1 files changed, 308 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/plugins/ServerPlugin.java b/java/com/google/gerrit/server/plugins/ServerPlugin.java
new file mode 100644
index 0000000000..f2362020d0
--- /dev/null
+++ b/java/com/google/gerrit/server/plugins/ServerPlugin.java
@@ -0,0 +1,308 @@
+// Copyright (C) 2012 The Android Open Source Project
+//
+// 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.google.gerrit.server.plugins;
+
+import com.google.common.base.Strings;
+import com.google.common.collect.Lists;
+import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.common.Nullable;
+import com.google.gerrit.extensions.registration.RegistrationHandle;
+import com.google.gerrit.extensions.registration.ReloadableRegistrationHandle;
+import com.google.gerrit.lifecycle.LifecycleManager;
+import com.google.gerrit.server.PluginUser;
+import com.google.gerrit.server.config.GerritRuntime;
+import com.google.gerrit.server.util.RequestContext;
+import com.google.inject.Guice;
+import com.google.inject.Injector;
+import com.google.inject.Module;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.jar.Attributes;
+import java.util.jar.Manifest;
+import org.eclipse.jgit.internal.storage.file.FileSnapshot;
+
+public class ServerPlugin extends Plugin {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  private final Manifest manifest;
+  private final PluginContentScanner scanner;
+  private final Path dataDir;
+  private final String pluginCanonicalWebUrl;
+  private final ClassLoader classLoader;
+  private final String metricsPrefix;
+  private final GerritRuntime gerritRuntime;
+  protected Class<? extends Module> sysModule;
+  protected Class<? extends Module> batchModule;
+  protected Class<? extends Module> sshModule;
+  protected Class<? extends Module> httpModule;
+
+  private Injector sysInjector;
+  private Injector sshInjector;
+  private Injector httpInjector;
+  private LifecycleManager serverManager;
+  private List<ReloadableRegistrationHandle<?>> reloadableHandles;
+
+  public ServerPlugin(
+      String name,
+      String pluginCanonicalWebUrl,
+      PluginUser pluginUser,
+      Path srcJar,
+      FileSnapshot snapshot,
+      PluginContentScanner scanner,
+      Path dataDir,
+      ClassLoader classLoader,
+      String metricsPrefix,
+      GerritRuntime gerritRuntime)
+      throws InvalidPluginException {
+    super(
+        name,
+        srcJar,
+        pluginUser,
+        snapshot,
+        scanner == null ? ApiType.PLUGIN : Plugin.getApiType(getPluginManifest(scanner)));
+    this.pluginCanonicalWebUrl = pluginCanonicalWebUrl;
+    this.scanner = scanner;
+    this.dataDir = dataDir;
+    this.classLoader = classLoader;
+    this.manifest = scanner == null ? null : getPluginManifest(scanner);
+    this.metricsPrefix = metricsPrefix;
+    this.gerritRuntime = gerritRuntime;
+    if (manifest != null) {
+      loadGuiceModules(manifest, classLoader);
+    }
+  }
+
+  private void loadGuiceModules(Manifest manifest, ClassLoader classLoader)
+      throws InvalidPluginException {
+    Attributes main = manifest.getMainAttributes();
+    String sysName = main.getValue("Gerrit-Module");
+    String sshName = main.getValue("Gerrit-SshModule");
+    String httpName = main.getValue("Gerrit-HttpModule");
+    String batchName = main.getValue("Gerrit-BatchModule");
+
+    if (!Strings.isNullOrEmpty(sshName) && getApiType() != Plugin.ApiType.PLUGIN) {
+      throw new InvalidPluginException(
+          String.format(
+              "Using Gerrit-SshModule requires Gerrit-ApiType: %s", Plugin.ApiType.PLUGIN));
+    }
+
+    try {
+      this.batchModule = load(batchName, classLoader);
+      this.sysModule = load(sysName, classLoader);
+      this.sshModule = load(sshName, classLoader);
+      this.httpModule = load(httpName, classLoader);
+    } catch (ClassNotFoundException e) {
+      throw new InvalidPluginException("Unable to load plugin Guice Modules", e);
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  protected static Class<? extends Module> load(@Nullable String name, ClassLoader pluginLoader)
+      throws ClassNotFoundException {
+    if (Strings.isNullOrEmpty(name)) {
+      return null;
+    }
+
+    Class<?> clazz = Class.forName(name, false, pluginLoader);
+    if (!Module.class.isAssignableFrom(clazz)) {
+      throw new ClassCastException(
+          String.format("Class %s does not implement %s", name, Module.class.getName()));
+    }
+    return (Class<? extends Module>) clazz;
+  }
+
+  Path getDataDir() {
+    return dataDir;
+  }
+
+  String getPluginCanonicalWebUrl() {
+    return pluginCanonicalWebUrl;
+  }
+
+  String getMetricsPrefix() {
+    return metricsPrefix;
+  }
+
+  private static Manifest getPluginManifest(PluginContentScanner scanner)
+      throws InvalidPluginException {
+    try {
