Examples with FileRegion io.netty.channel.FileRegion used on opensource projects

Example 1 with FileRegion

use of io.netty.channel.FileRegion in project rocketmq by apache.

the class Broker2Client method checkProducerTransactionState.

public void checkProducerTransactionState(final Channel channel, final CheckTransactionStateRequestHeader requestHeader, final SelectMappedBufferResult selectMappedBufferResult) {
    RemotingCommand request = RemotingCommand.createRequestCommand(RequestCode.CHECK_TRANSACTION_STATE, requestHeader);
    request.markOnewayRPC();
    try {
        FileRegion fileRegion = new OneMessageTransfer(request.encodeHeader(selectMappedBufferResult.getSize()), selectMappedBufferResult);
        channel.writeAndFlush(fileRegion).addListener(new ChannelFutureListener() {

            @Override
            public void operationComplete(ChannelFuture future) throws Exception {
                selectMappedBufferResult.release();
                if (!future.isSuccess()) {
                    log.error("invokeProducer failed,", future.cause());
                }
            }
        });
    } catch (Throwable e) {
        log.error("invokeProducer exception", e);
        selectMappedBufferResult.release();
    }
}

Example 2 with FileRegion

use of io.netty.channel.FileRegion in project rocketmq by apache.

the class PullMessageProcessor method processRequest.

