1 /*
2  * Copyright 2016, 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 REMOTE_DATA_SOURCE_H_
18 #define REMOTE_DATA_SOURCE_H_
19 
20 #include <binder/IMemory.h>
21 #include <binder/MemoryDealer.h>
22 #include <media/DataSource.h>
23 #include <media/IDataSource.h>
24 
25 namespace android {
26 
27 // Originally in MediaExtractor.cpp
28 class RemoteDataSource : public BnDataSource {
29 public:
wrap(const sp<DataSource> & source)30     static sp<IDataSource> wrap(const sp<DataSource> &source) {
31         if (source.get() == nullptr) {
32             return nullptr;
33         }
34         if (source->getIDataSource().get() != nullptr) {
35             return source->getIDataSource();
36         }
37         return new RemoteDataSource(source);
38     }
39 
~RemoteDataSource()40     virtual ~RemoteDataSource() {
41         close();
42     }
getIMemory()43     virtual sp<IMemory> getIMemory() {
44         return mMemory;
45     }
readAt(off64_t offset,size_t size)46     virtual ssize_t readAt(off64_t offset, size_t size) {
47         ALOGV("readAt(%lld, %zu)", (long long)offset, size);
48         if (size > kBufferSize) {
49             size = kBufferSize;
50         }
51         return mSource->readAt(offset, mMemory->pointer(), size);
52     }
getSize(off64_t * size)53     virtual status_t getSize(off64_t *size) {
54         return mSource->getSize(size);
55     }
close()56     virtual void close() {
57         // Protect strong pointer assignments. This also can be called from the binder
58         // clean-up procedure which is running on a separate thread.
59         Mutex::Autolock lock(mCloseLock);
60         mSource = nullptr;
61         mMemory = nullptr;
62     }
getFlags()63     virtual uint32_t getFlags() {
64         return mSource->flags();
65     }
toString()66     virtual String8 toString()  {
67         return mName;
68     }
69 
70 private:
71     enum {
72         kBufferSize = 64 * 1024,
73     };
74 
75     sp<IMemory> mMemory;
76     sp<DataSource> mSource;
77     String8 mName;
78     Mutex mCloseLock;
79 
RemoteDataSource(const sp<DataSource> & source)80     explicit RemoteDataSource(const sp<DataSource> &source) {
81         mSource = source;
82         sp<MemoryDealer> memoryDealer = new MemoryDealer(kBufferSize, "RemoteDataSource");
83         mMemory = memoryDealer->allocate(kBufferSize);
84         if (mMemory.get() == nullptr) {
85             ALOGE("Failed to allocate memory!");
86         }
87         mName = String8::format("RemoteDataSource(%s)", mSource->toString().string());
88     }
89 
90     DISALLOW_EVIL_CONSTRUCTORS(RemoteDataSource);
91 };
92 
93 }  // namespace android
94 
95 #endif  // REMOTE_DATA_SOURCE_H_
96