1 /*
2  * Copyright (C) 2006 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "include_platform/nativehelper/JNIPlatformHelp.h"
18 
19 #include <stddef.h>
20 
21 #include "JniConstants.h"
22 
GetBufferPosition(JNIEnv * env,jobject nioBuffer)23 static int GetBufferPosition(JNIEnv* env, jobject nioBuffer) {
24     return(*env)->GetIntField(env, nioBuffer, JniConstants_NioBuffer_position(env));
25 }
26 
GetBufferLimit(JNIEnv * env,jobject nioBuffer)27 static int GetBufferLimit(JNIEnv* env, jobject nioBuffer) {
28     return(*env)->GetIntField(env, nioBuffer, JniConstants_NioBuffer_limit(env));
29 }
30 
GetBufferElementSizeShift(JNIEnv * env,jobject nioBuffer)31 static int GetBufferElementSizeShift(JNIEnv* env, jobject nioBuffer) {
32     return(*env)->GetIntField(env, nioBuffer, JniConstants_NioBuffer__elementSizeShift(env));
33 }
34 
jniCreateFileDescriptor(JNIEnv * env,int fd)35 jobject jniCreateFileDescriptor(JNIEnv* env, int fd) {
36     jobject fileDescriptor = (*env)->NewObject(env,
37                                                JniConstants_FileDescriptorClass(env),
38                                                JniConstants_FileDescriptor_init(env));
39     // NOTE: NewObject ensures that an OutOfMemoryError will be seen by the Java
40     // caller if the alloc fails, so we just return nullptr when that happens.
41     if (fileDescriptor != NULL)  {
42         jniSetFileDescriptorOfFD(env, fileDescriptor, fd);
43     }
44     return fileDescriptor;
45 }
46 
jniGetFDFromFileDescriptor(JNIEnv * env,jobject fileDescriptor)47 int jniGetFDFromFileDescriptor(JNIEnv* env, jobject fileDescriptor) {
48     if (fileDescriptor != NULL) {
49         return (*env)->GetIntField(env, fileDescriptor,
50                                    JniConstants_FileDescriptor_descriptor(env));
51     } else {
52         return -1;
53     }
54 }
55 
jniSetFileDescriptorOfFD(JNIEnv * env,jobject fileDescriptor,int value)56 void jniSetFileDescriptorOfFD(JNIEnv* env, jobject fileDescriptor, int value) {
57     if (fileDescriptor == NULL) {
58         jniThrowNullPointerException(env, "null FileDescriptor");
59     } else {
60         (*env)->SetIntField(env,
61                             fileDescriptor, JniConstants_FileDescriptor_descriptor(env), value);
62     }
63 }
64 
jniGetNioBufferBaseArray(JNIEnv * env,jobject nioBuffer)65 jarray jniGetNioBufferBaseArray(JNIEnv* env, jobject nioBuffer) {
66     jclass nioAccessClass = JniConstants_NIOAccessClass(env);
67     jmethodID getBaseArrayMethod = JniConstants_NIOAccess_getBaseArray(env);
68     jobject object = (*env)->CallStaticObjectMethod(env,
69                                                     nioAccessClass, getBaseArrayMethod, nioBuffer);
70     return (jarray) object;
71 }
72 
jniGetNioBufferBaseArrayOffset(JNIEnv * env,jobject nioBuffer)73 int jniGetNioBufferBaseArrayOffset(JNIEnv* env, jobject nioBuffer) {
74     jclass nioAccessClass = JniConstants_NIOAccessClass(env);
75     jmethodID getBaseArrayOffsetMethod = JniConstants_NIOAccess_getBaseArrayOffset(env);
76     return (*env)->CallStaticIntMethod(env, nioAccessClass, getBaseArrayOffsetMethod, nioBuffer);
77 }
78 
jniGetNioBufferPointer(JNIEnv * env,jobject nioBuffer)79 jlong jniGetNioBufferPointer(JNIEnv* env, jobject nioBuffer) {
80     jlong baseAddress = (*env)->GetLongField(env, nioBuffer, JniConstants_NioBuffer_address(env));
81     if (baseAddress != 0) {
82         const int position = GetBufferPosition(env, nioBuffer);
83         const int shift = GetBufferElementSizeShift(env, nioBuffer);
84         baseAddress += position << shift;
85     }
86     return baseAddress;
87 }
88 
jniGetNioBufferFields(JNIEnv * env,jobject nioBuffer,jint * position,jint * limit,jint * elementSizeShift)89 jlong jniGetNioBufferFields(JNIEnv* env, jobject nioBuffer,
90                             jint* position, jint* limit, jint* elementSizeShift) {
91     *position = GetBufferPosition(env, nioBuffer);
92     *limit = GetBufferLimit(env, nioBuffer);
93     *elementSizeShift = GetBufferElementSizeShift(env, nioBuffer);
94     return (*env)->GetLongField(env, nioBuffer, JniConstants_NioBuffer_address(env));
95 }
96