- enhanced generation of url objects

- enhanced computation of link structure graphics
- enhanced collection of data for link structures

20 files changed, 184 insertions, 128 deletions

diff --git a/htroot/CrawlStartScanner_p.java b/htroot/CrawlStartScanner_p.java
index b70d8c7af..295ded2e4 100644
--- a/htroot/CrawlStartScanner_p.java
+++ b/htroot/CrawlStartScanner_p.java
@@ -181,7 +181,7 @@ public class CrawlStartScanner_p
                     final Scanner.Service u = se.next().getKey();
                     DigestURI uu;
                     try {
-                        uu = new DigestURI(u.url());
+                        uu = DigestURI.toDigestURI(u.url());
                         pkmap.put(uu.hash(), uu);
                     } catch ( final MalformedURLException e ) {
                         Log.logException(e);
@@ -236,7 +236,7 @@ public class CrawlStartScanner_p
                         while ( se.hasNext() ) {
                             host = se.next();
                             try {
-                                u = new DigestURI(host.getKey().url());
+                                u = DigestURI.toDigestURI(host.getKey().url());
                                 urlString = u.toNormalform(true);
                                 if ( host.getValue() == Access.granted
                                     && Scanner.inIndex(apiCommentCache, urlString) == null ) {
diff --git a/htroot/Crawler_p.java b/htroot/Crawler_p.java
index 88d38eaf3..eb62823d5 100644
--- a/htroot/Crawler_p.java
+++ b/htroot/Crawler_p.java
@@ -296,7 +296,7 @@ public class Crawler_p {
                             scraper = sb.loader.loadDocument(sitelistURL, CacheStrategy.IFFRESH, BlacklistType.CRAWLER, CrawlQueues.queuedMinLoadDelay);
                             // get links and generate filter
                             for (MultiProtocolURI u: scraper.getAnchors().keySet()) {
-                                newRootURLs.add(new DigestURI(u));
+                                newRootURLs.add(DigestURI.toDigestURI(u));
                             }
                         } catch (IOException e) {
                             Log.logException(e);
diff --git a/htroot/ServerScannerList.java b/htroot/ServerScannerList.java
index 49c096dd3..4bd7b531c 100644
--- a/htroot/ServerScannerList.java
+++ b/htroot/ServerScannerList.java
@@ -63,7 +63,7 @@ public class ServerScannerList {
                     while (se.hasNext()) {
                         host = se.next();
                         try {
-                            u = new DigestURI(host.getKey().url());
+                            u = DigestURI.toDigestURI(host.getKey().url());
                             urlString = u.toNormalform(true);
                             prop.put("servertable_list_" + i + "_edit", edit ? 1 : 0);
                             prop.put("servertable_list_" + i + "_edit_pk", ASCII.String(u.hash()));
diff --git a/htroot/WatchWebStructure_p.html b/htroot/WatchWebStructure_p.html
index 8683ddf19..9dc529666 100644
--- a/htroot/WatchWebStructure_p.html
+++ b/htroot/WatchWebStructure_p.html
@@ -68,6 +68,17 @@ To see a list of all APIs, please visit the <a href="http://www.yacy-websuche.de
 
 <h2>Web Structure</h2>
 
+    #(hosts)#::
+     <fieldset><legend>Host List</legend>
+      #{list}#
+      <div style="float:left; padding:1px 5px 1px 5px;">
+        <div style="width:160px; text-align:left; float: left; white-space:nowrap; overflow:hidden;"><a href="/WatchWebStructure_p.html?host=#[host]#&depth=3&time=1000">#[host]#</a></div>
+        <div style="width:80px; text-align:right; float: left; white-space:nowrap; overflow:hidden;">#[count]# outlinks</div>
+      </div>
+      #{/list}#
+    </fieldset>
+    #(/hosts)#
+    
 <div id="left">
 <form action="/WatchWebStructure_p.html" accept-charset="UTF-8" onsubmit="return checkform(this);">
 <fieldset>
diff --git a/htroot/WatchWebStructure_p.java b/htroot/WatchWebStructure_p.java
index 8875d368b..be8ce12ca 100644
--- a/htroot/WatchWebStructure_p.java
+++ b/htroot/WatchWebStructure_p.java
@@ -4,7 +4,10 @@
 //$LastChangedBy$
 //
 
