[macdoc] Restore index tab

1 files changed, 108 insertions, 0 deletions

diff --git a/IndexSearcher.cs b/IndexSearcher.cs
new file mode 100644
index 0000000..26aa374
--- /dev/null
+++ b/IndexSearcher.cs
@@ -0,0 +1,108 @@
+using System;
+using Monodoc;
+
+namespace macdoc
+{
+	public class IndexSearcher
+	{
+		IndexReader index_reader;
+		
+		public IndexSearcher (IndexReader indexReader)
+		{
+			this.index_reader = indexReader;
+		}
+		
+		public int FindClosest (string text)
+		{
+			if (index_reader == null)
+				return -1;
+			
+			int low = 0;
+			int top = index_reader.Rows-1;
+			int high = top;
+			int best_rate_idx = Int32.MaxValue, best_rate = -1;
+			
+			while (low < high){
+				int mid = (high+low)/2;
+				int p = mid;
+				string s;
+				
+				for (s = index_reader.GetValue (mid); s [0] == ' ';){
+					if (p == high){
+						if (p == low){
+							if (best_rate_idx != Int32.MaxValue)
+								return best_rate_idx;
+							else
+								return p;
+						}
+						high = mid;
+						break;
+					}
+					if (p < 0)
+						return 0;
+					s = index_reader.GetValue (++p);
+				}
+				if (s [0] == ' ')
+					continue;
+				int c, rate;
+				c = Rate (text, s, out rate);
+				if (rate > best_rate){
+					best_rate = rate;
+					best_rate_idx = p;
+				}
+				if (c == 0)
+					return mid;
+				if (low == high){
+					if (best_rate_idx != Int32.MaxValue)
+						return best_rate_idx;
+					else
+						return low;
+				}
+				if (c < 0)
+					high = mid;
+				else {
+					if (low == mid)
+						low = high;
+					else
+						low = mid;
+				}
+			}
+			return high;
+		}
+		
+		int Rate (string user_text, string db_text, out int rate)
+		{
+			int c = String.Compare (user_text, db_text, true);
+			if (c == 0){
+				rate = 0;
+				return 0;
+			}
+			int i;
+			for (i = 0; i < user_text.Length; i++){
+				if (db_text [i] != user_text [i]){
+					rate = i;
+					return c;
+				}
+			}
+			rate = i;
+			return c;
+		}
+		
+		public IndexEntry GetIndexEntry (int idx)
+		{
+			if (index_reader == null || idx >= index_reader.Rows || idx < 0)
+				return null;
+			return index_reader.GetIndexEntry (idx);
+		}
+		
+		public IndexReader Index {
+			get {
+				return index_reader;
+			}
+			set {
+				index_reader = value;
+			}
+		}
+	}
+}
+