enhanced Network Graph Caching

3 files changed, 103 insertions, 80 deletions

diff --git a/source/net/yacy/htroot/NetworkPicture.java b/source/net/yacy/htroot/NetworkPicture.java
index 0ebfb7f91..ea89744f7 100644
--- a/source/net/yacy/htroot/NetworkPicture.java
+++ b/source/net/yacy/htroot/NetworkPicture.java
@@ -37,13 +37,17 @@ import net.yacy.search.SwitchboardConstants;
 import net.yacy.server.serverObjects;

 import net.yacy.server.serverSwitch;

 

+

 /** draw a picture of the yacy network */

 public class NetworkPicture {

 

-    private static final ConcurrentLog log = new ConcurrentLog("NetworkPicture");

-    private static final Semaphore sync = new Semaphore(1, true);

-    private static long lastAccessSeconds = 0;

+    private static final ConcurrentLog log = new ConcurrentLog("NetworkPicture");
+    private static final Semaphore sync = new Semaphore(1, true);
 

+    private static final int  NETWORK_PICTURE_CACHE_MAX_SIZE = 20;

+    private static final long NETWORK_PICTURE_CACHE_MAX_AGE_MILLIS = 10000;

+    public static final NetworkGraph.Cache cache = new NetworkGraph.Cache(NETWORK_PICTURE_CACHE_MAX_AGE_MILLIS, NETWORK_PICTURE_CACHE_MAX_SIZE);

+    

     public static EncodedImage respond(
         final RequestHeader header,
         final serverObjects post,
@@ -51,35 +55,8 @@ public class NetworkPicture {
         final Switchboard sb = (Switchboard) env;
         final boolean authorized = sb.adminAuthenticated(header) >= 2;
 
-        final long timeSeconds = System.currentTimeMillis() / 1000;
-        if (NetworkGraph.buffer != null && timeSeconds - lastAccessSeconds < 2) {
-            if (log.isFine()) log.fine("cache hit (1); authorized = "
-                + authorized
-                + ", timeSeconds - lastAccessSeconds = "
-                + (timeSeconds - lastAccessSeconds));
-            return NetworkGraph.buffer;
-        }
-
-        boolean lockAcquired = sync.tryAcquire();
-        if (!lockAcquired) {
-            if (NetworkGraph.buffer != null) {
-                return NetworkGraph.buffer;
-            }
-            sync.acquireUninterruptibly();
-            lockAcquired = true;
-        }
-        try {
-            final long refreshCheckSeconds = System.currentTimeMillis() / 1000;
-            if (NetworkGraph.buffer != null && refreshCheckSeconds - lastAccessSeconds < 2) {
-                if (log.isFine()) log.fine("cache hit (2); authorized = "
-                    + authorized
-                    + ", timeSeconds - lastAccessSeconds = "
-                    + (refreshCheckSeconds - lastAccessSeconds));
-                return NetworkGraph.buffer;
-            }
-
-            int width = 1280; // 640x480 = VGA, 768x576 = SD/4:3, 1024x576 =SD/16:9 1280x720 = HD/16:9, 1920x1080 = FULL HD/16:9
-        int height = 720;

+        int width = 1280; // 640x480 = VGA, 768x576 = SD/4:3, 1024x576 =SD/16:9 1280x720 = HD/16:9, 1920x1080 = FULL HD/16:9
+        int height = 720;
         int passiveLimit = 1440; // minutes; 1440 = 1 day; 720 = 12 hours; 1440 = 24 hours, 10080 = 1 week;

         int potentialLimit = 1440;

         int maxCount = 9000;

@@ -111,11 +88,34 @@ public class NetworkPicture {
         if ( potentialLimit > 1000000 ) {

             potentialLimit = 1000000;

         }

-        if ( maxCount > 10000 ) {

-            maxCount = 10000;

