Home | History | Annotate | Download | only in include 
      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         Scoped ## NAME ## ArrayRO(JNIEnv* env, PRIMITIVE_TYPE ## Array javaArray) \
     30         : mEnv(env), mJavaArray(javaArray), mRawArray(NULL) { \
     31             if (mJavaArray == NULL) { \
     32                 jniThrowNullPointerException(mEnv, NULL); \
     33             } else { \
     34                 mRawArray = mEnv->Get ## NAME ## ArrayElements(mJavaArray, NULL); \
     35             } \
     36         } \
     37         ~Scoped ## NAME ## ArrayRO() { \
     38             if (mRawArray) { \
     39                 mEnv->Release ## NAME ## ArrayElements(mJavaArray, mRawArray, JNI_ABORT); \
     40             } \
     41         } \
     42         const PRIMITIVE_TYPE* get() const { return mRawArray; } \
     43         PRIMITIVE_TYPE ## Array getJavaArray() const { return mJavaArray; } \
     44         const PRIMITIVE_TYPE& operator[](size_t n) const { return mRawArray[n]; } \
     45         size_t size() const { return mEnv->GetArrayLength(mJavaArray); } \
     46     private: \
     47         JNIEnv* mEnv; \
     48         PRIMITIVE_TYPE ## Array mJavaArray; \
     49         PRIMITIVE_TYPE* mRawArray; \
     50         Scoped ## NAME ## ArrayRO(const Scoped ## NAME ## ArrayRO&); \
     51         void operator=(const Scoped ## NAME ## ArrayRO&); \
     52     }
     53 
     54 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jboolean, Boolean);
     55 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jbyte, Byte);
     56 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jchar, Char);
     57 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jdouble, Double);
     58 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jfloat, Float);
     59 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jint, Int);
     60 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jlong, Long);
     61 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO(jshort, Short);
     62 
     63 #undef INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RO
     64 
     65 // ScopedBooleanArrayRW, ScopedByteArrayRW, ScopedCharArrayRW, ScopedDoubleArrayRW,
     66 // ScopedFloatArrayRW, ScopedIntArrayRW, ScopedLongArrayRW, and ScopedShortArrayRW provide
     67 // convenient read-write access to Java arrays from JNI code. These are more expensive,
     68 // since they entail a copy back onto the Java heap, and should only be used when necessary.
     69 #define INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(PRIMITIVE_TYPE, NAME) \
     70     class Scoped ## NAME ## ArrayRW { \
     71     public: \
     72         Scoped ## NAME ## ArrayRW(JNIEnv* env, PRIMITIVE_TYPE ## Array javaArray) \
     73         : mEnv(env), mJavaArray(javaArray), mRawArray(NULL) { \
     74             if (mJavaArray == NULL) { \
     75                 jniThrowNullPointerException(mEnv, NULL); \
     76             } else { \
     77                 mRawArray = mEnv->Get ## NAME ## ArrayElements(mJavaArray, NULL); \
     78             } \
     79         } \
     80         ~Scoped ## NAME ## ArrayRW() { \
     81             if (mRawArray) { \
     82                 mEnv->Release ## NAME ## ArrayElements(mJavaArray, mRawArray, 0); \
     83             } \
     84         } \
     85         const PRIMITIVE_TYPE* get() const { return mRawArray; } \
     86         PRIMITIVE_TYPE ## Array getJavaArray() const { return mJavaArray; } \
     87         const PRIMITIVE_TYPE& operator[](size_t n) const { return mRawArray[n]; } \
     88         PRIMITIVE_TYPE* get() { return mRawArray; } \
     89         PRIMITIVE_TYPE& operator[](size_t n) { return mRawArray[n]; } \
     90         size_t size() const { return mEnv->GetArrayLength(mJavaArray); } \
     91     private: \
     92         JNIEnv* mEnv; \
     93         PRIMITIVE_TYPE ## Array mJavaArray; \
     94         PRIMITIVE_TYPE* mRawArray; \
     95         Scoped ## NAME ## ArrayRW(const Scoped ## NAME ## ArrayRW&); \
     96         void operator=(const Scoped ## NAME ## ArrayRW&); \
     97     }
     98 
     99 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jboolean, Boolean);
    100 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jbyte, Byte);
    101 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jchar, Char);
    102 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jdouble, Double);
    103 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jfloat, Float);
    104 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jint, Int);
    105 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jlong, Long);
    106 INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW(jshort, Short);
    107 
    108 #undef INSTANTIATE_SCOPED_PRIMITIVE_ARRAY_RW
    109 
    110 #endif  // SCOPED_PRIMITIVE_ARRAY_H_included
    111