package org.apache.lucene.store;
/**
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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.
*/
import java.io.IOException;
/**
* A memory-resident {@link IndexOutput} implementation.
*
* @version $Id: RAMOutputStream.java 381429 2006-02-27 20:17:01Z cutting $
*/
public class RAMOutputStream extends BufferedIndexOutput {
private RAMFile file;
private int pointer = 0;
/** Construct an empty output buffer. */
public RAMOutputStream() {
this(new RAMFile());
}
RAMOutputStream(RAMFile f) {
file = f;
}
/** Copy the current contents of this buffer to the named output. */
public void writeTo(IndexOutput out) throws IOException {
flush();
final long end = file.length;
long pos = 0;
int buffer = 0;
while (pos < end) {
int length = BUFFER_SIZE;
long nextPos = pos + length;
if (nextPos > end) { // at the last buffer
length = (int)(end - pos);
}
out.writeBytes((byte[])file.buffers.elementAt(buffer++), length);
pos = nextPos;
}
}
/** Resets this to an empty buffer. */
public void reset() {
try {
seek(0);
} catch (IOException e) { // should never happen
throw new RuntimeException(e.toString());
}
file.length = 0;
}
public void flushBuffer(byte[] src, int len) {
byte[] buffer;
int bufferPos = 0;
while (bufferPos != len) {
int bufferNumber = pointer/BUFFER_SIZE;
int bufferOffset = pointer%BUFFER_SIZE;
int bytesInBuffer = BUFFER_SIZE - bufferOffset;
int remainInSrcBuffer = len - bufferPos;
int bytesToCopy = bytesInBuffer >= remainInSrcBuffer ? remainInSrcBuffer : bytesInBuffer;
if (bufferNumber == file.buffers.size()) {
buffer = new byte[BUFFER_SIZE];
file.buffers.addElement(buffer);
} else {
buffer = (byte[]) file.buffers.elementAt(bufferNumber);
}
System.arraycopy(src, bufferPos, buffer, bufferOffset, bytesToCopy);
bufferPos += bytesToCopy;
pointer += bytesToCopy;
}
if (pointer > file.length)
file.length = pointer;
file.lastModified = System.currentTimeMillis();
}
public void close() throws IOException {
super.close();
}
public void seek(long pos) throws IOException {
super.seek(pos);
pointer = (int)pos;
}
public long length() {
return file.length;
}
}
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