1 /*
2  * Copyright (C) 2010 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 #ifndef SCOPED_PRIMITIVE_ARRAY_H_included
18 #define SCOPED_PRIMITIVE_ARRAY_H_included
19 
20 #include "JNIHelp.h"
21 
22 // ScopedBooleanArrayRO, ScopedByteArrayRO, ScopedCharArrayRO, ScopedDoubleArrayRO,
23 // ScopedFloatArrayRO, ScopedIntArrayRO, ScopedLongArrayRO, and ScopedShortArrayRO provide
24 // convenient read-only access to Java arrays from JNI code. This is cheaper than read-write
25 // access and should be used by default.
26 #define INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(PRIMITIVE_TYPE, NAME) \
27     class Scoped ## NAME ## ArrayRO { \
28     public: \
29         explicit Scoped ## NAME ## ArrayRO(JNIEnv* env) \
30         : mEnv(env), mJavaArray(NULL), mRawArray(NULL) {} \
31         Scoped ## NAME ## ArrayRO(JNIEnv* env, PRIMITIVE_TYPE ## Array javaArray) \
32         : mEnv(env), mJavaArray(javaArray), mRawArray(NULL) { \
33             if (mJavaArray == NULL) { \
34                 jniThrowNullPointerException(mEnv, NULL); \
35             } else { \
36                 mRawArray = mEnv->Get ## NAME ## ArrayElements(mJavaArray, NULL); \
37             } \
38         } \
39         ~Scoped ## NAME ## ArrayRO() { \
40             if (mRawArray) { \
41                 mEnv->Release ## NAME ## ArrayElements(mJavaArray, mRawArray, JNI_ABORT); \
42             } \
43         } \
44         void reset(PRIMITIVE_TYPE ## Array javaArray) { \
45             mJavaArray = javaArray; \
46             mRawArray = mEnv->Get ## NAME ## ArrayElements(mJavaArray, NULL); \
47         } \
48         const PRIMITIVE_TYPE* get() const { return mRawArray; } \
49         PRIMITIVE_TYPE ## Array getJavaArray() const { return mJavaArray; } \
50         const PRIMITIVE_TYPE& operator[](size_t n) const { return mRawArray[n]; } \
51         size_t size() const { return mEnv->GetArrayLength(mJavaArray); } \
52     private: \
53         JNIEnv* mEnv; \
54         PRIMITIVE_TYPE ## Array mJavaArray; \
55         PRIMITIVE_TYPE* mRawArray; \
56         Scoped ## NAME ## ArrayRO(const Scoped ## NAME ## ArrayRO&); \
57         void operator=(const Scoped ## NAME ## ArrayRO&); \
58     }
59 
60 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jboolean, Boolean);
61 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jbyte, Byte);
62 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jchar, Char);
63 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jdouble, Double);
64 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jfloat, Float);
65 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jint, Int);
66 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jlong, Long);
67 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jshort, Short);
68 
69 #undef INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO
70 
71 // ScopedBooleanArrayRW, ScopedByteArrayRW, ScopedCharArrayRW, ScopedDoubleArrayRW,
72 // ScopedFloatArrayRW, ScopedIntArrayRW, ScopedLongArrayRW, and ScopedShortArrayRW provide
73 // convenient read-write access to Java arrays from JNI code. These are more expensive,
74 // since they entail a copy back onto the Java heap, and should only be used when necessary.
75 #define INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(PRIMITIVE_TYPE, NAME) \
76     class Scoped ## NAME ## ArrayRW { \
77     public: \
78         explicit Scoped ## NAME ## ArrayRW(JNIEnv* env) \
79         : mEnv(env), mJavaArray(NULL), mRawArray(NULL) {} \
80         Scoped ## NAME ## ArrayRW(JNIEnv* env, PRIMITIVE_TYPE ## Array javaArray) \
81         : mEnv(env), mJavaArray(javaArray), mRawArray(NULL) { \
82             if (mJavaArray == NULL) { \
83                 jniThrowNullPointerException(mEnv, NULL); \
84             } else { \
85                 mRawArray = mEnv->Get ## NAME ## ArrayElements(mJavaArray, NULL); \
86             } \
87         } \
88         ~Scoped ## NAME ## ArrayRW() { \
89             if (mRawArray) { \
90                 mEnv->Release ## NAME ## ArrayElements(mJavaArray, mRawArray, 0); \
91             } \
92         } \
93         void reset(PRIMITIVE_TYPE ## Array javaArray) { \
94             mJavaArray = javaArray; \
95             mRawArray = mEnv->Get ## NAME ## ArrayElements(mJavaArray, NULL); \
96         } \
97         const PRIMITIVE_TYPE* get() const { return mRawArray; } \
98         PRIMITIVE_TYPE ## Array getJavaArray() const { return mJavaArray; } \
99         const PRIMITIVE_TYPE& operator[](size_t n) const { return mRawArray[n]; } \
100         PRIMITIVE_TYPE* get() { return mRawArray; } \
101         PRIMITIVE_TYPE& operator[](size_t n) { return mRawArray[n]; } \
102         size_t size() const { return mEnv->GetArrayLength(mJavaArray); } \
103     private: \
104         JNIEnv* mEnv; \
105         PRIMITIVE_TYPE ## Array mJavaArray; \
106         PRIMITIVE_TYPE* mRawArray; \
107         Scoped ## NAME ## ArrayRW(const Scoped ## NAME ## ArrayRW&); \
108         void operator=(const Scoped ## NAME ## ArrayRW&); \
109     }
110 
111 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jboolean, Boolean);
112 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jbyte, Byte);
113 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jchar, Char);
114 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jdouble, Double);
115 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jfloat, Float);
116 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jint, Int);
117 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jlong, Long);
118 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jshort, Short);
119 
120 #undef INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW
121 
122 #endif  // SCOPED_PRIMITIVE_ARRAY_H_included
123