delay sending of results to prevent duplicates

core/src/main/groovy/com/muwire/core/search/SearchManager.groovy

@@ -1,7 +1,10 @@
 package com.muwire.core.search
 
+import java.util.concurrent.ConcurrentHashMap
+
 import com.muwire.core.EventBus
 import com.muwire.core.Persona
+import com.muwire.core.SharedFile
 
 import groovy.util.logging.Log
 import net.i2p.data.Destination
@@ -11,11 +14,14 @@ public class SearchManager {
 
     private static final int EXPIRE_TIME = 60 * 1000 * 1000
     private static final int CHECK_INTERVAL = 60 * 1000
+    private static final int RESULT_DELAY = 100
 
     private final EventBus eventBus
     private final Persona me
     private final ResultsSender resultsSender
     private final Map<UUID, QueryEvent> responderAddress = Collections.synchronizedMap(new HashMap<>())
+    
+    private final Map<UUID, ResultBatch> pendingResults = new HashMap<>()
 
     SearchManager(){}
 
@@ -25,6 +31,7 @@ public class SearchManager {
         this.resultsSender = resultsSender
         Timer timer = new Timer("query-expirer", true)
         timer.schedule({cleanup()} as TimerTask, CHECK_INTERVAL, CHECK_INTERVAL)
+        timer.schedule({sendBatched()}, RESULT_DELAY, RESULT_DELAY)
     }
 
     void onQueryEvent(QueryEvent event) {
@@ -36,7 +43,7 @@ public class SearchManager {
         eventBus.publish(event.searchEvent)
     }
 
-    void onResultsEvent(ResultsEvent event) {
+    synchronized void onResultsEvent(ResultsEvent event) {
         Destination target = responderAddress.get(event.uuid)?.replyTo
         if (target == null)
             throw new IllegalStateException("UUID unknown $event.uuid")
@@ -44,7 +51,10 @@ public class SearchManager {
             log.info("No results for search uuid $event.uuid")
             return
         }
-        resultsSender.sendResults(event.uuid, event.results, target, event.searchEvent.oobInfohash, event.searchEvent.compressedResults)
+        
+        ResultBatch batch = pendingResults.putIfAbsent(event.uuid, new ResultBatch(event, target))
+        if (batch != null)
+            batch.results.addAll(event.results)
     }
 
     boolean hasLocalSearch(UUID uuid) {
@@ -62,4 +72,30 @@ public class SearchManager {
             }
         }
     }
+    
+    private synchronized void sendBatched() {
+        if (pendingResults.isEmpty())
+            return
+            
+        Set<ResultBatch> copy = new HashSet<>(pendingResults.values())
+        pendingResults.clear()
+        
+        copy.each { 
+            SharedFile[] results = it.results.toArray()
+            resultsSender.sendResults(it.resultsEvent.uuid, results, it.target, 
+                it.resultsEvent.searchEvent.oobInfohash, 
+                it.resultsEvent.searchEvent.compressedResults)
+        }
+    }
+    
+    private static class ResultBatch {
+        final ResultsEvent resultsEvent
+        final Destination target
+        final Set<SharedFile> results = new HashSet<>()
+        ResultBatch(ResultsEvent resultsEvent, Destination target) {
+            this.resultsEvent = resultsEvent
+            this.target = target
+            results.addAll(resultsEvent.results)
+        }
+    }
 }