supporting cache the persists across runs (faster development)

src/main/java/com/inteligr8/git/ExtendedGit.java

@@ -31,9 +31,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class ExtendedGit extends CachedGit {
-	
+
+	private static final Pattern gitUrlPattern = Pattern.compile("(((ssh|http(s)?)://([^@]+@)?([^:/]+)(:[0-9]+)?/)|git@([^:]+):)([\\w\\.@\\:/\\-~]+)(\\.git)");
 	private final Logger logger = LoggerFactory.getLogger(ExtendedGit.class);
-	private final Pattern gitUrlPattern = Pattern.compile("(((ssh|http(s)?)://([^@]+@)?([^:/]+)(:[0-9]+)?/)|git@([^:]+):)([\\w\\.@\\:/\\-~]+)(\\.git)");
 	
 	public ExtendedGit(Git git) {
 		super(git.getRepository());
@@ -51,10 +51,13 @@ public class ExtendedGit extends CachedGit {
 		String gitUrl = this.getFirstRemoteUrl();
 		if (this.logger.isDebugEnabled())
 			this.logger.debug("Remote URL: " + gitUrl);
-		
+		return getRepositoryFullyQualifiedName(gitUrl);
-		Matcher matcher = this.gitUrlPattern.matcher(gitUrl);
+	}
+	
+	public static String getRepositoryFullyQualifiedName(String gitUrl) throws URISyntaxException {
+		Matcher matcher = gitUrlPattern.matcher(gitUrl);
 		if (!matcher.find())
-			throw new URISyntaxException(gitUrl, "The Git URL does not match the expected regular expression: " + this.gitUrlPattern.toString());
+			throw new URISyntaxException(gitUrl, "The Git URL does not match the expected regular expression: " + gitUrlPattern.toString());
 		return matcher.group(9);
 	}
 	

src/main/java/com/inteligr8/git/LocalRepositoryCache.java

@@ -16,6 +16,7 @@ import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.api.errors.InvalidRemoteException;
 import org.eclipse.jgit.api.errors.RefNotFoundException;
 import org.eclipse.jgit.api.errors.TransportException;
+import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.transport.CredentialsProvider;
 import org.eclipse.jgit.util.FileUtils;
 import org.slf4j.Logger;
@@ -36,13 +37,24 @@ public class LocalRepositoryCache {
 	private final LRUExpiringHashMap<String, CachedGit> cachedGits = new LRUExpiringHashMap<>(30);
 	private final Map<String, Semaphore> gitUrlSemaphores = new HashMap<>();
 	final File cacheDirectory = new File(System.getProperty("java.io.tmpdir"), "git");
-	private final int simultaneousProcessesPerGitRepo = 1;
+	private int simultaneousThreadsPerGitRepo = 1;
 	
 	private LocalRepositoryCache() {
 		this.cacheDirectory.mkdir();
 		this.cachedGits.addListener(new RepositoryCacheMapListener<CachedGit>());
 	}
 	
+	/**
+	 * This is helpful for the tweaking performance based on the environment of
+	 * execution.  A value of 1 disables concurrency which results in the
+	 * persistence of Git Repositories between executions and disables cache
+	 * expiration.  This is great for development, testing, and command line
+	 * usage.  It is not recommended with web service frontends.
+	 */
+	public void setSimultaneousThreadsPerGitRepository(int threads) {
+		this.simultaneousThreadsPerGitRepo = threads;
+	}
+	
 	@Override
 	protected void finalize() throws Throwable {
 		try {
@@ -91,17 +103,32 @@ public class LocalRepositoryCache {
     	synchronized (this) {
 	    	semaphore = this.gitUrlSemaphores.get(url);
 	    	if (semaphore == null)
-	    		this.gitUrlSemaphores.put(url, semaphore = new Semaphore(this.simultaneousProcessesPerGitRepo));
+	    		this.gitUrlSemaphores.put(url, semaphore = new Semaphore(this.simultaneousThreadsPerGitRepo));
     	}
     	
+    	File gitRepoDirectory = null;
+    	
     	semaphore.acquire();
     	try {
 			CachedGit git = this.cachedGits.remove(url);
 			if (git == null) {
-				File gitRepoDirectory = new File(this.cacheDirectory, UUID.randomUUID().toString() + ".git");
+				String directoryBaseName;
+				if (this.simultaneousThreadsPerGitRepo == 1)
+					directoryBaseName = ExtendedGit.getRepositoryFullyQualifiedName(url).replace('/', '_');
+				else directoryBaseName = UUID.randomUUID().toString();
+				
+				gitRepoDirectory = new File(this.cacheDirectory, directoryBaseName + ".git");
 		    	if (this.logger.isDebugEnabled())
 		    		this.logger.debug("Git directory cache for clone: " + gitRepoDirectory);
 				
+		    	if (gitRepoDirectory.exists()) {
+			    	if (this.logger.isInfoEnabled())
+			    		this.logger.info("Git Repository already exists; reusing: " + gitRepoDirectory);
+		    		git = creds != null ? new CredentialedGit(Git.open(gitRepoDirectory), creds) : new ExtendedGit(Git.open(gitRepoDirectory));
+		    	}
+			}
+			
+			if (git == null) {
 				CloneCommand clone = new CloneCommand()
 		    			.setURI(url)
 		    			.setDirectory(gitRepoDirectory);
@@ -115,13 +142,17 @@ public class LocalRepositoryCache {
 		    		this.logger.info("Cloned Git Repository: " + ((ExtendedGit)git).getRepositoryFullyQualifiedName());
 			} else {
 		    	if (this.logger.isDebugEnabled())
-		    		this.logger.debug("reseting Git");
+		    		this.logger.debug("resetting Git");
 				git.reset().setMode(ResetType.HARD).call();
 				
-				if (branch != null) {
+				if (branch != null && !branch.equals(git.getRepository().getBranch())) {
 			    	if (this.logger.isDebugEnabled())
 			    		this.logger.debug("switching Git branches: " + branch);
-					git.checkout().setName(branch).call();
+			    	if (git.getRepository().exactRef(Constants.R_HEADS + branch) == null) {
+			    		git.checkout().setName(branch).setStartPoint("origin/" + branch).setCreateBranch(true).call();
+			    	} else {
+			    		git.checkout().setName(branch).call();
+			    	}
 				}
 	
 		    	if (this.logger.isDebugEnabled())