org.elasticsearch.hadoop.util.BytesArrayPool Maven / Gradle / Ivy
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* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.
*/
package org.elasticsearch.hadoop.util;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
/**
* Basic class acting as a pool of {@link BytesArray}. The goal here is to reuse the arrays even when dealing with a unknown/dynamic list of "bytes" and reuse them across calls.
*/
public class BytesArrayPool implements ByteSequence {
private final List pool = new ArrayList();
private int inUse = 0;
@Override
public int length() {
int size = 0;
for (int i = 0; i < inUse; i++) {
size += pool.get(i).length();
}
return size;
}
@Override
public void writeTo(OutputStream out) throws IOException {
throw new UnsupportedOperationException();
}
public void reset() {
for (BytesArray ba : pool) {
ba.reset();
}
inUse = 0;
}
public BytesArray get() {
if (inUse < pool.size() - 1) {
return pool.get(inUse++);
}
else {
BytesArray ba = new BytesArray(64);
pool.add(ba);
inUse++;
return ba;
}
}
public List inUse() {
// don't need to sublist since pool is reset between uses.
return pool;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
for (BytesArray ba : pool) {
sb.append(ba.toString());
sb.append(";");
}
return sb.toString();
}
}