FileSource.cpp revision d912f4646ece79832f9d852b39eb6b0d836ccfc4 
1/*
2 * Copyright (C) 2009 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#include <media/stagefright/FileSource.h>
18#include <media/stagefright/MediaDebug.h>
19
20namespace android {
21
22FileSource::FileSource(const char *filename)
23    : mFile(fopen(filename, "rb")),
24      mOffset(0),
25      mLength(-1) {
26}
27
28FileSource::FileSource(int fd, int64_t offset, int64_t length)
29    : mFile(fdopen(fd, "rb")),
30      mOffset(offset),
31      mLength(length) {
32    CHECK(offset >= 0);
33    CHECK(length >= 0);
34}
35
36FileSource::~FileSource() {
37    if (mFile != NULL) {
38        fclose(mFile);
39        mFile = NULL;
40    }
41}
42
43status_t FileSource::initCheck() const {
44    return mFile != NULL ? OK : NO_INIT;
45}
46
47ssize_t FileSource::readAt(off_t offset, void *data, size_t size) {
48    Mutex::Autolock autoLock(mLock);
49
50    if (mLength >= 0) {
51        if (offset >= mLength) {
52            return 0;  // read beyond EOF.
53        }
54        int64_t numAvailable = mLength - offset;
55        if ((int64_t)size > numAvailable) {
56            size = numAvailable;
57        }
58    }
59
60    int err = fseeko(mFile, offset + mOffset, SEEK_SET);
61    CHECK(err != -1);
62
63    return fread(data, 1, size, mFile);
64}
65
66status_t FileSource::getSize(off_t *size) {
67    if (mLength >= 0) {
68        *size = mLength;
69
70        return OK;
71    }
72
73    fseek(mFile, 0, SEEK_END);
74    *size = ftello(mFile);
75
76    return OK;
77}
78
79}  // namespace android
80