package greenfoot.sound;

import java.io.IOException;
import java.net.URL;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.UnsupportedAudioFileException;




| A cache for soundclip data.
|
| @author Davin McCall
|
public class ClipCache
{       


| Data for clips that aren't currently in use
|
private LinkedHashMap<String,ClipData> freeClips = new LinkedHashMap<String,ClipData>();
   
   private int numberFreeClips = 0;
    
   
   private static int MAX_CACHED_CLIPS = 20;
    
   
   

| Data for clips that are in use
|
private Map<String,ClipData> cachedClips = new HashMap<String,ClipData>();
    
   
   public synchronized ClipData getCachedClip(URL url)
       
   throws IOException, UnsupportedAudioFileException
   {
      String urlStr = url.toString();
      ClipData data = cachedClips.get(urlStr);
      if (data == null) {            
         
         data = freeClips.remove(urlStr);
         if (data != null) {                
            numberFreeClips --;
            cachedClips.put(urlStr, data);             
            }         
         }
      if (data == null) {            
         
         AudioInputStream ais = AudioSystem.getAudioInputStream(url);
         AudioFormat af = ais.getFormat();
         long frameLength = ais.getFrameLength();
            
         int total = (int)(af.getFrameSize() * frameLength);
           
         byte[] allBytes = new byte[(int)(af.getFrameSize() * frameLength)];
           
         int pos = 0;
            
           
         try {
         while (pos < total){
            int r = ais.read(allBytes, pos, total - pos);
            if (r == -1) {                        
               break;                     
               }
                   
            pos += r;                 
            }             
         }
           
      finally {
      ais.close();             
      }
            
           
   data = new ClipData(urlStr, allBytes, af, (int) frameLength);         
   }
       

else {
data.addUser();         
}
        
       
return data;     
}
    
   
public synchronized void releaseClipData(ClipData data)
   {
   if (data.release()) {
      cachedClips.remove(data.getUrl());
      freeClips.put(data.getUrl(), data);
           
      numberFreeClips++;
      if (numberFreeClips > MAX_CACHED_CLIPS) {                
         
         Iterator<ClipData> it = freeClips.values().iterator();
         it.next();
         it.remove();
               
         numberFreeClips = MAX_CACHED_CLIPS;             
         }         
      }     
   } 
}