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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkMMapStream.h"
#include <unistd.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <errno.h>
SkMMAPStream::SkMMAPStream(const char filename[])
{
fAddr = NULL; // initialize to failure case
fSize = 0;
int fildes = open(filename, O_RDONLY);
if (fildes < 0)
{
SkDEBUGF(("---- failed to open(%s) for mmap stream error=%d\n", filename, errno));
return;
}
off_t offset = lseek(fildes, 0, SEEK_END); // find the file size
if (offset == -1)
{
SkDEBUGF(("---- failed to lseek(%s) for mmap stream error=%d\n", filename, errno));
close(fildes);
return;
}
(void)lseek(fildes, 0, SEEK_SET); // restore file offset to beginning
// to avoid a 64bit->32bit warning, I explicitly create a size_t size
size_t size = static_cast<size_t>(offset);
void* addr = mmap(NULL, size, PROT_READ, MAP_SHARED, fildes, 0);
// According to the POSIX documentation of mmap it adds an extra reference
// to the file associated with the fildes which is not removed by a
// subsequent close() on that fildes. This reference is removed when there
// are no more mappings to the file.
close(fildes);
if (MAP_FAILED == addr)
{
SkDEBUGF(("---- failed to mmap(%s) for mmap stream error=%d\n", filename, errno));
return;
}
this->INHERITED::setMemory(addr, size);
fAddr = addr;
fSize = size;
}
SkMMAPStream::~SkMMAPStream()
{
this->closeMMap();
}
void SkMMAPStream::setMemory(const void* data, size_t length, bool copyData)
{
this->closeMMap();
this->INHERITED::setMemory(data, length, copyData);
}
void SkMMAPStream::closeMMap()
{
if (fAddr)
{
munmap(fAddr, fSize);
fAddr = NULL;
}
}
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