src/main/java/com/ericsson/gerrit/plugins/highavailability/Configuration.java

// Copyright (C) 2015 Ericsson
//
// 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.ericsson.gerrit.plugins.highavailability;

import static java.util.concurrent.TimeUnit.HOURS;
import static java.util.concurrent.TimeUnit.MILLISECONDS;

import com.google.common.base.CharMatcher;
import com.google.common.base.Strings;
import com.google.gerrit.extensions.annotations.PluginName;
import com.google.gerrit.server.config.ConfigUtil;
import com.google.gerrit.server.config.PluginConfigFactory;
import com.google.inject.Inject;
import com.google.inject.ProvisionException;
import com.google.inject.Singleton;
import org.eclipse.jgit.lib.Config;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Singleton
public class Configuration {
  private static final Logger log = LoggerFactory.getLogger(Configuration.class);

  // main section
  static final String MAIN_SECTION = "main";
  static final String SHARED_DIRECTORY_KEY = "sharedDirectory";

  // peerInfo section
  static final String PEER_INFO_SECTION = "peerInfo";
  static final String URL_KEY = "url";

  // http section
  static final String HTTP_SECTION = "http";
  static final String USER_KEY = "user";
  static final String PASSWORD_KEY = "password";
  static final String CONNECTION_TIMEOUT_KEY = "connectionTimeout";
  static final String SOCKET_TIMEOUT_KEY = "socketTimeout";
  static final String MAX_TRIES_KEY = "maxTries";
  static final String RETRY_INTERVAL_KEY = "retryInterval";

  // cache section
  static final String CACHE_SECTION = "cache";

  // index section
  static final String INDEX_SECTION = "index";

  // common parameters to cache and index section
  static final String THREAD_POOL_SIZE_KEY = "threadPoolSize";

  // websession section
  static final String WEBSESSION_SECTION = "websession";
  static final String CLEANUP_INTERVAL_KEY = "cleanupInterval";

  static final int DEFAULT_TIMEOUT_MS = 5000;
  static final int DEFAULT_MAX_TRIES = 5;
  static final int DEFAULT_RETRY_INTERVAL = 1000;
  static final int DEFAULT_THREAD_POOL_SIZE = 1;
  static final String DEFAULT_CLEANUP_INTERVAL = "24 hours";
  static final long DEFAULT_CLEANUP_INTERVAL_MS = HOURS.toMillis(24);

  private final Main main;
  private final PeerInfo peerInfo;
  private final Http http;
  private final Cache cache;
  private final Index index;
  private final Websession websession;

  @Inject
  Configuration(PluginConfigFactory pluginConfigFactory, @PluginName String pluginName) {
    Config cfg = pluginConfigFactory.getGlobalPluginConfig(pluginName);
    main = new Main(cfg);
    peerInfo = new PeerInfo(cfg);
    http = new Http(cfg);
    cache = new Cache(cfg);
    index = new Index(cfg);
    websession = new Websession(cfg);
  }

  public Main main() {
    return main;
  }

  public PeerInfo peerInfo() {
    return peerInfo;
  }

  public Http http() {
    return http;
  }

  public Cache cache() {
    return cache;
  }

  public Index index() {
    return index;
  }

  public Websession websession() {
    return websession;
  }

  private static int getInt(Config cfg, String section, String name, int defaultValue) {
    try {
      return cfg.getInt(section, name, defaultValue);
    } catch (IllegalArgumentException e) {
      log.error(String.format("invalid value for %s; using default value %d", name, defaultValue));
      log.debug("Failed retrieve integer value: " + e.getMessage(), e);
      return defaultValue;
    }
  }

  public static class Main {
    private final String sharedDirectory;

    private Main(Config cfg) {
      sharedDirectory =
          Strings.emptyToNull(cfg.getString(MAIN_SECTION, null, SHARED_DIRECTORY_KEY));
      if (sharedDirectory == null) {
        throw new ProvisionException(SHARED_DIRECTORY_KEY + " must be configured");
      }
    }

    public String sharedDirectory() {
      return sharedDirectory;
    }
  }

  public static class PeerInfo {
    private final String url;

    private PeerInfo(Config cfg) {
      url =
          CharMatcher.is('/')
              .trimTrailingFrom(
                  Strings.nullToEmpty(cfg.getString(PEER_INFO_SECTION, null, URL_KEY)));
    }

    public String url() {
      return url;
    }
  }

  public static class Http {
    private final String user;
    private final String password;
    private final int connectionTimeout;
    private final int socketTimeout;
    private final int maxTries;
    private final int retryInterval;

    private Http(Config cfg) {
      user = Strings.nullToEmpty(cfg.getString(HTTP_SECTION, null, USER_KEY));
      password = Strings.nullToEmpty(cfg.getString(HTTP_SECTION, null, PASSWORD_KEY));
      connectionTimeout = getInt(cfg, HTTP_SECTION, CONNECTION_TIMEOUT_KEY, DEFAULT_TIMEOUT_MS);
      socketTimeout = getInt(cfg, HTTP_SECTION, SOCKET_TIMEOUT_KEY, DEFAULT_TIMEOUT_MS);
      maxTries = getInt(cfg, HTTP_SECTION, MAX_TRIES_KEY, DEFAULT_MAX_TRIES);
      retryInterval = getInt(cfg, HTTP_SECTION, RETRY_INTERVAL_KEY, DEFAULT_RETRY_INTERVAL);
    }

    public String user() {
      return user;
    }

    public String password() {
      return password;
    }

    public int connectionTimeout() {
      return connectionTimeout;
    }

    public int socketTimeout() {
      return socketTimeout;
    }

    public int maxTries() {
      return maxTries;
    }

    public int retryInterval() {
      return retryInterval;
    }
  }

  public static class Cache {
    private final int threadPoolSize;

    private Cache(Config cfg) {
      threadPoolSize = getInt(cfg, CACHE_SECTION, THREAD_POOL_SIZE_KEY, DEFAULT_THREAD_POOL_SIZE);
    }

    public int threadPoolSize() {
      return threadPoolSize;
    }
  }

  public static class Index {
    private final int threadPoolSize;

    private Index(Config cfg) {
      threadPoolSize = getInt(cfg, INDEX_SECTION, THREAD_POOL_SIZE_KEY, DEFAULT_THREAD_POOL_SIZE);
    }

    public int threadPoolSize() {
      return threadPoolSize;
    }
  }

  public static class Websession {
    private final long cleanupInterval;

    private Websession(Config cfg) {
      this.cleanupInterval =
          ConfigUtil.getTimeUnit(
              Strings.nullToEmpty(cfg.getString(WEBSESSION_SECTION, null, CLEANUP_INTERVAL_KEY)),
              DEFAULT_CLEANUP_INTERVAL_MS,
              MILLISECONDS);
    }

    public long cleanupInterval() {
      return cleanupInterval;
    }
  }
}