64 lines
1.3 KiB
Java
64 lines
1.3 KiB
Java
package org.warp.jcwdb;
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import java.io.IOException;
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import java.nio.channels.SeekableByteChannel;
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public class FileAllocator implements AutoCloseable {
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private final SeekableByteChannel dataFileChannel;
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private volatile long allocableOffset;
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private volatile boolean closed;
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private final Object closeLock = new Object();
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private final Object allocateLock = new Object();
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public FileAllocator(SeekableByteChannel dataFileChannel) throws IOException {
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this.dataFileChannel = dataFileChannel;
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this.allocableOffset = this.dataFileChannel.size();
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}
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/**
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* TODO: not implemented
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*
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* @param size
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* @return offset
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*/
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public long allocate(int size) {
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checkClosed();
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synchronized (allocateLock) {
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long allocatedOffset = allocableOffset;
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allocableOffset += size;
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return allocatedOffset;
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}
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}
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public void close() throws IOException {
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if (closed) {
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return;
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}
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synchronized (closeLock) {
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if (closed) {
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return;
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}
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closed = true;
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}
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}
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/**
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* Frees the unused bytes
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*
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* @param startPosition
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* @param length
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*/
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public void markFree(long startPosition, int length) {
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checkClosed();
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// TODO: advanced feature, not implemented.
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}
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private void checkClosed() {
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if (closed) {
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throw new RuntimeException("Index Manager is closed.");
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}
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}
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}
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