예제 #1
0
 public virtual Differences VisitBlockList(BlockList list1, BlockList list2,
   out BlockList changes, out BlockList deletions, out BlockList insertions){
   changes = list1 == null ? null : list1.Clone();
   deletions = list1 == null ? null : list1.Clone();
   insertions = list1 == null ? new BlockList() : list1.Clone();
   //^ assert insertions != null;
   Differences differences = new Differences();
   for (int j = 0, n = list2 == null ? 0 : list2.Count; j < n; j++){
     //^ assert list2 != null;
     Block nd2 = list2[j];
     if (nd2 == null) continue;
     insertions.Add(null);
   }
   TrivialHashtable savedDifferencesMapFor = this.differencesMapFor;
   this.differencesMapFor = null;
   TrivialHashtable matchedNodes = new TrivialHashtable();
   for (int i = 0, k = 0, n = list1 == null ? 0 : list1.Count; i < n; i++){
     //^ assert list1 != null && changes != null && deletions != null;
     Block nd1 = list1[i]; 
     if (nd1 == null) continue;
     Differences diff;
     int j;
     Block nd2 = this.GetClosestMatch(nd1, list1, list2, i, ref k, matchedNodes, out diff, out j);
     if (nd2 == null || diff == null){Debug.Assert(nd2 == null && diff == null); continue;}
     matchedNodes[nd1.UniqueKey] = nd1;
     matchedNodes[nd2.UniqueKey] = nd2;
     changes[i] = diff.Changes as Block;
     deletions[i] = diff.Deletions as Block;
     insertions[i] = diff.Insertions as Block;
     insertions[n+j] = nd1; //Records the position of nd2 in list2 in case the change involved a permutation
     Debug.Assert(diff.Changes == changes[i] && diff.Deletions == deletions[i] && diff.Insertions == insertions[i]);
     differences.NumberOfDifferences += diff.NumberOfDifferences;
     differences.NumberOfSimilarities += diff.NumberOfSimilarities;
   }
   //Find deletions
   for (int i = 0, n = list1 == null ? 0 : list1.Count; i < n; i++){
     //^ assert list1 != null && changes != null && deletions != null;
     Block nd1 = list1[i]; 
     if (nd1 == null) continue;
     if (matchedNodes[nd1.UniqueKey] != null) continue;
     changes[i] = null;
     deletions[i] = nd1;
     insertions[i] = null;
     differences.NumberOfDifferences += 1;
   }
   //Find insertions
   for (int j = 0, n = list1 == null ? 0 : list1.Count, m = list2 == null ? 0 : list2.Count; j < m; j++){
     //^ assert list2 != null;
     Block nd2 = list2[j]; 
     if (nd2 == null) continue;
     if (matchedNodes[nd2.UniqueKey] != null) continue;
     insertions[n+j] = nd2;  //Records nd2 as an insertion into list1, along with its position in list2
     differences.NumberOfDifferences += 1; //REVIEW: put the size of the tree here?
   }
   if (differences.NumberOfDifferences == 0){
     changes = null;
     deletions = null;
     insertions = null;
   }
   this.differencesMapFor = savedDifferencesMapFor;
   return differences;
 }