+      return scanner.getManifest();
+    } catch (IOException e) {
+      throw new InvalidPluginException("Cannot get plugin manifest", e);
+    }
+  }
+
+  @Override
+  @Nullable
+  public String getVersion() {
+    Attributes main = manifest.getMainAttributes();
+    return main.getValue(Attributes.Name.IMPLEMENTATION_VERSION);
+  }
+
+  @Override
+  protected boolean canReload() {
+    Attributes main = manifest.getMainAttributes();
+    String v = main.getValue("Gerrit-ReloadMode");
+    if (Strings.isNullOrEmpty(v) || "reload".equalsIgnoreCase(v)) {
+      return true;
+    } else if ("restart".equalsIgnoreCase(v)) {
+      return false;
+    } else {
+      logger.atWarning().log(
+          "Plugin %s has invalid Gerrit-ReloadMode %s; assuming restart", getName(), v);
+      return false;
+    }
+  }
+
+  @Override
+  protected void start(PluginGuiceEnvironment env) throws Exception {
+    RequestContext oldContext = env.enter(this);
+    try {
+      startPlugin(env);
+    } finally {
+      env.exit(oldContext);
+    }
+  }
+
+  private void startPlugin(PluginGuiceEnvironment env) throws Exception {
+    Injector root = newRootInjector(env);
+    serverManager = new LifecycleManager();
+    serverManager.add(root);
+
+    if (gerritRuntime == GerritRuntime.BATCH) {
+      if (batchModule != null) {
+        sysInjector = root.createChildInjector(root.getInstance(batchModule));
+        serverManager.add(sysInjector);
+      } else {
+        sysInjector = root;
+      }
+
+      serverManager.start();
+      return;
+    }
+
+    AutoRegisterModules auto = null;
+    if (sysModule == null && sshModule == null && httpModule == null) {
+      auto = new AutoRegisterModules(getName(), env, scanner, classLoader);
+      auto.discover();
+    }
+
+    if (sysModule != null) {
+      sysInjector = root.createChildInjector(root.getInstance(sysModule));
+      serverManager.add(sysInjector);
+    } else if (auto != null && auto.sysModule != null) {
+      sysInjector = root.createChildInjector(auto.sysModule);
+      serverManager.add(sysInjector);
+    } else {
+      sysInjector = root;
+    }
+
+    if (env.hasSshModule()) {
+      List<Module> modules = new ArrayList<>();
+      if (getApiType() == ApiType.PLUGIN) {
+        modules.add(env.getSshModule());
+      }
+      if (sshModule != null) {
+        modules.add(sysInjector.getInstance(sshModule));
+        sshInjector = sysInjector.createChildInjector(modules);
+        serverManager.add(sshInjector);
+      } else if (auto != null && auto.sshModule != null) {
+        modules.add(auto.sshModule);
+        sshInjector = sysInjector.createChildInjector(modules);
+        serverManager.add(sshInjector);
+      }
+    }
+
+    if (env.hasHttpModule()) {
+      List<Module> modules = new ArrayList<>();
+      if (getApiType() == ApiType.PLUGIN) {
+        modules.add(env.getHttpModule());
+      }
+      if (httpModule != null) {
+        modules.add(sysInjector.getInstance(httpModule));
+        httpInjector = sysInjector.createChildInjector(modules);
+        serverManager.add(httpInjector);
+      } else if (auto != null && auto.httpModule != null) {
+        modules.add(auto.httpModule);
+        httpInjector = sysInjector.createChildInjector(modules);
+        serverManager.add(httpInjector);
+      }
+    }
+
+    serverManager.start();
+  }
+
+  private Injector newRootInjector(PluginGuiceEnvironment env) {
+    List<Module> modules = Lists.newArrayListWithCapacity(2);
+    if (getApiType() == ApiType.PLUGIN) {
+      modules.add(env.getSysModule());
+    }
+    modules.add(new ServerPluginInfoModule(this, env.getServerMetrics()));
+    return Guice.createInjector(modules);
+  }
+
+  @Override
+  protected void stop(PluginGuiceEnvironment env) {
+    if (serverManager != null) {
+      RequestContext oldContext = env.enter(this);
+      try {
+        serverManager.stop();
+      } finally {
+        env.exit(oldContext);
+      }
+      serverManager = null;
+      sysInjector = null;
+      sshInjector = null;
+      httpInjector = null;
+    }
+  }
+
+  @Override
+  public Injector getSysInjector() {
+    return sysInjector;
+  }
+
+  @Override
+  @Nullable
+  public Injector getSshInjector() {
+    return sshInjector;
+  }
+
+  @Override
+  @Nullable
+  public Injector getHttpInjector() {
+    return httpInjector;
+  }
+
+  @Override
+  public void add(RegistrationHandle handle) {
+    if (serverManager != null) {
+      if (handle instanceof ReloadableRegistrationHandle) {
+        if (reloadableHandles == null) {
+          reloadableHandles = new ArrayList<>();
+        }
+        reloadableHandles.add((ReloadableRegistrationHandle<?>) handle);
+      }
+      serverManager.add(handle);
+    }
+  }
+
+  @Override
+  public PluginContentScanner getContentScanner() {
+    return scanner;
+  }
+}