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      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 
     27 static int readAt(void *handle, void *buffer, int pos, int size) {
     28     return ((android::MidiIoWrapper*)handle)->readAt(buffer, pos, size);
     29 }
     30 static int size(void *handle) {
     31     return ((android::MidiIoWrapper*)handle)->size();
     32 }
     33 
     34 namespace android {
     35 
     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 
     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 
     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 
     62 MidiIoWrapper::~MidiIoWrapper() {
     63     ALOGV("~MidiIoWrapper");
     64     if (mFd >= 0) {
     65         close(mFd);
     66     }
     67 }
     68 
     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 
     86 int MidiIoWrapper::size() {
     87     ALOGV("size() = %d", int(mLength));
     88     return mLength;
     89 }
     90 
     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