+import java.util.Iterator;
+
 import net.yacy.cora.protocol.RequestHeader;
+import net.yacy.cora.sorting.ReversibleScoreMap;
 import net.yacy.crawler.CrawlSwitchboard;
 import net.yacy.crawler.data.CrawlProfile;
 import net.yacy.kelondro.data.meta.DigestURI;
@@ -27,7 +30,7 @@ public class WatchWebStructure_p {
         int width = 1024;
         int height = 576;
         int depth = 3;
-        int nodes = 500; // maximum number of host nodes that are painted
+        int nodes = 300; // maximum number of host nodes that are painted
         int time = -1;
         String host = "auto";
         String besthost;
@@ -36,7 +39,7 @@ public class WatchWebStructure_p {
             width         = post.getInt("width", 1024);
             height        = post.getInt("height", 576);
             depth         = post.getInt("depth", 3);
-            nodes         = post.getInt("nodes", width * height * 100 / 1024 / 576);
+            nodes         = post.getInt("nodes", width * height * 300 / 1024 / 576);
             time          = post.getInt("time", -1);
             host          = post.get("host", "auto");
             color_text    = post.get("colortext",    color_text);
@@ -70,6 +73,22 @@ public class WatchWebStructure_p {
                 host = "www." + host;
             }
         }
+        
+        if (post != null && post.containsKey("hosts")) {
+            int maxcount = 200;
+            ReversibleScoreMap<String> score = sb.webStructure.hostReferenceScore();
+            int c = 0;
+            Iterator<String> i = score.keys(false);
+            String h;
+            while (i.hasNext() && c < maxcount) {
+                h = i.next();
+                prop.put("hosts_list_" + c + "_host", h);
+                prop.put("hosts_list_" + c + "_count", score.get(h));
+                c++;
+            }
+            prop.put("hosts_list", c);
+            prop.put("hosts", 1);
+        }
 
         // find start point
         if (host == null ||
diff --git a/htroot/WebStructurePicture_p.java b/htroot/WebStructurePicture_p.java
index 2caee7b66..9b777de04 100644
--- a/htroot/WebStructurePicture_p.java
+++ b/htroot/WebStructurePicture_p.java
@@ -28,7 +28,6 @@ import java.net.MalformedURLException;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
@@ -61,7 +60,7 @@ public class WebStructurePicture_p {
         int width = 1024;
         int height = 576;
         int depth = 3;
-        int nodes = 100; // maximum number of host nodes that are painted
+        int nodes = 300; // maximum number of host nodes that are painted
         int time = -1;
         String host = null;
         int cyc = 0;
@@ -156,16 +155,13 @@ public class WebStructurePicture_p {
         final double radius = 1.0 / (1 << nextlayer);
         final WebStructureGraph.StructureEntry sr = structure.outgoingReferences(centerhash);
         final Map<String, Integer> next = (sr == null) ? new HashMap<String, Integer>() : sr.references;
-        Map.Entry<String, Integer> entry;
         String targethash, targethost;
         // first set points to next hosts
-        final Iterator<Map.Entry<String, Integer>> i = next.entrySet().iterator();
         final List<String[]> targets = new ArrayList<String[]>();
         int maxtargetrefs = 8, maxthisrefs = 8;
         int targetrefs, thisrefs;
         double rr, re;
-        while (i.hasNext() && maxnodes > 0 && System.currentTimeMillis() < timeout) {
-            entry = i.next();
+        for (Map.Entry<String, Integer> entry: next.entrySet()) {
             targethash = entry.getKey();
             targethost = structure.hostHash2hostName(targethash);
             if (targethost == null) continue;
@@ -181,15 +177,12 @@ public class WebStructurePicture_p {
             rr = radius * 0.25 * (1 - targetrefs / (double) maxtargetrefs);
             re = radius * 0.5 * (thisrefs / (double) maxthisrefs);
             graph.addNode(targethost, x + (radius - rr - re) * Math.cos(angle), y + (radius - rr - re) * Math.sin(angle), nextlayer);
-            maxnodes--;
             mynodes++;
+            if (maxnodes-- <= 0 || System.currentTimeMillis() >= timeout) break;
         }
         // recursively set next hosts
-        final Iterator<String[]> j = targets.iterator();
-        String[] target;
         int nextnodes;
-        while (j.hasNext()) {
-            target = j.next();
+        for (String[] target: targets) {
             targethash = target[0];
             targethost = target[1];
             final GraphPlotter.Point c = graph.getNode(targethost);
diff --git a/htroot/api/webstructure.java b/htroot/api/webstructure.java
index 313184ba1..76fa0cb2c 100644
--- a/htroot/api/webstructure.java
+++ b/htroot/api/webstructure.java
@@ -79,14 +79,14 @@ public class webstructure {
                 prop.put("out", 1);
                 prop.put("in", 1);
                 WebStructureGraph.StructureEntry sentry = sb.webStructure.outgoingReferences(hosthash);
-                if (sentry != null) {
+                if (sentry != null && sentry.references.size() > 0) {
                     reference(prop, "out", 0, sentry, sb.webStructure);
                     prop.put("out_domains", 1);
                 } else {
                     prop.put("out_domains", 0);
                 }
                 sentry = sb.webStructure.incomingReferences(hosthash);
-                if (sentry != null) {
+                if (sentry != null && sentry.references.size() > 0) {
                     reference(prop, "in", 0, sentry, sb.webStructure);
                     prop.put("in_domains", 1);
                 } else {
@@ -113,7 +113,7 @@ public class webstructure {
                     int d = 0;
                     Iterator<MultiProtocolURI> i = scraper.inboundLinks().iterator();
             		while (i.hasNext()) {
-            			DigestURI refurl = new DigestURI(i.next());
+            			DigestURI refurl = DigestURI.toDigestURI(i.next());
                     	byte[] refhash = refurl.hash();
                     	prop.putXML("references_documents_0_anchors_" + d + "_url", refurl.toNormalform(true));
                     	prop.put("references_documents_0_anchors_" + d + "_hash", refhash);
@@ -122,7 +122,7 @@ public class webstructure {
             		}
                     i = scraper.outboundLinks().iterator();
             		while (i.hasNext()) {
-            			DigestURI refurl = new DigestURI(i.next());
+            			DigestURI refurl = DigestURI.toDigestURI(i.next());
                     	byte[] refhash = refurl.hash();
                     	prop.putXML("references_documents_0_anchors_" + d + "_url", refurl.toNormalform(true));
                     	prop.put("references_documents_0_anchors_" + d + "_hash", refhash);
diff --git a/source/net/yacy/crawler/CrawlStacker.java b/source/net/yacy/crawler/CrawlStacker.java
index 2b0c392a2..ffd388ef4 100644
--- a/source/net/yacy/crawler/CrawlStacker.java
+++ b/source/net/yacy/crawler/CrawlStacker.java
@@ -204,7 +204,7 @@ public final class CrawlStacker {
             if (e.getKey() == null) continue;

