platform/lang-impl/src/com/intellij/find/ngrams/TrigramIndex.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /*
  18  * @author max
  19  */
  20 package com.intellij.find.ngrams;
  21
  22 import com.intellij.openapi.util.text.TrigramBuilder;
  23 import com.intellij.openapi.vfs.VirtualFile;
  24 import com.intellij.util.indexing.*;
  25 import com.intellij.util.io.EnumeratorIntegerDescriptor;
  26 import com.intellij.util.io.KeyDescriptor;
  27 import gnu.trove.THashMap;
  28 import gnu.trove.TIntHashSet;
  29 import gnu.trove.TIntProcedure;
  30 import org.jetbrains.annotations.NotNull;
  31
  32 import java.util.Map;
  33
  34 public class TrigramIndex extends ScalarIndexExtension<Integer> {
  35   public static final boolean ENABLED = "true".equals(System.getProperty("idea.internal.trigramindex.enabled"));
  36
  37   public static final ID<Integer,Void> INDEX_ID = ID.create("Trigram.Index");
  38
  39   private static final FileBasedIndex.InputFilter INPUT_FILTER = new FileBasedIndex.InputFilter() {
  40     public boolean acceptInput(VirtualFile file) {
  41       return !file.getFileType().isBinary();
  42     }
  43   };
  44   private static final FileBasedIndex.InputFilter NO_FILES = new FileBasedIndex.InputFilter() {
  45     public boolean acceptInput(VirtualFile file) {
  46       return false;
  47     }
  48   };
  49
  50   public ID<Integer, Void> getName() {
  51     return INDEX_ID;
  52   }
  53
  54   public DataIndexer<Integer, Void, FileContent> getIndexer() {
  55     return new DataIndexer<Integer, Void, FileContent>() {
  56       @NotNull
  57       public Map<Integer, Void> map(FileContent inputData) {
  58         final Map<Integer, Void> result = new THashMap<Integer, Void>();
  59         TIntHashSet built = TrigramBuilder.buildTrigram(inputData.getContentAsText());
  60         built.forEach(new TIntProcedure() {
  61           public boolean execute(int value) {
  62             result.put(value, null);
  63             return true;
  64           }
  65         });
  66         return result;
  67       }
  68     };
  69   }
  70
  71   public KeyDescriptor<Integer> getKeyDescriptor() {
  72     return new EnumeratorIntegerDescriptor();
  73   }
  74
  75   public FileBasedIndex.InputFilter getInputFilter() {
  76     if (ENABLED) {
  77       return INPUT_FILTER;
  78     }
  79     else {
  80       return NO_FILES;
  81     }
  82   }
  83
  84   public boolean dependsOnFileContent() {
  85     return true;
  86   }
  87
  88   public int getVersion() {
  89     return ENABLED ? 2 : 1;
  90   }
  91 }