cache Course::GetCourseInfo results

stepmania/src/Course.cpp

@@ -548,29 +548,42 @@ static vector<Song*> GetFilteredBestSongs( StepsType nt )
 	return ret;
 }
 
+/* This is called by many simple functions, like Course::GetTotalSeconds, and may
+ * be called on all songs to sort.  It can take time to execute, so we cache the
+ * results. */
 void Course::GetCourseInfo( StepsType nt, vector<Course::Info> &ci, int Difficult ) const
 {
-	vector<CourseEntry> entries = m_entries;
+	const InfoParams params( nt, IsDifficult(Difficult) );
+	InfoCache::const_iterator it = m_InfoCache.find( params );
+	if( it != m_InfoCache.end() )
+	{
+		ci = it->second;
+		return;
+	}
 
 	/* Different seed for each course, but the same for the whole round: */
 	RandomGen rnd( GAMESTATE->m_iRoundSeed + GetHashForString(m_sName) );
 
+	vector<CourseEntry> tmp_entries;
 	if( m_bRandomize )
 	{
 		/* Always randomize the same way per round.  Otherwise, the displayed course
 		 * will change every time it's viewed, and the displayed order will have no
 		 * bearing on what you'll actually play. */
-		random_shuffle( entries.begin(), entries.end(), rnd );
+		tmp_entries = m_entries;
+		random_shuffle( tmp_entries.begin(), tmp_entries.end(), rnd );
 	}
 
+	const vector<CourseEntry> &entries = m_bRandomize? tmp_entries:m_entries;
+
 	/* This can take some time, so don't fill it out unless we need it. */
 	bool bMostPlayedSet = false;
 	vector<Song*> vSongsByMostPlayed;
 	
-	vector<Song*> AllSongsShuffled = SONGMAN->GetAllSongs();
-	random_shuffle( AllSongsShuffled.begin(), AllSongsShuffled.end(), rnd );
-	int CurSong = 0; /* Current offset into AllSongsShuffled */
+	bool bShuffledSet = false;
+	vector<Song*> AllSongsShuffled;
 
+	int CurSong = 0; /* Current offset into AllSongsShuffled */
 	ci.clear(); 
 
 	for( unsigned i=0; i<entries.size(); i++ )
@@ -602,6 +615,13 @@ void Course::GetCourseInfo( StepsType nt, vector<Course::Info> &ci, int Difficul
 		case COURSE_ENTRY_RANDOM:
 		case COURSE_ENTRY_RANDOM_WITHIN_GROUP:
 			{
+				if( !bShuffledSet )
+				{
+					AllSongsShuffled = SONGMAN->GetAllSongs();
+					random_shuffle( AllSongsShuffled.begin(), AllSongsShuffled.end(), rnd );
+					bShuffledSet = true;
+				}
+
 				// find a song with the notes we want
 				for( unsigned j=0; j<AllSongsShuffled.size(); j++ )
 				{
@@ -695,6 +715,14 @@ void Course::GetCourseInfo( StepsType nt, vector<Course::Info> &ci, int Difficul
 		cinfo.Difficult = IsDifficult(Difficult);
 		ci.push_back( cinfo ); 
 	}
+
+	/* Cache results. */
+	m_InfoCache[params] = ci;
+}
+
+void Course::ClearCache()
+{
+	m_InfoCache.clear();
 }
 
 RageColor Course::GetColor() const

stepmania/src/Course.h

@@ -14,6 +14,7 @@
 #include "PlayerNumber.h"
 #include "GameConstantsAndTypes.h"
 #include "Attack.h"
+#include <map>
 
 struct PlayerOptions;
 struct SongOptions;
@@ -196,8 +197,16 @@ public:
 
 	void UpdateCourseStats();
 
+	/* Call per-screen, and if song or notes pointers change: */
+	void ClearCache();
+
 private:
 	void GetMeterRange( int stage, int& iMeterLowOut, int& iMeterHighOut, int Difficult = -1 ) const;
+
+	typedef pair<StepsType,bool> InfoParams;
+	typedef vector<Course::Info> InfoData;
+	typedef map<InfoParams, InfoData> InfoCache;
+	mutable InfoCache m_InfoCache;
 };
 
 

stepmania/src/ScreenManager.cpp

@@ -477,6 +477,10 @@ Screen* ScreenManager::MakeNewScreen( CString sClassName )
 	 * screens turn this off in their ctor if they handle timers themselves (gameplay, edit). */
 	SOUND->HandleSongTimer( true );
 
+	/* Cleanup song data.  This can free up a fair bit of memory, so do it before
+	 * creating the new screen, to lower peak memory usage slightly. */
+	SONGMAN->Cleanup();
+
 	Screen *ret = Screen::Create( sClassName );
 
 	/* Loading probably took a little while.  Let's reset stats.  This prevents us
@@ -485,9 +489,6 @@ Screen* ScreenManager::MakeNewScreen( CString sClassName )
 	 * apparent. */
 	DISPLAY->ResetStats();
 
-	/* This is a convenient time to clean up our song cache. */
-	SONGMAN->CompressSongs();
-
 	return ret;
 }
 

stepmania/src/Song.cpp

@@ -19,6 +19,7 @@
 #include "NoteData.h"
 #include "RageSound.h"
 #include "RageException.h"
+#include "SongManager.h"
 #include "SongCacheIndex.h"
 #include "GameManager.h"
 #include "PrefsManager.h"
@@ -100,6 +101,10 @@ void Song::Reset()
 
 	Song empty;
 	*this = empty;
+
+	/* Courses cache Notes* pointers.  On the off chance that this isn't the last
+	 * thing this screen does, clear that cache. */
+	SONGMAN->Cleanup();
 }
 
 

stepmania/src/SongManager.cpp

@@ -567,9 +567,10 @@ void SongManager::FreeCourses()
 
 /* Called periodically to wipe out cached NoteData.  This is called when we change
  * screens. */
-void SongManager::CompressSongs()
+void SongManager::Cleanup()
 {
-	for( unsigned i=0; i<m_pSongs.size(); i++ )
+	unsigned i;
+	for( i=0; i<m_pSongs.size(); i++ )
 	{
 		Song* pSong = m_pSongs[i];
 		for( unsigned n=0; n<pSong->m_apNotes.size(); n++ )
@@ -578,6 +579,10 @@ void SongManager::CompressSongs()
 			pNotes->Compress();
 		}
 	}
+
+	/* Erase cached course info. */
+	for( i=0; i < m_pCourses.size(); i++ )
+		m_pCourses[i]->ClearCache();
 }
 
 void SongManager::GetAllCourses( vector<Course*> &AddTo, bool bIncludeAutogen )

stepmania/src/SongManager.h

@@ -34,7 +34,8 @@ public:
 
 	void InitSongsFromDisk( LoadingWindow *ld );
 	void FreeSongs();
-	void CompressSongs();
+	void Cleanup();
+
 	void LoadGroupSymLinks( CString sDir, CString sGroupFolder );
 
 	void InitCoursesFromDisk( LoadingWindow *ld );