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/*
* Copyright (C) 2010 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.
*/
#ifndef SCOPED_BYTES_H_included
#define SCOPED_BYTES_H_included
#include "JNIHelp.h"
/**
* ScopedBytesRO and ScopedBytesRW attempt to paper over the differences between byte[]s and
* ByteBuffers. This in turn helps paper over the differences between non-direct ByteBuffers backed
* by byte[]s, direct ByteBuffers backed by bytes[]s, and direct ByteBuffers not backed by byte[]s.
* (On Android, this last group only contains MappedByteBuffers.)
*/
template<bool readOnly>
class ScopedBytes {
public:
ScopedBytes(JNIEnv* env, jobject object)
: mEnv(env), mObject(object), mByteArray(NULL), mPtr(NULL)
{
if (mObject == NULL) {
jniThrowNullPointerException(mEnv, NULL);
} else if (mEnv->IsInstanceOf(mObject, JniConstants::byteArrayClass)) {
mByteArray = reinterpret_cast<jbyteArray>(mObject);
mPtr = mEnv->GetByteArrayElements(mByteArray, NULL);
} else {
mPtr = reinterpret_cast<jbyte*>(mEnv->GetDirectBufferAddress(mObject));
}
}
~ScopedBytes() {
if (mByteArray != NULL) {
mEnv->ReleaseByteArrayElements(mByteArray, mPtr, readOnly ? JNI_ABORT : 0);
}
}
private:
JNIEnv* mEnv;
jobject mObject;
jbyteArray mByteArray;
protected:
jbyte* mPtr;
private:
// Disallow copy and assignment.
ScopedBytes(const ScopedBytes&);
void operator=(const ScopedBytes&);
};
class ScopedBytesRO : public ScopedBytes<true> {
public:
ScopedBytesRO(JNIEnv* env, jobject object) : ScopedBytes<true>(env, object) {}
const jbyte* get() const {
return mPtr;
}
};
class ScopedBytesRW : public ScopedBytes<false> {
public:
ScopedBytesRW(JNIEnv* env, jobject object) : ScopedBytes<false>(env, object) {}
jbyte* get() {
return mPtr;
}
};
#endif // SCOPED_BYTES_H_included
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