/*
* Copyright 2000-2016 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.intellij.util.gist;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.progress.ProgressManager;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.Pair;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.openapi.vfs.VirtualFileWithId;
import com.intellij.openapi.vfs.newvfs.FileAttribute;
import com.intellij.openapi.vfs.newvfs.persistent.PersistentFS;
import com.intellij.util.containers.FactoryMap;
import com.intellij.util.io.DataExternalizer;
import com.intellij.util.io.DataInputOutputUtil;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Map;
/**
* @author peter
*/
class VirtualFileGistImpl<Data> implements VirtualFileGist<Data> {
private static final Logger LOG = Logger.getInstance("#com.intellij.util.gist.VirtualFileGist");
private static final int ourInternalVersion = 2;
@NotNull private final String myId;
private final int myVersion;
@NotNull private final GistCalculator<Data> myCalculator;
@NotNull private final DataExternalizer<Data> myExternalizer;
VirtualFileGistImpl(@NotNull String id, int version, @NotNull DataExternalizer<Data> externalizer, @NotNull GistCalculator<Data> calcData) {
myId = id;
myVersion = version;
myExternalizer = externalizer;
myCalculator = calcData;
}
@Override
public Data getFileData(@NotNull Project project, @NotNull VirtualFile file) {
ApplicationManager.getApplication().assertReadAccessAllowed();
ProgressManager.checkCanceled();
if (!(file instanceof VirtualFileWithId)) return myCalculator.calcData(project, file);
int stamp = PersistentFS.getInstance().getModificationCount(file) + ((GistManagerImpl)GistManager.getInstance()).getReindexCount();
try (DataInputStream stream = getFileAttribute(project).readAttribute(file)) {
if (stream != null && DataInputOutputUtil.readINT(stream) == stamp) {
return stream.readBoolean() ? myExternalizer.read(stream) : null;
}
}
catch (IOException e) {
LOG.error(e);
}
Data result = myCalculator.calcData(project, file);
cacheResult(stamp, result, project, file);
return result;
}
private void cacheResult(int modCount, @Nullable Data result, Project project, VirtualFile file) {
try (DataOutputStream out = getFileAttribute(project).writeAttribute(file)) {
DataInputOutputUtil.writeINT(out, modCount);
out.writeBoolean(result != null);
if (result != null) {
myExternalizer.save(out, result);
}
}
catch (IOException e) {
LOG.error(e);
}
}
@SuppressWarnings("MismatchedQueryAndUpdateOfCollection")
private static final Map<Pair<String, Integer>, FileAttribute> ourAttributes = new FactoryMap<Pair<String, Integer>, FileAttribute>() {
@Nullable
@Override
protected FileAttribute create(Pair<String, Integer> key) {
return new FileAttribute(key.first, key.second, false);
}
};
private FileAttribute getFileAttribute(Project project) {
synchronized (ourAttributes) {
return ourAttributes.get(Pair.create(myId + project.getLocationHash(), myVersion + ourInternalVersion));
}
}
}