Add plugins/extension infrastructure

Plugins are stored in `${baseFolder}/plugins` and are loaded
during startup by the PluginManager.

A plugin defines it's metadata in META-INF/MANIFEST.MF:

    Plugin-Class: com.gitblit.plugins.cookbook.CookbookPlugin
    Plugin-Dependencies: foo, bar
    Plugin-Id: gitblit-plugin
    Plugin-Provider: John Doe
    Plugin-Version: 1.0

Plugins can define extension points that can be implemented
by other plugins and they can depend on other plugins:

    Plugin-Dependencies: foo, bar

During the load phase, a directed acyclic graph is built and the loading
order of the dependency chain is reversed using a topological sort;
parent followed by children. The parent plugin classloader is the
combined classloader of all parent plugins.

Change-Id: I738821fa2bff02a5dbe339a944cc7e3c4dd8e299

1 files changed, 17 insertions, 1 deletions

diff --git a/src/main/java/com/gitblit/manager/GitblitManager.java b/src/main/java/com/gitblit/manager/GitblitManager.java
index 8856715a..34c101e2 100644
--- a/src/main/java/com/gitblit/manager/GitblitManager.java
+++ b/src/main/java/com/gitblit/manager/GitblitManager.java
@@ -43,6 +43,8 @@ import org.eclipse.jgit.transport.RefSpec;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import ro.fortsoft.pf4j.PluginWrapper;
+
 import com.gitblit.Constants;
 import com.gitblit.Constants.AccessPermission;
 import com.gitblit.Constants.AccessRestrictionType;
@@ -116,6 +118,8 @@ public class GitblitManager implements IGitblit {
 
 	protected final IFederationManager federationManager;
 
+	protected final IPluginManager pluginManager;
+
 	public GitblitManager(
 			IRuntimeManager runtimeManager,
 			INotificationManager notificationManager,
@@ -124,7 +128,8 @@ public class GitblitManager implements IGitblit {
 			IPublicKeyManager publicKeyManager,
 			IRepositoryManager repositoryManager,
 			IProjectManager projectManager,
-			IFederationManager federationManager) {
+			IFederationManager federationManager,
+			IPluginManager pluginManager) {
 
 		this.settings = runtimeManager.getSettings();
 		this.runtimeManager = runtimeManager;
@@ -135,6 +140,7 @@ public class GitblitManager implements IGitblit {
 		this.repositoryManager = repositoryManager;
 		this.projectManager = projectManager;
 		this.federationManager = federationManager;
+		this.pluginManager = pluginManager;
 	}
 
 	@Override
@@ -1171,4 +1177,14 @@ public class GitblitManager implements IGitblit {
 	public boolean isIdle(Repository repository) {
 		return repositoryManager.isIdle(repository);
 	}
+
+	@Override
+	public <T> List<T> getExtensions(Class<T> clazz) {
+		return pluginManager.getExtensions(clazz);
+	}
+
+	@Override
+	public PluginWrapper whichPlugin(Class<?> clazz) {
+		return pluginManager.whichPlugin(clazz);
+	}
 }