com.google.gerrit.server.change.LimitedByteArrayOutputStream Maven / Gradle / Ivy
// Copyright (C) 2016 The Android Open Source Project
//
// 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.
package com.google.gerrit.server.change;
import static com.google.common.base.Preconditions.checkArgument;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
class LimitedByteArrayOutputStream extends OutputStream {
private final int maxSize;
private final ByteArrayOutputStream buffer;
/**
* Constructs a LimitedByteArrayOutputStream, which stores output in memory up to a certain
* specified size. When the output exceeds the specified size a LimitExceededException is thrown.
*
* @param max the maximum size in bytes which may be stored.
* @param initial the initial size. It must be smaller than the max size.
*/
LimitedByteArrayOutputStream(int max, int initial) {
checkArgument(initial <= max);
maxSize = max;
buffer = new ByteArrayOutputStream(initial);
}
private void checkOversize(int additionalSize) throws IOException {
if (buffer.size() + additionalSize > maxSize) {
throw new LimitExceededException();
}
}
@Override
public void write(int b) throws IOException {
checkOversize(1);
buffer.write(b);
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
checkOversize(len);
buffer.write(b, off, len);
}
/** @return a newly allocated byte array with contents of the buffer. */
public byte[] toByteArray() {
return buffer.toByteArray();
}
static class LimitExceededException extends IOException {
private static final long serialVersionUID = 1L;
}
}