used comparator for did-you-mean that uses index sizes for comparisment, but:

- limit comparisment to only the first 10 elements that had been sorted before without IO
- added a size cache to index computation because the size is computed at least twice in set comparator


git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6306 6c8d7289-2bf4-0310-a012-ef5d649a1542

htroot/yacysearch.java

@@ -488,7 +488,7 @@ public class yacysearch {
             prop.put("meanCount", meanMax);
             if (meanMax > 0) {
                 DidYouMean didYouMean = new DidYouMean(sb.indexSegment.termIndex());
-            	Iterator<String> meanIt = didYouMean.getSuggestion(querystring).iterator();
+            	Iterator<String> meanIt = didYouMean.getSuggestions(querystring, 300, 10).iterator();
                 int meanCount = 0;
                 String suggestion;
                 while(meanCount<meanMax && meanIt.hasNext()) {

source/de/anomic/data/DidYouMean.java

@@ -27,11 +27,12 @@ import de.anomic.yacy.logging.Log;
  */
 public class DidYouMean {
 
-    protected static final char[] alphabet = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p',
+    protected static final char[] alphabet = {
+        'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p',
 		'q','r','s','t','u','v','w','x','y','z','\u00e4','\u00f6','\u00fc','\u00df'}; 
 	private   static final String poisonString = "\n";
 	public    static final int availableCPU = Runtime.getRuntime().availableProcessors();
-	private static final wordLengthComparator wlComp = new wordLengthComparator();
+	protected static final wordLengthComparator wlComp = new wordLengthComparator();
 	
 	protected final IndexCell<WordReference> index;
     protected String word;
@@ -46,10 +47,7 @@ public class DidYouMean {
 	 * @param index a termIndex - most likely retrieved from a switchboard object.
 	 * @param sort true/false -  sorts the resulting TreeSet by index.count(); <b>Warning:</b> this causes heavy i/o.
 	 */
-	public DidYouMean(final IndexCell<WordReference> index, boolean sort) {
+	public DidYouMean(final IndexCell<WordReference> index) {
-		if(sort)
-			this.resultSet = Collections.synchronizedSortedSet(new TreeSet<String>(new indexSizeComparator()));
-		else
 		this.resultSet = Collections.synchronizedSortedSet(new TreeSet<String>(wlComp));
 		this.word = "";
 		this.wordLen = 0;
@@ -60,20 +58,50 @@ public class DidYouMean {
 	}
 	
 	/**
-	 * @param index a termIndex - most likely retrieved from a switchboard object.
+	 * get a single suggestion
+	 * @param word
+	 * @param timeout
+	 * @return
 	 */
-	public DidYouMean(final IndexCell<WordReference> index) {
+	public String getSuggestion(final String word, long timeout) {
-		this(index, false);
+	    Set<String> s = getSuggestions(word, timeout);
+	    if (s == null || s.size() == 0) return null;
+	    return s.iterator().next();
 	}
 	
 	/**
-	 * This method triggers the producer and consumer threads of DidYouMean.
+     * get a single suggestion with additional sort
-	 * <p/><b>Note:</b> the default timeout is 500ms
+     * @param word
-	 * @param word a String with a single word
+     * @param timeout
-	 * @return a Set&lt;String&gt; with word variations contained in index.
+     * @return
      */
-	public Set<String> getSuggestion(final String word) {
+    public String getSuggestion(final String word, long timeout, int preSortSelection) {
-		return getSuggestion(word, 500);
+        Set<String> s = getSuggestions(word, timeout, preSortSelection);
+        if (s == null || s.size() == 0) return null;
+        return s.iterator().next();
+    }
+	
+	/**
+	 * get suggestions for a given word. The result is first ordered using a term size ordering,
+	 * and a subset of the result is sorted again with a IO-intensive order based on the index size
+	 * @param word
+	 * @param timeout
+	 * @param preSortSelection the number of words that participate in the IO-intensive sort
+	 * @return
+	 */
+	public Set<String> getSuggestions(final String word, long timeout, int preSortSelection) {
+	    long startTime = System.currentTimeMillis();
+	    Set<String> preSorted = getSuggestions(word, timeout);
+	    long timelimit = 2 * System.currentTimeMillis() - startTime + timeout;
+        if (System.currentTimeMillis() > timelimit) return preSorted;
+        Set<String> countSorted = Collections.synchronizedSortedSet(new TreeSet<String>(new indexSizeComparator()));
+        for (String s: preSorted) {
+	        if (System.currentTimeMillis() > timelimit) break;
+	        if (preSortSelection <= 0) break;
+	        countSorted.add(s);
+	        preSortSelection--;
+	    }
+	    return countSorted;
 	}
 	
 	/**
@@ -82,7 +110,7 @@ public class DidYouMean {
 	 * @param timeout execution time in ms.
 	 * @return a Set&lt;String&gt; with word variations contained in term index.
 	 */
-	public Set<String> getSuggestion(final String word, long timeout) {
+	public Set<String> getSuggestions(final String word, long timeout) {
 		long startTime = System.currentTimeMillis();
 		this.timeLimit = startTime + timeout;
 		this.word = word.toLowerCase();
@@ -251,7 +279,7 @@ public class DidYouMean {
 		public int compare(final String o1, final String o2) {
     		final int i1 = index.count(Word.word2hash(o1));
     		final int i2 = index.count(Word.word2hash(o2));
-    		if (i1 == i2) return o1.compareTo(o2);
+    		if (i1 == i2) return wlComp.compare(o1, o2);
     		return (i1 < i2) ? 1 : -1; // '<' is correct, because the largest count shall be ordered to be the first position in the result
     	}    	
     }

