Implemented commit cache for the dashboards, activity, and project pages

1 files changed, 253 insertions, 0 deletions

diff --git a/src/main/java/com/gitblit/utils/CommitCache.java b/src/main/java/com/gitblit/utils/CommitCache.java
new file mode 100644
index 00000000..e188ff9a
--- /dev/null
+++ b/src/main/java/com/gitblit/utils/CommitCache.java
@@ -0,0 +1,253 @@
+/*
+ * Copyright 2013 gitblit.com.
+ *
+ * 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.gitblit.utils;
+
+import java.text.MessageFormat;
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.gitblit.models.RefModel;
+import com.gitblit.models.RepositoryCommit;
+
+/**
+ * Caches repository commits for re-use in the dashboard and activity pages.
+ * 
+ * @author James Moger
+ *
+ */
+public class CommitCache {
+	
+	private static final CommitCache instance;
+	
+	protected final Logger logger = LoggerFactory.getLogger(getClass());
+	
+	protected final Map<String, ObjectCache<List<RepositoryCommit>>> cache;
+	
+	protected int cacheDays = -1;
+	
+	public static CommitCache instance() {
+		return instance;
+	}
+	
+	static {
+		instance = new CommitCache();
+	}
+	
+	protected CommitCache() {
+		cache = new ConcurrentHashMap<String, ObjectCache<List<RepositoryCommit>>>();
+	}
+	
+	/**
+	 * Returns the cutoff date for the cache.  Commits after this date are cached.
+	 * Commits before this date are not cached.
+	 * 
+	 * @return
+	 */
+	protected Date getCacheCutoffDate() {
+		final Calendar cal = Calendar.getInstance();
+		cal.setTimeInMillis(System.currentTimeMillis());
+		cal.set(Calendar.HOUR_OF_DAY, 0);
+		cal.set(Calendar.MINUTE, 0);
+		cal.set(Calendar.SECOND, 0);
+		cal.set(Calendar.MILLISECOND, 0);
+		cal.add(Calendar.DATE, -1*cacheDays);
+		return cal.getTime();
+	}
+	
+	/**
+	 * Sets the number of days to cache.
+	 * 
+	 * @param days
+	 */
+	public synchronized void setCacheDays(int days) {
+		this.cacheDays = days;
+		clear();
+	}
+	
+	/**
+	 * Clears the entire commit cache.
+	 * 
+	 */
+	public void clear() {
+		cache.clear();
+	}
+	
+	/**
+	 * Clears the commit cache for a specific repository.
+	 * 
+	 * @param repositoryName
+	 */
+	public void clear(String repositoryName) {
+		String repoKey = repositoryName.toLowerCase();
+		ObjectCache<List<RepositoryCommit>> repoCache = cache.remove(repoKey);
+		if (repoCache != null) {
+			logger.info(MessageFormat.format("{0} commit cache cleared", repositoryName));
+		}
+	}
+	
+	/**
+	 * Get all commits for the specified repository:branch that are in the cache.
+	 * 
+	 * @param repositoryName
+	 * @param repository
+	 * @param branch
+	 * @return a list of commits
+	 */
+	public List<RepositoryCommit> getCommits(String repositoryName, Repository repository, String branch) {
+		return getCommits(repositoryName, repository, branch, getCacheCutoffDate());
+	}
+	
+	/**
+	 * Get all commits for the specified repository:branch since a specific date.
+	 * These commits may be retrieved from the cache if the sinceDate is after
+	 * the cacheCutoffDate.
