1 /*
2 * Copyright (C) 2008 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 "android_nio_utils.h"
18
19 #include "core_jni_helpers.h"
20
21 struct NioJNIData {
22 jclass nioAccessClass;
23
24 jmethodID getBasePointerID;
25 jmethodID getBaseArrayID;
26 jmethodID getBaseArrayOffsetID;
27 };
28
29 static NioJNIData gNioJNI;
30
nio_getPointer(JNIEnv * _env,jobject buffer,jarray * array)31 void* android::nio_getPointer(JNIEnv *_env, jobject buffer, jarray *array) {
32 assert(array);
33
34 jlong pointer;
35 jint offset;
36 void *data;
37
38 pointer = _env->CallStaticLongMethod(gNioJNI.nioAccessClass,
39 gNioJNI.getBasePointerID, buffer);
40 if (pointer != 0L) {
41 *array = NULL;
42 return reinterpret_cast<void *>(pointer);
43 }
44
45 *array = (jarray) _env->CallStaticObjectMethod(gNioJNI.nioAccessClass,
46 gNioJNI.getBaseArrayID, buffer);
47 offset = _env->CallStaticIntMethod(gNioJNI.nioAccessClass,
48 gNioJNI.getBaseArrayOffsetID, buffer);
49 data = _env->GetPrimitiveArrayCritical(*array, (jboolean *) 0);
50
51 return (void *) ((char *) data + offset);
52 }
53
54
nio_releasePointer(JNIEnv * _env,jarray array,void * data,jboolean commit)55 void android::nio_releasePointer(JNIEnv *_env, jarray array, void *data,
56 jboolean commit) {
57 _env->ReleasePrimitiveArrayCritical(array, data,
58 commit ? 0 : JNI_ABORT);
59 }
60
61 ///////////////////////////////////////////////////////////////////////////////
62
AutoBufferPointer(JNIEnv * env,jobject nioBuffer,jboolean commit)63 android::AutoBufferPointer::AutoBufferPointer(JNIEnv* env, jobject nioBuffer,
64 jboolean commit) {
65 fEnv = env;
66 fCommit = commit;
67 fPointer = android::nio_getPointer(env, nioBuffer, &fArray);
68 }
69
~AutoBufferPointer()70 android::AutoBufferPointer::~AutoBufferPointer() {
71 if (NULL != fArray) {
72 android::nio_releasePointer(fEnv, fArray, fPointer, fCommit);
73 }
74 }
75
76 ///////////////////////////////////////////////////////////////////////////////
77
78 namespace android {
79
register_android_nio_utils(JNIEnv * env)80 int register_android_nio_utils(JNIEnv* env) {
81 jclass localClass = FindClassOrDie(env, "java/nio/NIOAccess");
82 gNioJNI.getBasePointerID = GetStaticMethodIDOrDie(env, localClass, "getBasePointer",
83 "(Ljava/nio/Buffer;)J");
84 gNioJNI.getBaseArrayID = GetStaticMethodIDOrDie(env, localClass, "getBaseArray",
85 "(Ljava/nio/Buffer;)Ljava/lang/Object;");
86 gNioJNI.getBaseArrayOffsetID = GetStaticMethodIDOrDie(env, localClass, "getBaseArrayOffset",
87 "(Ljava/nio/Buffer;)I");
88
89 // now record a permanent version of the class ID
90 gNioJNI.nioAccessClass = MakeGlobalRefOrDie(env, localClass);
91
92 return 0;
93 }
94
95 }
96