bundles/org.simantics.db.common/src/org/simantics/db/common/QueryMemoryWatcher.java

   1 package org.simantics.db.common;
   2
   3 import org.simantics.db.ReadGraph;
   4 import org.simantics.db.service.QueryControl;
   5
   6 public class QueryMemoryWatcher {
   7
   8     final ReadGraph graph;
   9     final QueryControl support;
  10     final int stopTime;
  11     final long baseline;
  12     final long highLimit;
  13     final long lowLimit;
  14     boolean collecting = false;
  15
  16     public QueryMemoryWatcher(ReadGraph graph, int allowedQueries) {
  17         this(graph, allowedQueries, 0.5, 10);
  18     }
  19
  20     public QueryMemoryWatcher(ReadGraph graph, int allowedQueries, double ratio, int stopTime) {
  21         this.support = graph.getService(QueryControl.class);
  22         baseline = support.count();
  23         highLimit = baseline + allowedQueries;
  24         lowLimit = baseline + (int)(allowedQueries*ratio);
  25         this.graph = graph;
  26         this.stopTime = 10;
  27         //System.err.println("QueryMemoryWatcher started with " + baseline + " queries.");
  28     }
  29
  30     public void maintain() {
  31         long current = support.count();
  32         if(collecting) {
  33             if(current > lowLimit) support.gc(graph, stopTime);
  34             else {
  35 //                System.err.println("QueryMemoryWatcher stops collecting");
  36                 collecting = false;
  37             }
  38         } else {
  39             if(current > highLimit) {
  40 //                System.err.println("QueryMemoryWatcher starts collecting");
  41                 collecting = true;
  42             }
  43         }
  44     }
  45
  46 }