 

             // delete old entry, if exists to force a re-load of the url (thats wanted here)

-            final DigestURI url = new DigestURI(e.getKey());

+            final DigestURI url = DigestURI.toDigestURI(e.getKey());

             final byte[] urlhash = url.hash();

             if (replace) {

                 this.indexSegment.fulltext().remove(urlhash);

diff --git a/source/net/yacy/crawler/retrieval/HTTPLoader.java b/source/net/yacy/crawler/retrieval/HTTPLoader.java
index f24dc0146..dfa668c95 100644
--- a/source/net/yacy/crawler/retrieval/HTTPLoader.java
+++ b/source/net/yacy/crawler/retrieval/HTTPLoader.java
@@ -150,7 +150,7 @@ public final class HTTPLoader {
             }

 

             // normalize URL

-            final DigestURI redirectionUrl = new DigestURI(MultiProtocolURI.newURL(request.url(), redirectionUrlString));

+            final DigestURI redirectionUrl = DigestURI.toDigestURI(MultiProtocolURI.newURL(request.url(), redirectionUrlString));

 

             // restart crawling with new url

             this.log.logInfo("CRAWLER Redirection detected ('" + client.getHttpResponse().getStatusLine() + "') for URL " + requestURLString);

@@ -289,7 +289,7 @@ public final class HTTPLoader {
                     }

 

                     // normalizing URL

-                    final DigestURI redirectionUrl = new DigestURI(MultiProtocolURI.newURL(request.url(), redirectionUrlString));

+                    final DigestURI redirectionUrl = DigestURI.toDigestURI(MultiProtocolURI.newURL(request.url(), redirectionUrlString));

 

 

                     // if we are already doing a shutdown we don't need to retry crawling

diff --git a/source/net/yacy/data/BookmarkHelper.java b/source/net/yacy/data/BookmarkHelper.java
index 76abc6fe8..ac22158de 100644
--- a/source/net/yacy/data/BookmarkHelper.java
+++ b/source/net/yacy/data/BookmarkHelper.java
@@ -155,7 +155,7 @@ public class BookmarkHelper {
             if ("".equals(title)) {//cannot be displayed
                 title = url.toString();
             }
-            bm = db.new Bookmark(new DigestURI(url));
+            bm = db.new Bookmark(DigestURI.toDigestURI(url));
             bm.setProperty(Bookmark.BOOKMARK_TITLE, title);
             bm.setTags(tags);
             bm.setPublic(importPublic);
diff --git a/source/net/yacy/document/parser/sevenzipParser.java b/source/net/yacy/document/parser/sevenzipParser.java
index 3f53af4c6..b4812211a 100644
--- a/source/net/yacy/document/parser/sevenzipParser.java
+++ b/source/net/yacy/document/parser/sevenzipParser.java
@@ -168,7 +168,7 @@ public class sevenzipParser extends AbstractParser implements Parser {
                      Document[] theDocs;
                      // workaround for relative links in file, normally '#' shall be used behind the location, see
                      // below for reversion of the effects
-                     final DigestURI url = new DigestURI(MultiProtocolURI.newURL(this.doc.dc_source(), this.prefix + "/" + super.filePath));
+                     final DigestURI url = DigestURI.toDigestURI(MultiProtocolURI.newURL(this.doc.dc_source(), this.prefix + "/" + super.filePath));
                      final String mime = TextParser.mimeOf(super.filePath.substring(super.filePath.lastIndexOf('.') + 1));
                      theDocs = TextParser.parseSource(url, mime, null, this.cfos.toByteArray());
 
diff --git a/source/net/yacy/document/parser/tarParser.java b/source/net/yacy/document/parser/tarParser.java
index 9edf3986d..3e098d5c5 100644
--- a/source/net/yacy/document/parser/tarParser.java
+++ b/source/net/yacy/document/parser/tarParser.java
@@ -90,7 +90,7 @@ public class tarParser extends AbstractParser implements Parser {
                 try {

                     tmp = FileUtils.createTempFile(this.getClass(), name);

                     FileUtils.copy(tis, tmp, entry.getSize());

-                    subDocs = TextParser.parseSource(new DigestURI(MultiProtocolURI.newURL(url,"#" + name)), mime, null, tmp);

