| /* |
| * 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(); |
| } |
| } |
| } |