private RemotingCommand processRequest(final Channel channel, RemotingCommand request, boolean brokerAllowSuspend) throws RemotingCommandException {
    RemotingCommand response = RemotingCommand.createResponseCommand(PullMessageResponseHeader.class);
    final PullMessageResponseHeader responseHeader = (PullMessageResponseHeader) response.readCustomHeader();
    final PullMessageRequestHeader requestHeader = (PullMessageRequestHeader) request.decodeCommandCustomHeader(PullMessageRequestHeader.class);
    response.setOpaque(request.getOpaque());
    log.debug("receive PullMessage request command, {}", request);
    if (!PermName.isReadable(this.brokerController.getBrokerConfig().getBrokerPermission())) {
        response.setCode(ResponseCode.NO_PERMISSION);
        response.setRemark(String.format("the broker[%s] pulling message is forbidden", this.brokerController.getBrokerConfig().getBrokerIP1()));
        return response;
    }
    SubscriptionGroupConfig subscriptionGroupConfig = this.brokerController.getSubscriptionGroupManager().findSubscriptionGroupConfig(requestHeader.getConsumerGroup());
    if (null == subscriptionGroupConfig) {
        response.setCode(ResponseCode.SUBSCRIPTION_GROUP_NOT_EXIST);
        response.setRemark(String.format("subscription group [%s] does not exist, %s", requestHeader.getConsumerGroup(), FAQUrl.suggestTodo(FAQUrl.SUBSCRIPTION_GROUP_NOT_EXIST)));
        return response;
    }
    if (!subscriptionGroupConfig.isConsumeEnable()) {
        response.setCode(ResponseCode.NO_PERMISSION);
        response.setRemark("subscription group no permission, " + requestHeader.getConsumerGroup());
        return response;
    }
    final boolean hasSuspendFlag = PullSysFlag.hasSuspendFlag(requestHeader.getSysFlag());
    final boolean hasCommitOffsetFlag = PullSysFlag.hasCommitOffsetFlag(requestHeader.getSysFlag());
    final boolean hasSubscriptionFlag = PullSysFlag.hasSubscriptionFlag(requestHeader.getSysFlag());
    final long suspendTimeoutMillisLong = hasSuspendFlag ? requestHeader.getSuspendTimeoutMillis() : 0;
    TopicConfig topicConfig = this.brokerController.getTopicConfigManager().selectTopicConfig(requestHeader.getTopic());
    if (null == topicConfig) {
        log.error("the topic {} not exist, consumer: {}", requestHeader.getTopic(), RemotingHelper.parseChannelRemoteAddr(channel));
        response.setCode(ResponseCode.TOPIC_NOT_EXIST);
        response.setRemark(String.format("topic[%s] not exist, apply first please! %s", requestHeader.getTopic(), FAQUrl.suggestTodo(FAQUrl.APPLY_TOPIC_URL)));
        return response;
    }
    if (!PermName.isReadable(topicConfig.getPerm())) {
        response.setCode(ResponseCode.NO_PERMISSION);
        response.setRemark("the topic[" + requestHeader.getTopic() + "] pulling message is forbidden");
        return response;
    }
    if (requestHeader.getQueueId() < 0 || requestHeader.getQueueId() >= topicConfig.getReadQueueNums()) {
        String errorInfo = String.format("queueId[%d] is illegal, topic:[%s] topicConfig.readQueueNums:[%d] consumer:[%s]", requestHeader.getQueueId(), requestHeader.getTopic(), topicConfig.getReadQueueNums(), channel.remoteAddress());
        log.warn(errorInfo);
        response.setCode(ResponseCode.SYSTEM_ERROR);
        response.setRemark(errorInfo);
        return response;
    }
    SubscriptionData subscriptionData = null;
    ConsumerFilterData consumerFilterData = null;
    if (hasSubscriptionFlag) {
        try {
            subscriptionData = FilterAPI.build(requestHeader.getTopic(), requestHeader.getSubscription(), requestHeader.getExpressionType());
            if (!ExpressionType.isTagType(subscriptionData.getExpressionType())) {
                consumerFilterData = ConsumerFilterManager.build(requestHeader.getTopic(), requestHeader.getConsumerGroup(), requestHeader.getSubscription(), requestHeader.getExpressionType(), requestHeader.getSubVersion());
                assert consumerFilterData != null;
            }
        } catch (Exception e) {
            log.warn("Parse the consumer's subscription[{}] failed, group: {}", requestHeader.getSubscription(), requestHeader.getConsumerGroup());
            response.setCode(ResponseCode.SUBSCRIPTION_PARSE_FAILED);
            response.setRemark("parse the consumer's subscription failed");
            return response;
        }
    } else {
        ConsumerGroupInfo consumerGroupInfo = this.brokerController.getConsumerManager().getConsumerGroupInfo(requestHeader.getConsumerGroup());
        if (null == consumerGroupInfo) {
            log.warn("the consumer's group info not exist, group: {}", requestHeader.getConsumerGroup());
            response.setCode(ResponseCode.SUBSCRIPTION_NOT_EXIST);
            response.setRemark("the consumer's group info not exist" + FAQUrl.suggestTodo(FAQUrl.SAME_GROUP_DIFFERENT_TOPIC));
            return response;
        }
        if (!subscriptionGroupConfig.isConsumeBroadcastEnable() && consumerGroupInfo.getMessageModel() == MessageModel.BROADCASTING) {
            response.setCode(ResponseCode.NO_PERMISSION);
            response.setRemark("the consumer group[" + requestHeader.getConsumerGroup() + "] can not consume by broadcast way");
