1 // newcache.cxx -- routines to handle scenery tile caching
3 // Written by Curtis Olson, started December 2000.
5 // Copyright (C) 2000 Curtis L. Olson - http://www.flightgear.org/~curt
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
24 # include <simgear_config.h>
27 #include <simgear/bucket/newbucket.hxx>
28 #include <simgear/debug/logstream.hxx>
29 #include <simgear/misc/sg_path.hxx>
31 #include "TileEntry.hxx"
32 #include "TileCache.hxx"
34 using simgear::TileEntry;
35 using simgear::TileCache;
37 TileCache::TileCache( void ) :
38 max_cache_size(100), current_time(0.0)
44 TileCache::~TileCache( void ) {
49 // Free a tile cache entry
50 void TileCache::entry_free( long cache_index ) {
51 SG_LOG( SG_TERRAIN, SG_DEBUG, "FREEING CACHE ENTRY = " << cache_index );
52 TileEntry *tile = tile_cache[cache_index];
53 tile->removeFromSceneGraph();
57 tile_cache.erase( cache_index );
61 // Initialize the tile cache subsystem
62 void TileCache::init( void ) {
63 SG_LOG( SG_TERRAIN, SG_INFO, "Initializing the tile cache." );
65 SG_LOG( SG_TERRAIN, SG_INFO, " max cache size = "
67 SG_LOG( SG_TERRAIN, SG_INFO, " current cache size = "
68 << tile_cache.size() );
70 #if 0 // don't clear the cache
74 SG_LOG( SG_TERRAIN, SG_INFO, " done with init()" );
78 // Search for the specified "bucket" in the cache
79 bool TileCache::exists( const SGBucket& b ) const {
80 long tile_index = b.gen_index();
81 const_tile_map_iterator it = tile_cache.find( tile_index );
83 return ( it != tile_cache.end() );
87 // Return the index of the oldest tile in the cache, return -1 if
88 // nothing available to be removed.
89 long TileCache::get_oldest_tile() {
90 // we need to free the furthest entry
92 double timestamp = 0.0;
93 double min_time = DBL_MAX;
95 tile_map_iterator current = tile_cache.begin();
96 tile_map_iterator end = tile_cache.end();
98 for ( ; current != end; ++current ) {
99 long index = current->first;
100 TileEntry *e = current->second;
101 if ( e->is_loaded() ) {
102 timestamp = e->get_timestamp();
103 if ( timestamp < min_time ) {
104 min_time = timestamp;
108 SG_LOG( SG_TERRAIN, SG_DEBUG, "loaded = " << e->is_loaded()
109 << " time stamp = " << e->get_timestamp() );
113 SG_LOG( SG_TERRAIN, SG_DEBUG, " index = " << min_index );
114 SG_LOG( SG_TERRAIN, SG_DEBUG, " min_time = " << min_time );
120 // Clear the inner ring flag for all tiles in the cache so that the
121 // external tile scheduler can flag the inner ring correctly.
122 void TileCache::clear_inner_ring_flags() {
123 tile_map_iterator current = tile_cache.begin();
124 tile_map_iterator end = tile_cache.end();
126 for ( ; current != end; ++current ) {
127 TileEntry *e = current->second;
128 if ( e->is_loaded() ) {
129 e->set_inner_ring( false );
134 // Clear a cache entry, note that the cache only holds pointers
135 // and this does not free the object which is pointed to.
136 void TileCache::clear_entry( long cache_index ) {
137 tile_cache.erase( cache_index );
141 // Clear all completely loaded tiles (ignores partially loaded tiles)
142 void TileCache::clear_cache() {
143 std::vector<long> indexList;
144 tile_map_iterator current = tile_cache.begin();
145 tile_map_iterator end = tile_cache.end();
147 for ( ; current != end; ++current ) {
148 long index = current->first;
149 SG_LOG( SG_TERRAIN, SG_DEBUG, "clearing " << index );
150 TileEntry *e = current->second;
151 if ( e->is_loaded() ) {
152 e->tile_bucket.make_bad();
153 // entry_free modifies tile_cache, so store index and call entry_free() later;
154 indexList.push_back( index);
157 for (unsigned int it = 0; it < indexList.size(); it++) {
158 entry_free( indexList[ it]);
163 * Create a new tile and schedule it for loading.
165 bool TileCache::insert_tile( TileEntry *e ) {
166 // register tile in the cache
167 long tile_index = e->get_tile_bucket().gen_index();
168 tile_cache[tile_index] = e;
169 e->set_timestamp(current_time);