jsancio commented on a change in pull request #10085: URL: https://github.com/apache/kafka/pull/10085#discussion_r610934045
########## File path: raft/src/main/java/org/apache/kafka/raft/internals/SerdeRecordsIterator.java ########## @@ -0,0 +1,231 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.kafka.raft.internals; + +import java.io.IOException; +import java.nio.ByteBuffer; +import java.util.ArrayList; +import java.util.Iterator; +import java.util.List; +import java.util.NoSuchElementException; +import java.util.Optional; +import org.apache.kafka.common.protocol.DataInputStreamReadable; +import org.apache.kafka.common.protocol.Readable; +import org.apache.kafka.common.record.DefaultRecordBatch; +import org.apache.kafka.common.record.FileRecords; +import org.apache.kafka.common.record.MemoryRecords; +import org.apache.kafka.common.record.MutableRecordBatch; +import org.apache.kafka.common.record.Records; +import org.apache.kafka.common.utils.BufferSupplier; +import org.apache.kafka.raft.BatchReader.Batch; +import org.apache.kafka.raft.RecordSerde; + +public final class SerdeRecordsIterator<T> implements Iterator<Batch<T>>, AutoCloseable { + private final Records records; + private final RecordSerde<T> serde; + private final BufferSupplier bufferSupplier; + private final int maxBatchSize; + + private Optional<Iterator<MutableRecordBatch>> nextBatches = Optional.empty(); + private Optional<Batch<T>> nextBatch = Optional.empty(); + // Buffer used to as the backing store for nextBatches if needed + private Optional<ByteBuffer> allocatedBuffer = Optional.empty(); + // Number of bytes from records that read + private int bytesRead = 0; + private boolean isClosed = false; + + public SerdeRecordsIterator( + Records records, + RecordSerde<T> serde, + BufferSupplier bufferSupplier, + int maxBatchSize + ) { + this.records = records; + this.serde = serde; + this.bufferSupplier = bufferSupplier; + this.maxBatchSize = maxBatchSize; + } + + @Override + public boolean hasNext() { + checkIfClosed(); + + if (!nextBatch.isPresent()) { + nextBatch = nextBatch(); + } + + return nextBatch.isPresent(); + } + + @Override + public Batch<T> next() { + if (!hasNext()) { + throw new NoSuchElementException("Batch iterator doesn't have any more elements"); + } + + Batch<T> batch = nextBatch.get(); + nextBatch = Optional.empty(); + + return batch; + } + + @Override + public void close() { + isClosed = true; + allocatedBuffer.ifPresent(bufferSupplier::release); + allocatedBuffer = Optional.empty(); + } + + private void checkIfClosed() { + if (isClosed) { + throw new IllegalStateException("Serde record batch itererator was closed"); + } + } + + private Optional<Iterator<MutableRecordBatch>> nextBatches() { + int recordSize = records.sizeInBytes(); + if (bytesRead < recordSize) { + final MemoryRecords memoryRecords; + if (records instanceof MemoryRecords) { + bytesRead = recordSize; + memoryRecords = (MemoryRecords) records; + } else if (records instanceof FileRecords) { + final ByteBuffer buffer; + if (allocatedBuffer.isPresent()) { + buffer = allocatedBuffer.get(); + buffer.compact(); + + if (!buffer.hasRemaining()) { + // The buffer is not big enough to read an entire batch + throw new IllegalStateException( + String.format( + "Unable to read batch from file records buffer %s with maximum batch %s and record size %s", + buffer, + maxBatchSize, + records.sizeInBytes() + ) + ); + } + } else { + buffer = bufferSupplier.get(Math.min(maxBatchSize, records.sizeInBytes())); + allocatedBuffer = Optional.of(buffer); + } + + int start = buffer.position(); + try { + ((FileRecords) records).readInto(buffer, bytesRead); + } catch (IOException e) { + throw new RuntimeException("Failed to read records into memory", e); + } + + bytesRead += buffer.limit() - start; + memoryRecords = MemoryRecords.readableRecords(buffer.slice()); + } else { + throw new IllegalStateException(String.format("Unexpected Records type %s", records.getClass())); + } + + return Optional.of(memoryRecords.batchIterator()); + } else { + return Optional.empty(); + } + } + + private Optional<Batch<T>> nextBatch() { + if (!nextBatches.isPresent()) { + nextBatches = nextBatches(); + } + + while (nextBatches.isPresent()) { + if (nextBatches.get().hasNext()) { + MutableRecordBatch nextBatch = nextBatches.get().next(); + + // Update the buffer position to reflect the read batch + allocatedBuffer.ifPresent(buffer -> buffer.position(buffer.position() + nextBatch.sizeInBytes())); + + if (!(nextBatch instanceof DefaultRecordBatch)) { + throw new IllegalStateException( + String.format("DefaultRecordBatch expected by record type was %s", nextBatch.getClass()) + ); + } + return Optional.of(readBatch((DefaultRecordBatch) nextBatch)); + } + + nextBatches = nextBatches(); + } + + return Optional.empty(); + } + + private Batch<T> readBatch(DefaultRecordBatch batch) { + final Batch<T> result; + if (batch.isControlBatch()) { + result = Batch.empty(batch.baseOffset(), batch.partitionLeaderEpoch(), batch.lastOffset()); + } else { + Integer numRecords = batch.countOrNull(); Review comment: Yes. I can do this in a followup PR. Do we want to add a new method or do we want to replace the existing method? Is `interface RecordBatch` considered a public API? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to 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
