added a buffer for network images to reduced load on yacy.net network image server

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@7007 6c8d7289-2bf4-0310-a012-ef5d649a1542

htroot/NetworkPicture.java

@@ -24,21 +24,32 @@
 // along with this program; if not, write to the Free Software
 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
-import net.yacy.visualization.RasterPlotter;
+import java.util.TreeMap;
+
 import de.anomic.http.server.RequestHeader;
 import de.anomic.search.Switchboard;
 import de.anomic.search.SwitchboardConstants;
 import de.anomic.server.serverObjects;
 import de.anomic.server.serverSwitch;
+import de.anomic.yacy.graphics.EncodedImage;
 import de.anomic.yacy.graphics.NetworkGraph;
 
 /** draw a picture of the yacy network */
 public class NetworkPicture {
     
-    public static RasterPlotter respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
+    private static final TreeMap<Long, EncodedImage> buffer = new TreeMap<Long, EncodedImage>();
+    
+    public static EncodedImage respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
         final Switchboard sb = (Switchboard) env;
         final boolean authorized = sb.adminAuthenticated(header) >= 2;
         
+        long timeSeconds = System.currentTimeMillis() / 1000;
+        EncodedImage bufferedImage = null;
+        synchronized (buffer) {
+            bufferedImage = buffer.get(timeSeconds);
+        }
+        if (bufferedImage != null) return bufferedImage;
+        
         int width = 768;
         int height = 576;
         int passiveLimit = 720; // 12 hours
@@ -73,7 +84,12 @@ public class NetworkPicture {
         if (passiveLimit > 1000000) passiveLimit = 1000000;
         if (potentialLimit > 1000000) potentialLimit = 1000000;
         if (maxCount > 10000) maxCount = 10000;
-        return NetworkGraph.getNetworkPicture(sb.peers, 10000, width, height, passiveLimit, potentialLimit, maxCount, coronaangle, communicationTimeout, env.getConfig(SwitchboardConstants.NETWORK_NAME, "unspecified"), env.getConfig("network.unit.description", "unspecified"), bgcolor);
+        bufferedImage = new EncodedImage(NetworkGraph.getNetworkPicture(sb.peers, 10000, width, height, passiveLimit, potentialLimit, maxCount, coronaangle, communicationTimeout, env.getConfig(SwitchboardConstants.NETWORK_NAME, "unspecified"), env.getConfig("network.unit.description", "unspecified"), bgcolor).getImage(), "png");
+        synchronized (buffer) {
+            buffer.put(timeSeconds, bufferedImage);
+            while (buffer.size() > 8) buffer.remove(buffer.firstKey());
+        }
+        return bufferedImage;
     }
     
 }

source/de/anomic/http/server/HTTPDFileHandler.java

@@ -101,6 +101,7 @@ import de.anomic.server.serverObjects;
 import de.anomic.server.serverSwitch;
 import de.anomic.server.servletProperties;
 import de.anomic.yacy.yacyBuildProperties;
+import de.anomic.yacy.graphics.EncodedImage;
 
 public final class HTTPDFileHandler {
     
@@ -548,6 +549,20 @@ public final class HTTPDFileHandler {
                             result.writeTo(out);
                         }
                     }
+                    if (img instanceof EncodedImage) {
+                        final EncodedImage yp = (EncodedImage) img;
+                        // send an image to client
+                        targetDate = new Date(System.currentTimeMillis());
+                        nocache = true;
+                        final String mimeType = MimeTable.ext2mime(targetExt, "text/html");
+                        final ByteBuffer result = yp.getImage();
+
+                        // write the array to the client
+                        HTTPDemon.sendRespondHeader(conProp, out, httpVersion, 200, null, mimeType, result.length(), targetDate, null, null, null, null, nocache);
+                        if (!method.equals(HeaderFramework.METHOD_HEAD)) {
+                            result.writeTo(out);
+                        }
+                    }
                     if (img instanceof Image) {
                         final Image i = (Image) img;
                         // send an image to client

source/de/anomic/yacy/graphics/EncodedImage.java

@@ -0,0 +1,24 @@
+package de.anomic.yacy.graphics;
+
+import java.awt.image.BufferedImage;
+
+import net.yacy.kelondro.util.ByteBuffer;
+import net.yacy.visualization.RasterPlotter;
+
+public class EncodedImage {
+    private ByteBuffer image;
+    private String extension;
+    
+    public EncodedImage(final BufferedImage sourceImage, final String targetExt) {
+        this.image = RasterPlotter.exportImage(sourceImage, targetExt);
+        this.extension = targetExt;
+    }
+    
+    public ByteBuffer getImage() {
+        return this.image;
+    }
+    
+    public String getExtension() {
+        return this.extension;
+    }
+}