content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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.alibaba.nacos.client.config.impl;
  
  import com.alibaba.nacos.api.common.Constants;
  import com.alibaba.nacos.api.config.ConfigChangeEvent;
  import com.alibaba.nacos.api.config.ConfigChangeItem;
  import com.alibaba.nacos.api.config.listener.AbstractSharedListener;
  import com.alibaba.nacos.api.config.listener.Listener;
  import com.alibaba.nacos.api.exception.NacosException;
  import com.alibaba.nacos.client.config.filter.impl.ConfigFilterChainManager;
  import com.alibaba.nacos.client.config.filter.impl.ConfigResponse;
  import com.alibaba.nacos.client.config.listener.impl.AbstractConfigChangeListener;
  import com.alibaba.nacos.client.env.NacosClientProperties;
  import com.alibaba.nacos.client.utils.LogUtils;
  import com.alibaba.nacos.client.utils.TenantUtil;
  import com.alibaba.nacos.common.executor.NameThreadFactory;
  import com.alibaba.nacos.common.notify.NotifyCenter;
  import com.alibaba.nacos.common.utils.MD5Utils;
  import com.alibaba.nacos.common.utils.NumberUtils;
  import com.alibaba.nacos.common.utils.StringUtils;
  import com.alibaba.nacos.common.utils.ThreadUtils;
  import org.slf4j.Logger;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.CopyOnWriteArrayList;
  import java.util.concurrent.ScheduledFuture;
  import java.util.concurrent.ScheduledThreadPoolExecutor;
  import java.util.concurrent.ThreadPoolExecutor;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * Listener Management.
   *
   * @author Nacos
   */
  public class CacheData {
      
      private static final Logger LOGGER = LogUtils.logger(CacheData.class);
      
      private static final long DEFAULT_NOTIF_WARN_TIMEOUTS = 60000;
      
      private static long notifyWarnTimeout = DEFAULT_NOTIF_WARN_TIMEOUTS;
      
      static {
          initNotifyWarnTimeout();
      }
      
      static long initNotifyWarnTimeout() {
          String notifyTimeouts = System.getProperty("nacos.listener.notify.warn.timeout");
          if (StringUtils.isNotBlank(notifyTimeouts) && NumberUtils.isDigits(notifyTimeouts)) {
              notifyWarnTimeout = Long.valueOf(notifyTimeouts);
              LOGGER.info("config listener notify warn timeout millis is set to {}", notifyWarnTimeout);
          } else {
              LOGGER.info("config listener notify warn timeout millis use default {} millis ",
                      DEFAULT_NOTIF_WARN_TIMEOUTS);
              notifyWarnTimeout = DEFAULT_NOTIF_WARN_TIMEOUTS;
          }
          return notifyWarnTimeout;
      }
  
      /**
       * double check lock initialization of scheduledExecutor.
       */
      static volatile ScheduledThreadPoolExecutor scheduledExecutor;
      
      static ScheduledThreadPoolExecutor getNotifyBlockMonitor() {
          if (scheduledExecutor == null) {
              synchronized (CacheData.class) {
                  if (scheduledExecutor == null) {
                      scheduledExecutor = new ScheduledThreadPoolExecutor(1,
                              new NameThreadFactory("com.alibaba.nacos.client.notify.block.monitor"),
                              new ThreadPoolExecutor.DiscardPolicy());
                      scheduledExecutor.setRemoveOnCancelPolicy(true);
                      // it will shut down when jvm exit.
                      ThreadUtils.addShutdownHook(CacheData::shutdownScheduledExecutor);
                  }
              }
          }
          return scheduledExecutor;
      }
  
      /**
       * shutdownScheduledExecutor.
       */
      public static void shutdownScheduledExecutor() {
          if (scheduledExecutor != null && !scheduledExecutor.isShutdown()) {
              try {
                  scheduledExecutor.shutdown();
                  // help gc
                  scheduledExecutor = null;
              } catch (Exception e) {
                  // ignore
              }
          }
      }
  
      static boolean initSnapshot;
      
      static {
          initSnapshot = NacosClientProperties.PROTOTYPE.getBoolean("nacos.cache.data.init.snapshot", true);
          LOGGER.info("nacos.cache.data.init.snapshot = {} ", initSnapshot);
      }
      
      public final String envName;
      
      private final ConfigFilterChainManager configFilterChainManager;
      
      public final String dataId;
      
      public final String group;
      
      public final String tenant;
      
      private final CopyOnWriteArrayList<ManagerListenerWrap> listeners;
      
      private volatile String md5;
      
