From 584f853c4b2abae5cab26dc4481799d280cbb5b4 Mon Sep 17 00:00:00 2001
From: Michael Christen <mc@yacy.net>
Date: Tue, 6 Dec 2011 02:53:30 +0100
Subject: [PATCH] added YBR computation process as servlet

---
 htroot/YBRFetch_p.html |  0
 htroot/YBRFetch_p.java | 72 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 htroot/YBRFetch_p.html
 create mode 100644 htroot/YBRFetch_p.java

diff --git a/htroot/YBRFetch_p.html b/htroot/YBRFetch_p.html
new file mode 100644
index 000000000..e69de29bb
diff --git a/htroot/YBRFetch_p.java b/htroot/YBRFetch_p.java
new file mode 100644
index 000000000..4f97ea207
--- /dev/null
+++ b/htroot/YBRFetch_p.java
@@ -0,0 +1,72 @@
+import java.io.File;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+import net.yacy.cora.protocol.RequestHeader;
+import net.yacy.kelondro.logging.Log;
+import net.yacy.kelondro.rwi.ReferenceContainerCache;
+import net.yacy.kelondro.util.MemoryControl;
+import net.yacy.peers.graphics.WebStructureGraph.HostReference;
+import net.yacy.search.Switchboard;
+import net.yacy.search.SwitchboardConstants;
+import net.yacy.search.index.MetadataRepository;
+import net.yacy.search.index.MetadataRepository.HostStat;
+import net.yacy.search.index.Segment;
+import net.yacy.search.ranking.BlockRank;
+import de.anomic.server.serverObjects;
+import de.anomic.server.serverSwitch;
+import de.anomic.server.servletProperties;
+
+public class YBRFetch_p
+{
+
+    public static servletProperties respond(
+        final RequestHeader requestHeader,
+        final serverObjects post,
+        final serverSwitch env) {
+        final servletProperties prop = new servletProperties();
+        final Switchboard sb = (Switchboard) env;
+
+        if ( post == null || !post.containsKey("ghrt4") || MemoryControl.available() < 1024 * 1024 * 1024 ) {
+            return prop;
+        }
+        final File hostIndexFile = new File(sb.queuesRoot, "hostIndex.blob");
+
+        ReferenceContainerCache<HostReference> hostIndex; // this will get large, more than 0.5 million entries by now
+        if ( !hostIndexFile.exists() ) {
+            hostIndex = BlockRank.collect(sb.peers, sb.webStructure, Integer.MAX_VALUE);
+            BlockRank.saveHostIndex(hostIndex, hostIndexFile);
+        } else {
+            hostIndex = BlockRank.loadHostIndex(hostIndexFile);
+        }
+
+        // use an index segment to find hosts for given host hashes
+        final String segmentName = sb.getConfig(SwitchboardConstants.SEGMENT_PUBLIC, "default");
+        final Segment segment = sb.indexSegments.segment(segmentName);
+        final MetadataRepository metadata = segment.urlMetadata();
+        Map<String, HostStat> hostHashResolver;
+        try {
+            hostHashResolver = metadata.domainHashResolver(metadata.domainSampleCollector());
+        } catch ( final IOException e ) {
+            hostHashResolver = new HashMap<String, HostStat>();
+        }
+
+        // recursively compute a new ranking table
+        Log.logInfo("BLOCK RANK", "computing new ranking tables...");
+        BlockRank.ybrTables = BlockRank.evaluate(hostIndex, hostHashResolver, null, 0);
+        hostIndex = null; // we don't need that here any more, so free the memory
+
+        // use the web structure and the hostHash resolver to analyse the ranking table
+        Log.logInfo("BLOCK RANK", "analysis of " + BlockRank.ybrTables.length + " tables...");
+        BlockRank.analyse(sb.webStructure, hostHashResolver);
+        // store the new table
+        Log.logInfo("BLOCK RANK", "storing fresh table...");
+        final File rankingPath = new File(sb.appPath, "ranking/YBR".replace('/', File.separatorChar));
+        BlockRank.storeBlockRankTable(rankingPath);
+        BlockRank.loadBlockRankTable(rankingPath, 16);
+
+        return prop;
+    }
+
+}