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/*
* Copyright (C) 2024 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.
*/
#include <nativehelper/JNIPlatformHelp.h>
#include <stddef.h>
#include "JniConstants.h"
static int GetBufferPosition(JNIEnv* env, jobject nioBuffer) {
return(*env)->GetIntField(env, nioBuffer, JniConstants_NioBuffer_position(env));
}
static int GetBufferLimit(JNIEnv* env, jobject nioBuffer) {
return(*env)->GetIntField(env, nioBuffer, JniConstants_NioBuffer_limit(env));
}
static int GetBufferElementSizeShift(JNIEnv* env, jobject nioBuffer) {
jclass byteBufferClass = JniConstants_NioByteBufferClass(env);
jclass shortBufferClass = JniConstants_NioShortBufferClass(env);
jclass charBufferClass = JniConstants_NioCharBufferClass(env);
jclass intBufferClass = JniConstants_NioIntBufferClass(env);
jclass floatBufferClass = JniConstants_NioFloatBufferClass(env);
jclass longBufferClass = JniConstants_NioLongBufferClass(env);
jclass doubleBufferClass = JniConstants_NioDoubleBufferClass(env);
// Check the type of the Buffer
if ((*env)->IsInstanceOf(env, nioBuffer, byteBufferClass)) {
return 0;
} else if ((*env)->IsInstanceOf(env, nioBuffer, shortBufferClass) ||
(*env)->IsInstanceOf(env, nioBuffer, charBufferClass)) {
return 1;
} else if ((*env)->IsInstanceOf(env, nioBuffer, intBufferClass) ||
(*env)->IsInstanceOf(env, nioBuffer, floatBufferClass)) {
return 2;
} else if ((*env)->IsInstanceOf(env, nioBuffer, longBufferClass) ||
(*env)->IsInstanceOf(env, nioBuffer, doubleBufferClass)) {
return 3;
}
return 0;
}
jarray jniGetNioBufferBaseArray(JNIEnv* env, jobject nioBuffer) {
jmethodID hasArrayMethod = JniConstants_NioBuffer_hasArray(env);
jboolean hasArray = (*env)->CallBooleanMethod(env, nioBuffer, hasArrayMethod);
if (hasArray) {
jmethodID arrayMethod = JniConstants_NioBuffer_array(env);
return (*env)->CallObjectMethod(env, nioBuffer, arrayMethod);
} else {
return NULL;
}
}
int jniGetNioBufferBaseArrayOffset(JNIEnv* env, jobject nioBuffer) {
jmethodID hasArrayMethod = JniConstants_NioBuffer_hasArray(env);
jboolean hasArray = (*env)->CallBooleanMethod(env, nioBuffer, hasArrayMethod);
if (hasArray) {
jmethodID arrayOffsetMethod = JniConstants_NioBuffer_arrayOffset(env);
jint arrayOffset = (*env)->CallIntMethod(env, nioBuffer, arrayOffsetMethod);
const int position = GetBufferPosition(env, nioBuffer);
jint elementSizeShift = GetBufferElementSizeShift(env, nioBuffer);
return (arrayOffset + position) << elementSizeShift;
} else {
return 0;
}
}
jlong jniGetNioBufferPointer(JNIEnv* env, jobject nioBuffer) {
// in Java 11, the address field of a HeapByteBuffer contains a non-zero value despite
// HeapByteBuffer being a non-direct buffer. In that case, this should still return 0.
jmethodID isDirectMethod = JniConstants_NioBuffer_isDirect(env);
jboolean isDirect = (*env)->CallBooleanMethod(env, nioBuffer, isDirectMethod);
if (isDirect == JNI_FALSE) {
return 0L;
}
jlong baseAddress = (*env)->GetLongField(env, nioBuffer, JniConstants_NioBuffer_address(env));
if (baseAddress != 0) {
const int position = GetBufferPosition(env, nioBuffer);
const int shift = GetBufferElementSizeShift(env, nioBuffer);
baseAddress += position << shift;
}
return baseAddress;
}
jlong jniGetNioBufferFields(JNIEnv* env, jobject nioBuffer,
jint* position, jint* limit, jint* elementSizeShift) {
*position = GetBufferPosition(env, nioBuffer);
*limit = GetBufferLimit(env, nioBuffer);
*elementSizeShift = GetBufferElementSizeShift(env, nioBuffer);
return (*env)->GetLongField(env, nioBuffer, JniConstants_NioBuffer_address(env));
}
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