bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/CacheCollectionResult.java

   1 package org.simantics.db.impl.query;\r
   2 \r
   3 import java.util.ArrayList;\r
   4 import java.util.Collection;\r
   5 \r
   6 public class CacheCollectionResult {\r
   7         public static final int LEVELS = 10;\r
   8         private int level = 0;\r
   9         private int position = -1;\r
  10         private int currentLength = 0;\r
  11         private int size = 0;\r
  12         private ArrayList<CacheEntryBase> currentLevel;\r
  13         public ArrayList<CacheEntryBase> levels[] = new ArrayList[LEVELS];\r
  14         public CacheCollectionResult() {\r
  15                 for(int i=0;i<LEVELS;i++) {\r
  16                         levels[i] = new ArrayList<CacheEntryBase>();\r
  17                 }\r
  18         }\r
  19         public void add(CacheEntryBase entry) {\r
  20                 short level = entry.getLevel();\r
  21                 if(level < (LEVELS-1)) levels[level].add(entry);\r
  22                 else levels[(LEVELS-1)].add(entry);\r
  23                 size++;\r
  24         }\r
  25         public Collection<CacheEntryBase> toCollection() {\r
  26                 ArrayList<CacheEntryBase> result = new ArrayList<CacheEntryBase>(size());\r
  27                 for(int i=0;i<LEVELS;i++)\r
  28                         result.addAll(levels[i]);\r
  29                 return result;\r
  30         }\r
  31         public int size() {\r
  32                 return size;\r
  33         }\r
  34         public boolean isAtStart() {\r
  35                 return level == 0 && position == -1;\r
  36         }\r
  37         public void restart() {\r
  38                 level = 0;\r
  39                 position = -1;\r
  40                 currentLevel = levels[0];\r
  41                 currentLength = currentLevel.size();\r
  42         }\r
  43         public CacheEntryBase next(int maxLevel) {\r
  44                 //System.err.println("next " + position + " " + level);\r
  45                 position++;\r
  46                 if(position >= currentLength) {\r
  47                         if(level == (LEVELS-1)) return null;\r
  48                         if(level == maxLevel) return null;\r
  49                         level++;\r
  50                         position=-1;\r
  51                         currentLevel = levels[level];\r
  52                         currentLength = currentLevel.size();\r
  53                         return next(maxLevel);\r
  54                 }\r
  55                 return currentLevel.get(position);\r
  56         }\r
  57         public void remove() {\r
  58                 int lastPosition = currentLevel.size()-1;\r
  59                 CacheEntryBase last = currentLevel.remove(lastPosition);\r
  60                 if(lastPosition > position) {\r
  61                         currentLevel.set(position, last);\r
  62                 }\r
  63                 currentLength--;\r
  64                 position--;\r
  65                 size--;\r
  66         }\r
  67         public void setLevel(CacheEntryBase current, int level) {\r
  68                 if(level == current.level) return;\r
  69                 current.level = (short)level;\r
  70                 remove();\r
  71                 add(current);\r
  72         }\r
  73 }