platform/vcs-impl/src/com/intellij/openapi/vcs/changes/VcsCurrentRevisionProxy.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 package com.intellij.openapi.vcs.changes;
  17
  18 import org.jetbrains.annotations.Nullable;
  19 import org.jetbrains.annotations.NotNull;
  20 import com.intellij.openapi.vcs.VcsException;
  21 import com.intellij.openapi.vcs.FilePath;
  22 import com.intellij.openapi.vcs.FilePathImpl;
  23 import com.intellij.openapi.vcs.diff.DiffProvider;
  24 import com.intellij.openapi.vcs.history.VcsRevisionNumber;
  25 import com.intellij.openapi.vfs.VirtualFile;
  26
  27 /**
  28  * @author yole
  29  */
  30 public class VcsCurrentRevisionProxy implements ContentRevision {
  31   private final DiffProvider myDiffProvider;
  32   private final VirtualFile myFile;
  33   private ContentRevision myVcsRevision;
  34
  35   public VcsCurrentRevisionProxy(final DiffProvider diffProvider, final VirtualFile file) {
  36     myDiffProvider = diffProvider;
  37     myFile = file;
  38   }
  39
  40   @Nullable
  41   public String getContent() throws VcsException {
  42     return getVcsRevision().getContent();
  43   }
  44
  45   @NotNull
  46   public FilePath getFile() {
  47     return new FilePathImpl(myFile);
  48   }
  49
  50   @NotNull
  51   public VcsRevisionNumber getRevisionNumber() {
  52     try {
  53       return getVcsRevision().getRevisionNumber();
  54     }
  55     catch(VcsException ex) {
  56       return VcsRevisionNumber.NULL;
  57     }
  58   }
  59
  60   private ContentRevision getVcsRevision() throws VcsException {
  61     if (myVcsRevision == null) {
  62       final VcsRevisionNumber currentRevision = myDiffProvider.getCurrentRevision(myFile);
  63       if (currentRevision == null) {
  64         throw new VcsException("Failed to fetch current revision");
  65       }
  66       myVcsRevision = myDiffProvider.createFileContent(currentRevision, myFile);
  67       if (myVcsRevision == null) {
  68         throw new VcsException("Failed to create content for current revision");
  69       }
  70     }
  71     return myVcsRevision;
  72   }
  73 }