+	 * 
+	 * @param repositoryName
+	 * @param repository
+	 * @param branch
+	 * @param sinceDate
+	 * @return a list of commits
+	 */
+	public List<RepositoryCommit> getCommits(String repositoryName, Repository repository, String branch, Date sinceDate) {
+		long start = System.nanoTime();
+		Date cacheCutoffDate = getCacheCutoffDate();
+		List<RepositoryCommit> list;
+		if (cacheDays > 0 && (sinceDate.getTime() >= cacheCutoffDate.getTime())) {
+			// request fits within the cache window
+			String repoKey = repositoryName.toLowerCase();
+			if (!cache.containsKey(repoKey)) {
+				cache.put(repoKey, new ObjectCache<List<RepositoryCommit>>());
+			}
+			
+			ObjectCache<List<RepositoryCommit>> repoCache = cache.get(repoKey);
+			String branchKey = branch.toLowerCase();
+			
+			RevCommit tip = JGitUtils.getCommit(repository, branch);
+			Date tipDate = JGitUtils.getCommitDate(tip);
+			
+			List<RepositoryCommit> commits;
+			if (!repoCache.hasCurrent(branchKey, tipDate)) {
+				commits = repoCache.getObject(branchKey);
+				if (ArrayUtils.isEmpty(commits)) {
+					// we don't have any cached commits for this branch, reload
+					commits = get(repositoryName, repository, branch, cacheCutoffDate);
+					repoCache.updateObject(branchKey, tipDate, commits);
+					logger.debug(MessageFormat.format("parsed {0} commits from {1}:{2} since {3,date,yyyy-MM-dd} in {4} msecs",
+							commits.size(), repositoryName, branch, cacheCutoffDate, TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start)));
+				} else {
+					// incrementally update cache since the last cached commit
+					ObjectId sinceCommit = commits.get(0).getId();
+					List<RepositoryCommit> incremental = get(repositoryName, repository, branch, sinceCommit);
+					logger.info(MessageFormat.format("incrementally added {0} commits to cache for {1}:{2} in {3} msecs",
+							incremental.size(), repositoryName, branch, TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start)));
+					incremental.addAll(commits);
+					repoCache.updateObject(branchKey, tipDate, incremental);
+					commits = incremental;
+				}
+			} else {
+				// cache is current
+				commits = repoCache.getObject(branchKey);
+				// evict older commits outside the cache window
+				commits = reduce(commits, cacheCutoffDate);
+				// update cache
+				repoCache.updateObject(branchKey, tipDate, commits);
+			}
+			
+			if (sinceDate.equals(cacheCutoffDate)) {
+				list = commits;
+			} else {
+				// reduce the commits to those since the specified date
+				list = reduce(commits, sinceDate);
+			}
+			logger.debug(MessageFormat.format("retrieved {0} commits from cache of {1}:{2} since {3,date,yyyy-MM-dd} in {4} msecs",
+					list.size(), repositoryName, branch, sinceDate, TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start)));
+		} else {
+			// not caching or request outside cache window
+			list = get(repositoryName, repository, branch, sinceDate);
+			logger.debug(MessageFormat.format("parsed {0} commits from {1}:{2} since {3,date,yyyy-MM-dd} in {4} msecs",
+					list.size(), repositoryName, branch, sinceDate, TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start)));
+		}
+		return list;
+	}
+	
+	/**
+	 * Returns a list of commits for the specified repository branch. 
+	 * 
+	 * @param repositoryName
+	 * @param repository
+	 * @param branch
+	 * @param sinceDate
+	 * @return a list of commits
+	 */
+	protected List<RepositoryCommit> get(String repositoryName, Repository repository, String branch, Date sinceDate) {
+		Map<ObjectId, List<RefModel>> allRefs = JGitUtils.getAllRefs(repository, false);
+		List<RepositoryCommit> commits = new ArrayList<RepositoryCommit>();
+		for (RevCommit commit : JGitUtils.getRevLog(repository, branch, sinceDate)) {
+			RepositoryCommit commitModel = new RepositoryCommit(repositoryName, branch, commit);
+			commitModel.setRefs(allRefs.get(commitModel.getName()));
+			commits.add(commitModel);
+		}
+		return commits;
+	}
+	
+	/**
+	 * Returns a list of commits for the specified repository branch since the specified commit. 
+	 * 
+	 * @param repositoryName
+	 * @param repository
+	 * @param branch
+	 * @param sinceCommit
+	 * @return a list of commits
+	 */
+	protected List<RepositoryCommit> get(String repositoryName, Repository repository, String branch, ObjectId sinceCommit) {
+		Map<ObjectId, List<RefModel>> allRefs = JGitUtils.getAllRefs(repository, false);
+		List<RepositoryCommit> commits = new ArrayList<RepositoryCommit>();
+		for (RevCommit commit : JGitUtils.getRevLog(repository, sinceCommit.getName(), branch)) {
+			RepositoryCommit commitModel = new RepositoryCommit(repositoryName, branch, commit);
+			commitModel.setRefs(allRefs.get(commitModel.getName()));
+			commits.add(commitModel);
+		}
+		return commits;
+	}
+	
+	/**
+	 * Reduces the list of commits to those since the specified date.
+	 * 
+	 * @param commits
+	 * @param sinceDate
+	 * @return  a list of commits
+	 */
+	protected List<RepositoryCommit> reduce(List<RepositoryCommit> commits, Date sinceDate) {
+		List<RepositoryCommit> filtered = new ArrayList<RepositoryCommit>();
+		for (RepositoryCommit commit : commits) {
+			if (commit.getCommitDate().compareTo(sinceDate) >= 0) {
+				filtered.add(commit);
+			}
+		}
+		return filtered;
+	}
+}