168 lines
3.7 KiB
Java
168 lines
3.7 KiB
Java
package it.cavallium.dbengine.lucene.directory;
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import io.net5.buffer.ByteBuf;
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import io.net5.buffer.ByteBufAllocator;
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import io.net5.buffer.Unpooled;
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import java.io.EOFException;
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import java.io.IOException;
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import org.apache.lucene.store.IndexInput;
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public class RocksdbInputStream extends IndexInput {
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private final int bufferSize;
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private long position;
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private final long length;
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private ByteBuf currentBuffer;
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private final RocksdbFileStore store;
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private final String name;
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public RocksdbInputStream(String name, RocksdbFileStore store, int bufferSize) throws IOException {
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this(name, store, bufferSize, store.getSize(name));
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}
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public RocksdbInputStream(String name, RocksdbFileStore store, int bufferSize, long length) {
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this(name,
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store,
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bufferSize,
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length,
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ByteBufAllocator.DEFAULT.ioBuffer(bufferSize, bufferSize).writerIndex(bufferSize)
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);
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}
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private RocksdbInputStream(String name, RocksdbFileStore store, int bufferSize, long length, ByteBuf currentBuffer) {
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super("RocksdbInputStream(name=" + name + ")");
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this.name = name;
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this.store = store;
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this.bufferSize = bufferSize;
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this.currentBuffer = currentBuffer;
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currentBuffer.readerIndex(bufferSize);
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this.position = 0;
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this.length = length;
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}
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@Override
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public void close() throws IOException {
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currentBuffer.release();
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}
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@Override
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public long getFilePointer() {
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return position;
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}
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@Override
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public void seek(long pos) {
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if (pos < 0 || pos > length) {
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throw new IllegalArgumentException("pos must be between 0 and " + length);
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}
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position = pos;
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currentBuffer.readerIndex(bufferSize);
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}
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@Override
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public long length() {
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return this.length;
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}
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@Override
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public IndexInput slice(String sliceDescription, final long offset, final long length) throws IOException {
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if (offset < 0 || length < 0 || offset + length > this.length) {
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throw new IllegalArgumentException("slice() " + sliceDescription + " out of bounds: " + this);
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}
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return new RocksdbInputStream(name,
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store,
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bufferSize,
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offset + length,
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Unpooled.buffer(bufferSize, bufferSize).writerIndex(bufferSize)
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) {
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{
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seek(0L);
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}
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@Override
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public void seek(long pos) {
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if (pos < 0L) {
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throw new IllegalArgumentException("Seeking to negative position: " + this);
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}
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super.seek(pos + offset);
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}
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@Override
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public long getFilePointer() {
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return super.getFilePointer() - offset;
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}
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@Override
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public long length() {
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return super.length() - offset;
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}
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@Override
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public IndexInput slice(String sliceDescription, long ofs, long len) throws IOException {
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return super.slice(sliceDescription, offset + ofs, len);
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}
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};
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}
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@Override
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public byte readByte() throws IOException {
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if (position >= length) {
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throw new EOFException("Read end");
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}
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loadBufferIfNeed();
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byte b = currentBuffer.readByte();
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position++;
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return b;
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}
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protected void loadBufferIfNeed() throws IOException {
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if (currentBuffer.readerIndex() == this.bufferSize) {
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int n = store.load(name, position, currentBuffer, 0, bufferSize);
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if (n == -1) {
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throw new EOFException("Read end");
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}
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currentBuffer.readerIndex(0);
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}
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}
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@Override
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public void readBytes(byte[] b, int offset, int len) throws IOException {
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if (position >= length) {
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throw new EOFException("Read end");
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}
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int f = offset;
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int n = Math.min((int) (length - position), len);
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do {
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loadBufferIfNeed();
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int r = Math.min(bufferSize - currentBuffer.readerIndex(), n);
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currentBuffer.readBytes(b, f, r);
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f += r;
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position += r;
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n -= r;
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} while (n != 0);
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}
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@Override
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public IndexInput clone() {
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RocksdbInputStream in = (RocksdbInputStream) super.clone();
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in.currentBuffer = in.currentBuffer.duplicate();
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return in;
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}
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} |