1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/*
* Copyright 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//#define LOG_NDEBUG 0
#define LOG_TAG "CallbackDataSource"
#include <utils/Log.h>
#include "include/CallbackDataSource.h"
#include <android/IDataSource.h>
#include <binder/IMemory.h>
#include <binder/IPCThreadState.h>
#include <media/stagefright/foundation/ADebug.h>
#include <algorithm>
namespace android {
CallbackDataSource::CallbackDataSource(
const sp<IDataSource>& binderDataSource)
: mIDataSource(binderDataSource),
mIsClosed(false) {
// Set up the buffer to read into.
mMemory = mIDataSource->getIMemory();
mName = String8::format("CallbackDataSource(%d->%d, %s)",
getpid(),
IPCThreadState::self()->getCallingPid(),
mIDataSource->toString().string());
}
CallbackDataSource::~CallbackDataSource() {
ALOGV("~CallbackDataSource");
close();
}
status_t CallbackDataSource::initCheck() const {
if (mMemory == NULL) {
return UNKNOWN_ERROR;
}
return OK;
}
ssize_t CallbackDataSource::readAt(off64_t offset, void* data, size_t size) {
if (mMemory == NULL || data == NULL) {
return -1;
}
// IDataSource can only read up to mMemory->size() bytes at a time, but this
// method should be able to read any number of bytes, so read in a loop.
size_t totalNumRead = 0;
size_t numLeft = size;
const size_t bufferSize = mMemory->size();
while (numLeft > 0) {
size_t numToRead = std::min(numLeft, bufferSize);
ssize_t numRead =
mIDataSource->readAt(offset + totalNumRead, numToRead);
// A negative return value represents an error. Pass it on.
if (numRead < 0) {
return numRead == ERROR_END_OF_STREAM && totalNumRead > 0 ? totalNumRead : numRead;
}
// A zero return value signals EOS. Return the bytes read so far.
if (numRead == 0) {
return totalNumRead;
}
if ((size_t)numRead > numToRead) {
return ERROR_OUT_OF_RANGE;
}
CHECK(numRead >= 0 && (size_t)numRead <= bufferSize);
memcpy(((uint8_t*)data) + totalNumRead, mMemory->unsecurePointer(),
numRead);
numLeft -= numRead;
totalNumRead += numRead;
}
return totalNumRead;
}
status_t CallbackDataSource::getSize(off64_t *size) {
status_t err = mIDataSource->getSize(size);
if (err != OK) {
return err;
}
if (*size < 0) {
// IDataSource will set size to -1 to indicate unknown size, but
// DataSource returns ERROR_UNSUPPORTED for that.
return ERROR_UNSUPPORTED;
}
return OK;
}
uint32_t CallbackDataSource::flags() {
return mIDataSource->getFlags();
}
void CallbackDataSource::close() {
if (!mIsClosed) {
mIDataSource->close();
mIsClosed = true;
}
}
sp<IDataSource> CallbackDataSource::getIDataSource() const {
return mIDataSource;
}
TinyCacheSource::TinyCacheSource(const sp<DataSource>& source)
: mSource(source), mCachedOffset(0), mCachedSize(0) {
mName = String8::format("TinyCacheSource(%s)", mSource->toString().string());
}
status_t TinyCacheSource::initCheck() const {
return mSource->initCheck();
}
ssize_t TinyCacheSource::readAt(off64_t offset, void* data, size_t size) {
// Check if the cache satisfies the read.
if (mCachedOffset <= offset
&& offset < (off64_t) (mCachedOffset + mCachedSize)) {
if (offset + size <= mCachedOffset + mCachedSize) {
memcpy(data, &mCache[offset - mCachedOffset], size);
return size;
} else {
// If the cache hits only partially, flush the cache and read the
// remainder.
// This value is guaranteed to be greater than 0 because of the
// enclosing if statement.
const ssize_t remaining = mCachedOffset + mCachedSize - offset;
memcpy(data, &mCache[offset - mCachedOffset], remaining);
const ssize_t readMore = readAt(offset + remaining,
(uint8_t*)data + remaining, size - remaining);
if (readMore < 0) {
return readMore;
}
return remaining + readMore;
}
}
if (size >= kCacheSize) {
return mSource->readAt(offset, data, size);
}
// Fill the cache and copy to the caller.
const ssize_t numRead = mSource->readAt(offset, mCache, kCacheSize);
if (numRead <= 0) {
// Flush cache on error
mCachedSize = 0;
mCachedOffset = 0;
return numRead;
}
if ((size_t)numRead > kCacheSize) {
// Flush cache on error
mCachedSize = 0;
mCachedOffset = 0;
return ERROR_OUT_OF_RANGE;
}
mCachedSize = numRead;
mCachedOffset = offset;
CHECK(mCachedSize <= kCacheSize && mCachedOffset >= 0);
const size_t numToReturn = std::min(size, (size_t)numRead);
memcpy(data, mCache, numToReturn);
return numToReturn;
}
status_t TinyCacheSource::getSize(off64_t *size) {
return mSource->getSize(size);
}
uint32_t TinyCacheSource::flags() {
return mSource->flags();
}
sp<IDataSource> TinyCacheSource::getIDataSource() const {
return mSource->getIDataSource();
}
} // namespace android
|
