aosp12/libnativehelper/header_only_include/nativehelper/scoped_primitive_array.h

149 lines
6.1 KiB
C++

/*
* 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.
*/
#pragma once
#include <stddef.h>
#include <jni.h>
#include "nativehelper_utils.h"
#ifdef POINTER_TYPE
#error POINTER_TYPE is defined.
#else
#define POINTER_TYPE(T) T* /* NOLINT */
#endif
#ifdef REFERENCE_TYPE
#error REFERENCE_TYPE is defined.
#else
#define REFERENCE_TYPE(T) T& /* NOLINT */
#endif
// ScopedBooleanArrayRO, ScopedByteArrayRO, ScopedCharArrayRO, ScopedDoubleArrayRO,
// ScopedFloatArrayRO, ScopedIntArrayRO, ScopedLongArrayRO, and ScopedShortArrayRO provide
// convenient read-only access to Java arrays from JNI code. This is cheaper than read-write
// access and should be used by default.
#define INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(PRIMITIVE_TYPE, NAME) \
class Scoped ## NAME ## ArrayRO { \
public: \
explicit Scoped ## NAME ## ArrayRO(JNIEnv* env) \
: mEnv(env), mJavaArray(nullptr), mRawArray(nullptr), mSize(0) {} \
Scoped ## NAME ## ArrayRO(JNIEnv* env, PRIMITIVE_TYPE ## Array javaArray) \
: mEnv(env) { \
if (javaArray == nullptr) { \
mJavaArray = nullptr; \
mSize = 0; \
mRawArray = nullptr; \
jniThrowNullPointerException(mEnv); \
} else { \
reset(javaArray); \
} \
} \
~Scoped ## NAME ## ArrayRO() { \
if (mRawArray != nullptr && mRawArray != mBuffer) { \
mEnv->Release ## NAME ## ArrayElements(mJavaArray, mRawArray, JNI_ABORT); \
} \
} \
void reset(PRIMITIVE_TYPE ## Array javaArray) { \
mJavaArray = javaArray; \
mSize = mEnv->GetArrayLength(mJavaArray); \
if (mSize <= buffer_size) { \
mEnv->Get ## NAME ## ArrayRegion(mJavaArray, 0, mSize, mBuffer); \
mRawArray = mBuffer; \
} else { \
mRawArray = mEnv->Get ## NAME ## ArrayElements(mJavaArray, nullptr); \
} \
} \
const PRIMITIVE_TYPE* get() const { return mRawArray; } \
PRIMITIVE_TYPE ## Array getJavaArray() const { return mJavaArray; } \
const PRIMITIVE_TYPE& operator[](size_t n) const { return mRawArray[n]; } \
size_t size() const { return mSize; } \
private: \
static const jsize buffer_size = 1024; \
JNIEnv* const mEnv; \
PRIMITIVE_TYPE ## Array mJavaArray; \
POINTER_TYPE(PRIMITIVE_TYPE) mRawArray; \
jsize mSize; \
PRIMITIVE_TYPE mBuffer[buffer_size]; \
DISALLOW_COPY_AND_ASSIGN(Scoped ## NAME ## ArrayRO); \
}
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jboolean, Boolean);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jbyte, Byte);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jchar, Char);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jdouble, Double);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jfloat, Float);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jint, Int);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jlong, Long);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jshort, Short);
#undef INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO
// ScopedBooleanArrayRW, ScopedByteArrayRW, ScopedCharArrayRW, ScopedDoubleArrayRW,
// ScopedFloatArrayRW, ScopedIntArrayRW, ScopedLongArrayRW, and ScopedShortArrayRW provide
// convenient read-write access to Java arrays from JNI code. These are more expensive,
// since they entail a copy back onto the Java heap, and should only be used when necessary.
#define INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(PRIMITIVE_TYPE, NAME) \
class Scoped ## NAME ## ArrayRW { \
public: \
explicit Scoped ## NAME ## ArrayRW(JNIEnv* env) \
: mEnv(env), mJavaArray(nullptr), mRawArray(nullptr) {} \
Scoped ## NAME ## ArrayRW(JNIEnv* env, PRIMITIVE_TYPE ## Array javaArray) \
: mEnv(env), mJavaArray(javaArray), mRawArray(nullptr) { \
if (mJavaArray == nullptr) { \
jniThrowNullPointerException(mEnv); \
} else { \
mRawArray = mEnv->Get ## NAME ## ArrayElements(mJavaArray, nullptr); \
} \
} \
~Scoped ## NAME ## ArrayRW() { \
if (mRawArray) { \
mEnv->Release ## NAME ## ArrayElements(mJavaArray, mRawArray, 0); \
} \
} \
void reset(PRIMITIVE_TYPE ## Array javaArray) { \
mJavaArray = javaArray; \
mRawArray = mEnv->Get ## NAME ## ArrayElements(mJavaArray, nullptr); \
} \
const PRIMITIVE_TYPE* get() const { return mRawArray; } \
PRIMITIVE_TYPE ## Array getJavaArray() const { return mJavaArray; } \
const PRIMITIVE_TYPE& operator[](size_t n) const { return mRawArray[n]; } \
POINTER_TYPE(PRIMITIVE_TYPE) get() { return mRawArray; } \
REFERENCE_TYPE(PRIMITIVE_TYPE) operator[](size_t n) { return mRawArray[n]; } \
size_t size() const { return mEnv->GetArrayLength(mJavaArray); } \
private: \
JNIEnv* const mEnv; \
PRIMITIVE_TYPE ## Array mJavaArray; \
POINTER_TYPE(PRIMITIVE_TYPE) mRawArray; \
DISALLOW_COPY_AND_ASSIGN(Scoped ## NAME ## ArrayRW); \
}
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jboolean, Boolean);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jbyte, Byte);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jchar, Char);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jdouble, Double);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jfloat, Float);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jint, Int);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jlong, Long);
INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jshort, Short);
#undef INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW
#undef POINTER_TYPE
#undef REFERENCE_TYPE