All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.google.firebase.database.connection.PersistentConnectionImpl Maven / Gradle / Ivy

Go to download

This is the official Firebase Admin Java SDK. Build extraordinary native JVM apps in minutes with Firebase. The Firebase platform can power your app’s backend, user authentication, static hosting, and more.

There is a newer version: 9.2.0
Show newest version
/*
 * Copyright 2017 Google Inc.
 *
 * 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.firebase.database.connection;

import static com.google.firebase.database.connection.ConnectionUtils.hardAssert;

import com.google.firebase.database.connection.util.RetryHelper;
import com.google.firebase.database.util.GAuthToken;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class PersistentConnectionImpl implements Connection.Delegate, PersistentConnection {

  private static final String REQUEST_ERROR = "error";
  private static final String REQUEST_QUERIES = "q";
  private static final String REQUEST_TAG = "t";
  private static final String REQUEST_STATUS = "s";
  private static final String REQUEST_PATH = "p";
  private static final String REQUEST_NUMBER = "r";
  private static final String REQUEST_PAYLOAD = "b";
  private static final String REQUEST_COUNTERS = "c";
  private static final String REQUEST_DATA_PAYLOAD = "d";
  private static final String REQUEST_DATA_HASH = "h";
  private static final String REQUEST_COMPOUND_HASH = "ch";
  private static final String REQUEST_COMPOUND_HASH_PATHS = "ps";
  private static final String REQUEST_COMPOUND_HASH_HASHES = "hs";
  private static final String REQUEST_CREDENTIAL = "cred";
  private static final String REQUEST_AUTHVAR = "authvar";
  private static final String REQUEST_ACTION = "a";
  private static final String REQUEST_ACTION_STATS = "s";
  private static final String REQUEST_ACTION_QUERY = "q";
  private static final String REQUEST_ACTION_PUT = "p";
  private static final String REQUEST_ACTION_MERGE = "m";
  private static final String REQUEST_ACTION_QUERY_UNLISTEN = "n";
  private static final String REQUEST_ACTION_ONDISCONNECT_PUT = "o";
  private static final String REQUEST_ACTION_ONDISCONNECT_MERGE = "om";
  private static final String REQUEST_ACTION_ONDISCONNECT_CANCEL = "oc";
  private static final String REQUEST_ACTION_AUTH = "auth";
  private static final String REQUEST_ACTION_GAUTH = "gauth";
  private static final String REQUEST_ACTION_UNAUTH = "unauth";
  private static final String REQUEST_NOAUTH = "noauth";
  private static final String RESPONSE_FOR_REQUEST = "b";
  private static final String SERVER_ASYNC_ACTION = "a";
  private static final String SERVER_ASYNC_PAYLOAD = "b";
  private static final String SERVER_ASYNC_DATA_UPDATE = "d";
  private static final String SERVER_ASYNC_DATA_MERGE = "m";
  private static final String SERVER_ASYNC_DATA_RANGE_MERGE = "rm";
  private static final String SERVER_ASYNC_AUTH_REVOKED = "ac";
  private static final String SERVER_ASYNC_LISTEN_CANCELLED = "c";
  private static final String SERVER_ASYNC_SECURITY_DEBUG = "sd";
  private static final String SERVER_DATA_UPDATE_PATH = "p";
  private static final String SERVER_DATA_UPDATE_BODY = "d";
  private static final String SERVER_DATA_START_PATH = "s";
  private static final String SERVER_DATA_END_PATH = "e";
  private static final String SERVER_DATA_RANGE_MERGE = "m";
  private static final String SERVER_DATA_TAG = "t";
  private static final String SERVER_DATA_WARNINGS = "w";
  private static final String SERVER_RESPONSE_DATA = "d";
  /** Delay after which a established connection is considered successful. */
  private static final long SUCCESSFUL_CONNECTION_ESTABLISHED_DELAY = 30 * 1000;

  private static final long IDLE_TIMEOUT = 60 * 1000;
  /** If auth fails repeatedly, we'll assume something is wrong and log a warning / back off. */
  private static final long INVALID_AUTH_TOKEN_THRESHOLD = 3;

  private static final String SERVER_KILL_INTERRUPT_REASON = "server_kill";
  private static final String IDLE_INTERRUPT_REASON = "connection_idle";
  private static final String TOKEN_REFRESH_INTERRUPT_REASON = "token_refresh";

  private static final Logger logger = LoggerFactory.getLogger(PersistentConnection.class);

  private static long connectionIds = 0;

  private final Delegate delegate;
  private final HostInfo hostInfo;
  private final ConnectionContext context;
  private final ConnectionFactory connFactory;
  private final ConnectionAuthTokenProvider authTokenProvider;
  private final ScheduledExecutorService executorService;
  private final RetryHelper retryHelper;
  private final String label;

  private String cachedHost;
  private HashSet interruptReasons = new HashSet<>();
  private boolean firstConnection = true;
  private long lastConnectionEstablishedTime;
  private Connection realtime;
  private ConnectionState connectionState = ConnectionState.Disconnected;
  private long writeCounter = 0;
  private long requestCounter = 0;
  private Map requestCBHash;
  private List onDisconnectRequestQueue;
  private Map outstandingPuts;
  private Map listens;
  private String authToken;
  private boolean forceAuthTokenRefresh;
  private String lastSessionId;
  /** Counter to check whether the callback is for the last getToken call. */
  private long currentGetTokenAttempt = 0;

  private int invalidAuthTokenCount = 0;
  private ScheduledFuture inactivityTimer = null;
  private long lastWriteTimestamp;
  private boolean hasOnDisconnects;

  public PersistentConnectionImpl(ConnectionContext context, HostInfo info, Delegate delegate) {
    this(context, info, delegate, new DefaultConnectionFactory());
  }

