void BSONObjExternalSorter::finishMap(){
uassert( 10050 , "bad" , _cur );
_curSizeSoFar = 0;
if ( _cur->size() == 0 )
return;
_sortInMem();
stringstream ss;
ss << _root.string() << "/file." << _files.size();
string file = ss.str();
ofstream out;
out.open( file.c_str() , ios_base::out | ios_base::binary );
assertStreamGood( 10051 , (string)"couldn't open file: " + file , out );
int num = 0;
for ( InMemory::iterator i=_cur->begin(); i != _cur->end(); ++i ){
Data p = *i;
out.write( p.first.objdata() , p.first.objsize() );
out.write( (char*)(&p.second) , sizeof( DiskLoc ) );
num++;
}
_cur->clear();
_files.push_back( file );
out.close();
log(2) << "Added file: " << file << " with " << num << "objects for external sort" << endl;
}
void BSONObjExternalSorter::finishMap() {
uassert( 10050 , "bad" , _cur );
_curSizeSoFar = 0;
if ( _cur->size() == 0 )
return;
_sortInMem();
stringstream ss;
ss << _root.string() << "/file." << _files.size();
string file = ss.str();
// todo: it may make sense to fadvise that this not be cached so that building the index doesn't
// eject other things the db is using from the file system cache. while we will soon be reading
// this back, if it fit in ram, there wouldn't have been a need for an external sort in the first
// place.
ofstream out;
out.open( file.c_str() , ios_base::out | ios_base::binary );
assertStreamGood( 10051 , (string)"couldn't open file: " + file , out );
int num = 0;
for ( InMemory::iterator i=_cur->begin(); i != _cur->end(); ++i ) {
Data p = *i;
out.write( p.first.objdata() , p.first.objsize() );
out.write( (char*)(&p.second) , sizeof( DiskLoc ) );
num++;
}
_cur->clear();
_files.push_back( file );
out.close();
log(2) << "Added file: " << file << " with " << num << "objects for external sort" << endl;
}
void BSONObjExternalSorter::sort(){
uassert( 10048 , "already sorted" , ! _sorted );
_sorted = true;
if ( _cur && _files.size() == 0 ){
_sortInMem();
log(1) << "\t\t not using file. size:" << _curSizeSoFar << " _compares:" << _compares << endl;
return;
}
if ( _cur ){
finishMap();
}
if ( _cur ){
delete _cur;
_cur = 0;
}
if ( _files.size() == 0 )
return;
}