+                    subDocs = TextParser.parseSource(DigestURI.toDigestURI(MultiProtocolURI.newURL(url,"#" + name)), mime, null, tmp);

                     if (subDocs == null) continue;

                     for (final Document d: subDocs) docacc.add(d);

                 } catch (final Parser.Failure e) {

diff --git a/source/net/yacy/document/parser/zipParser.java b/source/net/yacy/document/parser/zipParser.java
index 8fca97350..a124bd946 100644
--- a/source/net/yacy/document/parser/zipParser.java
+++ b/source/net/yacy/document/parser/zipParser.java
@@ -87,7 +87,7 @@ public class zipParser extends AbstractParser implements Parser {
                 try {

                     tmp = FileUtils.createTempFile(this.getClass(), name);

                     FileUtils.copy(zis, tmp, entry.getSize());

-                    final DigestURI virtualURL = new DigestURI(MultiProtocolURI.newURL(url, "#" + name));

+                    final DigestURI virtualURL = DigestURI.toDigestURI(MultiProtocolURI.newURL(url, "#" + name));

                     //this.log.logInfo("ZIP file parser: " + virtualURL.toNormalform(false, false));

                     docs = TextParser.parseSource(virtualURL, mime, null, tmp);

                     if (docs == null) continue;

diff --git a/source/net/yacy/kelondro/data/meta/DigestURI.java b/source/net/yacy/kelondro/data/meta/DigestURI.java
index 90ca65da3..fb65695f6 100644
--- a/source/net/yacy/kelondro/data/meta/DigestURI.java
+++ b/source/net/yacy/kelondro/data/meta/DigestURI.java
@@ -133,13 +133,18 @@ public class DigestURI extends MultiProtocolURI implements Serializable {
 

     /**

      * DigestURI from general URI

-     * @param baseURL

+     * @param u

      */

-    public DigestURI(final MultiProtocolURI baseURL) {

-        super(baseURL);

-        this.hash = (baseURL instanceof DigestURI) ? ((DigestURI) baseURL).hash : null;

+    private DigestURI(final MultiProtocolURI u) {

+        super(u);

+        this.hash = (u instanceof DigestURI) ? ((DigestURI) u).hash : null;

     }

 

+

+    public static DigestURI toDigestURI(MultiProtocolURI u) {

+        return (u instanceof DigestURI) ? ((DigestURI) u) : new DigestURI(u);

+    }

+    

     /**

      * DigestURI from general URI, hash already calculated

      * @param baseURL

diff --git a/source/net/yacy/peers/graphics/WebStructureGraph.java b/source/net/yacy/peers/graphics/WebStructureGraph.java
index 896a21462..a3e8305ae 100644
--- a/source/net/yacy/peers/graphics/WebStructureGraph.java
+++ b/source/net/yacy/peers/graphics/WebStructureGraph.java
@@ -49,6 +49,8 @@ import net.yacy.cora.document.ASCII;
 import net.yacy.cora.document.MultiProtocolURI;
 import net.yacy.cora.document.UTF8;
 import net.yacy.cora.order.Base64Order;
+import net.yacy.cora.sorting.ClusteredScoreMap;
+import net.yacy.cora.sorting.ReversibleScoreMap;
 import net.yacy.cora.util.LookAheadIterator;
 import net.yacy.cora.util.SpaceExceededException;
 import net.yacy.document.Document;
@@ -64,8 +66,7 @@ import net.yacy.kelondro.rwi.ReferenceFactory;
 import net.yacy.kelondro.util.FileUtils;
 import net.yacy.search.Switchboard;
 
-public class WebStructureGraph
-{
+public class WebStructureGraph {
 
     public static int maxref = 300; // maximum number of references, to avoid overflow when a large link farm occurs (i.e. wikipedia)
     public static int maxhosts = 50000; // maximum number of hosts in web structure map
@@ -75,17 +76,16 @@ public class WebStructureGraph
     private final File structureFile;
     private final TreeMap<String, byte[]> structure_old; // <b64hash(6)>','<host> to <date-yyyymmdd(8)>{<target-b64hash(6)><target-count-hex(4)>}*
     private final TreeMap<String, byte[]> structure_new;
-    private final BlockingQueue<leanrefObject> publicRefDNSResolvingQueue;
+    private final BlockingQueue<LearnObject> publicRefDNSResolvingQueue;
     private final PublicRefDNSResolvingProcess publicRefDNSResolvingWorker;
 
-    private final static leanrefObject leanrefObjectPOISON = new leanrefObject(null, null);
+    private final static LearnObject leanrefObjectPOISON = new LearnObject(null, null);
 
-    private static class leanrefObject
-    {
+    private static class LearnObject {
         private final DigestURI url;
         private final Set<MultiProtocolURI> globalRefURLs;
 
-        private leanrefObject(final DigestURI url, final Set<MultiProtocolURI> globalRefURLs) {
+        private LearnObject(final DigestURI url, final Set<MultiProtocolURI> globalRefURLs) {
             this.url = url;
             this.globalRefURLs = globalRefURLs;
         }
@@ -95,7 +95,7 @@ public class WebStructureGraph
         this.structure_old = new TreeMap<String, byte[]>();
         this.structure_new = new TreeMap<String, byte[]>();
         this.structureFile = structureFile;
-        this.publicRefDNSResolvingQueue = new LinkedBlockingQueue<leanrefObject>();
+        this.publicRefDNSResolvingQueue = new LinkedBlockingQueue<LearnObject>();
 