  PersistentConnectionImpl(
      ConnectionContext context, HostInfo info, Delegate delegate, ConnectionFactory connFactory) {

    this.context = context;
    this.hostInfo = info;
    this.delegate = delegate;
    this.connFactory = connFactory;
    this.executorService = context.getExecutorService();
    this.authTokenProvider = context.getAuthTokenProvider();
    this.listens = new HashMap<>();
    this.requestCBHash = new HashMap<>();
    this.outstandingPuts = new HashMap<>();
    this.onDisconnectRequestQueue = new ArrayList<>();
    this.retryHelper =
        new RetryHelper.Builder(this.executorService, RetryHelper.class)
            .withMinDelayAfterFailure(1000)
            .withRetryExponent(1.3)
            .withMaxDelay(30 * 1000)
            .withJitterFactor(0.7)
            .build();

    long connId = connectionIds++;
    this.label = "[pc_" + connId + "]";
    this.lastSessionId = null;
    doIdleCheck();
  }

  // Connection.Delegate methods
  @Override
  public void onReady(long timestamp, String sessionId) {
    logger.debug("{} onReady", label);
    lastConnectionEstablishedTime = System.currentTimeMillis();
    handleTimestamp(timestamp);

    if (this.firstConnection) {
      sendConnectStats();
    }

    restoreAuth();
    this.firstConnection = false;
    this.lastSessionId = sessionId;
    delegate.onConnect();
  }

  @Override
  public void onCacheHost(String host) {
    this.cachedHost = host;
  }

  @Override
  public void listen(
      List path,
      Map queryParams,
      ListenHashProvider currentHashFn,
      Long tag,
      RequestResultCallback listener) {
    ListenQuerySpec query = new ListenQuerySpec(path, queryParams);
    logger.debug("{} Listening on {}", label, query);
    // TODO: Fix this somehow?
    //hardAssert(query.isDefault() || !query.loadsAllData(), "listen() called for non-default but "
    //          + "complete query");
    hardAssert(!listens.containsKey(query), "listen() called twice for same QuerySpec.");
    logger.debug("{} Adding listen query: {}", label, query);
    OutstandingListen outstandingListen =
        new OutstandingListen(listener, query, tag, currentHashFn);
    listens.put(query, outstandingListen);
    if (connected()) {
      sendListen(outstandingListen);
    }
    doIdleCheck();
  }

  @Override
  public void initialize() {
    this.tryScheduleReconnect();
  }

  @Override
  public void shutdown() {
    this.interrupt("shutdown");
  }

  @Override
  public void put(List path, Object data, RequestResultCallback onComplete) {
    putInternal(REQUEST_ACTION_PUT, path, data, /*hash=*/ null, onComplete);
  }

  @Override
  public void compareAndPut(
      List path, Object data, String hash, RequestResultCallback onComplete) {
    putInternal(REQUEST_ACTION_PUT, path, data, hash, onComplete);
  }

  @Override
  public void merge(List path, Map data, RequestResultCallback onComplete) {
    putInternal(REQUEST_ACTION_MERGE, path, data, /*hash=*/ null, onComplete);
  }

  @Override
  public void purgeOutstandingWrites() {
    for (OutstandingPut put : this.outstandingPuts.values()) {
      if (put.onComplete != null) {
        put.onComplete.onRequestResult("write_canceled", null);
      }
    }
    for (OutstandingDisconnect onDisconnect : this.onDisconnectRequestQueue) {
      if (onDisconnect.onComplete != null) {
        onDisconnect.onComplete.onRequestResult("write_canceled", null);
      }
    }
    this.outstandingPuts.clear();
    this.onDisconnectRequestQueue.clear();
    // Only if we are not connected can we reliably determine that we don't have onDisconnects
    // (outstanding) anymore. Otherwise we leave the flag untouched.
    if (!connected()) {
      this.hasOnDisconnects = false;
    }
    doIdleCheck();
  }

