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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
/**
* @author Peter Boros
* @date 2004/10/01
* @version $Id$
* @file metadata.cpp
* @brief Generic meta data class implementation.
*
*/
#include "metadata.h"
#include "fstream"
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h> // for ::mmap()
#include <sys/time.h>
#include <sys/resource.h> // for getrlimit(), setrlimit(), etc.
namespace fsa {
// {{{ constants
const uint32_t MetaData::MAGIC;
// }}}
// {{{ MetaData::MetaData()
MetaData::MetaData(const char *datafile, FileAccessMethod fam) : _mmap_addr(NULL), _mmap_length(0), _ok(false), _header(), _data(NULL)
{
_ok = read(datafile,fam);
}
MetaData::MetaData(const std::string &datafile, FileAccessMethod fam) : _mmap_addr(NULL), _mmap_length(0), _ok(false), _header(), _data(NULL)
{
_ok = read(datafile.c_str(),fam);
}
// }}}
// {{{ MetaData::~MetaData()
MetaData::~MetaData()
{
reset();
}
// }}}
// {{{ MetaData::reset()
void MetaData::reset()
{
if(_mmap_addr!=NULL && _mmap_addr!=MAP_FAILED){
munmap(_mmap_addr,_mmap_length);
}
else{
if(_data!=NULL) free(_data);
}
_mmap_addr=NULL; _mmap_length=0;
_ok=false;
_data=NULL;
}
// }}}
// {{{ MetaData::read()
bool MetaData::read(const char *datafile, FileAccessMethod fam)
{
size_t r;
reset();
if(fam==FILE_ACCESS_UNDEF)
fam=_default_file_access_method;
if(datafile==NULL)
return false;
int fd = ::open(datafile,O_RDONLY);
if(fd<0)
return false;
r=::read(fd,&_header,sizeof(_header));
if(r!=sizeof(_header) || _header._magic!=MetaData::MAGIC){
::close(fd);
return false;
}
if(fam==FILE_ACCESS_MMAP || fam==FILE_ACCESS_MMAP_WITH_MLOCK){
_mmap_length = sizeof(_header) + _header._size;
_mmap_addr = ::mmap((void*)0, _mmap_length, PROT_READ, MAP_SHARED, fd, 0);
if(_mmap_addr==MAP_FAILED){
::close(fd);
reset();
return false;
}
if(fam==FILE_ACCESS_MMAP_WITH_MLOCK){
if(mlock(_mmap_addr, _mmap_length)<0) {
/* try to increase RLIMIT_MEMLOCK then mlock() again */
struct rlimit rl;
if(getrlimit(RLIMIT_MEMLOCK, &rl) >= 0) {
rl.rlim_cur += _mmap_length + getpagesize();
rl.rlim_max += _mmap_length + getpagesize();
if(setrlimit(RLIMIT_MEMLOCK, &rl) >= 0)
mlock(_mmap_addr, _mmap_length);
}
}
}
}
if(_mmap_addr==NULL){
_data = malloc(_header._size);
r=::read(fd,_data,_header._size);
if(r!=_header._size){
::close(fd);
reset();
return false;
}
}
else {
_data = (void*)((uint8_t*)_mmap_addr + sizeof(_header));
}
::close(fd);
return true;
}
// }}}
} // namespace fsa
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