         // load web structure
         Map<String, byte[]> loadedStructureB;
@@ -142,7 +142,7 @@ public class WebStructureGraph
 
         @Override
         public void run() {
-            leanrefObject lro;
+            LearnObject lro;
             try {
                 while ( (lro = WebStructureGraph.this.publicRefDNSResolvingQueue.take()) != leanrefObjectPOISON ) {
                     learnrefs(lro);
@@ -170,7 +170,7 @@ public class WebStructureGraph
                 globalRefURLs.add(u);
             }
         }
-        final leanrefObject lro = new leanrefObject(url, globalRefURLs);
+        final LearnObject lro = new LearnObject(url, globalRefURLs);
         if ( !globalRefURLs.isEmpty() ) {
             try {
                 if ( this.publicRefDNSResolvingWorker.isAlive() ) {
@@ -184,34 +184,6 @@ public class WebStructureGraph
         }
     }
 
-    private void learnrefs(final leanrefObject lro) {
-        final StringBuilder cpg = new StringBuilder(240);
-        assert cpg.length() % 12 == 0 : "cpg.length() = " + cpg.length() + ", cpg = " + cpg.toString();
-        //final String refhashp = ASCII.String(lro.url.hash(), 6, 6); // ref hash part
-        String nexturlhash;
-        for ( final MultiProtocolURI u : lro.globalRefURLs ) {
-            if (Switchboard.getSwitchboard().shallTerminate()) break;
-            final byte[] nexturlhashb = new DigestURI(u).hash();
-            assert nexturlhashb != null;
-            if ( nexturlhashb != null ) {
-                nexturlhash = ASCII.String(nexturlhashb);
-                assert nexturlhash.length() == 12 : "nexturlhash.length() = "
-                    + nexturlhash.length()
-                    + ", nexturlhash = "
-                    + nexturlhash;
-                //assert !nexturlhash.substring(6).equals(refhashp);
-                // this is a global link
-                cpg.append(nexturlhash); // store complete hash
-                assert cpg.length() % 12 == 0 : "cpg.length() = "
-                    + cpg.length()
-                    + ", cpg = "
-                    + cpg.toString();
-            }
-        }
-        assert cpg.length() % 12 == 0 : "cpg.length() = " + cpg.length() + ", cpg = " + cpg.toString();
-        learn(lro.url, cpg);
-    }
-
     private static int refstr2count(final String refs) {
         if ( (refs == null) || (refs.length() <= 8) ) {
             return 0;
@@ -220,7 +192,7 @@ public class WebStructureGraph
         return (refs.length() - 8) / 10;
     }
 
-    static Map<String, Integer> refstr2map(final String refs) {
+    private static Map<String, Integer> refstr2map(final String refs) {
         if ( (refs == null) || (refs.length() <= 8) ) {
             return new HashMap<String, Integer>();
         }
@@ -240,8 +212,12 @@ public class WebStructureGraph
         return map;
     }
 
+    private static String none2refstr() {
+        return GenericFormatter.SHORT_DAY_FORMATTER.format();
+    }
+    
     private static String map2refstr(final Map<String, Integer> map) {
-        final StringBuilder s = new StringBuilder(map.size() * 10);
+        final StringBuilder s = new StringBuilder(GenericFormatter.PATTERN_SHORT_DAY.length() + map.size() * 10);
         s.append(GenericFormatter.SHORT_DAY_FORMATTER.format());
         String h;
         for ( final Map.Entry<String, Integer> entry : map.entrySet() ) {
@@ -265,6 +241,31 @@ public class WebStructureGraph
         return s.toString();
     }
 
+    public boolean exists(final String hosthash) {
+        // returns a map with a hosthash(String):refcount(Integer) relation
+        assert hosthash.length() == 6;
+        SortedMap<String, byte[]> tailMap;
+        synchronized ( this.structure_old ) {
+            tailMap = this.structure_old.tailMap(hosthash);
+            if ( !tailMap.isEmpty() ) {
+                final String key = tailMap.firstKey();
+                if ( key.startsWith(hosthash) ) {
+                    return true;
+                }
+            }
+        }
+        synchronized ( this.structure_new ) {
+            tailMap = this.structure_new.tailMap(hosthash);
+            if ( !tailMap.isEmpty() ) {
+                final String key = tailMap.firstKey();
+                if ( key.startsWith(hosthash) ) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+    
     public StructureEntry outgoingReferences(final String hosthash) {
         // returns a map with a hosthash(String):refcount(Integer) relation
         assert hosthash.length() == 6;
@@ -279,7 +280,7 @@ public class WebStructureGraph
                 final String key = tailMap.firstKey();
                 if ( key.startsWith(hosthash) ) {
                     hostname = key.substring(7);
-                    ref = UTF8.String(tailMap.get(key));
+                    ref = ASCII.String(tailMap.get(key));
                     date = ref.substring(0, 8);
                     h = refstr2map(ref);
                 }
@@ -290,7 +291,7 @@ public class WebStructureGraph
             if ( !tailMap.isEmpty() ) {
                 final String key = tailMap.firstKey();
                 if ( key.startsWith(hosthash) ) {
-                    ref = UTF8.String(tailMap.get(key));
+                    ref = ASCII.String(tailMap.get(key));
                     if ( hostname.isEmpty() ) {
                         hostname = key.substring(7);
                     }
@@ -371,7 +372,7 @@ public class WebStructureGraph
 
         private final Row.Entry entry;
 