            return response;
        }
        subscriptionData = consumerGroupInfo.findSubscriptionData(requestHeader.getTopic());
        if (null == subscriptionData) {
            log.warn("the consumer's subscription not exist, group: {}, topic:{}", requestHeader.getConsumerGroup(), requestHeader.getTopic());
            response.setCode(ResponseCode.SUBSCRIPTION_NOT_EXIST);
            response.setRemark("the consumer's subscription not exist" + FAQUrl.suggestTodo(FAQUrl.SAME_GROUP_DIFFERENT_TOPIC));
            return response;
        }
        if (subscriptionData.getSubVersion() < requestHeader.getSubVersion()) {
            log.warn("The broker's subscription is not latest, group: {} {}", requestHeader.getConsumerGroup(), subscriptionData.getSubString());
            response.setCode(ResponseCode.SUBSCRIPTION_NOT_LATEST);
            response.setRemark("the consumer's subscription not latest");
            return response;
        }
        if (!ExpressionType.isTagType(subscriptionData.getExpressionType())) {
            consumerFilterData = this.brokerController.getConsumerFilterManager().get(requestHeader.getTopic(), requestHeader.getConsumerGroup());
            if (consumerFilterData == null) {
                response.setCode(ResponseCode.FILTER_DATA_NOT_EXIST);
                response.setRemark("The broker's consumer filter data is not exist!Your expression may be wrong!");
                return response;
            }
            if (consumerFilterData.getClientVersion() < requestHeader.getSubVersion()) {
                log.warn("The broker's consumer filter data is not latest, group: {}, topic: {}, serverV: {}, clientV: {}", requestHeader.getConsumerGroup(), requestHeader.getTopic(), consumerFilterData.getClientVersion(), requestHeader.getSubVersion());
                response.setCode(ResponseCode.FILTER_DATA_NOT_LATEST);
                response.setRemark("the consumer's consumer filter data not latest");
                return response;
            }
        }
    }
    if (!ExpressionType.isTagType(subscriptionData.getExpressionType()) && !this.brokerController.getBrokerConfig().isEnablePropertyFilter()) {
        response.setCode(ResponseCode.SYSTEM_ERROR);
        response.setRemark("The broker does not support consumer to filter message by " + subscriptionData.getExpressionType());
        return response;
    }
    MessageFilter messageFilter;
    if (this.brokerController.getBrokerConfig().isFilterSupportRetry()) {
        messageFilter = new ExpressionForRetryMessageFilter(subscriptionData, consumerFilterData, this.brokerController.getConsumerFilterManager());
    } else {
        messageFilter = new ExpressionMessageFilter(subscriptionData, consumerFilterData, this.brokerController.getConsumerFilterManager());
    }
    final GetMessageResult getMessageResult = this.brokerController.getMessageStore().getMessage(requestHeader.getConsumerGroup(), requestHeader.getTopic(), requestHeader.getQueueId(), requestHeader.getQueueOffset(), requestHeader.getMaxMsgNums(), messageFilter);
    if (getMessageResult != null) {
        response.setRemark(getMessageResult.getStatus().name());
        responseHeader.setNextBeginOffset(getMessageResult.getNextBeginOffset());
        responseHeader.setMinOffset(getMessageResult.getMinOffset());
        responseHeader.setMaxOffset(getMessageResult.getMaxOffset());
        if (getMessageResult.isSuggestPullingFromSlave()) {
            responseHeader.setSuggestWhichBrokerId(subscriptionGroupConfig.getWhichBrokerWhenConsumeSlowly());
        } else {
            responseHeader.setSuggestWhichBrokerId(MixAll.MASTER_ID);
        }
        switch(this.brokerController.getMessageStoreConfig().getBrokerRole()) {
            case ASYNC_MASTER:
            case SYNC_MASTER:
                break;
            case SLAVE:
                if (!this.brokerController.getBrokerConfig().isSlaveReadEnable()) {
                    response.setCode(ResponseCode.PULL_RETRY_IMMEDIATELY);
                    responseHeader.setSuggestWhichBrokerId(MixAll.MASTER_ID);
                }
                break;
        }
        if (this.brokerController.getBrokerConfig().isSlaveReadEnable()) {
            // consume too slow ,redirect to another machine
            if (getMessageResult.isSuggestPullingFromSlave()) {
                responseHeader.setSuggestWhichBrokerId(subscriptionGroupConfig.getWhichBrokerWhenConsumeSlowly());
            } else // consume ok
            {
                responseHeader.setSuggestWhichBrokerId(subscriptionGroupConfig.getBrokerId());
            }
        } else {
            responseHeader.setSuggestWhichBrokerId(MixAll.MASTER_ID);
        }
        switch(getMessageResult.getStatus()) {
            case FOUND:
                response.setCode(ResponseCode.SUCCESS);
                break;
            case MESSAGE_WAS_REMOVING:
                response.setCode(ResponseCode.PULL_RETRY_IMMEDIATELY);
                break;
            case NO_MATCHED_LOGIC_QUEUE:
            case NO_MESSAGE_IN_QUEUE:
                if (0 != requestHeader.getQueueOffset()) {
