| /** |
| * 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.kahadb.journal; |
| |
| import java.io.IOException; |
| import java.io.RandomAccessFile; |
| import java.util.Map; |
| |
| import org.apache.kahadb.journal.DataFileAppender.WriteCommand; |
| import org.apache.kahadb.journal.DataFileAppender.WriteKey; |
| import org.apache.kahadb.util.ByteSequence; |
| |
| /** |
| * Optimized Store reader and updater. Single threaded and synchronous. Use in |
| * conjunction with the DataFileAccessorPool of concurrent use. |
| * |
| * |
| */ |
| final class DataFileAccessor { |
| |
| private final DataFile dataFile; |
| private final Map<WriteKey, WriteCommand> inflightWrites; |
| private final RandomAccessFile file; |
| private boolean disposed; |
| |
| /** |
| * Construct a Store reader |
| * |
| * @param fileId |
| * @throws IOException |
| */ |
| public DataFileAccessor(Journal dataManager, DataFile dataFile) throws IOException { |
| this.dataFile = dataFile; |
| this.inflightWrites = dataManager.getInflightWrites(); |
| this.file = dataFile.openRandomAccessFile(); |
| } |
| |
| public DataFile getDataFile() { |
| return dataFile; |
| } |
| |
| public void dispose() { |
| if (disposed) { |
| return; |
| } |
| disposed = true; |
| try { |
| dataFile.closeRandomAccessFile(file); |
| } catch (IOException e) { |
| e.printStackTrace(); |
| } |
| } |
| |
| public ByteSequence readRecord(Location location) throws IOException { |
| |
| if (!location.isValid()) { |
| throw new IOException("Invalid location: " + location); |
| } |
| |
| WriteCommand asyncWrite = (WriteCommand)inflightWrites.get(new WriteKey(location)); |
| if (asyncWrite != null) { |
| return asyncWrite.data; |
| } |
| |
| try { |
| |
| if (location.getSize() == Location.NOT_SET) { |
| file.seek(location.getOffset()); |
| location.setSize(file.readInt()); |
| location.setType(file.readByte()); |
| } else { |
| file.seek(location.getOffset() + Journal.RECORD_HEAD_SPACE); |
| } |
| |
| byte[] data = new byte[location.getSize() - Journal.RECORD_HEAD_SPACE]; |
| file.readFully(data); |
| return new ByteSequence(data, 0, data.length); |
| |
| } catch (RuntimeException e) { |
| throw new IOException("Invalid location: " + location + ", : " + e); |
| } |
| } |
| |
| public void readFully(long offset, byte data[]) throws IOException { |
| file.seek(offset); |
| file.readFully(data); |
| } |
| |
| public int read(long offset, byte data[]) throws IOException { |
| file.seek(offset); |
| return file.read(data); |
| } |
| |
| public void readLocationDetails(Location location) throws IOException { |
| WriteCommand asyncWrite = (WriteCommand)inflightWrites.get(new WriteKey(location)); |
| if (asyncWrite != null) { |
| location.setSize(asyncWrite.location.getSize()); |
| location.setType(asyncWrite.location.getType()); |
| } else { |
| file.seek(location.getOffset()); |
| location.setSize(file.readInt()); |
| location.setType(file.readByte()); |
| } |
| } |
| |
| // public boolean readLocationDetailsAndValidate(Location location) { |
| // try { |
| // WriteCommand asyncWrite = (WriteCommand)inflightWrites.get(new WriteKey(location)); |
| // if (asyncWrite != null) { |
| // location.setSize(asyncWrite.location.getSize()); |
| // location.setType(asyncWrite.location.getType()); |
| // } else { |
| // file.seek(location.getOffset()); |
| // location.setSize(file.readInt()); |
| // location.setType(file.readByte()); |
| // |
| // byte data[] = new byte[3]; |
| // file.seek(location.getOffset() + Journal.ITEM_HEAD_OFFSET_TO_SOR); |
| // file.readFully(data); |
| // if (data[0] != Journal.ITEM_HEAD_SOR[0] |
| // || data[1] != Journal.ITEM_HEAD_SOR[1] |
| // || data[2] != Journal.ITEM_HEAD_SOR[2]) { |
| // return false; |
| // } |
| // file.seek(location.getOffset() + location.getSize() - Journal.ITEM_FOOT_SPACE); |
| // file.readFully(data); |
| // if (data[0] != Journal.ITEM_HEAD_EOR[0] |
| // || data[1] != Journal.ITEM_HEAD_EOR[1] |
| // || data[2] != Journal.ITEM_HEAD_EOR[2]) { |
| // return false; |
| // } |
| // } |
| // } catch (IOException e) { |
| // return false; |
| // } |
| // return true; |
| // } |
| |
| public void updateRecord(Location location, ByteSequence data, boolean sync) throws IOException { |
| |
| file.seek(location.getOffset() + Journal.RECORD_HEAD_SPACE); |
| int size = Math.min(data.getLength(), location.getSize()); |
| file.write(data.getData(), data.getOffset(), size); |
| if (sync) { |
| file.getFD().sync(); |
| } |
| |
| } |
| |
| } |