  @Override
  public void onDataMessage(Map message) {
    if (message.containsKey(REQUEST_NUMBER)) {
      // this is a response to a request we sent
      // TODO: this is a hack. Make the json parser give us a Long
      long rn = (Integer) message.get(REQUEST_NUMBER);
      ConnectionRequestCallback responseListener = requestCBHash.remove(rn);
      if (responseListener != null) {
        // jackson gives up Map for json objects
        @SuppressWarnings("unchecked")
        Map response = (Map) message.get(RESPONSE_FOR_REQUEST);
        responseListener.onResponse(response);
      }
    } else if (message.containsKey(REQUEST_ERROR)) {
      // TODO: log the error? probably shouldn't throw here...
    } else if (message.containsKey(SERVER_ASYNC_ACTION)) {
      String action = (String) message.get(SERVER_ASYNC_ACTION);
      // jackson gives up Map for json objects
      @SuppressWarnings("unchecked")
      Map body = (Map) message.get(SERVER_ASYNC_PAYLOAD);
      onDataPush(action, body);
    } else {
      logger.debug("{} Ignoring unknown message: {}", label, message);
    }
  }

  @Override
  public void onDisconnect(Connection.DisconnectReason reason) {
    logger.debug("{} Got on disconnect due to {}", label, reason.name());
    this.connectionState = ConnectionState.Disconnected;
    this.realtime = null;
    this.hasOnDisconnects = false;
    requestCBHash.clear();
    if (inactivityTimer != null) {
      logger.debug("{} Cancelling idle time checker", label);
      inactivityTimer.cancel(false);
      inactivityTimer = null;
    }
    cancelSentTransactions();
    if (shouldReconnect()) {
      long timeSinceLastConnectSucceeded =
          System.currentTimeMillis() - lastConnectionEstablishedTime;
      boolean lastConnectionWasSuccessful;
      if (lastConnectionEstablishedTime > 0) {
        lastConnectionWasSuccessful =
            timeSinceLastConnectSucceeded > SUCCESSFUL_CONNECTION_ESTABLISHED_DELAY;
      } else {
        lastConnectionWasSuccessful = false;
      }
      if (reason == Connection.DisconnectReason.SERVER_RESET || lastConnectionWasSuccessful) {
        retryHelper.signalSuccess();
      }
      tryScheduleReconnect();
    }
    lastConnectionEstablishedTime = 0;
    delegate.onDisconnect();
  }

  @Override
  public void onKill(String reason) {
    logger.debug(
        "{} Firebase Database connection was forcefully killed by the server. Will not attempt "
            + "reconnect. Reason: {}", label, reason);
    interrupt(SERVER_KILL_INTERRUPT_REASON);
  }

  @Override
  public void unlisten(List path, Map queryParams) {
    ListenQuerySpec query = new ListenQuerySpec(path, queryParams);
    logger.debug("{} Unlistening on {}", label, query);

    // TODO: fix this by understanding query params?
    //Utilities.hardAssert(query.isDefault() || !query.loadsAllData(),
    //    "unlisten() called for non-default but complete query");
    OutstandingListen listen = removeListen(query);
    if (listen != null && connected()) {
      sendUnlisten(listen);
    }
    doIdleCheck();
  }

  private boolean connected() {
    return connectionState == ConnectionState.Authenticating
        || connectionState == ConnectionState.Connected;
  }

  @Override
  public void onDisconnectPut(List path, Object data, RequestResultCallback onComplete) {
    this.hasOnDisconnects = true;
    if (canSendWrites()) {
      sendOnDisconnect(REQUEST_ACTION_ONDISCONNECT_PUT, path, data, onComplete);
    } else {
      onDisconnectRequestQueue.add(
          new OutstandingDisconnect(REQUEST_ACTION_ONDISCONNECT_PUT, path, data, onComplete));
    }
    doIdleCheck();
  }

  private boolean canSendWrites() {
    return connectionState == ConnectionState.Connected;
  }

  @Override
  public void onDisconnectMerge(
      List path, Map updates, final RequestResultCallback onComplete) {
    this.hasOnDisconnects = true;
    if (canSendWrites()) {
      sendOnDisconnect(REQUEST_ACTION_ONDISCONNECT_MERGE, path, updates, onComplete);
    } else {
      onDisconnectRequestQueue.add(
          new OutstandingDisconnect(REQUEST_ACTION_ONDISCONNECT_MERGE, path, updates, onComplete));
    }
    doIdleCheck();
  }

  @Override
  public void onDisconnectCancel(List path, RequestResultCallback onComplete) {
    // We do not mark hasOnDisconnects true here, because we only are removing disconnects.
    // However, we can also not reliably determine whether we had onDisconnects, so we can't
    // and do not reset the flag.
    if (canSendWrites()) {
      sendOnDisconnect(REQUEST_ACTION_ONDISCONNECT_CANCEL, path, null, onComplete);
    } else {
      onDisconnectRequestQueue.add(
          new OutstandingDisconnect(REQUEST_ACTION_ONDISCONNECT_CANCEL, path, null, onComplete));
    }
    doIdleCheck();
  }

  @Override
  public void interrupt(String reason) {
    logger.debug("{} Connection interrupted for: {}", label, reason);
    interruptReasons.add(reason);

    if (realtime != null) {
      // Will call onDisconnect and set the connection state to Disconnected
      realtime.close();
      realtime = null;
    } else {
      retryHelper.cancel();
      this.connectionState = ConnectionState.Disconnected;
    }
    // Reset timeouts
    retryHelper.signalSuccess();
  }

  @Override
  public void resume(String reason) {
    logger.debug("{} Connection no longer interrupted for: {}", label, reason);
    interruptReasons.remove(reason);

    if (shouldReconnect() && connectionState == ConnectionState.Disconnected) {
      tryScheduleReconnect();
    }
  }

  @Override
  public boolean isInterrupted(String reason) {
    return interruptReasons.contains(reason);
  }

  private boolean shouldReconnect() {
    return interruptReasons.size() == 0;
  }

  @Override
  public void refreshAuthToken() {
    // Old versions of the database client library didn't have synchronous access to the
    // new token and call this instead of the overload that includes the new token.