                    response.setCode(ResponseCode.PULL_OFFSET_MOVED);
                    // XXX: warn and notify me
                    log.info("the broker store no queue data, fix the request offset {} to {}, Topic: {} QueueId: {} Consumer Group: {}", requestHeader.getQueueOffset(), getMessageResult.getNextBeginOffset(), requestHeader.getTopic(), requestHeader.getQueueId(), requestHeader.getConsumerGroup());
                } else {
                    response.setCode(ResponseCode.PULL_NOT_FOUND);
                }
                break;
            case NO_MATCHED_MESSAGE:
                response.setCode(ResponseCode.PULL_RETRY_IMMEDIATELY);
                break;
            case OFFSET_FOUND_NULL:
                response.setCode(ResponseCode.PULL_NOT_FOUND);
                break;
            case OFFSET_OVERFLOW_BADLY:
                response.setCode(ResponseCode.PULL_OFFSET_MOVED);
                // XXX: warn and notify me
                log.info("the request offset: {} over flow badly, broker max offset: {}, consumer: {}", requestHeader.getQueueOffset(), getMessageResult.getMaxOffset(), channel.remoteAddress());
                break;
            case OFFSET_OVERFLOW_ONE:
                response.setCode(ResponseCode.PULL_NOT_FOUND);
                break;
            case OFFSET_TOO_SMALL:
                response.setCode(ResponseCode.PULL_OFFSET_MOVED);
                log.info("the request offset too small. group={}, topic={}, requestOffset={}, brokerMinOffset={}, clientIp={}", requestHeader.getConsumerGroup(), requestHeader.getTopic(), requestHeader.getQueueOffset(), getMessageResult.getMinOffset(), channel.remoteAddress());
                break;
            default:
                assert false;
                break;
        }
        if (this.hasConsumeMessageHook()) {
            ConsumeMessageContext context = new ConsumeMessageContext();
            context.setConsumerGroup(requestHeader.getConsumerGroup());
            context.setTopic(requestHeader.getTopic());
            context.setQueueId(requestHeader.getQueueId());
            String owner = request.getExtFields().get(BrokerStatsManager.COMMERCIAL_OWNER);
            switch(response.getCode()) {
                case ResponseCode.SUCCESS:
                    int commercialBaseCount = brokerController.getBrokerConfig().getCommercialBaseCount();
                    int incValue = getMessageResult.getMsgCount4Commercial() * commercialBaseCount;
                    context.setCommercialRcvStats(BrokerStatsManager.StatsType.RCV_SUCCESS);
                    context.setCommercialRcvTimes(incValue);
                    context.setCommercialRcvSize(getMessageResult.getBufferTotalSize());
                    context.setCommercialOwner(owner);
                    break;
                case ResponseCode.PULL_NOT_FOUND:
                    if (!brokerAllowSuspend) {
                        context.setCommercialRcvStats(BrokerStatsManager.StatsType.RCV_EPOLLS);
                        context.setCommercialRcvTimes(1);
                        context.setCommercialOwner(owner);
                    }
                    break;
                case ResponseCode.PULL_RETRY_IMMEDIATELY:
                case ResponseCode.PULL_OFFSET_MOVED:
                    context.setCommercialRcvStats(BrokerStatsManager.StatsType.RCV_EPOLLS);
                    context.setCommercialRcvTimes(1);
                    context.setCommercialOwner(owner);
                    break;
                default:
                    assert false;
                    break;
            }
            this.executeConsumeMessageHookBefore(context);
        }
        switch(response.getCode()) {
            case ResponseCode.SUCCESS:
                this.brokerController.getBrokerStatsManager().incGroupGetNums(requestHeader.getConsumerGroup(), requestHeader.getTopic(), getMessageResult.getMessageCount());
                this.brokerController.getBrokerStatsManager().incGroupGetSize(requestHeader.getConsumerGroup(), requestHeader.getTopic(), getMessageResult.getBufferTotalSize());
                this.brokerController.getBrokerStatsManager().incBrokerGetNums(getMessageResult.getMessageCount());
                if (this.brokerController.getBrokerConfig().isTransferMsgByHeap()) {
                    final long beginTimeMills = this.brokerController.getMessageStore().now();
                    final byte[] r = this.readGetMessageResult(getMessageResult, requestHeader.getConsumerGroup(), requestHeader.getTopic(), requestHeader.getQueueId());
                    this.brokerController.getBrokerStatsManager().incGroupGetLatency(requestHeader.getConsumerGroup(), requestHeader.getTopic(), requestHeader.getQueueId(), (int) (this.brokerController.getMessageStore().now() - beginTimeMills));
                    response.setBody(r);
                } else {
                    try {
                        FileRegion fileRegion = new ManyMessageTransfer(response.encodeHeader(getMessageResult.getBufferTotalSize()), getMessageResult);
                        channel.writeAndFlush(fileRegion).addListener(new ChannelFutureListener() {

