NicoK commented on a change in pull request #6417: [FLINK-9913][runtime] Improve output serialization only once in RecordWriter URL: https://github.com/apache/flink/pull/6417#discussion_r217404839
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/api/writer/RecordWriter.java ########## @@ -89,77 +88,95 @@ public RecordWriter(ResultPartitionWriter writer, ChannelSelector<T> channelSele this.numChannels = writer.getNumberOfSubpartitions(); - /* - * The runtime exposes a channel abstraction for the produced results - * (see {@link ChannelSelector}). Every channel has an independent - * serializer. - */ - this.serializers = new SpanningRecordSerializer[numChannels]; + this.serializer = new SpanningRecordSerializer<T>(); this.bufferBuilders = new Optional[numChannels]; + this.broadcastChannels = new int[numChannels]; for (int i = 0; i < numChannels; i++) { - serializers[i] = new SpanningRecordSerializer<T>(); + broadcastChannels[i] = i; bufferBuilders[i] = Optional.empty(); } } public void emit(T record) throws IOException, InterruptedException { - for (int targetChannel : channelSelector.selectChannels(record, numChannels)) { - sendToTarget(record, targetChannel); - } + emit(record, channelSelector.selectChannels(record, numChannels)); } /** * This is used to broadcast Streaming Watermarks in-band with records. This ignores * the {@link ChannelSelector}. */ public void broadcastEmit(T record) throws IOException, InterruptedException { - for (int targetChannel = 0; targetChannel < numChannels; targetChannel++) { - sendToTarget(record, targetChannel); - } + emit(record, broadcastChannels); } /** * This is used to send LatencyMarks to a random target channel. */ public void randomEmit(T record) throws IOException, InterruptedException { - sendToTarget(record, rng.nextInt(numChannels)); + serializer.serializeRecord(record); + + if (copyFromSerializerToTargetChannel(rng.nextInt(numChannels))) { + serializer.prune(); + } } - private void sendToTarget(T record, int targetChannel) throws IOException, InterruptedException { - RecordSerializer<T> serializer = serializers[targetChannel]; + private void emit(T record, int[] targetChannels) throws IOException, InterruptedException { + serializer.serializeRecord(record); + + boolean pruneAfterCopying = false; + for (int channel : targetChannels) { + if (copyFromSerializerToTargetChannel(channel)) { + pruneAfterCopying = true; + } + } - SerializationResult result = serializer.addRecord(record); + // Make sure we don't hold onto the large intermediate serialization buffer for too long + if (pruneAfterCopying) { + serializer.prune(); + } + } + /** + * @param targetChannel + * @return <tt>true</tt> if the intermediate serialization buffer should be pruned + */ + private boolean copyFromSerializerToTargetChannel(int targetChannel) throws IOException, InterruptedException { + // We should reset the initial position of the intermediate serialization buffer before + // copying, so the serialization results can be copied to multiple target buffers. + serializer.reset(); + + boolean pruneTriggered = false; + BufferBuilder bufferBuilder = getBufferBuilder(targetChannel); + SerializationResult result = serializer.copyToBufferBuilder(bufferBuilder); while (result.isFullBuffer()) { - if (tryFinishCurrentBufferBuilder(targetChannel, serializer)) { - // If this was a full record, we are done. Not breaking - // out of the loop at this point will lead to another - // buffer request before breaking out (that would not be - // a problem per se, but it can lead to stalls in the - // pipeline). - if (result.isFullRecord()) { - break; - } + tryFinishCurrentBufferBuilder(targetChannel); + + // If this was a full record, we are done. Not breaking + // out of the loop at this point will lead to another + // buffer request before breaking out (that would not be + // a problem per se, but it can lead to stalls in the pipeline). Review comment: nit: compared to the surrounding code, this was broken apart quite early - I guess, you can use slightly longer lines like the code ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services