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/*
* Copyright (C) 2009 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 "MmapSource"
#include <utils/Log.h>
#include <sys/mman.h>
#undef NDEBUG
#include <assert.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <media/stagefright/MmapSource.h>
namespace android {
MmapSource::MmapSource(const char *filename)
: mFd(open(filename, O_RDONLY)),
mBase(NULL),
mSize(0) {
LOGV("MmapSource '%s'", filename);
assert(mFd >= 0);
off_t size = lseek(mFd, 0, SEEK_END);
mSize = (size_t)size;
mBase = mmap(0, mSize, PROT_READ, MAP_FILE | MAP_SHARED, mFd, 0);
if (mBase == (void *)-1) {
mBase = NULL;
close(mFd);
mFd = -1;
}
}
MmapSource::MmapSource(int fd, int64_t offset, int64_t length)
: mFd(fd),
mBase(NULL),
mSize(length) {
LOGV("MmapSource fd:%d offset:%lld length:%lld", fd, offset, length);
assert(fd >= 0);
mBase = mmap(0, mSize, PROT_READ, MAP_FILE | MAP_SHARED, mFd, offset);
if (mBase == (void *)-1) {
mBase = NULL;
close(mFd);
mFd = -1;
}
}
MmapSource::~MmapSource() {
if (mFd != -1) {
munmap(mBase, mSize);
mBase = NULL;
mSize = 0;
close(mFd);
mFd = -1;
}
}
status_t MmapSource::InitCheck() const {
return mFd == -1 ? NO_INIT : OK;
}
ssize_t MmapSource::read_at(off_t offset, void *data, size_t size) {
LOGV("read_at offset:%ld data:%p size:%d", offset, data, size);
assert(offset >= 0);
size_t avail = 0;
if (offset >= 0 && offset < (off_t)mSize) {
avail = mSize - offset;
}
if (size > avail) {
size = avail;
}
memcpy(data, (const uint8_t *)mBase + offset, size);
return (ssize_t)size;
}
status_t MmapSource::getSize(off_t *size) {
*size = mSize;
return OK;
}
} // namespace android
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