      /**
       * whether use local config.
       */
      private volatile boolean isUseLocalConfig = false;
      
      /**
       * last modify time.
       */
      private volatile long localConfigLastModified;
      
      private volatile String content;
      
      private volatile String encryptedDataKey;
      
      /**
       * local cache change timestamp.
       */
      private final AtomicLong lastModifiedTs = new AtomicLong(0);
      
      /**
       * notify change flag,for notify&sync concurrent control. 1.reset to false if starting to sync with server. 2.update
       * to true if receive config change notification.
       */
      private final AtomicBoolean receiveNotifyChanged = new AtomicBoolean(false);
      
      private int taskId;
      
      private volatile boolean isInitializing = true;
      
      /**
       * if is cache data md5 sync with the server.
       */
      private final AtomicBoolean isConsistentWithServer = new AtomicBoolean();
      
      /**
       * if is cache data is discard,need to remove.
       */
      private volatile boolean isDiscard = false;
      
      private String type;
      
      public boolean isInitializing() {
          return isInitializing;
      }
      
      public void setInitializing(boolean isInitializing) {
          this.isInitializing = isInitializing;
      }
      
      public String getMd5() {
          return md5;
      }
      
      public String getTenant() {
          return tenant;
      }
      
      public String getContent() {
          return content;
      }
      
      public void setContent(String content) {
          this.content = content;
          this.md5 = getMd5String(this.content);
      }
      
      public AtomicBoolean getReceiveNotifyChanged() {
          return receiveNotifyChanged;
      }
      
      /**
       * Getter method for property <tt>lastModifiedTs</tt>.
       *
       * @return property value of lastModifiedTs
       */
      public AtomicLong getLastModifiedTs() {
          return lastModifiedTs;
      }
      
      /**
       * Setter method for property <tt>lastModifiedTs</tt>.
       *
       * @param lastModifiedTs value to be assigned to property lastModifiedTs
       */
      public void setLastModifiedTs(long lastModifiedTs) {
          this.lastModifiedTs.set(lastModifiedTs);
      }
      
      public String getType() {
          return type;
      }
      
      public void setType(String type) {
          this.type = type;
      }
      
      /**
       * Add listener if CacheData already set new content, Listener should init lastCallMd5 by CacheData.md5
       *
       * @param listener listener
       */
      public void addListener(Listener listener) throws NacosException {
          if (null == listener) {
              throw new IllegalArgumentException("listener is null");
          }
          ManagerListenerWrap wrap;
          if (listener instanceof AbstractConfigChangeListener) {
              ConfigResponse cr = new ConfigResponse();
              cr.setDataId(dataId);
              cr.setGroup(group);
              cr.setContent(content);
              cr.setEncryptedDataKey(encryptedDataKey);
              configFilterChainManager.doFilter(null, cr);
              String contentTmp = cr.getContent();
              wrap = new ManagerListenerWrap(listener, md5, contentTmp);
          } else {
              wrap = new ManagerListenerWrap(listener, md5);
          }
          
          if (listeners.addIfAbsent(wrap)) {
              LOGGER.info("[{}] [add-listener] ok, tenant={}, dataId={}, group={}, cnt={}", envName, tenant, dataId,
                      group, listeners.size());
          }
      }
      
      /**
       * Remove listener.
       *
       * @param listener listener
       */
      public void removeListener(Listener listener) {
          if (null == listener) {
              throw new IllegalArgumentException("listener is null");
          }
          ManagerListenerWrap wrap = new ManagerListenerWrap(listener);
          if (listeners.remove(wrap)) {
              LOGGER.info("[{}] [remove-listener] ok, dataId={}, group={},tenant={}, cnt={}", envName, dataId, group,
                      tenant, listeners.size());
          }
      }
      
