commons-mmf.rar_java nio_java共享内存_共享内存

/* * @(#)MemoryMappedFile.java 1.00 2007-12-5 * * Copyright 2007 BCINFO. All Rights Reserved. * Programmer: Xuym. */ package com.bci.commons.mmf; // import org.apache.log4j.Logger; import java.io.FileNotFoundException; import java.io.IOException; import java.io.RandomAccessFile; import java.nio.MappedByteBuffer; import java.nio.channels.FileChannel; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReadWriteLock; import java.util.concurrent.locks.ReentrantReadWriteLock; import com.bci.commons.mmf.cell.AbstractCell; import com.bci.commons.util.IOUtils; /** * 共享内存读写类，对java.nio.MappedByteBuffer封装，提供简单的读写操作。 * 采用java.util.concurrent.locks.Lock加锁机制支持多线程安全。 * * @author xuym * @version 1.00, 2007-12-5 * @since JDK 1.5 * @see java.nio.MappedByteBuffer */ public abstract class MemoryMappedFile { /** * Logger for this class */ // private static final Logger logger = // Logger.getLogger(SharedMemory.class); protected MappedByteBuffer mapBuf = null; protected String file = null; protected long capacity; protected ReadWriteLock lock = new ReentrantReadWriteLock(); protected Lock readLock = lock.readLock(); protected Lock writeLock = lock.writeLock(); /** * Load the map file into memory. * * @param file * The file name to be load. * @param size * The file's size or the max map size. * @throws MemoryMapException * If some exception occurs when loading the file * @throws MemoryNotMappedException * If the file not mapped into memory * @throws MemoryReadException * If some exception occurs when reading the memory. */ public void load(String file, int size) throws MemoryMapException, MemoryNotMappedException, MemoryReadException { this.file = file; this.capacity = size; // logger.debug("loading the file " + this.file + " into memory..."); try { RandomAccessFile RAFile = new RandomAccessFile(this.file, "rw"); FileChannel fc = RAFile.getChannel(); mapBuf = fc.map(FileChannel.MapMode.READ_WRITE, 0, size); mapBuf.load(); fc.close(); RAFile.close(); } catch (FileNotFoundException e) { throw new MemoryMapException(e); } catch (IOException e) { throw new MemoryMapException(e); } } /** * 在内存映象的指定位置写入对象 * * @param desPos * The dest position of the memory map. * @param message * The message object. * @return The boolean value if successed. * @see com.bci.commons.mmf.cell.AbstractCell * @throws MemoryNotMappedException * If the file not mapped into memory * @throws MemoryWriteException * If some exception occurs when write the object. */ public MemoryMappedFile write(int desPos, AbstractCell message) throws MemoryNotMappedException, MemoryWriteException { if (message == null) throw new MemoryWriteException("The input object is null."); return write(desPos, message.getBytes()); } /** * 在内存映象的指定位置写入字节数组 * * @param desPos * The dest position of the memory map. * @param buf * The byte array to be writen. * @return The boolean value if successed. * @throws MemoryNotMappedException * If the file not mapped into memory * @throws MemoryWriteException * If some exception occurs when write the object. */ public MemoryMappedFile write(int desPos, byte[] buf) throws MemoryNotMappedException, MemoryWriteException { if (buf == null) throw new MemoryWriteException("The input data is null."); return write(desPos, buf, 0, buf.length); } /** * 在内存映象的指定位置写入字节数组 * * @param desPos * The dest position of the memory map. * @param buf * The byte array to be writen. * @param srcPos * The start position of the source byte array. * @param len * The bytes length. * @return The boolean value if successed. * @throws MemoryNotMappedException * If the file not mapped into memory * @throws MemoryWriteException * If some exception occurs when write the object. */ public MemoryMappedFile write(int desPos, byte[] buf, int srcPos, int len) throws MemoryNotMappedException, MemoryWriteException { if (buf == null) throw new MemoryWriteException("the input data is null."); if (mapBuf == null) throw new MemoryNotMappedException( "the file not mapped into memory."); if (desPos < 0) throw new MemoryWriteException("the memory map is underflow."); if (desPos >= this.capacity - len) throw new MemoryWriteException("the memory map is overflow."); writeLock.lock(); try { // logger.debug(Thread.currentThread().getId() + ".writing...pos:" // + desPos + ",data:" + com.bci.imas.util.IOUtils.encodeHex(buf)); mapBuf.position(desPos); mapBuf.put(buf, srcPos, len); // mapBuf.force(); } finally { writeLock.unlock(); } return this; } /** * 在内存映象的指定位置写入一个字节 * * @param desPos * The dest position of the memory map. * @param b * The byte value to be writen. * @return The boolean value if successed. * @throws MemoryNotMappedException * If the file not mapped into memory * @throws MemoryWriteException * If some exception occurs when write the object. */ public MemoryMappedFile write(int desPos, byte b) throws MemoryNotMappedException, MemoryWriteException { if (mapBuf == null) throw new MemoryNotMappedException( "the file not mapped into memory."); if (desPos < 0) throw new MemoryWriteException("the memory map is underflow."); if (desPos >= this.capacity) throw new MemoryWriteException("the memory map is overflow."); writeLock.lock(); try { mapBuf.position(desPos); mapBuf.put(b); // mapBuf.force(); } finally { writeLock.unlock(); } return this; } /** * 在内存映象的指定位置写入一个整数 * * @param desPos * The dest position of the memory map. * @param i * The integer number to be writen. * @param len * The integer's byte length. * @return The boolean value if successed. * @throws MemoryNotMappedException * If the file not mapped into memory * @throws MemoryWriteException * If some exception occurs when write the object. */ public MemoryMappedFile write(int desPos, int i, int len) throws MemoryNotMappedException, MemoryWriteException { if (mapBuf == null) throw new MemoryNotMappedException( "the file not mapped into memory."); if (desPos < 0) throw new MemoryWriteException("the memory map is underflow."); if (desPos >= this.capacity - len) throw new MemoryWriteException("the memory map is overflow."); writeLock.lock(); try { mapBuf.position(desPos); byte[] buf = new byte[len]; buf = IOUtils.intToBytes(i, len); // logger.debug(Thread.currentThread().getId() + ".writing...pos:" // + desPos + ",data:" + com.bci.imas.util.IOUtils.encodeHex(buf)); mapBuf.put(buf); // mapBuf.force(); } finally { writeLock.unlock(); } return this; } /** * 在内存映象的指定位置写入一个长整数 * * @param desPos * The dest position of the memory map. * @param value * The long number to be writen. * @param len * The long number's byte length. * @return The boolean value if successed. * @throws MemoryNotMappedException * If the file not mapped into memory * @throws MemoryWriteException * If some exception occurs when write the object. */ public MemoryMappedFile wri