-        }

-

-            NetworkGraph.buffer =
+        if ( maxCount > 10000 ) {
+            maxCount = 10000;
+        }
+
+        EncodedImage cachedPicture = cache.getFresh(width, height, coronaangle);
+        if (cachedPicture != null) {
+            if (log.isFine()) log.fine("cache hit (1); authorized = " + authorized + ", width = " + width + ", height = " + height);
+            return cachedPicture;
+        }
+
+        boolean lockAcquired = sync.tryAcquire();
+        if (!lockAcquired) {
+            /* A stale picture is preferable to waiting, but only for a matching variant. */
+            cachedPicture = cache.getCached(width, height, coronaangle);
+            if (cachedPicture != null) {
+                return cachedPicture;
+            }
+            sync.acquireUninterruptibly();
+            lockAcquired = true;
+        }
+        try {
+            cachedPicture = cache.getFresh(width, height, coronaangle);
+            if (cachedPicture != null) {
+                if (log.isFine()) log.fine("cache hit (2); authorized = " + authorized + ", width = " + width + ", height = " + height);
+                return cachedPicture;
+            }
+
+            final EncodedImage networkPicture =
                 new EncodedImage(NetworkGraph.getNetworkPicture(
                     sb.peers,
                     width,
@@ -130,24 +130,8 @@ public class NetworkPicture {
                     Long.parseLong(bgcolor, 16),
                     cyc), "png", false);
 

-        /*

-        NetworkGraph.buffer =

-            new EncodedImage(NetworkSkylineGraph.getNetworkSkylinePicture(

-                sb.peers,

-                width,

-                height,

-                passiveLimit,

-                potentialLimit,

-                maxCount,

-                coronaangle,

-                communicationTimeout,

-                env.getConfig(SwitchboardConstants.NETWORK_NAME, "unspecified"),

-                env.getConfig("network.unit.description", "unspecified"),

-                Long.parseLong(bgcolor, 16),

-                cyc), "png", false);

-         */

-            lastAccessSeconds = System.currentTimeMillis() / 1000;
-            return NetworkGraph.buffer;
+            cache.put(width, height, coronaangle, networkPicture);
+            return networkPicture;
         } finally {
             if (lockAcquired) {
                 sync.release();
diff --git a/source/net/yacy/peers/graphics/NetworkGraph.java b/source/net/yacy/peers/graphics/NetworkGraph.java
index cd501dccd..1b14b0379 100644
--- a/source/net/yacy/peers/graphics/NetworkGraph.java
+++ b/source/net/yacy/peers/graphics/NetworkGraph.java
@@ -30,9 +30,12 @@ import java.awt.Color;
 import java.awt.Graphics2D;

 import java.awt.RenderingHints;

 import java.awt.image.BufferedImage;

-import java.util.Date;

-import java.util.Iterator;

+import java.util.AbstractMap;

+import java.util.Date;
+import java.util.Iterator;
 import java.util.List;

+import java.util.Map;

+import java.util.concurrent.ConcurrentHashMap;

 

 import net.yacy.cora.document.encoding.ASCII;

 import net.yacy.cora.document.encoding.UTF8;

@@ -50,12 +53,11 @@ import net.yacy.search.query.SearchEventCache;
 import net.yacy.visualization.PrintTool;

 import net.yacy.visualization.RasterPlotter;

 

-public class NetworkGraph {

+public class NetworkGraph {
 

-    private final static double DOUBLE_LONG_MAX_VALUE = Long.MAX_VALUE;

     

-    public static EncodedImage buffer = null;

-

+    private static final double DOUBLE_LONG_MAX_VALUE = Long.MAX_VALUE;

+    

     private static int shortestName = 10;

     private static int longestName = 30;

 

@@ -81,13 +83,62 @@ public class NetworkGraph {
     private static final long COL_NORMAL_TEXT    = 0x000000;

     private static final long COL_LOAD_BG        = 0xF7F7F7;

 

-    /** Private constructor to avoid instantiation of utility class. */

-    private NetworkGraph() { }

     

-    public static void clearcache() {

-        buffer = null;

+    public static class Cache {

+        

+        private final Map<String, Map.Entry<Long, EncodedImage>> cache;

+        private final long maxAge;

+        private final int maxSize;

+        

+        public Cache(long maxAge, int maxSize) {

+            this.maxAge = maxAge;

+            this.maxSize = maxSize;

+            this.cache = new ConcurrentHashMap<>();

+        }

+        

+        private String cacheKey(final int width, final int height, final int coronaangle) {

+            return "key-" + width + "-" + height + "-" + coronaangle;

+        }

+        

+        public EncodedImage getCached(final int width, final int height, final int coronaangle) {