      /**
       * Returns the iterator on the listener list, read-only. It is guaranteed not to return NULL.
       */
      public List<Listener> getListeners() {
          List<Listener> result = new ArrayList<>();
          for (ManagerListenerWrap wrap : listeners) {
              result.add(wrap.listener);
          }
          return result;
      }
      
      public long getLocalConfigInfoVersion() {
          return localConfigLastModified;
      }
      
      public void setLocalConfigInfoVersion(long localConfigLastModified) {
          this.localConfigLastModified = localConfigLastModified;
      }
      
      public boolean isUseLocalConfigInfo() {
          return isUseLocalConfig;
      }
      
      public void setUseLocalConfigInfo(boolean useLocalConfigInfo) {
          this.isUseLocalConfig = useLocalConfigInfo;
          if (!useLocalConfigInfo) {
              localConfigLastModified = -1;
          }
      }
      
      public int getTaskId() {
          return taskId;
      }
      
      public void setTaskId(int taskId) {
          this.taskId = taskId;
      }
      
      @Override
      public int hashCode() {
          final int prime = 31;
          int result = 1;
          result = prime * result + ((dataId == null) ? 0 : dataId.hashCode());
          result = prime * result + ((group == null) ? 0 : group.hashCode());
          return result;
      }
      
      @Override
      public boolean equals(Object obj) {
          if (null == obj || obj.getClass() != getClass()) {
              return false;
          }
          if (this == obj) {
              return true;
          }
          CacheData other = (CacheData) obj;
          return dataId.equals(other.dataId) && group.equals(other.group);
      }
      
      @Override
      public String toString() {
          return "CacheData [" + dataId + ", " + group + "]";
      }
      
      void checkListenerMd5() {
          for (ManagerListenerWrap wrap : listeners) {
              if (!md5.equals(wrap.lastCallMd5)) {
                  safeNotifyListener(dataId, group, content, type, md5, encryptedDataKey, wrap);
              }
          }
      }
      
      /**
       * check if all listeners md5 is equal with cache data.
       */
      public boolean checkListenersMd5Consistent() {
          for (ManagerListenerWrap wrap : listeners) {
              if (!md5.equals(wrap.lastCallMd5)) {
                  return false;
              }
          }
          return true;
      }
      
      class LongNotifyHandler implements Runnable {
          
          public LongNotifyHandler(String listenerClass, String dataId, String group, String tenant, String md5,
                  long timeoutMills, Thread thread) {
              this.listenerClass = listenerClass;
              this.dataId = dataId;
              this.group = group;
              this.tenant = tenant;
              this.md5 = md5;
              this.timeoutMills = timeoutMills;
              this.thread = thread;
          }
          
          String listenerClass;
          
          long startTime = System.currentTimeMillis();
          
          long timeoutMills;
          
          String dataId;
          
          String group;
          
          String tenant;
          
          String md5;
          
          Thread thread;
          
          @Override
          public void run() {
              String blockTrace = getTrace(thread.getStackTrace(), 5);
              LOGGER.warn("[{}] [notify-block-monitor] dataId={}, group={},tenant={}, md5={}, "
                              + "receiveConfigInfo execute over {} mills，thread trace block : {}", envName, dataId, group, tenant,
                      md5, timeoutMills, blockTrace);
              NotifyCenter.publishEvent(
                      new ChangeNotifyBlockEvent(this.listenerClass, dataId, group, tenant, this.startTime,
                              System.currentTimeMillis(), blockTrace));
          }
          
      }
      
      private static String getTrace(StackTraceElement[] stackTrace, int traceDeep) {
          StringBuilder stringBuilder = new StringBuilder();
          stringBuilder.append("\n");
          int deep = 0;
          for (StackTraceElement element : stackTrace) {
              stringBuilder.append("\tat " + element + "\n");
              deep++;
              if (traceDeep > 0 && deep > traceDeep) {
                  stringBuilder.append("\tat ... \n");
                  break;
              }
          }
          return stringBuilder.toString();
      }
      
      @SuppressWarnings("PMD.MethodTooLongRule")
      private void safeNotifyListener(final String dataId, final String group, final String content, final String type,
              final String md5, final String encryptedDataKey, final ManagerListenerWrap listenerWrap) {
          final Listener listener = listenerWrap.listener;
          if (listenerWrap.inNotifying) {
              LOGGER.warn(
                      "[{}] [notify-currentSkip] dataId={}, group={},tenant={}, md5={}, listener={}, listener is not finish yet,will try next time.",
                      envName, dataId, group, tenant, md5, listener);
              return;
          }
          NotifyTask job = new NotifyTask() {
              
