split out RageSoundPosMap (too much code in RageSound)

2004-04-11 04:51:03 +00:00
parent 0b0db1cbe0
commit b21fd54b8e
4 changed files with 210 additions and 114 deletions
@@ -0,0 +1,153 @@
+#include "global.h"
+
+#include "RageSoundPosMap.h"
+#include "RageLog.h"
+#include "RageUtil.h"
+
+/* The number of frames we should keep pos_map data for.  This being too high
+ * is mostly harmless; the data is small. */
+const int pos_map_backlog_frames = 100000;
+
+pos_map_queue::pos_map_queue(): m_Mutex("pos_map_queue")
+{
+}
+
+
+pos_map_queue::pos_map_queue( const pos_map_queue &cpy ): m_Mutex("pos_map_queue")
+{
+	*this = cpy;
+}
+
+pos_map_queue &pos_map_queue::operator=( const pos_map_queue &cpy )
+{
+	/* Hack: to prevent deadlock, always lock the lesser pointer first. */
+	if( this < &cpy )
+	{
+		m_Mutex.Lock();
+		cpy.m_Mutex.Lock();
+	} else {
+		cpy.m_Mutex.Lock();
+		m_Mutex.Lock();
+	}
+
+	m_Queue = cpy.m_Queue;
+
+	/* Unlock order doesn't matter. */
+	m_Mutex.Unlock();
+	cpy.m_Mutex.Unlock();
+	return *this;
+}
+
+void pos_map_queue::Insert( int64_t frameno, int pos, int got_frames )
+{
+	LockMut(m_Mutex);
+
+	if( m_Queue.size() )
+	{
+		/* Optimization: If the last entry lines up with this new entry, just merge them. */
+		pos_map_t &last = m_Queue.back();
+		if( last.frameno+last.frames == frameno &&
+		    last.position+last.frames == pos )
+		{
+			last.frames += got_frames;
+			return;
+		}
+	}
+
+	m_Queue.push_back( pos_map_t( frameno, pos, got_frames ) );
+	
+	Cleanup();
+}
+
+void pos_map_queue::Cleanup()
+{
+	LockMut(m_Mutex);
+
+	/* Determine the number of frames of data we have. */
+	int64_t total_frames = 0;
+	for( unsigned i = 0; i < m_Queue.size(); ++i )
+		total_frames += m_Queue[i].frames;
+
+	/* Remove the oldest entry so long we'll stil have enough data.  Don't delete every
+	 * frame, so we'll always have some data to extrapolate from. */
+	while( m_Queue.size() > 1 && total_frames - m_Queue.front().frames > pos_map_backlog_frames )
+	{
+		total_frames -= m_Queue.front().frames;
+		m_Queue.pop_front();
+	}
+}
+
+int64_t pos_map_queue::Search( int64_t frame, bool *approximate ) const
+{
+	LockMut(m_Mutex);
+
+	if( IsEmpty() )
+	{
+		if( approximate )
+			*approximate = true;
+		return 0;
+	}
+
+	/* frame is probably in pos_map.  Search to figure out what position
+	 * it maps to. */
+	int64_t closest_position = 0, closest_position_dist = INT_MAX;
+	int closest_block = 0; /* print only */
+	for( unsigned i = 0; i < m_Queue.size(); ++i )
+	{
+		if( frame >= m_Queue[i].frameno &&
+			frame < m_Queue[i].frameno+m_Queue[i].frames )
+		{
+			/* frame lies in this block; it's an exact match.  Figure
+			 * out the exact position. */
+			int64_t diff = m_Queue[i].position - m_Queue[i].frameno;
+			return frame + diff;
+		}
+
+		/* See if the current position is close to the beginning of this block. */
+		int64_t dist = llabs( m_Queue[i].frameno - frame );
+		if( dist < closest_position_dist )
+		{
+			closest_position_dist = dist;
+			closest_block = i;
+			closest_position = m_Queue[i].position - dist;
+		}
+
+		/* See if the current position is close to the end of this block. */
+		dist = llabs( m_Queue[i].frameno + m_Queue[i].frames - frame );
+		if( dist < closest_position_dist )
+		{
+			closest_position_dist = dist;
+			closest_position = m_Queue[i].position + m_Queue[i].frames + dist;
+		}
+	}
+
+	/* The frame is out of the range of data we've actually sent.
+	 * Return the closest position.
+	 *
+	 * There are three cases when this happens: 
+	 * 1. After the first GetPCM call, but before it actually gets heard.
+	 * 2. After GetPCM returns EOF and the sound has flushed, but before
+	 *    SoundStopped has been called.
+	 * 3. Underflow; we'll be given a larger frame number than we know about.
+	 */
+	/* XXX: %lli normally, %I64i in Windows */
+	LOG->Trace( "Approximate sound time: driver frame %lli, m_Queue frame %lli (dist %lli), closest position is %lli",
+		frame, m_Queue[closest_block].frameno, closest_position_dist, closest_position );
+
+	if( approximate )
+		*approximate = true;
+	return closest_position;
+}
+
+void pos_map_queue::Clear()
+{
+	LockMut(m_Mutex);
+	m_Queue.clear();
+}
+
+bool pos_map_queue::IsEmpty() const
+{
+	LockMut(m_Mutex);
+	return m_Queue.empty();
+}
+