/* * 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.parquet; import java.io.IOException; import java.util.NoSuchElementException; import org.apache.iceberg.exceptions.RuntimeIOException; import org.apache.iceberg.io.CloseableGroup; import org.apache.iceberg.io.CloseableIterable; import org.apache.iceberg.io.CloseableIterator; import org.apache.parquet.hadoop.ParquetReader; public class ParquetIterable<T> extends CloseableGroup implements CloseableIterable<T> { private final ParquetReader.Builder<T> builder; ParquetIterable(ParquetReader.Builder<T> builder) { this.builder = builder; } @Override public CloseableIterator<T> iterator() { try { ParquetReader<T> reader = builder.build(); addCloseable(reader); return new ParquetIterator<>(reader); } catch (IOException e) { throw new RuntimeIOException(e, "Failed to create Parquet reader"); } } private static class ParquetIterator<T> implements CloseableIterator<T> { private final ParquetReader<T> parquet; private boolean needsAdvance = false; private boolean hasNext = false; private T next; ParquetIterator(ParquetReader<T> parquet) { this.parquet = parquet; this.next = advance(); } @Override public boolean hasNext() { if (needsAdvance) { this.next = advance(); } return hasNext; } @Override public T next() { if (!hasNext()) { throw new NoSuchElementException(); } this.needsAdvance = true; return next; } private T advance() { // this must be called in hasNext because it reuses an UnsafeRow try { T nextRecord = parquet.read(); this.needsAdvance = false; this.hasNext = nextRecord != null; return nextRecord; } catch (IOException e) { throw new RuntimeIOException(e); } } @Override public void remove() { throw new UnsupportedOperationException("Remove is not supported"); } @Override public void close() throws IOException { parquet.close(); } } }