    // After a refresh token any subsequent operations are expected to have the authentication
    // status at the point of this call. To avoid race conditions with delays after getToken,
    // we close the connection to make sure any writes/listens are queued until the connection
    // is reauthed with the current token after reconnecting. Note that this will trigger
    // onDisconnects which isn't ideal.
    logger.debug("{} Auth token refresh requested", label);

    // By using interrupt instead of closing the connection we make sure there are no race
    // conditions with other fetch token attempts (interrupt/resume is expected to handle those
    // correctly)
    interrupt(TOKEN_REFRESH_INTERRUPT_REASON);
    resume(TOKEN_REFRESH_INTERRUPT_REASON);
  }

  @Override
  public void refreshAuthToken(String token) {
    logger.debug("{} Auth token refreshed.", label);
    this.authToken = token;
    if (connected()) {
      if (token != null) {
        upgradeAuth();
      } else {
        sendUnauth();
      }
    }
  }

  private void tryScheduleReconnect() {
    if (shouldReconnect()) {
      hardAssert(
          this.connectionState == ConnectionState.Disconnected,
          "Not in disconnected state: %s",
          this.connectionState);
      final boolean forceRefresh = this.forceAuthTokenRefresh;
      logger.debug("{} Scheduling connection attempt", label);
      this.forceAuthTokenRefresh = false;
      retryHelper.retry(
          new Runnable() {
            @Override
            public void run() {
              logger.debug("{} Trying to fetch auth token", label);
              hardAssert(
                  connectionState == ConnectionState.Disconnected,
                  "Not in disconnected state: %s",
                  connectionState);
              connectionState = ConnectionState.GettingToken;
              currentGetTokenAttempt++;
              final long thisGetTokenAttempt = currentGetTokenAttempt;
              authTokenProvider.getToken(
                  forceRefresh,
                  new ConnectionAuthTokenProvider.GetTokenCallback() {
                    @Override
                    public void onSuccess(String token) {
                      if (thisGetTokenAttempt == currentGetTokenAttempt) {
                        // Someone could have interrupted us while fetching the token,
                        // marking the connection as Disconnected
                        if (connectionState == ConnectionState.GettingToken) {
                          logger.debug("{} Successfully fetched token, opening connection", label);
                          openNetworkConnection(token);
                        } else {
                          hardAssert(
                              connectionState == ConnectionState.Disconnected,
                              "Expected connection state disconnected, but was %s",
                              connectionState);
                          logger.debug(
                              "{} Not opening connection after token refresh, because connection "
                                  + "was set to disconnected", label);
                        }
                      } else {
                        logger.debug(
                            "{} Ignoring getToken result, because this was not the "
                                + "latest attempt.", label);
                      }
                    }

                    @Override
                    public void onError(String error) {
                      if (thisGetTokenAttempt == currentGetTokenAttempt) {
                        connectionState = ConnectionState.Disconnected;
                        logger.debug("{} Error fetching token: {}", label, error);
                        tryScheduleReconnect();
                      } else {
                        logger.debug(
                            "{} Ignoring getToken error, because this was not the "
                                + "latest attempt.", label);
                      }
                    }
                  });
            }
          });
    }
  }

  private void openNetworkConnection(String token) {
    hardAssert(
        connectionState == ConnectionState.GettingToken,
        "Trying to open network connection while in the wrong state: %s",
        connectionState);
    // User might have logged out. Positive auth status is handled after authenticating with
    // the server
    if (token == null) {
      delegate.onAuthStatus(false);
    }
    authToken = token;
    connectionState = ConnectionState.Connecting;
    realtime = connFactory.newConnection(this);
    realtime.open();
  }

  private void sendOnDisconnect(
      String action, List path, Object data, final RequestResultCallback onComplete) {
    Map request = new HashMap<>();
    request.put(REQUEST_PATH, ConnectionUtils.pathToString(path));
    request.put(REQUEST_DATA_PAYLOAD, data);
    //
    //if (logger.logsDebug()) logger.debug("onDisconnect " + action + " " + request);
    sendAction(
        action,
        request,
        new ConnectionRequestCallback() {
          @Override
          public void onResponse(Map response) {
            String status = (String) response.get(REQUEST_STATUS);
            String errorMessage = null;
            String errorCode = null;
            if (!status.equals("ok")) {
              errorCode = status;
              errorMessage = (String) response.get(SERVER_DATA_UPDATE_BODY);
            }
            if (onComplete != null) {
              onComplete.onRequestResult(errorCode, errorMessage);
            }
          }
        });
  }

  private void cancelSentTransactions() {
    List cancelledTransactionWrites = new ArrayList<>();

