/*
* Copyright (C) 2014 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.android.builder.png;
import com.android.annotations.NonNull;
import com.google.common.collect.Maps;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.Map;
/**
* A small util class to do byte conversion.
*
* This class allocates a couple of buffers and reuse them. Each new instance
* gets new buffers.
*
* This is not thread-safe.
*/
class ByteUtils {
@NonNull
private final ByteBuffer mIntBuffer;
@NonNull
private final ByteBuffer mLongBuffer;
ByteUtils() {
// ByteBuffer for endian-ness conversion
mIntBuffer = ByteBuffer.allocate(4).order(ByteOrder.BIG_ENDIAN);
mLongBuffer = ByteBuffer.allocate(8).order(ByteOrder.BIG_ENDIAN);
}
@NonNull
byte[] getLongAsIntArray(long value) {
return ((ByteBuffer) mLongBuffer.rewind()).putLong(value).array();
}
@NonNull
byte[] getIntAsArray(int value) {
return ((ByteBuffer) mIntBuffer.rewind()).putInt(value).array();
}
static class Cache {
private static final Cache sPngCache = new Cache();
private final Map<Long, ByteUtils> map = Maps.newHashMap();
@NonNull
static Cache getCache() {
return sPngCache;
}
synchronized ByteUtils getUtils(long key) {
ByteUtils utils = map.get(key);
if (utils == null) {
utils = new ByteUtils();
map.put(key, utils);
}
return utils;
}
static ByteUtils get() {
return getCache().getUtils(Thread.currentThread().getId());
}
synchronized void clear() {
map.clear();
}
}
}