MidiIoWrapper.cpp revision 0e8928bf4f2b01b783f6da97d15e8f1abb0fd7d7 
1/*
2 * Copyright (C) 2014 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//#define LOG_NDEBUG 0
18#define LOG_TAG "MidiIoWrapper"
19#include <utils/Log.h>
20#include <utils/RefBase.h>
21
22#include <sys/stat.h>
23#include <fcntl.h>
24
25#include "media/MidiIoWrapper.h"
26
27static int readAt(void *handle, void *buffer, int pos, int size) {
28    return ((android::MidiIoWrapper*)handle)->readAt(buffer, pos, size);
29}
30static int size(void *handle) {
31    return ((android::MidiIoWrapper*)handle)->size();
32}
33
34namespace android {
35
36MidiIoWrapper::MidiIoWrapper(const char *path) {
37    ALOGV("MidiIoWrapper(%s)", path);
38    mFd = open(path, O_RDONLY | O_LARGEFILE);
39    mBase = 0;
40    mLength = lseek(mFd, 0, SEEK_END);
41}
42
43MidiIoWrapper::MidiIoWrapper(int fd, off64_t offset, int64_t size) {
44    ALOGV("MidiIoWrapper(fd=%d)", fd);
45    mFd = dup(fd);
46    mBase = offset;
47    mLength = size;
48}
49
50MidiIoWrapper::MidiIoWrapper(const sp<DataSource> &source) {
51    mDataSource = source;
52    off64_t l;
53    if (mDataSource->getSize(&l) == OK) {
54        mLength = l;
55    } else {
56        mLength = 0;
57    }
58}
59
60MidiIoWrapper::~MidiIoWrapper() {
61    ALOGV("~MidiIoWrapper");
62    close(mFd);
63}
64
65int MidiIoWrapper::readAt(void *buffer, int offset, int size) {
66    ALOGV("readAt(%p, %d, %d)", buffer, offset, size);
67
68    if (mDataSource != NULL) {
69        return mDataSource->readAt(offset, buffer, size);
70    }
71    lseek(mFd, mBase + offset, SEEK_SET);
72    if (offset + size > mLength) {
73        size = mLength - offset;
74    }
75    return read(mFd, buffer, size);
76}
77
78int MidiIoWrapper::size() {
79    ALOGV("size() = %d", mLength);
80    return mLength;
81}
82
83EAS_FILE_LOCATOR MidiIoWrapper::getLocator() {
84    mEasFile.handle = this;
85    mEasFile.readAt = ::readAt;
86    mEasFile.size = ::size;
87    return &mEasFile;
88}
89
90}  // namespace android
91