                            @Override
                            public void operationComplete(ChannelFuture future) throws Exception {
                                getMessageResult.release();
                                if (!future.isSuccess()) {
                                    log.error("transfer many message by pagecache failed, {}", channel.remoteAddress(), future.cause());
                                }
                            }
                        });
                    } catch (Throwable e) {
                        log.error("transfer many message by pagecache exception", e);
                        getMessageResult.release();
                    }
                    response = null;
                }
                break;
            case ResponseCode.PULL_NOT_FOUND:
                if (brokerAllowSuspend && hasSuspendFlag) {
                    long pollingTimeMills = suspendTimeoutMillisLong;
                    if (!this.brokerController.getBrokerConfig().isLongPollingEnable()) {
                        pollingTimeMills = this.brokerController.getBrokerConfig().getShortPollingTimeMills();
                    }
                    String topic = requestHeader.getTopic();
                    long offset = requestHeader.getQueueOffset();
                    int queueId = requestHeader.getQueueId();
                    PullRequest pullRequest = new PullRequest(request, channel, pollingTimeMills, this.brokerController.getMessageStore().now(), offset, subscriptionData, messageFilter);
                    this.brokerController.getPullRequestHoldService().suspendPullRequest(topic, queueId, pullRequest);
                    response = null;
                    break;
                }
            case ResponseCode.PULL_RETRY_IMMEDIATELY:
                break;
            case ResponseCode.PULL_OFFSET_MOVED:
                if (this.brokerController.getMessageStoreConfig().getBrokerRole() != BrokerRole.SLAVE || this.brokerController.getMessageStoreConfig().isOffsetCheckInSlave()) {
                    MessageQueue mq = new MessageQueue();
                    mq.setTopic(requestHeader.getTopic());
                    mq.setQueueId(requestHeader.getQueueId());
                    mq.setBrokerName(this.brokerController.getBrokerConfig().getBrokerName());
                    OffsetMovedEvent event = new OffsetMovedEvent();
                    event.setConsumerGroup(requestHeader.getConsumerGroup());
                    event.setMessageQueue(mq);
                    event.setOffsetRequest(requestHeader.getQueueOffset());
                    event.setOffsetNew(getMessageResult.getNextBeginOffset());
                    this.generateOffsetMovedEvent(event);
                    log.warn("PULL_OFFSET_MOVED:correction offset. topic={}, groupId={}, requestOffset={}, newOffset={}, suggestBrokerId={}", requestHeader.getTopic(), requestHeader.getConsumerGroup(), event.getOffsetRequest(), event.getOffsetNew(), responseHeader.getSuggestWhichBrokerId());
                } else {
                    responseHeader.setSuggestWhichBrokerId(subscriptionGroupConfig.getBrokerId());
                    response.setCode(ResponseCode.PULL_RETRY_IMMEDIATELY);
                    log.warn("PULL_OFFSET_MOVED:none correction. topic={}, groupId={}, requestOffset={}, suggestBrokerId={}", requestHeader.getTopic(), requestHeader.getConsumerGroup(), requestHeader.getQueueOffset(), responseHeader.getSuggestWhichBrokerId());
                }
                break;
            default:
                assert false;
        }
    } else {
        response.setCode(ResponseCode.SYSTEM_ERROR);
        response.setRemark("store getMessage return null");
    }
    boolean storeOffsetEnable = brokerAllowSuspend;
    storeOffsetEnable = storeOffsetEnable && hasCommitOffsetFlag;
    storeOffsetEnable = storeOffsetEnable && this.brokerController.getMessageStoreConfig().getBrokerRole() != BrokerRole.SLAVE;
    if (storeOffsetEnable) {
        this.brokerController.getConsumerOffsetManager().commitOffset(RemotingHelper.parseChannelRemoteAddr(channel), requestHeader.getConsumerGroup(), requestHeader.getTopic(), requestHeader.getQueueId(), requestHeader.getCommitOffset());
    }
    return response;
}