+            final Map.Entry<Long, EncodedImage> cached = cache.get(cacheKey(width, height, coronaangle));

+            return cached == null ? null : cached.getValue();

+        }

+        

+        public EncodedImage getFresh(final int width, final int height, final int coronaangle) {

+            final String key = cacheKey(width, height, coronaangle);

+            final Map.Entry<Long, EncodedImage> cached = this.cache.get(key);

+            if (cached == null) return null;

+            if (System.currentTimeMillis() - cached.getKey() >= this.maxAge) return null;

+            return cached.getValue();

+        }

+        

+        public synchronized void put(final int width, final int height, final int coronaangle, final EncodedImage image) {

+            final String key = cacheKey(width, height, coronaangle);

+            if (!this.cache.containsKey(key) && this.cache.size() >= this.maxSize) {

+                String oldestKey = null;

+                long oldestCreationTime = Long.MAX_VALUE;

+                for (final Map.Entry<String, Map.Entry<Long, EncodedImage>> entry: this.cache.entrySet()) {

+                    if (entry.getValue().getKey() < oldestCreationTime) {

+                        oldestKey = entry.getKey();

+                        oldestCreationTime = entry.getValue().getKey();

+                    }

+                }

+                if (oldestKey != null) {

+                    this.cache.remove(oldestKey);

+                }

+            }

+            this.cache.put(key, new AbstractMap.SimpleEntry<Long, EncodedImage>(System.currentTimeMillis(), image));

+        }

+        

+        public void clear() {

+            this.cache.clear();

+        }

     }

 

+    /** Private constructor to avoid instantiation of utility class. */

+    private NetworkGraph() { }
+

     public static class CircleThreadPiece {

         private final String pieceName;

         private final Color color;

@@ -148,19 +199,6 @@ public class NetworkGraph {
             eventPicture.arcLine(cx, cy, cr - 20, cr, angle, true, null, null, -1, -1, -1, false);

         }

 

-        // draw in the secondary search peers

-        /*

-        if (secondarySearches != null) {

-            for (final Thread secondarySearche : secondarySearches) {

-                if (secondarySearche == null) continue;

-                eventPicture.setColor((secondarySearche.isAlive()) ? RasterPlotter.RED : RasterPlotter.GREEN);

-                angle = cyc + (360.0d * ((FlatWordPartitionScheme.std.dhtPosition(UTF8.getBytes(secondarySearche.target().hash), null)) / DOUBLE_LONG_MAX_VALUE));

-                eventPicture.arcLine(cx, cy, cr - 10, cr, angle - 1.0, true, null, null, -1, -1, -1, false);

-                eventPicture.arcLine(cx, cy, cr - 10, cr, angle + 1.0, true, null, null, -1, -1, -1, false);

-            }

-        }

-        */

-

         // draw in the search target

         final Iterator<byte[]> i = event.query.getQueryGoal().getIncludeHashes().iterator();

         eventPicture.setColor(RasterPlotter.GREY);

@@ -447,4 +485,4 @@ public class NetworkGraph {
     	g.drawChars(caption.toCharArray(), 0, caption.length(), x+LEGEND_BOX_SIZE+5,y);

     }

 

-}
\ No newline at end of file
+}
diff --git a/source/net/yacy/search/Switchboard.java b/source/net/yacy/search/Switchboard.java
index 1d0b8d42a..fb19d2a99 100644
--- a/source/net/yacy/search/Switchboard.java
+++ b/source/net/yacy/search/Switchboard.java
@@ -182,6 +182,7 @@ import net.yacy.document.parser.pdfParser;
 import net.yacy.document.parser.html.Evaluation;
 import net.yacy.gui.Audio;
 import net.yacy.gui.Tray;
+import net.yacy.htroot.NetworkPicture;
 import net.yacy.http.YaCyHttpServer;
 import net.yacy.kelondro.blob.ArrayStack;
 import net.yacy.kelondro.blob.BEncodedHeap;
@@ -2445,7 +2446,7 @@ public final class Switchboard extends serverSwitch {
 
         // clear graphics caches
         CircleTool.clearcache();
-        NetworkGraph.clearcache();
+        NetworkPicture.cache.clear();;
     }
 
     public int schedulerJobSize() {