    Iterator> iter = outstandingPuts.entrySet().iterator();
    while (iter.hasNext()) {
      Map.Entry entry = iter.next();
      OutstandingPut put = entry.getValue();
      if (put.getRequest().containsKey(REQUEST_DATA_HASH) && put.wasSent()) {
        cancelledTransactionWrites.add(put);
        iter.remove();
      }
    }

    for (OutstandingPut put : cancelledTransactionWrites) {
      // onRequestResult() may invoke rerunTransactions() and enqueue new writes. We defer calling
      // it until we've finished enumerating all existing writes.
      put.getOnComplete().onRequestResult("disconnected", null);
    }
  }

  private void sendUnlisten(OutstandingListen listen) {
    Map request = new HashMap<>();
    request.put(REQUEST_PATH, ConnectionUtils.pathToString(listen.query.path));

    Long tag = listen.getTag();
    if (tag != null) {
      request.put(REQUEST_QUERIES, listen.getQuery().queryParams);
      request.put(REQUEST_TAG, tag);
    }

    sendAction(REQUEST_ACTION_QUERY_UNLISTEN, request, null);
  }

  private OutstandingListen removeListen(ListenQuerySpec query) {
    logger.debug("{} removing query {}", label, query);
    if (!listens.containsKey(query)) {
      logger.debug(
          "{} Trying to remove listener for QuerySpec {} but no listener exists.", label, query);
      return null;
    } else {
      OutstandingListen oldListen = listens.get(query);
      listens.remove(query);
      doIdleCheck();
      return oldListen;
    }
  }

  private Collection removeListens(List path) {
    logger.debug("{} Removing all listens at path {}", label, path);
    List removedListens = new ArrayList<>();
    for (Map.Entry entry : listens.entrySet()) {
      ListenQuerySpec query = entry.getKey();
      OutstandingListen listen = entry.getValue();
      if (query.path.equals(path)) {
        removedListens.add(listen);
      }
    }

    for (OutstandingListen toRemove : removedListens) {
      listens.remove(toRemove.getQuery());
    }

    doIdleCheck();

    return removedListens;
  }

  private void onDataPush(String action, Map body) {
    logger.debug("{} handleServerMessage: {} {}", label, action, body);
    if (action.equals(SERVER_ASYNC_DATA_UPDATE) || action.equals(SERVER_ASYNC_DATA_MERGE)) {
      boolean isMerge = action.equals(SERVER_ASYNC_DATA_MERGE);

      String pathString = (String) body.get(SERVER_DATA_UPDATE_PATH);
      Object payloadData = body.get(SERVER_DATA_UPDATE_BODY);
      Long tagNumber = ConnectionUtils.longFromObject(body.get(SERVER_DATA_TAG));
      // ignore empty merges
      if (isMerge && (payloadData instanceof Map) && ((Map) payloadData).size() == 0) {
        logger.debug("{} Ignoring empty merge for path {}", label, pathString);
      } else {
        List path = ConnectionUtils.stringToPath(pathString);
        delegate.onDataUpdate(path, payloadData, isMerge, tagNumber);
      }
    } else if (action.equals(SERVER_ASYNC_DATA_RANGE_MERGE)) {
      String pathString = (String) body.get(SERVER_DATA_UPDATE_PATH);
      List path = ConnectionUtils.stringToPath(pathString);
      Object payloadData = body.get(SERVER_DATA_UPDATE_BODY);
      Long tag = ConnectionUtils.longFromObject(body.get(SERVER_DATA_TAG));
      @SuppressWarnings("unchecked")
      List> ranges = (List>) payloadData;
      List rangeMerges = new ArrayList<>();
      for (Map range : ranges) {
        String startString = (String) range.get(SERVER_DATA_START_PATH);
        String endString = (String) range.get(SERVER_DATA_END_PATH);
        List start = startString != null ? ConnectionUtils.stringToPath(startString) : null;
        List end = endString != null ? ConnectionUtils.stringToPath(endString) : null;
        Object update = range.get(SERVER_DATA_RANGE_MERGE);
        rangeMerges.add(new RangeMerge(start, end, update));
      }
      if (rangeMerges.isEmpty()) {
        logger.debug("{} Ignoring empty range merge for path {}", label, pathString);
      } else {
        this.delegate.onRangeMergeUpdate(path, rangeMerges, tag);
      }
    } else if (action.equals(SERVER_ASYNC_LISTEN_CANCELLED)) {
      String pathString = (String) body.get(SERVER_DATA_UPDATE_PATH);
      List path = ConnectionUtils.stringToPath(pathString);
      onListenRevoked(path);
    } else if (action.equals(SERVER_ASYNC_AUTH_REVOKED)) {
      String status = (String) body.get(REQUEST_STATUS);
      String reason = (String) body.get(SERVER_DATA_UPDATE_BODY);
      onAuthRevoked(status, reason);
    } else if (action.equals(SERVER_ASYNC_SECURITY_DEBUG)) {
      onSecurityDebugPacket(body);
    } else {
      logger.debug("{} Unrecognized action from server: {}", label, action);
    }
  }

  private void onListenRevoked(List path) {
    // Remove the listen and manufacture a "permission denied" error for the failed listen