              @Override
              public void run() {
                  long start = System.currentTimeMillis();
                  ClassLoader myClassLoader = Thread.currentThread().getContextClassLoader();
                  ClassLoader appClassLoader = listener.getClass().getClassLoader();
                  ScheduledFuture<?> timeSchedule = null;
                  
                  try {
                      if (listener instanceof AbstractSharedListener) {
                          AbstractSharedListener adapter = (AbstractSharedListener) listener;
                          adapter.fillContext(dataId, group);
                          LOGGER.info("[{}] [notify-context] dataId={}, group={},tenant={}, md5={}", envName, dataId,
                                  group, tenant, md5);
                      }
                      // Before executing the callback, set the thread classloader to the classloader of
                      // the specific webapp to avoid exceptions or misuses when calling the spi interface in
                      // the callback method (this problem occurs only in multi-application deployment).
                      Thread.currentThread().setContextClassLoader(appClassLoader);
                      
                      ConfigResponse cr = new ConfigResponse();
                      cr.setDataId(dataId);
                      cr.setGroup(group);
                      cr.setContent(content);
                      cr.setEncryptedDataKey(encryptedDataKey);
                      configFilterChainManager.doFilter(null, cr);
                      String contentTmp = cr.getContent();
                      timeSchedule = getNotifyBlockMonitor().schedule(
                              new LongNotifyHandler(listener.getClass().getSimpleName(), dataId, group, tenant, md5,
                                      notifyWarnTimeout, Thread.currentThread()), notifyWarnTimeout,
                              TimeUnit.MILLISECONDS);
                      listenerWrap.inNotifying = true;
                      listener.receiveConfigInfo(contentTmp);
                      // compare lastContent and content
                      if (listener instanceof AbstractConfigChangeListener) {
                          Map<String, ConfigChangeItem> data = ConfigChangeHandler.getInstance()
                                  .parseChangeData(listenerWrap.lastContent, contentTmp, type);
                          ConfigChangeEvent event = new ConfigChangeEvent(data);
                          ((AbstractConfigChangeListener) listener).receiveConfigChange(event);
                          listenerWrap.lastContent = contentTmp;
                      }
                      
                      listenerWrap.lastCallMd5 = md5;
                      LOGGER.info(
                              "[{}] [notify-ok] dataId={}, group={},tenant={}, md5={}, listener={} ,job run cost={} millis.",
                              envName, dataId, group, tenant, md5, listener, (System.currentTimeMillis() - start));
                  } catch (NacosException ex) {
                      LOGGER.error(
                              "[{}] [notify-error] dataId={}, group={},tenant={},md5={}, listener={} errCode={} errMsg={},stackTrace :{}",
                              envName, dataId, group, tenant, md5, listener, ex.getErrCode(), ex.getErrMsg(),
                              getTrace(ex.getStackTrace(), 3));
                  } catch (Throwable t) {
                      LOGGER.error("[{}] [notify-error] dataId={}, group={},tenant={}, md5={}, listener={} tx={}",
                              envName, dataId, group, tenant, md5, listener, getTrace(t.getStackTrace(), 3));
                  } finally {
                      listenerWrap.inNotifying = false;
                      Thread.currentThread().setContextClassLoader(myClassLoader);
                      if (timeSchedule != null) {
                          timeSchedule.cancel(true);
                      }
                  }
              }
          };
          
          try {
              if (null != listener.getExecutor()) {
                  LOGGER.info(
                          "[{}] [notify-listener] task submitted to user executor, dataId={}, group={},tenant={}, md5={}, listener={} ",
                          envName, dataId, group, tenant, md5, listener);
                  job.async = true;
                  listener.getExecutor().execute(job);
              } else {
                  LOGGER.info(
                          "[{}] [notify-listener] task execute in nacos thread, dataId={}, group={},tenant={}, md5={}, listener={} ",
                          envName, dataId, group, tenant, md5, listener);
                  job.run();
              }
          } catch (Throwable t) {
              LOGGER.error("[{}] [notify-listener-error] dataId={}, group={},tenant={}, md5={}, listener={} throwable={}",
                      envName, dataId, group, tenant, md5, listener, t.getCause());
          }
      }
      
