| /* |
| * 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.iotdb.consensus.multileader.snapshot; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.nio.channels.SeekableByteChannel; |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| |
| public class SnapshotFragmentReader { |
| |
| private static final int DEFAULT_FILE_FRAGMENT_SIZE = 10 * 1024 * 1024; |
| private final String snapshotId; |
| private final String filePath; |
| private final SeekableByteChannel fileChannel; |
| private final long fileSize; |
| private final ByteBuffer buf; |
| private long totalReadSize; |
| private SnapshotFragment cachedSnapshotFragment; |
| |
| public SnapshotFragmentReader(String snapshotId, Path path) throws IOException { |
| this.snapshotId = snapshotId; |
| this.filePath = path.toAbsolutePath().toString(); |
| this.fileSize = Files.size(path); |
| this.fileChannel = Files.newByteChannel(path); |
| this.buf = ByteBuffer.allocate(DEFAULT_FILE_FRAGMENT_SIZE); |
| } |
| |
| public boolean hasNext() throws IOException { |
| buf.clear(); |
| int actualReadSize = fileChannel.read(buf); |
| buf.flip(); |
| if (actualReadSize > 0) { |
| cachedSnapshotFragment = |
| new SnapshotFragment(snapshotId, filePath, fileSize, totalReadSize, actualReadSize, buf); |
| totalReadSize += actualReadSize; |
| return true; |
| } |
| return false; |
| } |
| |
| public SnapshotFragment next() { |
| return cachedSnapshotFragment; |
| } |
| |
| public void close() throws IOException { |
| if (fileChannel != null) { |
| fileChannel.close(); |
| } |
| } |
| } |