    Collection listens = removeListens(path);
    // The listen may have already been removed locally. If so, skip it
    if (listens != null) {
      for (OutstandingListen listen : listens) {
        listen.resultCallback.onRequestResult("permission_denied", null);
      }
    }
  }

  private void onAuthRevoked(String errorCode, String errorMessage) {
    // This might be for an earlier token than we just recently sent. But since we need to close
    // the connection anyways, we can set it to null here and we will refresh the token later
    // on reconnect.
    logger.debug("{} Auth token revoked: {} ({})", label, errorCode, errorMessage);
    this.authToken = null;
    this.forceAuthTokenRefresh = true;
    this.delegate.onAuthStatus(false);
    // Close connection and reconnect
    this.realtime.close();
  }

  private void onSecurityDebugPacket(Map message) {
    // TODO: implement on iOS too
    logger.info("{} {}", label, message.get("msg"));
  }

  private void upgradeAuth() {
    sendAuthHelper(/*restoreStateAfterComplete=*/ false);
  }

  private void sendAuthAndRestoreState() {
    sendAuthHelper(/*restoreStateAfterComplete=*/ true);
  }

  private void sendAuthHelper(final boolean restoreStateAfterComplete) {
    hardAssert(connected(), "Must be connected to send auth, but was: %s", this.connectionState);
    hardAssert(this.authToken != null, "Auth token must be set to authenticate!");

    ConnectionRequestCallback onComplete =
        new ConnectionRequestCallback() {
          @Override
          public void onResponse(Map response) {
            connectionState = ConnectionState.Connected;

            String status = (String) response.get(REQUEST_STATUS);
            if (status.equals("ok")) {
              invalidAuthTokenCount = 0;
              delegate.onAuthStatus(true);
              if (restoreStateAfterComplete) {
                restoreState();
              }
            } else {
              authToken = null;
              forceAuthTokenRefresh = true;
              delegate.onAuthStatus(false);
              String reason = (String) response.get(SERVER_RESPONSE_DATA);
              logger.debug("{} Authentication failed: {} ({})", label, status, reason);
              realtime.close();

              if (status.equals("invalid_token") || status.equals("permission_denied")) {
                // We'll wait a couple times before logging the warning / increasing the
                // retry period since oauth tokens will report as "invalid" if they're
                // just expired. Plus there may be transient issues that resolve themselves.
                invalidAuthTokenCount++;
                if (invalidAuthTokenCount >= INVALID_AUTH_TOKEN_THRESHOLD) {
                  // Set a long reconnect delay because recovery is unlikely.
                  retryHelper.setMaxDelay();
                  logger.warn(
                      "{} Provided authentication credentials are invalid. This "
                          + "usually indicates your FirebaseApp instance was not initialized "
                          + "correctly. Make sure your database URL is correct and that your "
                          + "service account is for the correct project and is authorized to "
                          + "access it.", label);
                }
              }
            }
          }
        };

    Map request = new HashMap<>();
    GAuthToken googleAuthToken = GAuthToken.tryParseFromString(this.authToken);
    if (googleAuthToken != null) {
      request.put(REQUEST_CREDENTIAL, googleAuthToken.getToken());
      if (googleAuthToken.getAuth() != null) {
        if (!googleAuthToken.getAuth().isEmpty()) {
          request.put(REQUEST_AUTHVAR, googleAuthToken.getAuth());
        }
      } else {
        request.put(REQUEST_NOAUTH, true);
      }
      sendSensitive(REQUEST_ACTION_GAUTH, /*isSensitive=*/ true, request, onComplete);
    } else {
      request.put(REQUEST_CREDENTIAL, authToken);
      sendSensitive(REQUEST_ACTION_AUTH, /*isSensitive=*/ true, request, onComplete);
    }
  }

  private void sendUnauth() {
    hardAssert(connected(), "Must be connected to send unauth.");
    hardAssert(authToken == null, "Auth token must not be set.");
    sendAction(REQUEST_ACTION_UNAUTH, Collections.emptyMap(), null);
  }

  private void restoreAuth() {
    logger.debug("{} Calling restore state", label);

    hardAssert(
        this.connectionState == ConnectionState.Connecting,
        "Wanted to restore auth, but was in wrong state: %s",
        this.connectionState);

    if (authToken == null) {
      logger.debug("{} Not restoring auth because token is null.", label);
      this.connectionState = ConnectionState.Connected;
      restoreState();
    } else {
      logger.debug("{} Restoring auth.", label);
      this.connectionState = ConnectionState.Authenticating;
      sendAuthAndRestoreState();
    }
  }

  private void restoreState() {
    hardAssert(
        this.connectionState == ConnectionState.Connected,
        "Should be connected if we're restoring state, but we are: %s",
        this.connectionState);

