overmap *overmapbuffer::get_existing(int x, int y)
{
if( last_requested_overmap != NULL && last_requested_overmap->pos().x == x &&
last_requested_overmap->pos().y == y ) {
return last_requested_overmap;
}
auto it = overmaps.find( point( x, y ) );
if( it != overmaps.end() ) {
return last_requested_overmap = it->second.get();
}
if (known_non_existing.count(point(x, y)) > 0) {
// This overmap does not exist on disk (this has already been
// checked in a previous call of this function).
return NULL;
}
// Check if the overmap exist on disk,
std::ifstream tmp(terrain_filename( x, y ).c_str(), std::ios::in);
if(tmp.is_open()) {
// File exists, load it normally (the get function
// indirectly call overmap::open to do so).
tmp.close();
return &get( x, y );
}
// File does not exist (or not readable which is essentially
// the same for our usage). A second call of this function with
// the same coordinates will not check the file system, and
// return early.
// If the overmap had been created in the mean time, the previous
// loop would have found and returned it.
known_non_existing.insert(point(x, y));
return NULL;
}
overmap *overmapbuffer::get_existing( int x, int y )
{
const point p {x, y};
if( last_requested_overmap && last_requested_overmap->pos() == p ) {
return last_requested_overmap;
}
const auto it = overmaps.find( p );
if( it != overmaps.end() ) {
return last_requested_overmap = it->second.get();
}
if( known_non_existing.count( p ) > 0 ) {
// This overmap does not exist on disk (this has already been
// checked in a previous call of this function).
return nullptr;
}
if( file_exist( terrain_filename( x, y ) ) ) {
// File exists, load it normally (the get function
// indirectly call overmap::open to do so).
return &get( x, y );
}
// File does not exist (or not readable which is essentially
// the same for our usage). A second call of this function with
// the same coordinates will not check the file system, and
// return early.
// If the overmap had been created in the mean time, the previous
// loop would have found and returned it.
known_non_existing.insert( p );
return nullptr;
}
