com.google.gerrit.server.plugincontext.PluginSetEntryContext Maven / Gradle / Ivy
// Copyright (C) 2018 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.plugincontext;
import static java.util.Objects.requireNonNull;
import com.google.gerrit.extensions.registration.DynamicSet;
import com.google.gerrit.extensions.registration.Extension;
import com.google.gerrit.server.plugincontext.PluginContext.CheckedExtensionImplFunction;
import com.google.gerrit.server.plugincontext.PluginContext.ExtensionImplConsumer;
import com.google.gerrit.server.plugincontext.PluginContext.ExtensionImplFunction;
import com.google.gerrit.server.plugincontext.PluginContext.PluginMetrics;
/**
* Context to invoke an extension from {@link DynamicSet}.
*
* When the plugin extension is invoked a logging tag with the plugin name is set. This way any
* errors that are triggered by the plugin extension (even if they happen in Gerrit code which is
* called by the plugin extension) can be easily attributed to the plugin.
*
*
The run* methods execute the extension but don't deliver a result back to the caller.
* Exceptions can be caught and logged.
*
*
The call* methods execute the extension and deliver a result back to the caller.
*
*
Example if all exceptions should be caught and logged:
*
*
{@code
* fooPluginSetEntryContext.run(foo -> foo.doFoo());
* }
*
* Example if all exceptions, but one, should be caught and logged:
*
*
{@code
* try {
* fooPluginSetEntryContext.run(foo -> foo.doFoo(), MyException.class);
* } catch (MyException e) {
* // handle the exception
* }
* }
*
* Example if return values should be handled:
*
*
{@code
* Object result = fooPluginSetEntryContext.call(foo -> foo.getFoo());
* }
*
* Example if return values and a single exception should be handled:
*
*
{@code
* Object result;
* try {
* result = fooPluginSetEntryContext.call(foo -> foo.getFoo(), MyException.class);
* } catch (MyException e) {
* // handle the exception
* }
* }
*
* Example if several exceptions should be handled:
*
*
{@code
* for (Extension fooExtension : fooDynamicSet.entries()) {
* try (TraceContext traceContext = PluginContext.newTrace(fooExtension)) {
* fooExtension.get().doFoo();
* } catch (MyException1 | MyException2 | MyException3 e) {
* // handle the exception
* }
* }
* }
*/
public class PluginSetEntryContext {
private final Extension extension;
private final PluginMetrics pluginMetrics;
PluginSetEntryContext(Extension extension, PluginMetrics pluginMetrics) {
this.extension = requireNonNull(extension);
this.pluginMetrics = pluginMetrics;
}
/**
* Returns the name of the plugin that registered this extension.
*
* @return the plugin name
*/
public String getPluginName() {
return extension.getPluginName();
}
/**
* Returns the implementation of this extension.
*
* Should only be used in exceptional cases to get direct access to the extension
* implementation. If possible the extension should be invoked through {@link
* #run(PluginContext.ExtensionImplConsumer)}, {@link #run(PluginContext.ExtensionImplConsumer,
* java.lang.Class)}, {@link #call(PluginContext.ExtensionImplFunction)} and {@link
* #call(PluginContext.CheckedExtensionImplFunction, java.lang.Class)}.
*
* @return the implementation of this extension
*/
public T get() {
return extension.get();
}
/**
* Invokes the plugin extension. All exceptions from the plugin extension are caught and logged.
*
*
The consumer gets the extension implementation provided that should be invoked.
*
* @param extensionImplConsumer consumer that invokes the extension
*/
public void run(ExtensionImplConsumer extensionImplConsumer) {
PluginContext.runLogExceptions(pluginMetrics, extension, extensionImplConsumer);
}
/**
* Invokes the plugin extension. All exceptions from the plugin extension are caught and logged.
*
* The consumer gets the extension implementation provided that should be invoked.
*
* @param extensionImplConsumer consumer that invokes the extension
* @param exceptionClass type of the exceptions that should be thrown
* @throws X expected exception from the plugin extension
*/
public void run(
ExtensionImplConsumer extensionImplConsumer, Class exceptionClass) throws X {
PluginContext.runLogExceptions(pluginMetrics, extension, extensionImplConsumer, exceptionClass);
}
/**
* Calls the plugin extension and returns the result from the plugin extension call.
*
* The function gets the extension point provided that should be invoked.
*
* @param extensionImplFunction function that invokes the extension
* @return the result from the plugin extension
*/
public R call(ExtensionImplFunction extensionImplFunction) {
return PluginContext.call(pluginMetrics, extension, extensionImplFunction);
}
/**
* Calls the plugin extension and returns the result from the plugin extension call. Exceptions of
* the specified type are thrown and must be handled by the caller.
*
* The function gets the extension implementation provided that should be invoked.
*
* @param checkedExtensionImplFunction function that invokes the extension
* @param exceptionClass type of the exceptions that should be thrown
* @return the result from the plugin extension
* @throws X expected exception from the plugin extension
*/
public R call(
CheckedExtensionImplFunction checkedExtensionImplFunction, Class exceptionClass)
throws X {
return PluginContext.call(
pluginMetrics, extension, checkedExtensionImplFunction, exceptionClass);
}
}