more concurrency for postprocessing

source/net/yacy/cora/federate/solr/connector/AbstractSolrConnector.java

@@ -163,17 +163,18 @@ public abstract class AbstractSolrConnector implements SolrConnector {
             final String ... fields) {
         assert buffersize > 0;
         if (!prefetchIDs) return concurrentDocumentsByQueryNoPrefetch(querystring, sort, offset, maxcount, maxtime, buffersize, concurrency, fields);
-        final BlockingQueue<String> idQueue = concurrentIDsByQuery(querystring, sort, offset, maxcount, maxtime, Math.min(maxcount, 10000000), 1);
+        final BlockingQueue<String> idQueue = concurrentIDsByQuery(querystring, sort, offset, maxcount, maxtime, Math.min(maxcount, 10000000), concurrency);
-        final BlockingQueue<SolrDocument> queue = buffersize <= 0 ? new LinkedBlockingQueue<SolrDocument>() : new ArrayBlockingQueue<SolrDocument>(buffersize);
+        final BlockingQueue<SolrDocument> queue = buffersize <= 0 ? new LinkedBlockingQueue<SolrDocument>() : new ArrayBlockingQueue<SolrDocument>(Math.max(buffersize, concurrency));
         final long endtime = maxtime == Long.MAX_VALUE ? Long.MAX_VALUE : System.currentTimeMillis() + maxtime; // we know infinity!
-        final Thread t = new Thread() {
+        final Thread[] t = new Thread[concurrency];
+        for (int i = 0; i < concurrency; i++) {
+            t[i] = new Thread() {
                 @Override
                 public void run() {
                     this.setName("AbstractSolrConnector:concurrentDocumentsByQueryWithPrefetch(" + querystring + ")");
                     String nextID;
                     try {
                         while (System.currentTimeMillis() < endtime && (nextID = idQueue.take()) != AbstractSolrConnector.POISON_ID) {
-                        
                             try {
                                 SolrDocument d = getDocumentById(nextID, fields);
                                 // document may be null if another process has deleted the document meanwhile
@@ -189,12 +190,11 @@ public abstract class AbstractSolrConnector implements SolrConnector {
                     } catch (InterruptedException e) {
                         ConcurrentLog.severe("AbstractSolrConnector", "interrupted concurrentDocumentsByQuery: " + e.getMessage());
                     }
-                for (int i = 0; i < Math.max(1, concurrency); i++) {
                     try {queue.put(AbstractSolrConnector.POISON_DOCUMENT);} catch (final InterruptedException e1) {}
                 }
-            }
             };
-        t.start();
+            t[i].start();
+        }
         return queue;
     }