nssalian commented on code in PR #14297: URL: https://github.com/apache/iceberg/pull/14297#discussion_r3190088632
########## core/src/main/java/org/apache/iceberg/io/BufferedFileAppender.java: ########## @@ -0,0 +1,147 @@ +/* + * 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.iceberg.io; + +import java.io.IOException; +import java.util.List; +import java.util.function.Function; +import java.util.function.UnaryOperator; +import org.apache.iceberg.Metrics; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; + +/** + * A FileAppender that buffers the first N rows, then creates a delegate appender via a factory. + * + * <p>The factory receives the buffered rows and is responsible for creating the real appender. Row + * replay is handled internally. All subsequent {@link #add} calls delegate directly to the real + * appender. + * + * <p>If fewer than {@code bufferSize} rows are written before close, the factory is called with + * whatever rows were buffered. If no rows were written, the factory is not called and no file is + * created on disk. In this case, {@link #metrics()} returns {@code new Metrics(0L)} and {@link + * #length()} returns {@code 0L}. + * + * @param <D> the row type + */ +public class BufferedFileAppender<D> implements FileAppender<D> { + private final int bufferRowCount; + private final Function<List<D>, FileAppender<D>> appenderFactory; + private final UnaryOperator<D> copyFunc; + private List<D> buffer; + private FileAppender<D> delegate; + private boolean closed = false; + + /** + * @param bufferRowCount number of rows to buffer before creating the delegate appender + * @param appenderFactory given the buffered rows, creates the delegate appender + */ + public BufferedFileAppender( + int bufferRowCount, Function<List<D>, FileAppender<D>> appenderFactory) { + this(bufferRowCount, appenderFactory, UnaryOperator.identity()); + } + + /** + * @param bufferRowCount number of rows to buffer before creating the delegate appender + * @param appenderFactory given the buffered rows, creates the delegate appender + * @param copyFunc copies a row before buffering (needed when row objects are reused, e.g. Spark + * InternalRow) + */ + public BufferedFileAppender( + int bufferRowCount, + Function<List<D>, FileAppender<D>> appenderFactory, + UnaryOperator<D> copyFunc) { + Preconditions.checkArgument( + bufferRowCount > 0, "bufferRowCount must be > 0, got %s", bufferRowCount); + Preconditions.checkNotNull(appenderFactory, "appenderFactory must not be null"); + Preconditions.checkNotNull(copyFunc, "copyFunc must not be null"); + this.bufferRowCount = bufferRowCount; + this.appenderFactory = appenderFactory; + this.copyFunc = copyFunc; + this.buffer = Lists.newArrayListWithCapacity(bufferRowCount); + } + + @Override + public void add(D datum) { + Preconditions.checkState(!closed, "Cannot add to a closed appender"); + if (delegate != null) { + delegate.add(datum); + } else { + buffer.add(copyFunc.apply(datum)); + if (buffer.size() >= bufferRowCount) { + initialize(); + } + } + } + + @Override + public Metrics metrics() { + Preconditions.checkState(closed, "Cannot return metrics for unclosed appender"); + if (delegate == null) { + return new Metrics(0L); + } + + return delegate.metrics(); + } + + @Override + public long length() { + if (delegate != null) { + return delegate.length(); + } + + // No bytes written to disk yet; data is buffered in memory + return 0L; + } + + @Override + public List<Long> splitOffsets() { + if (delegate != null) { + return delegate.splitOffsets(); + } + + return null; + } + + @Override + public void close() throws IOException { + if (!closed) { + if (delegate == null && buffer != null && !buffer.isEmpty()) { + initialize(); Review Comment: Good call out, will add this. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
