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

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