-        public HostReference(final byte[] hostHash, final long modified, final int count) {
+        private HostReference(final byte[] hostHash, final long modified, final int count) {
             assert (hostHash.length == 6) : "hostHash = " + ASCII.String(hostHash);
             this.entry = hostReferenceFactory.getRow().newEntry();
             this.entry.setCol(0, hostHash);
@@ -383,7 +384,7 @@ public class WebStructureGraph
             this.entry = hostReferenceFactory.getRow().newEntry(json, true);
         }
 
-        public HostReference(final Row.Entry entry) {
+        private HostReference(final Row.Entry entry) {
             this.entry = entry;
         }
 
@@ -402,7 +403,7 @@ public class WebStructureGraph
             return this.entry.getPrimaryKeyBytes();
         }
 
-        public int count() {
+        private int count() {
             return (int) this.entry.getColLong(2);
         }
 
@@ -436,9 +437,9 @@ public class WebStructureGraph
     }
 
     public static final HostReferenceFactory hostReferenceFactory = new HostReferenceFactory();
-    public static ReferenceContainerCache<HostReference> hostReferenceIndexCache = null;
-    public static long hostReferenceIndexCacheTime = 0;
-    public static final long hostReferenceIndexCacheTTL = 1000 * 60 * 60 * 12; // 12 hours time to live for cache
+    private static ReferenceContainerCache<HostReference> hostReferenceIndexCache = null;
+    private static long hostReferenceIndexCacheTime = 0;
+    private static final long hostReferenceIndexCacheTTL = 1000 * 60 * 60 * 12; // 12 hours time to live for cache
 
     public synchronized ReferenceContainerCache<HostReference> incomingReferences() {
         // we return a cache if the cache is filled and not stale
@@ -508,22 +509,6 @@ public class WebStructureGraph
         }
     }
 
-    /*
-    private void incomingReferencesTest(ReferenceContainerCache<HostReference> idx) {
-        for (ReferenceContainer<HostReference> references: idx) {
-            log.logInfo("Term-Host: " + hostHash2hostName(UTF8.String(references.getTermHash())));
-            Iterator<HostReference> referenceIterator = references.entries();
-            StringBuilder s = new StringBuilder();
-            HostReference reference;
-            while (referenceIterator.hasNext()) {
-                reference = referenceIterator.next();
-                s.append(reference.toPropertyForm());
-                log.logInfo("   ... referenced by " + hostHash2hostName(UTF8.String(reference.metadataHash())) + ", " + reference.count() + " references");
-            }
-        }
-    }
-    */
-
     public int referencesCount(final String hosthash) {
         // returns the number of hosts that are referenced by this hosthash
         assert hosthash.length() == 6 : "hosthash = " + hosthash;
@@ -578,21 +563,31 @@ public class WebStructureGraph
         return null;
     }
 
-    private void learn(final DigestURI url, final StringBuilder reference /*string of b64(12digits)-hashes*/) {
-        final String hosthash = ASCII.String(url.hash(), 6, 6);
+
+    private void learnrefs(final LearnObject lro) {
+        final Set<String> refhosts = new HashSet<String>();
+        DigestURI du;
+        String hosthash;
+        for ( final MultiProtocolURI u : lro.globalRefURLs ) {
+            if (Switchboard.getSwitchboard().shallTerminate()) break;
+            du = DigestURI.toDigestURI(u);
+            hosthash = ASCII.String(du.hash(), 6, 12);
+            if (!exists(hosthash)) {
+                // this must be recorded as an host with no references
+                synchronized ( this.structure_new ) {
+                    this.structure_new.put(hosthash + "," + u.getHost(), UTF8.getBytes(none2refstr()));
+                }
+            }
+            refhosts.add(hosthash);
+        }
+        final DigestURI url = lro.url;
+        hosthash = ASCII.String(url.hash(), 6, 6);
 
