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 
readAt(void * handle,void * buffer,int pos,int size)27 static int readAt(void *handle, void *buffer, int pos, int size) {
28     return ((android::MidiIoWrapper*)handle)->readAt(buffer, pos, size);
29 }
size(void * handle)30 static int size(void *handle) {
31     return ((android::MidiIoWrapper*)handle)->size();
32 }
33 
34 namespace android {
35 
MidiIoWrapper(const char * path)36 MidiIoWrapper::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 
MidiIoWrapper(int fd,off64_t offset,int64_t size)43 MidiIoWrapper::MidiIoWrapper(int fd, off64_t offset, int64_t size) {
44     ALOGV("MidiIoWrapper(fd=%d)", fd);
45     mFd = fd < 0 ? -1 : dup(fd);
46     mBase = offset;
47     mLength = size;
48 }
49 
MidiIoWrapper(const sp<DataSource> & source)50 MidiIoWrapper::MidiIoWrapper(const sp<DataSource> &source) {
51     ALOGV("MidiIoWrapper(DataSource)");
52     mFd = -1;
53     mDataSource = source;
54     off64_t l;
55     if (mDataSource->getSize(&l) == OK) {
56         mLength = l;
57     } else {
58         mLength = 0;
59     }
60 }
61 
~MidiIoWrapper()62 MidiIoWrapper::~MidiIoWrapper() {
63     ALOGV("~MidiIoWrapper");
64     if (mFd >= 0) {
65         close(mFd);
66     }
67 }
68 
readAt(void * buffer,int offset,int size)69 int MidiIoWrapper::readAt(void *buffer, int offset, int size) {
70     ALOGV("readAt(%p, %d, %d)", buffer, offset, size);
71 
72     if (mDataSource != NULL) {
73         return mDataSource->readAt(offset, buffer, size);
74     }
75     if (mFd < 0) {
76         errno = EBADF;
77         return -1; // as per failed read.
78     }
79     lseek(mFd, mBase + offset, SEEK_SET);
80     if (offset + size > mLength) {
81         size = mLength - offset;
82     }
83     return read(mFd, buffer, size);
84 }
85 
size()86 int MidiIoWrapper::size() {
87     ALOGV("size() = %d", int(mLength));
88     return mLength;
89 }
90 
getLocator()91 EAS_FILE_LOCATOR MidiIoWrapper::getLocator() {
92     mEasFile.handle = this;
93     mEasFile.readAt = ::readAt;
94     mEasFile.size = ::size;
95     return &mEasFile;
96 }
97 
98 }  // namespace android
99