Example 3 with FileRegion

use of io.netty.channel.FileRegion in project rocketmq by apache.

the class QueryMessageProcessor method queryMessage.

public RemotingCommand queryMessage(ChannelHandlerContext ctx, RemotingCommand request) throws RemotingCommandException {
    final RemotingCommand response = RemotingCommand.createResponseCommand(QueryMessageResponseHeader.class);
    final QueryMessageResponseHeader responseHeader = (QueryMessageResponseHeader) response.readCustomHeader();
    final QueryMessageRequestHeader requestHeader = (QueryMessageRequestHeader) request.decodeCommandCustomHeader(QueryMessageRequestHeader.class);
    response.setOpaque(request.getOpaque());
    String isUniqueKey = request.getExtFields().get(MixAll.UNIQUE_MSG_QUERY_FLAG);
    if (isUniqueKey != null && isUniqueKey.equals("true")) {
        requestHeader.setMaxNum(this.brokerController.getMessageStoreConfig().getDefaultQueryMaxNum());
    }
    final QueryMessageResult queryMessageResult = this.brokerController.getMessageStore().queryMessage(requestHeader.getTopic(), requestHeader.getKey(), requestHeader.getMaxNum(), requestHeader.getBeginTimestamp(), requestHeader.getEndTimestamp());
    assert queryMessageResult != null;
    responseHeader.setIndexLastUpdatePhyoffset(queryMessageResult.getIndexLastUpdatePhyoffset());
    responseHeader.setIndexLastUpdateTimestamp(queryMessageResult.getIndexLastUpdateTimestamp());
    if (queryMessageResult.getBufferTotalSize() > 0) {
        response.setCode(ResponseCode.SUCCESS);
        response.setRemark(null);
        try {
            FileRegion fileRegion = new QueryMessageTransfer(response.encodeHeader(queryMessageResult.getBufferTotalSize()), queryMessageResult);
            ctx.channel().writeAndFlush(fileRegion).addListener(new ChannelFutureListener() {

                @Override
                public void operationComplete(ChannelFuture future) throws Exception {
                    queryMessageResult.release();
                    if (!future.isSuccess()) {
                        log.error("transfer query message by page cache failed, ", future.cause());
                    }
                }
            });
        } catch (Throwable e) {
            log.error("", e);
            queryMessageResult.release();
        }
        return null;
    }
    response.setCode(ResponseCode.QUERY_NOT_FOUND);
    response.setRemark("can not find message, maybe time range not correct");
    return response;
}

Example 4 with FileRegion

use of io.netty.channel.FileRegion in project cassandra by apache.

the class TestChannel method doWrite.

private void doWrite(ChannelOutboundBuffer flush, long flushBytes) {
    while (true) {
        Object msg = flush.current();
        if (msg == null) {
            this.flush = null;
            this.flushBytes = 0;
            return;
        }
        if (inFlight >= inFlightLimit) {
            this.flush = flush;
            this.flushBytes = flushBytes;
            return;
        }
        ByteBuf buf;
        if (msg instanceof FileRegion) {
            buf = GlobalBufferPoolAllocator.instance.directBuffer((int) ((FileRegion) msg).count());
            try {
                ((FileRegion) msg).transferTo(new WritableByteChannel() {

                    public int write(ByteBuffer src) {
                        buf.setBytes(0, src);
                        return buf.writerIndex();
                    }

                    public boolean isOpen() {
                        return true;
                    }

                    public void close() {
                    }
                }, 0);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } else if (msg instanceof ByteBuf) {
            buf = ((ByteBuf) msg).copy();
        } else if (msg instanceof FrameEncoder.Payload) {
            buf = Unpooled.wrappedBuffer(((FrameEncoder.Payload) msg).buffer).copy();
        } else {
            System.err.println("Unexpected message type " + msg);
            throw new IllegalArgumentException();
        }
        inFlight += buf.readableBytes();
        handleOutboundMessage(buf);
        flush.remove();
    }
}

Example 5 with FileRegion

use of io.netty.channel.FileRegion in project netty by netty.

the class AbstractNioByteChannel method doWriteInternal.

private int doWriteInternal(ChannelOutboundBuffer in, Object msg) throws Exception {
    if (msg instanceof ByteBuf) {
        ByteBuf buf = (ByteBuf) msg;
        if (!buf.isReadable()) {
            in.remove();
            return 0;
        }
        final int localFlushedAmount = doWriteBytes(buf);
        if (localFlushedAmount > 0) {
            in.progress(localFlushedAmount);
            if (!buf.isReadable()) {
                in.remove();
            }
            return 1;
        }
    } else if (msg instanceof FileRegion) {
        FileRegion region = (FileRegion) msg;
        if (region.transferred() >= region.count()) {
            in.remove();
            return 0;
        }
        long localFlushedAmount = doWriteFileRegion(region);
        if (localFlushedAmount > 0) {
            in.progress(localFlushedAmount);
            if (region.transferred() >= region.count()) {
                in.remove();
            }
            return 1;
        }
    } else {
        // Should not reach here.
        throw new Error();
    }
    return WRITE_STATUS_SNDBUF_FULL;
}