xref: /aosp_15_r20/external/fbjni/cxx/fbjni/ByteBuffer.h (revision 65c59e023c5336bbd4a23be7af78407e3d80e7e7)
1 /*
2  * Copyright (c) Facebook, Inc. and its affiliates.
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 #pragma once
18 
19 #include <fbjni/fbjni.h>
20 
21 namespace facebook {
22 namespace jni {
23 
24 class JBuffer : public JavaClass<JBuffer> {
25  public:
26   static constexpr const char* kJavaDescriptor = "Ljava/nio/Buffer;";
27 
28   void rewind() const;
29   bool isDirect() const;
30   void* getDirectAddress() const;
31   size_t getDirectCapacity() const;
32 };
33 
34 class JByteOrder : public JavaClass<JByteOrder> {
35  public:
36   constexpr static const char* kJavaDescriptor = "Ljava/nio/ByteOrder;";
37 
38   static local_ref<JByteOrder> nativeOrder();
39   static local_ref<JByteOrder> bigEndian();
40   static local_ref<JByteOrder> littleEndian();
41 };
42 
43 // JNI's NIO support has some awkward preconditions and error reporting. This
44 // class provides much more user-friendly access.
45 class JByteBuffer : public JavaClass<JByteBuffer, JBuffer> {
46  public:
47   static constexpr const char* kJavaDescriptor = "Ljava/nio/ByteBuffer;";
48 
49   static local_ref<JByteBuffer> wrapBytes(uint8_t* data, size_t size);
50   static local_ref<JByteBuffer> allocateDirect(jint size);
51 
52   local_ref<JByteBuffer> order(alias_ref<JByteOrder>);
53 
getDirectBytes()54   uint8_t* getDirectBytes() const {
55     return static_cast<uint8_t*>(getDirectAddress());
56   }
57 
getDirectSize()58   size_t getDirectSize() const {
59     return getDirectCapacity();
60   }
61 };
62 
63 } // namespace jni
64 } // namespace facebook
65