bundles/org.simantics.document.server/src/org/simantics/document/server/DocumentHistoryCollector.java

   1 package org.simantics.document.server;\r
   2 \r
   3 import java.util.Collection;\r
   4 import java.util.Iterator;\r
   5 import java.util.Map;\r
   6 import java.util.Map.Entry;\r
   7 \r
   8 import org.simantics.db.procedure.Listener;\r
   9 import org.simantics.utils.datastructures.Pair;\r
  10 \r
  11 import gnu.trove.map.hash.THashMap;\r
  12 \r
  13 public class DocumentHistoryCollector {\r
  14 \r
  15         static Map<String, DocumentHistory> histories = new THashMap<String, DocumentHistory>();\r
  16 \r
  17         private static DocumentHistory getHistory(String location, boolean create) {\r
  18 \r
  19                 synchronized(histories) {\r
  20 \r
  21                         DocumentHistory history =  histories.get(location);\r
  22                         if(history == null && create) {\r
  23                                 history = new DocumentHistory();\r
  24                                 pruneHistories();\r
  25                                 histories.put(location, history);\r
  26                         }\r
  27                         return history;\r
  28                         \r
  29                 }\r
  30 \r
  31         }\r
  32         \r
  33         private static void pruneHistories() {\r
  34                 synchronized (histories) {\r
  35                         // remove histories with no listeners\r
  36                         Iterator<Map.Entry<String, DocumentHistory>> iter = histories.entrySet().iterator();\r
  37                         while (iter.hasNext()) {\r
  38                         Entry<String, DocumentHistory> entry = iter.next();\r
  39                         DocumentHistory entryHistory = entry.getValue();\r
  40                         synchronized(entryHistory) {\r
  41                                 if (!entryHistory.hasListeners()) {\r
  42                                         iter.remove();\r
  43                                 }\r
  44                         }\r
  45                 }\r
  46                 }\r
  47         }\r
  48 \r
  49         public static Pair<Integer, Collection<JSONObject>> readChanges(String location, int sequenceNumber) {\r
  50                 DocumentHistory history = getHistory(location, false);\r
  51                 if (history != null) {\r
  52                         return history.readChanges(sequenceNumber);\r
  53                 } else {\r
  54                         return null;\r
  55                 }\r
  56         }\r
  57 \r
  58         public static Pair<Integer, Collection<JSONObject>> getContent(Listener<Integer> listener, String location, int sequenceNumber) {\r
  59                 DocumentHistory history = getHistory(location, true);\r
  60                 return history.getContent(listener, location, sequenceNumber);\r
  61         }\r
  62 }