DidYouMean - changed to much simpler LinkedBlockingQueue

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6071 6c8d7289-2bf4-0310-a012-ef5d649a1542

source/de/anomic/tools/DidYouMean.java

@@ -2,8 +2,8 @@ package de.anomic.tools;
 
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.Set;
+import java.util.concurrent.LinkedBlockingQueue;
 
 import de.anomic.kelondro.text.IndexCell;
 import de.anomic.kelondro.text.referencePrototype.WordReference;
@@ -23,69 +23,66 @@ public class DidYouMean {
 									  'q','r','s','t','u','v','w','x','y','z','\u00e4','\u00f6','\u00fc','\u00df'}; 
 	private static final long TIMEOUT = 500;
 	
+	final LinkedBlockingQueue<String> queue = new LinkedBlockingQueue<String>();
+	
 	private final Set<String> set;
 	private final IndexCell<WordReference> index;
 	private String word;
 	private int len;
 	
-	private Thread ChangingOneLetter;
-	private Thread AddingOneLetter;
-	private Thread DeletingOneLetter;
-	private Thread ReversingTwoConsecutiveLetters;
-	
-	private final BlockingQueue bq = new BlockingQueue();
-	
 	public DidYouMean(final IndexCell<WordReference> index) {
 		// this.set = Collections.synchronizedSortedSet(new TreeSet<String>(new wordSizeComparator()));
 		this.set = Collections.synchronizedSet(new HashSet<String>());
 		this.word = "";
 		this.len = 0;
 		this.index = index;
-		
-		this.ChangingOneLetter = new ChangingOneLetter();
-		this.AddingOneLetter = new AddingOneLetter();
-		this.DeletingOneLetter = new DeletingOneLetter();
-		this.ReversingTwoConsecutiveLetters = new ReversingTwoConsecutiveLetters();
 	}
 	
 	public Set<String> getSuggestion(final String word) {
 		long startTime = System.currentTimeMillis();
 		this.word = word.toLowerCase();
 		this.len = word.length();
-
-	    // create worker threads
-	    Thread[] workers = new Thread[8];
-	    for (int i=0; i<workers.length; i++) {
-		      workers[i] = new Worker("WorkerThread_"+i);
-	    }
-	    // first push the tasks for calculation of word variations on blocking queue
-		bq.push(this.ChangingOneLetter);
-		bq.push(this.AddingOneLetter);
-		bq.push(this.DeletingOneLetter);
-		bq.push(this.ReversingTwoConsecutiveLetters);		
 		
-		// check for timeout
-		boolean run = true;
-		while(run && (System.currentTimeMillis()-startTime) < TIMEOUT) {
-			if(bq.size() > 0) {
-				run = true;
-			} else {
-				run = false;
-			}
+	    // create producers
+		Thread[] producers = new Thread[4];
+		producers[0] = new ChangingOneLetter();
+		producers[1] = new AddingOneLetter();		
+		producers[2] = new DeletingOneLetter();
+		producers[3] = new ReversingTwoConsecutiveLetters();
+		
+		// start producers
+	    for (int i=0; i<producers.length; i++) {
+		      producers[i].start();
+	    }
+	    
+	    // create and start 8 consumers threads
+	    Thread[] consumers = new Thread[8];
+	    for (int i=0; i<consumers.length; i++) {
+		      consumers[i] = new Consumer();
+		      consumers[i].start();
+	    }
+	    
+		// check if timeout has been reached
+		while(((System.currentTimeMillis()-startTime) < TIMEOUT) && queue.size()>0) {			
+			// consume more ...
 		}
 		
-		// push "poison pill" for each worker thread
-	    for (int i=0; i<workers.length; i++) {
-	    	bq.push(new Thread() {
-	    		public void run() {
-	    			Thread.currentThread().interrupt();
-	    		}
-	        });
+		// put "poison pill" for each consumer thread
+	    for (int i=0; i<consumers.length; i++) {
+	    	try {
+				queue.put("\n"); 
+			} catch (InterruptedException e) {
+			}
+	    }
+	    
+	    // interupt all remaining producer threads
+	    for (int i=0; i<producers.length; i++) {
+		      producers[i].interrupt();
 	    }
 	    
 		this.set.remove(word.toLowerCase());
 		Log.logInfo("DidYouMean", "found "+this.set.size()+" terms; execution time: "
-				+(System.currentTimeMillis()-startTime)+"ms"+ (run?"(timed out)":""));
+				+(System.currentTimeMillis()-startTime)+"ms"+ (queue.size()>0?"(timed out)":""));
 		
 		return this.set;
 			