      @SuppressWarnings("PMD.AbstractClassShouldStartWithAbstractNamingRule")
      abstract class NotifyTask implements Runnable {
          
          boolean async = false;
          
          public boolean isAsync() {
              return async;
          }
          
          public void setAsync(boolean async) {
              this.async = async;
          }
          
      }
      
      public static String getMd5String(String config) {
          return (null == config) ? Constants.NULL : MD5Utils.md5Hex(config, Constants.ENCODE);
      }
      
      private String loadCacheContentFromDiskLocal(String name, String dataId, String group, String tenant) {
          String content = LocalConfigInfoProcessor.getFailover(name, dataId, group, tenant);
          content = (null != content) ? content : LocalConfigInfoProcessor.getSnapshot(name, dataId, group, tenant);
          return content;
      }
      
      /**
       * 1.first add listener.default is false;need to check. 2.receive config change notify,set false;need to check.
       * 3.last listener is remove,set to false;need to check
       *
       * @return
       */
      public boolean isConsistentWithServer() {
          return isConsistentWithServer.get();
      }
      
      public void setConsistentWithServer(boolean consistentWithServer) {
          isConsistentWithServer.set(consistentWithServer);
      }
      
      public boolean isDiscard() {
          return isDiscard;
      }
      
      public void setDiscard(boolean discard) {
          isDiscard = discard;
      }
      
      public CacheData(ConfigFilterChainManager configFilterChainManager, String envName, String dataId, String group) {
          this(configFilterChainManager, envName, dataId, group, TenantUtil.getUserTenantForAcm());
      }
      
      public CacheData(ConfigFilterChainManager configFilterChainManager, String envName, String dataId, String group,
              String tenant) {
          if (null == dataId || null == group) {
              throw new IllegalArgumentException("dataId=" + dataId + ", group=" + group);
          }
          this.configFilterChainManager = configFilterChainManager;
          this.envName = envName;
          this.dataId = dataId;
          this.group = group;
          this.tenant = tenant;
          this.listeners = new CopyOnWriteArrayList<>();
          this.isInitializing = true;
          if (initSnapshot) {
              this.content = loadCacheContentFromDiskLocal(envName, dataId, group, tenant);
              this.encryptedDataKey = loadEncryptedDataKeyFromDiskLocal(envName, dataId, group, tenant);
              this.md5 = getMd5String(this.content);
          }
      }
      
      // ==================
      
      public String getEncryptedDataKey() {
          return encryptedDataKey;
      }
      
      public void setEncryptedDataKey(String encryptedDataKey) {
          this.encryptedDataKey = encryptedDataKey;
      }
      
      private String loadEncryptedDataKeyFromDiskLocal(String envName, String dataId, String group, String tenant) {
          String encryptedDataKey = LocalEncryptedDataKeyProcessor.getEncryptDataKeyFailover(envName, dataId, group,
                  tenant);
          
          if (encryptedDataKey != null) {
              return encryptedDataKey;
          }
          
          return LocalEncryptedDataKeyProcessor.getEncryptDataKeySnapshot(envName, dataId, group, tenant);
      }
      
      private static class ManagerListenerWrap {
          
          boolean inNotifying = false;
          
          final Listener listener;
          
          String lastCallMd5 = Constants.NULL;
          
          /**
           * here is a decryptContent.
           */
          String lastContent = null;
          
          ManagerListenerWrap(Listener listener) {
              this.listener = listener;
          }
          
          ManagerListenerWrap(Listener listener, String md5) {
              this.listener = listener;
              this.lastCallMd5 = md5;
          }
          
          ManagerListenerWrap(Listener listener, String md5, String lastContent) {
              this(listener, md5);
              this.lastContent = lastContent;
          }
          
          @Override
          public boolean equals(Object obj) {
              if (null == obj || obj.getClass() != getClass()) {
                  return false;
              }
              if (obj == this) {
                  return true;
              }
              ManagerListenerWrap other = (ManagerListenerWrap) obj;
              return listener.equals(other.listener);
          }
          
          @Override
          public int hashCode() {
              return super.hashCode();
          }
          
      }
  }
  