    // Restore listens
    logger.debug("{} Restoring outstanding listens", label);
    for (OutstandingListen listen : listens.values()) {
      logger.debug("{} Restoring listen {}", label, listen.getQuery());
      sendListen(listen);
    }

    logger.debug("{} Restoring writes.", label);
    // Restore puts
    ArrayList outstanding = new ArrayList<>(outstandingPuts.keySet());
    // Make sure puts are restored in order
    Collections.sort(outstanding);
    for (Long put : outstanding) {
      sendPut(put);
    }

    // Restore disconnect operations
    for (OutstandingDisconnect disconnect : onDisconnectRequestQueue) {
      sendOnDisconnect(
          disconnect.getAction(),
          disconnect.getPath(),
          disconnect.getData(),
          disconnect.getOnComplete());
    }
    onDisconnectRequestQueue.clear();
  }

  private void handleTimestamp(long timestamp) {
    logger.debug("{} Handling timestamp", label);
    long timestampDelta = timestamp - System.currentTimeMillis();
    Map updates = new HashMap<>();
    updates.put(Constants.DOT_INFO_SERVERTIME_OFFSET, timestampDelta);
    delegate.onServerInfoUpdate(updates);
  }

  private Map getPutObject(List path, Object data, String hash) {
    Map request = new HashMap<>();
    request.put(REQUEST_PATH, ConnectionUtils.pathToString(path));
    request.put(REQUEST_DATA_PAYLOAD, data);
    if (hash != null) {
      request.put(REQUEST_DATA_HASH, hash);
    }
    return request;
  }

  private void putInternal(
      String action,
      List path,
      Object data,
      String hash,
      RequestResultCallback onComplete) {
    Map request = getPutObject(path, data, hash);

    // local to PersistentConnection
    long writeId = this.writeCounter++;

    outstandingPuts.put(writeId, new OutstandingPut(action, request, onComplete));
    if (canSendWrites()) {
      sendPut(writeId);
    }
    this.lastWriteTimestamp = System.currentTimeMillis();
    doIdleCheck();
  }

  private void sendPut(final long putId) {
    assert canSendWrites()
        : "sendPut called when we can't send writes (we're disconnected or writes are paused).";
    final OutstandingPut put = outstandingPuts.get(putId);
    final RequestResultCallback onComplete = put.getOnComplete();
    final String action = put.getAction();

    put.markSent();
    sendAction(
        action,
        put.getRequest(),
        new ConnectionRequestCallback() {
          @Override
          public void onResponse(Map response) {
            logger.debug("{} {} response: {}", label, action, response);

            OutstandingPut currentPut = outstandingPuts.get(putId);
            if (currentPut == put) {
              outstandingPuts.remove(putId);

              if (onComplete != null) {
                String status = (String) response.get(REQUEST_STATUS);
                if (status.equals("ok")) {
                  onComplete.onRequestResult(null, null);
                } else {
                  String errorMessage = (String) response.get(SERVER_DATA_UPDATE_BODY);
                  onComplete.onRequestResult(status, errorMessage);
                }
              }
            } else {
              logger.debug("{} Ignoring on complete for put {} because it was removed already.",
                  label, putId);
            }
            doIdleCheck();
          }
        });
  }

  private void sendListen(final OutstandingListen listen) {
    Map request = new HashMap<>();
    request.put(REQUEST_PATH, ConnectionUtils.pathToString(listen.getQuery().path));
    Long tag = listen.getTag();
    // Only bother to send query if it's non-default
    if (tag != null) {
      request.put(REQUEST_QUERIES, listen.query.queryParams);
      request.put(REQUEST_TAG, tag);
    }

    ListenHashProvider hashFunction = listen.getHashFunction();
    request.put(REQUEST_DATA_HASH, hashFunction.getSimpleHash());

    if (hashFunction.shouldIncludeCompoundHash()) {
      CompoundHash compoundHash = hashFunction.getCompoundHash();

      List posts = new ArrayList<>();
      for (List path : compoundHash.getPosts()) {
        posts.add(ConnectionUtils.pathToString(path));
      }
      Map hash = new HashMap<>();
      hash.put(REQUEST_COMPOUND_HASH_HASHES, compoundHash.getHashes());
      hash.put(REQUEST_COMPOUND_HASH_PATHS, posts);
      request.put(REQUEST_COMPOUND_HASH, hash);
    }

    sendAction(
        REQUEST_ACTION_QUERY,
        request,
        new ConnectionRequestCallback() {

          @Override
          public void onResponse(Map response) {
            String status = (String) response.get(REQUEST_STATUS);
            // log warnings in any case, even if listener was already removed
            if (status.equals("ok")) {
              @SuppressWarnings("unchecked")
              Map serverBody =
                  (Map) response.get(SERVER_DATA_UPDATE_BODY);
              if (serverBody.containsKey(SERVER_DATA_WARNINGS)) {
                @SuppressWarnings("unchecked")
                List warnings = (List) serverBody.get(SERVER_DATA_WARNINGS);
                warnOnListenerWarnings(warnings, listen.query);
              }
            }