         // parse the new reference string and join it with the stored references
         final StructureEntry structure = outgoingReferences(hosthash);
-        final Map<String, Integer> refs =
-            (structure == null) ? new HashMap<String, Integer>() : structure.references;
-        assert reference.length() % 12 == 0 : "reference.length() = "
-            + reference.length()
-            + ", reference = "
-            + reference.toString();
-        String dom;
+        final Map<String, Integer> refs = (structure == null) ? new HashMap<String, Integer>() : structure.references;
         int c;
-        for ( int i = 0; i < reference.length() / 12; i++ ) {
-            dom = reference.substring(i * 12 + 6, (i + 1) * 12);
+        for (String dom: refhosts) {
             c = 0;
             if ( refs.containsKey(dom) ) {
                 c = (refs.get(dom)).intValue();
@@ -681,14 +676,27 @@ public class WebStructureGraph
         }
         return maxhost;
     }
-
+    
+    public ReversibleScoreMap<String> hostReferenceScore() {
+        ReversibleScoreMap<String> result = new ClusteredScoreMap<String>(ASCII.identityASCIIComparator);
+        synchronized ( this.structure_old ) {
+            for ( final Map.Entry<String, byte[]> entry : this.structure_old.entrySet() ) {
+                result.set(entry.getKey().substring(7), (entry.getValue().length - 8) / 10);
+            }
+        }
+        synchronized ( this.structure_new ) {
+            for ( final Map.Entry<String, byte[]> entry : this.structure_new.entrySet() ) {
+                result.set(entry.getKey().substring(7), (entry.getValue().length - 8) / 10);
+            }
+        }
+        return result;
+    }
+    
     public Iterator<StructureEntry> structureEntryIterator(final boolean latest) {
         return new StructureIterator(latest);
     }
 
-    private class StructureIterator extends LookAheadIterator<StructureEntry> implements
-        Iterator<StructureEntry>
-    {
+    private class StructureIterator extends LookAheadIterator<StructureEntry> implements Iterator<StructureEntry> {
 
         private final Iterator<Map.Entry<String, byte[]>> i;
 
@@ -727,23 +735,43 @@ public class WebStructureGraph
         }
     }
 
-    public static class StructureEntry
-    {
+    public static class StructureEntry implements Comparable<StructureEntry> {
+        
         public String hosthash; // the tail of the host hash
         public String hostname; // the host name
         public String date; // date of latest change
         public Map<String, Integer> references; // a map from the referenced host hash to the number of referenced to that host
 
+        private StructureEntry(final String hosthash, final String hostname) {
+            this(hosthash, hostname, GenericFormatter.SHORT_DAY_FORMATTER.format(), new HashMap<String, Integer>());
+        }
+        
         private StructureEntry(
-            final String hosthash,
-            final String hostname,
-            final String date,
-            final Map<String, Integer> references) {
+                final String hosthash,
+                final String hostname,
+                final String date,
+                final Map<String, Integer> references) {
             this.hosthash = hosthash;
             this.hostname = hostname;
             this.date = date;
             this.references = references;
         }
+        
+        @Override
+        public int compareTo(StructureEntry arg0) {
+            return hosthash.compareTo(arg0.hosthash);
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (!(o instanceof StructureEntry)) return false;
+            return hosthash.equals(((StructureEntry)o).hosthash); 
+        }
+
+        @Override
+        public int hashCode() {
+            return this.hosthash.hashCode();
+        }
     }
 
     public synchronized void close() {
diff --git a/source/net/yacy/search/Switchboard.java b/source/net/yacy/search/Switchboard.java
index e76346010..d337e3528 100644
--- a/source/net/yacy/search/Switchboard.java
+++ b/source/net/yacy/search/Switchboard.java
@@ -2552,7 +2552,7 @@ public final class Switchboard extends serverSwitch
 

         // CREATE INDEX

         final String dc_title = document.dc_title();

-        final DigestURI url = new DigestURI(document.dc_source());

+        final DigestURI url = DigestURI.toDigestURI(document.dc_source());

         final DigestURI referrerURL = queueEntry.referrerURL();

         EventOrigin processCase = queueEntry.processCase(this.peers.mySeed().hash);

 

@@ -2620,7 +2620,7 @@ public final class Switchboard extends serverSwitch
             rssRow.put("title", UTF8.getBytes(rssEntry.getValue()));

             rssRow.put("recording_date", new Date());

             try {

-                this.tables.update("rss", new DigestURI(rssEntry.getKey()).hash(), rssRow);

+                this.tables.update("rss", DigestURI.toDigestURI(rssEntry.getKey()).hash(), rssRow);

             } catch ( final IOException e ) {

                 Log.logException(e);

             }

@@ -3180,7 +3180,7 @@ public final class Switchboard extends serverSwitch
                             final Iterator<MultiProtocolURI> i = links.keySet().iterator();

                             final boolean globalcrawljob = sb.getConfigBool("heuristic.searchresults.crawlglobal",false);

                             while (i.hasNext()) {

-                                url = new DigestURI(i.next());

+                                url = DigestURI.toDigestURI(i.next());

                                 boolean islocal = url.getHost().contentEquals(startUrl.getHost());

                                 // add all external links or links to different page to crawler

                                 if ( !islocal ) {// || (!startUrl.getPath().endsWith(url.getPath()))) {

diff --git a/source/net/yacy/search/index/Segment.java b/source/net/yacy/search/index/Segment.java
index f6b7c27ed..8f67db66d 100644
--- a/source/net/yacy/search/index/Segment.java
+++ b/source/net/yacy/search/index/Segment.java
@@ -266,7 +266,7 @@ public class Segment {
         final long urldate = urlModified.getTime();
         for (Map.Entry<MultiProtocolURI, Properties> anchorEntry: anchors.entrySet()) {
         	MultiProtocolURI anchor = anchorEntry.getKey();
-        	byte[] refhash = new DigestURI(anchor).hash();
+        	byte[] refhash = DigestURI.toDigestURI(anchor).hash();
         	//System.out.println("*** addCitationIndex: urlhash = " + ASCII.String(urlhash) + ", refhash = " + ASCII.String(refhash) + ", urldate = " + urlModified.toString());
         	if (this.urlCitationIndex != null) try {
                 this.urlCitationIndex.add(refhash, new CitationReference(urlhash, urldate));
diff --git a/source/net/yacy/search/index/SolrConfiguration.java b/source/net/yacy/search/index/SolrConfiguration.java
index be40bf440..2b236e90f 100644
--- a/source/net/yacy/search/index/SolrConfiguration.java
+++ b/source/net/yacy/search/index/SolrConfiguration.java
@@ -213,7 +213,7 @@ public class SolrConfiguration extends ConfigurationSet implements Serializable
     	}
 
