68 lines
2.1 KiB
Java
68 lines
2.1 KiB
Java
package it.cavallium.strangedb.database.references;
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import it.cavallium.strangedb.database.IReferencesIO;
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import it.cavallium.strangedb.database.blocks.DatabaseBlocksIO;
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import java.io.IOException;
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import java.nio.ByteBuffer;
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import java.util.concurrent.locks.ReentrantReadWriteLock;
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import static it.cavallium.strangedb.database.IBlocksMetadata.EMPTY_BLOCK_ID;
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public class DatabaseReferencesIO implements IReferencesIO {
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private final DatabaseBlocksIO blocksIO;
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private final DatabaseReferencesMetadata referencesMetadata;
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private ReentrantReadWriteLock lock = new ReentrantReadWriteLock(false);
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public DatabaseReferencesIO(DatabaseBlocksIO blocksIO, DatabaseReferencesMetadata referencesMetadata) {
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this.blocksIO = blocksIO;
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this.referencesMetadata = referencesMetadata;
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}
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@Override
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public long allocateReference() throws IOException {
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return referencesMetadata.newReference(EMPTY_BLOCK_ID);
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}
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@Override
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public long allocateReference(int size, ByteBuffer data) throws IOException {
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long blockId = (size == 0) ? EMPTY_BLOCK_ID : blocksIO.newBlock(size, data);
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return referencesMetadata.newReference(blockId);
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}
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@Override
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public void writeToReference(long reference, byte cleanerId, int size, ByteBuffer data) throws IOException {
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long blockId = (size == 0) ? EMPTY_BLOCK_ID : blocksIO.newBlock(size, data);
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lock.writeLock().lock();
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try {
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referencesMetadata.editReference(reference, cleanerId, blockId);
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} finally {
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lock.writeLock().unlock();
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}
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}
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@Override
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public ByteBuffer readFromReference(long reference) throws IOException {
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long blockId;
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lock.readLock().lock();
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try {
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blockId = referencesMetadata.getReferenceBlockId(reference);
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} finally {
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lock.readLock().unlock();
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}
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return blocksIO.readBlock(blockId);
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}
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public ByteBuffer readFromReferenceSizeAndLastElementOfReferencesList(long reference) throws IOException {
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long blockId;
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lock.readLock().lock();
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try {
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blockId = referencesMetadata.getReferenceBlockId(reference);
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} finally {
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lock.readLock().unlock();
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}
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return blocksIO.readBlockSizeAndLastElementOfReferencesList(blockId);
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}
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}
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