@@ -93,17 +90,17 @@ public class DidYouMean {
 	
 	private class ChangingOneLetter extends Thread {
 		
-		public ChangingOneLetter() {
-			this.setName("ChangingOneLetter");
-		}
-		
 		// tests: alphabet.length * len
 		public void run() {
 			String s;
 			for(int i=0; i<len; i++) {
 				for(int j=0; j<alphabet.length; j++) {
 					s = word.substring(0, i) + alphabet[j] + word.substring(i+1);
-					bq.push(new Tester(s));
+					try {
+						queue.put(s);
+					} catch (InterruptedException e) {
+						return;
+					}
 				}
 			}
 		}
@@ -111,104 +108,75 @@ public class DidYouMean {
 	
 	private class DeletingOneLetter extends Thread {
 		
-		public DeletingOneLetter() {
-			this.setName("DeletingOneLetter");
-		}
-		
 		// tests: len
 		public void run() {
 			String s;
 			for(int i=0; i<len;i++) {
 				s = word.substring(0, i) + word.substring(i+1);
-				bq.push(new Tester(s));
+				try {
+					queue.put(s);
+				} catch (InterruptedException e) {
+					return;
+				}
 			}
 		}
 	}
 	
 	private class AddingOneLetter extends Thread {
 		
-		public AddingOneLetter() {
-			this.setName("AddingOneLetter");
-		}
-		
 		// tests: alphabet.length * len
 		public void run() {
 			String s;
 			for(int i=0; i<=len;i++) {
 				for(int j=0; j<alphabet.length; j++) {
 					s = word.substring(0, i) + alphabet[j] + word.substring(i);
-					bq.push(new Tester(s));
+					try {
+						queue.put(s);
+					} catch (InterruptedException e) {
+						return;
+					}
 				}			
 			}
 		}
 	}
 	
 	private class ReversingTwoConsecutiveLetters extends Thread {
-		
-		public ReversingTwoConsecutiveLetters() {
-			this.setName("ReversingTwoConsecutiveLetters");
-		}
-		
+	
 		// tests: (len - 1)
 		public void run() {
 			String s;
 			for(int i=0; i<len-1; i++) {
 				s = word.substring(0,i)+word.charAt(i+1)+word.charAt(i)+word.substring(i+2);
-				bq.push(new Tester(s));
-			}
-		}
-	}
-	
-	private class Tester extends Thread {
-		
-		private String s;
-		
-		public Tester(String s) {
-			this.s = s;
-		}
-		public void run() {
-			if (index.has(Word.word2hash(s))) {
-				set.add(s);
+				try {
+					queue.put(s);
+				} catch (InterruptedException e) {
+					return;
+				}
 			}
 		}
 	}
-	
-	private class Worker extends Thread {
-		public Worker(String name) { 
-			super(name); 
-			start(); 
-		}		
+
+	class Consumer extends Thread {
+
 		public void run() {
 			try {
-				while(!isInterrupted()) {
-					((Runnable)bq.pop()).run();
+				while(true) { 
+					String s = (String)queue.take();
+					if(s.equals("\n"))
+						this.interrupt();
+					else
+						consume(s); 
 				}
-			} catch(InterruptedException e) {				
-			}
-		}
-	}
-	
-	private class BlockingQueue {
-		private final LinkedList<Thread> queue = new LinkedList<Thread>();
-
-		public void push(Thread t) {
-			synchronized(queue) {
-				queue.add(t);
-				queue.notify();
+			} catch (InterruptedException e) { 
+				return; 
 			}
 		}
-		public Object pop() throws InterruptedException {
-			synchronized(queue) {
-				while (queue.isEmpty()) {
-					queue.wait();
-				}
-				return queue.removeFirst();
+		void consume(String s) { 	
+			if (index.has(Word.word2hash(s))) {
+				set.add(s);
 			}
 		}
-		public int size() {
-			return queue.size();
-		}
-	}
+	}	
 	
 	/*
     private class wordSizeComparator implements Comparator<String> {