plugins/git4idea/src/git4idea/history/wholeTree/DetailsCache.java

/*
 * Copyright 2000-2014 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 git4idea.history.wholeTree;

import com.intellij.openapi.application.ModalityState;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.progress.BackgroundTaskQueue;
import com.intellij.openapi.progress.ProgressIndicator;
import com.intellij.openapi.progress.Task;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.Pair;
import com.intellij.openapi.vcs.VcsException;
import com.intellij.openapi.vcs.changes.BackgroundFromStartOption;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.util.Consumer;
import com.intellij.util.Processor;
import com.intellij.util.containers.MultiMap;
import com.intellij.util.containers.SLRUMap;
import git4idea.GitBranch;
import git4idea.history.browser.CachedRefs;
import git4idea.history.browser.GitHeavyCommit;
import git4idea.history.browser.LowLevelAccessImpl;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import javax.swing.*;
import java.util.*;

/**
 * @author irengrig
 */
public class DetailsCache {
  private final static int ourSize = 500;
  private final SLRUMap<Pair<VirtualFile, AbstractHash>, GitHeavyCommit> myCache;
  private final SLRUMap<Pair<VirtualFile, AbstractHash>, List<String>> myBranches;
  private final Project myProject;
  private final DetailsLoaderImpl myDetailsLoader;
  private final BackgroundTaskQueue myQueue;
  private UIRefresh myRefresh;
  private final Map<VirtualFile, Map<AbstractHash, String>> myStash;
  private final Object myLock;
  private final static Logger LOG = Logger.getInstance("git4idea.history.wholeTree.DetailsCache");
  private ModalityState myState;

  public DetailsCache(final Project project,
                      final UIRefresh uiRefresh,
                      final DetailsLoaderImpl detailsLoader,
                      final BackgroundTaskQueue queue) {
    myProject = project;
    myDetailsLoader = detailsLoader;
    myQueue = queue;
    myStash = new HashMap<VirtualFile, Map<AbstractHash,String>>();
    myRefresh = uiRefresh;
    myLock = new Object();
    myCache = new SLRUMap<Pair<VirtualFile, AbstractHash>, GitHeavyCommit>(ourSize, 150);
    myBranches = new SLRUMap<Pair<VirtualFile, AbstractHash>, List<String>>(20, 20);
  }

  public GitHeavyCommit convert(final VirtualFile root, final AbstractHash hash) {
    synchronized (myLock) {
      return myCache.get(Pair.create(root, hash));
    }
  }

  public void acceptQuestion(final MultiMap<VirtualFile,AbstractHash> hashes) {
    if (hashes.isEmpty()) return;
    myDetailsLoader.load(hashes);
  }

  public void acceptAnswer(final Collection<GitHeavyCommit> commits, final VirtualFile root) {
    synchronized (myLock) {
      for (GitHeavyCommit commit : commits) {
        myCache.put(Pair.create(root, commit.getShortHash()), commit);
      }
    }
    SwingUtilities.invokeLater(new Runnable() {
      @Override
      public void run() {
        myRefresh.detailsLoaded();
      }
    });
  }

  public void rootsChanged(final Collection<VirtualFile> roots) {
    myDetailsLoader.setRoots(roots);
  }

  public void putBranches(final VirtualFile root, final AbstractHash hash, final List<String> s) {
    synchronized (myLock) {
      myBranches.put(Pair.create(root, hash), s);
    }
  }

  @Nullable
  public List<String> getBranches(final VirtualFile root, final AbstractHash hash) {
    synchronized (myLock) {
      return myBranches.get(Pair.create(root, hash));
    }
  }

  public void resetAsideCaches() {
    synchronized (myLock) {
      myBranches.clear();
      myStash.clear();
      // will be cleared by itself; commits are not changed while they have same hash
      // uncommented because of reference caching
      //myCache.clear();
      final Set<Pair<VirtualFile, AbstractHash>> forDeletion = new HashSet<Pair<VirtualFile, AbstractHash>>();
      for (Map.Entry<Pair<VirtualFile, AbstractHash>, GitHeavyCommit> entry : myCache.entrySet()) {
        final GitHeavyCommit value = entry.getValue();
        if (! value.getLocalBranches().isEmpty() || ! value.getRemoteBranches().isEmpty() ||
            ! value.getTags().isEmpty()) {
          forDeletion.add(Pair.create(entry.getKey().getFirst(), entry.getKey().getSecond()));
        }
      }
      for (Pair<VirtualFile, AbstractHash> pair : forDeletion) {
        myCache.remove(pair);
      }
    }
  }

  public void putStash(final VirtualFile root, final Map<AbstractHash, String> stash) {
    synchronized (myLock) {
      myStash.put(root, stash);
    }
  }

  @Nullable
  public String getStashName(final VirtualFile root, final AbstractHash hash) {
    synchronized (myLock) {
      final Map<AbstractHash, String> map = myStash.get(root);
      return map == null ? null : map.get(hash);
    }
  }

  public void clearBranches() {
    synchronized (myLock) {
      myBranches.clear();
    }
  }

  public void loadAndPutBranches(final VirtualFile root,
                                 final AbstractHash abstractHash,
                                 final Consumer<List<String>> continuation, final Processor<AbstractHash> recheck) {
    myQueue.run(new Task.Backgroundable(myProject, "Load contained in branches", true, BackgroundFromStartOption.getInstance()) {
                  @Override
                  public void run(@NotNull ProgressIndicator indicator) {
                    if (!recheck.process(abstractHash)) return;
                    if (getBranches(root, abstractHash) != null) return;
                    List<String> branches;
                    try {
                      branches = new LowLevelAccessImpl(myProject, root).getBranchesWithCommit(abstractHash.getString());
                    }
                    catch (VcsException e) {
                      LOG.info(e);
                      branches = Collections.singletonList("Can not load branches due to error: " + e.getMessage());
                    }
                    putBranches(root, abstractHash, branches);
                    final List<String> finalBranches = branches;
                    SwingUtilities.invokeLater(new Runnable() {
                      @Override
                      public void run() {
                        continuation.consume(finalBranches);
                      }
                    });
                  }
                }, myState, null);
  }

  public void setModalityState(ModalityState state) {
    myState = state;
  }

  public void reportRefs(VirtualFile root, CachedRefs refs) {
    synchronized (myLock) {
      final Set<Pair<VirtualFile, AbstractHash>> forDeletion = new HashSet<Pair<VirtualFile, AbstractHash>>();
      final Set<String> hashes = new HashSet<String>();
      AbstractHash headHash = refs.getHeadHash();
      Collection<? extends GitBranch> local = refs.getLocal();
      for (GitBranch branch : local) {
        hashes.add(branch.getHash());
      }
      Collection<? extends GitBranch> remote = refs.getRemote();
      for (GitBranch branch : remote) {
        hashes.add(branch.getHash());
      }

      for (Map.Entry<Pair<VirtualFile, AbstractHash>, GitHeavyCommit> entry : myCache.entrySet()) {
        final GitHeavyCommit value = entry.getValue();
        if (! root.equals(entry.getKey().getFirst())) continue;
        AbstractHash hash = value.getShortHash();
        if (hash.equals(headHash) || hashes.contains(value.getHash().getValue())) {
          forDeletion.add(Pair.create(entry.getKey().getFirst(), entry.getKey().getSecond()));
        }
      }
      for (Pair<VirtualFile, AbstractHash> pair : forDeletion) {
        myCache.remove(pair);
      }
    }
  }
}