writer.write(record);
    }
    return writeResult.map(new AbstractFunction1<DLSN, WriteResponse>() {
        @Override
        public WriteResponse apply(DLSN value) {
            successRecordCounter.inc();
            return ResponseUtils.writeSuccess().setDlsn(value.serialize(dlsnVersion));
        }
    });
}
 

import com.twitter.util.Future; //导入方法依赖的package包/类
@Override
protected Future<WriteResponse> executeOp(AsyncLogWriter writer,
                                          Sequencer sequencer,
                                          Object txnLock) {
    Future<Void> result = streamManager.closeAndRemoveAsync(streamName());
    return result.map(new AbstractFunction1<Void, WriteResponse>() {
        @Override
        public WriteResponse apply(Void value) {
            return ResponseUtils.writeSuccess();
        }
    });
}
 

import com.twitter.util.Future; //导入方法依赖的package包/类
private synchronized Future<DLSN> asyncWrite(final LogRecord record,
                                             boolean flush) {
    // The passed in writer may be stale since we acquire the writer outside of sync
    // lock. If we recently rolled and the new writer is cached, use that instead.
    Future<DLSN> result = null;
    BKLogSegmentWriter w;
    try {
        w = getCachedLogSegmentWriter();
    } catch (WriteException we) {
        return Future.exception(we);
    }
    if (null != rollingFuture) {
        if (streamFailFast) {
            result = Future.exception(new StreamNotReadyException("Rolling log segment"));
        } else {
            result = queueRequest(record, flush);
        }
    } else if (shouldRollLog(w)) {
        // insert a last record, so when it called back, we will trigger a log segment rolling
        startQueueingRequests();
        if (null != w) {
            LastPendingLogRecord lastLogRecordInCurrentSegment = new LastPendingLogRecord(record, flush);
            w.asyncWrite(record, true).addEventListener(lastLogRecordInCurrentSegment);
            result = lastLogRecordInCurrentSegment.promise;
        } else { // no log segment yet. roll the log segment and issue pending requests.
            result = queueRequest(record, flush);
            rollLogSegmentAndIssuePendingRequests(record);
        }
    } else {
        result = w.asyncWrite(record, flush);
    }
    // use map here rather than onSuccess because we want lastTxId to be updated before
    // satisfying the future
    return result.map(new AbstractFunction1<DLSN, DLSN>() {
        @Override
        public DLSN apply(DLSN dlsn) {
            setLastTxId(record.getTransactionId());
            return dlsn;
        }
    });
}