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/*
* Copyright (C) 2007 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.
*/
/*
* JNI helper functions.
*
* This file may be included by C or C++ code, which is trouble because jni.h
* uses different typedefs for JNIEnv in each language.
*/
#pragma once
#include <sys/cdefs.h>
#include <jni.h>
#include <nativehelper/JNIHelp.h>
__BEGIN_DECLS
/*
* Gets the managed heap array backing a java.nio.Buffer instance.
*
* Returns nullptr if there is no array backing.
*
* This method performs a JNI call to java.nio.NIOAccess.getBaseArray().
*/
jarray jniGetNioBufferBaseArray(C_JNIEnv* env, jobject nioBuffer);
/*
* Gets the offset of the current buffer position in bytes from the start of the managed heap
* array backing the buffer.
*
* Returns 0 if there is no array backing.
*
* This method performs a JNI call to java.nio.NIOAccess.getBaseArrayOffset().
*/
jint jniGetNioBufferBaseArrayOffset(C_JNIEnv* env, jobject nioBuffer);
/*
* Gets field information from a java.nio.Buffer instance.
*
* Reads the |position|, |limit|, and |elementSizeShift| fields from the buffer instance.
*
* Returns the |address| field of the java.nio.Buffer instance which is only valid (non-zero) when
* the buffer is backed by a direct buffer.
*/
jlong jniGetNioBufferFields(C_JNIEnv* env,
jobject nioBuffer,
/*out*/jint* position,
/*out*/jint* limit,
/*out*/jint* elementSizeShift);
/*
* Gets the current position from a java.nio.Buffer as a pointer to memory in a fixed buffer.
*
* Returns 0 if |nioBuffer| is not backed by a direct buffer.
*
* This method reads the |address|, |position|, and |elementSizeShift| fields from the
* java.nio.Buffer instance to calculate the pointer address for the current position.
*/
jlong jniGetNioBufferPointer(C_JNIEnv* env, jobject nioBuffer);
/*
* Clear the cache of constants libnativehelper is using.
*/
void jniUninitializeConstants();
__END_DECLS
/*
* For C++ code, we provide inlines that map to the C functions. g++ always
* inlines these, even on non-optimized builds.
*/
#if defined(__cplusplus)
#include <android/file_descriptor_jni.h>
inline jobject jniCreateFileDescriptor(JNIEnv* env, int fd) {
jobject fileDescriptor = AFileDescriptor_create(env);
if (fileDescriptor != nullptr) {
AFileDescriptor_setFd(env, fileDescriptor, fd);
}
return fileDescriptor;
}
inline int jniGetFDFromFileDescriptor(JNIEnv* env, jobject fileDescriptor) {
if (fileDescriptor == nullptr) {
return -1;
}
return AFileDescriptor_getFd(env, fileDescriptor);
}
inline void jniSetFileDescriptorOfFD(JNIEnv* env, jobject fileDescriptor, int value) {
if (fileDescriptor == nullptr) {
jniThrowNullPointerException(env, "fileDescriptor is null");
return;
}
AFileDescriptor_setFd(env, fileDescriptor, value);
}
inline jarray jniGetNioBufferBaseArray(JNIEnv* env, jobject nioBuffer) {
return jniGetNioBufferBaseArray(&env->functions, nioBuffer);
}
inline jint jniGetNioBufferBaseArrayOffset(JNIEnv* env, jobject nioBuffer) {
return jniGetNioBufferBaseArrayOffset(&env->functions, nioBuffer);
}
inline jlong jniGetNioBufferFields(JNIEnv* env, jobject nioBuffer,
jint* position, jint* limit, jint* elementSizeShift) {
return jniGetNioBufferFields(&env->functions, nioBuffer,
position, limit, elementSizeShift);
}
inline jlong jniGetNioBufferPointer(JNIEnv* env, jobject nioBuffer) {
return jniGetNioBufferPointer(&env->functions, nioBuffer);
}
#endif // defined(__cplusplus)