source/de/anomic/data/OpenGeoDB.java

@@ -191,7 +191,7 @@ public class OpenGeoDB {
     /**
      * read the dictionary and construct a set of recommendations to a given string 
      * @param s input value that is used to match recommendations
-     * @return a set that contains all words that start or end with the input value
+     * @return a set that contains all words that start with the input value
      */
     public Set<String> recommend(String s) {
         Set<String> a = new HashSet<String>();

source/de/anomic/kelondro/text/IndexCell.java

@@ -32,10 +32,12 @@ import java.util.HashSet;
 import java.util.Set;
 
 import de.anomic.kelondro.index.Row;
+import de.anomic.kelondro.index.SimpleARC;
 import de.anomic.kelondro.order.ByteOrder;
 import de.anomic.kelondro.order.CloneableIterator;
 import de.anomic.kelondro.order.MergeIterator;
 import de.anomic.kelondro.order.Order;
+import de.anomic.kelondro.util.ByteArray;
 import de.anomic.kelondro.util.MemoryControl;
 import de.anomic.server.serverProfiling;
 
@@ -62,7 +64,7 @@ public final class IndexCell<ReferenceType extends Reference> extends AbstractBu
     private       long                                   lastCleanup;
     private final long                                   targetFileSize, maxFileSize;
     private final int                                    writeBufferSize;
-    
+    private final SimpleARC<ByteArray, Integer>          countCache;
     
     public IndexCell(
             final File cellPath,
@@ -86,6 +88,7 @@ public final class IndexCell<ReferenceType extends Reference> extends AbstractBu
         this.targetFileSize = targetFileSize;
         this.maxFileSize = maxFileSize;
         this.writeBufferSize = writeBufferSize;
+        this.countCache = new SimpleARC<ByteArray, Integer>(1000);
         //cleanCache();
     }
 
@@ -123,20 +126,41 @@ public final class IndexCell<ReferenceType extends Reference> extends AbstractBu
         return this.array.has(termHash);
     }
 
+    /**
+     * count number of references for a given term
+     * this method may cause strong IO load if called too frequently, because it is
+     * necessary to read the corresponding reference containers from the files and
+     * count the resulting index object.
+     * To reduce the load for processes that frequently need access to the same
+     * term objects, a ARC cache is here to reduce IO load.
+     */
     public int count(byte[] termHash) {
-        ReferenceContainer<ReferenceType> c0 = this.ram.get(termHash, null);
+        
+        // check if value is in cache
+        ByteArray ba = new ByteArray(termHash);
+        Integer countCache = this.countCache.get(ba);
+        int countFile;
+        if (countCache == null) {
+            // read fresh values from file
             ReferenceContainer<ReferenceType> c1;
             try {
                 c1 = this.array.get(termHash);
             } catch (IOException e) {
                 c1 = null;
             }
-        if (c1 == null) {
+            countFile = (c1 == null) ? 0 : c1.size();
-            if (c0 == null) return 0;
+            
-            return c0.size();
+            // store to cache
+            this.countCache.put(ba, countFile);
+        } else {
+            // value was in ram
+            countFile = countCache.intValue();
         }
-        if (c0 == null) return c1.size();
+        
-        return c1.size() + c0.size();
+        // count from container in ram
+        ReferenceContainer<ReferenceType> countRam = this.ram.get(termHash, null);
+
+        return (countRam == null) ? countFile : countFile + countRam.size();
     }
     
     /**
@@ -161,7 +185,10 @@ public final class IndexCell<ReferenceType extends Reference> extends AbstractBu
      */
     public ReferenceContainer<ReferenceType> delete(byte[] termHash) throws IOException {
         ReferenceContainer<ReferenceType> c1 = this.array.get(termHash);
-        if (c1 != null) this.array.delete(termHash);
+        if (c1 != null) {
+            this.array.delete(termHash);
+            this.countCache.remove(new ByteArray(termHash));
+        }
         ReferenceContainer<ReferenceType> c0 = this.ram.delete(termHash);
         cleanCache();
         if (c1 == null) return c0;
@@ -179,12 +206,14 @@ public final class IndexCell<ReferenceType extends Reference> extends AbstractBu
     public int remove(byte[] termHash, Set<String> urlHashes) throws IOException {
         int removed = this.ram.remove(termHash, urlHashes);
         int reduced = this.array.replace(termHash, new RemoveRewriter<ReferenceType>(urlHashes));
+        this.countCache.remove(new ByteArray(termHash));
         return removed + (reduced / this.array.rowdef().objectsize);
     }
 
     public boolean remove(byte[] termHash, String urlHash) throws IOException {
         boolean removed = this.ram.remove(termHash, urlHash);
         int reduced = this.array.replace(termHash, new RemoveRewriter<ReferenceType>(urlHash));
+        this.countCache.remove(new ByteArray(termHash));
         return removed || (reduced > 0);
     }
 
@@ -245,6 +274,7 @@ public final class IndexCell<ReferenceType extends Reference> extends AbstractBu
     public synchronized void clear() throws IOException {
         this.ram.clear();
         this.array.clear();
+        this.countCache.clear();
     }
     
     /**
@@ -257,6 +287,7 @@ public final class IndexCell<ReferenceType extends Reference> extends AbstractBu
         // close all
         this.ram.close();
         this.array.close();
+        this.countCache.clear();
     }
 
     public int size() {
@@ -292,6 +323,7 @@ public final class IndexCell<ReferenceType extends Reference> extends AbstractBu
      */
     
     private void cleanCache() {
+    	this.countCache.clear();
     	
         // dump the cache if necessary
     	if (this.ram.size() >= this.maxRamEntries || (this.ram.size() > 3000 && !MemoryControl.request(80L * 1024L * 1024L, false))) synchronized (this) {