         final SolrInputDocument doc = new SolrInputDocument();
-        final DigestURI digestURI = new DigestURI(md.url());
+        final DigestURI digestURI = DigestURI.toDigestURI(md.url());
         boolean allAttr = this.isEmpty();
 
         if (allAttr || contains(YaCySchema.failreason_t)) add(doc, YaCySchema.failreason_t, "");
@@ -341,7 +341,7 @@ public class SolrConfiguration extends ConfigurationSet implements Serializable
     public SolrInputDocument yacy2solr(final String id, final CrawlProfile profile, final ResponseHeader header, final Document yacydoc, Condenser condenser, final URIMetadata metadata) {
         // we use the SolrCell design as index scheme
         final SolrInputDocument doc = new SolrInputDocument();
-        final DigestURI digestURI = new DigestURI(yacydoc.dc_source());
+        final DigestURI digestURI = DigestURI.toDigestURI(yacydoc.dc_source());
         boolean allAttr = this.isEmpty();
         add(doc, YaCySchema.id, id);
         if (allAttr || contains(YaCySchema.failreason_t)) add(doc, YaCySchema.failreason_t, ""); // overwrite a possible fail reason (in case that there was a fail reason before)
diff --git a/source/net/yacy/search/snippet/MediaSnippet.java b/source/net/yacy/search/snippet/MediaSnippet.java
index 395375736..cd424551c 100644
--- a/source/net/yacy/search/snippet/MediaSnippet.java
+++ b/source/net/yacy/search/snippet/MediaSnippet.java
@@ -177,7 +177,7 @@ public class MediaSnippet implements Comparable<MediaSnippet>, Comparator<MediaS
         final List<MediaSnippet> result = new ArrayList<MediaSnippet>();

         while (i.hasNext()) {

             entry = i.next();

-            url = new DigestURI(entry.getKey());

+            url = DigestURI.toDigestURI(entry.getKey());

             desc = entry.getValue();
             if (isUrlBlacklisted(BlacklistType.SEARCH, url)) continue;
             final int ranking = removeAppearanceHashes(url.toNormalform(true), queryhashes).size() +

@@ -202,7 +202,7 @@ public class MediaSnippet implements Comparable<MediaSnippet>, Comparator<MediaS
         final List<MediaSnippet> result = new ArrayList<MediaSnippet>();

         while (i.hasNext()) {

             ientry = i.next();

-            url = new DigestURI(ientry.url());

+            url = DigestURI.toDigestURI(ientry.url());

             final String u = url.toString();
             if (isUrlBlacklisted(BlacklistType.SEARCH, url)) continue;
             if (u.indexOf(".ico",0) >= 0 || u.indexOf("favicon",0) >= 0) continue;

diff --git a/source/net/yacy/server/http/HTTPDProxyHandler.java b/source/net/yacy/server/http/HTTPDProxyHandler.java
index abf7467a8..95bea1ec0 100644
--- a/source/net/yacy/server/http/HTTPDProxyHandler.java
+++ b/source/net/yacy/server/http/HTTPDProxyHandler.java
@@ -308,7 +308,7 @@ public final class HTTPDProxyHandler {
 

             DigestURI url = null;

             try {

-                url = new DigestURI(HeaderFramework.getRequestURL(conProp));

+                url = DigestURI.toDigestURI(HeaderFramework.getRequestURL(conProp));

                 if (log.isFine()) log.logFine(reqID +" GET "+ url);

                 if (log.isFinest()) log.logFinest(reqID +"    header: "+ requestHeader);

 

@@ -391,7 +391,7 @@ public final class HTTPDProxyHandler {
             	final Request request = new Request(

             			null,

                         url,

-                        requestHeader.referer() == null ? null : new DigestURI(requestHeader.referer()).hash(),

+                        requestHeader.referer() == null ? null : DigestURI.toDigestURI(requestHeader.referer()).hash(),

                         "",

                         cachedResponseHeader.lastModified(),

                         sb.crawler.defaultProxyProfile.handle(),

@@ -527,7 +527,7 @@ public final class HTTPDProxyHandler {
                 final Request request = new Request(

             			null,

                         url,

-                        requestHeader.referer() == null ? null : new DigestURI(requestHeader.referer()).hash(),

+                        requestHeader.referer() == null ? null : DigestURI.toDigestURI(requestHeader.referer()).hash(),

                         "",

                         responseHeader.lastModified(),

                         sb.crawler.defaultProxyProfile.handle(),