            OutstandingListen currentListen = listens.get(listen.getQuery());
            // only trigger actions if the listen hasn't been removed (and maybe readded)
            if (currentListen == listen) {
              if (!status.equals("ok")) {
                removeListen(listen.getQuery());
                String errorMessage = (String) response.get(SERVER_DATA_UPDATE_BODY);
                listen.resultCallback.onRequestResult(status, errorMessage);
              } else {
                listen.resultCallback.onRequestResult(null, null);
              }
            }
          }
        });
  }

  private void sendStats(final Map stats) {
    if (!stats.isEmpty()) {
      Map request = new HashMap<>();
      request.put(REQUEST_COUNTERS, stats);
      sendAction(
          REQUEST_ACTION_STATS,
          request,
          new ConnectionRequestCallback() {
            @Override
            public void onResponse(Map response) {
              String status = (String) response.get(REQUEST_STATUS);
              if (!status.equals("ok")) {
                String errorMessage = (String) response.get(SERVER_DATA_UPDATE_BODY);
                logger.debug(
                    "{} Failed to send stats: {} (message: {})", label, stats, errorMessage);
              }
            }
          });
    } else {
      logger.debug("{} Not sending stats because stats are empty", label);
    }
  }

  @SuppressWarnings("unchecked")
  private void warnOnListenerWarnings(List warnings, ListenQuerySpec query) {
    if (warnings.contains("no_index")) {
      String indexSpec = "\".indexOn\": \"" + query.queryParams.get("i") + '\"';
      logger.warn(
          "{} Using an unspecified index. Consider adding '{}' at {} to your security and "
              + "Firebase Database rules for better performance",
          label, indexSpec, ConnectionUtils.pathToString(query.path));
    }
  }

  private void sendConnectStats() {
    Map stats = new HashMap<>();
    assert !this.context.isPersistenceEnabled()
        : "Stats for persistence on JVM missing (persistence not yet supported)";
    stats.put("sdk.admin_java." + context.getClientSdkVersion().replace('.', '-'), 1);
    logger.debug("{} Sending first connection stats", label);
    sendStats(stats);
  }

  private void sendAction(
      String action, Map message, ConnectionRequestCallback onResponse) {
    sendSensitive(action, /*isSensitive=*/ false, message, onResponse);
  }

  private void sendSensitive(
      String action,
      boolean isSensitive,
      Map message,
      ConnectionRequestCallback onResponse) {
    long rn = nextRequestNumber();
    Map request = new HashMap<>();
    request.put(REQUEST_NUMBER, rn);
    request.put(REQUEST_ACTION, action);
    request.put(REQUEST_PAYLOAD, message);
    realtime.sendRequest(request, isSensitive);
    requestCBHash.put(rn, onResponse);
  }

  private long nextRequestNumber() {
    return requestCounter++;
  }

  private void doIdleCheck() {
    if (isIdle()) {
      if (this.inactivityTimer != null) {
        this.inactivityTimer.cancel(false);
      }

      this.inactivityTimer =
          this.executorService.schedule(
              new Runnable() {
                @Override
                public void run() {
                  inactivityTimer = null;
                  if (idleHasTimedOut()) {
                    interrupt(IDLE_INTERRUPT_REASON);
                  } else {
                    doIdleCheck();
                  }
                }
              },
              IDLE_TIMEOUT,
              TimeUnit.MILLISECONDS);
    } else if (isInterrupted(IDLE_INTERRUPT_REASON)) {
      hardAssert(!isIdle());
      this.resume(IDLE_INTERRUPT_REASON);
    }
  }

  /**
   * @return Returns true if the connection is currently not being used (for listen, outstanding
   *     operations).
   */
  private boolean isIdle() {
    return this.listens.isEmpty()
        && this.requestCBHash.isEmpty()
        && !this.hasOnDisconnects
        && this.outstandingPuts.isEmpty();
  }

  private boolean idleHasTimedOut() {
    long now = System.currentTimeMillis();
    return isIdle() && now > (this.lastWriteTimestamp + IDLE_TIMEOUT);
  }

  private enum ConnectionState {
    Disconnected,
    GettingToken,
    Connecting,
    Authenticating,
    Connected
  }

  private interface ConnectionRequestCallback {

    void onResponse(Map response);
  }

  private static class ListenQuerySpec {

    private final List path;
    private final Map queryParams;

    public ListenQuerySpec(List path, Map queryParams) {
      this.path = path;
      this.queryParams = queryParams;
    }

    @Override
    public boolean equals(Object o) {
      if (this == o) {
        return true;
      }
      if (!(o instanceof ListenQuerySpec)) {
        return false;
      }

      ListenQuerySpec that = (ListenQuerySpec) o;

      if (!path.equals(that.path)) {
        return false;
      }
      return queryParams.equals(that.queryParams);
    }

    @Override
    public int hashCode() {
      int result = path.hashCode();
      result = 31 * result + queryParams.hashCode();
      return result;
    }

    @Override
    public String toString() {
      return ConnectionUtils.pathToString(this.path) + " (params: " + queryParams + ")";
    }
  }

  private static class OutstandingListen {

    private final RequestResultCallback resultCallback;
    private final ListenQuerySpec query;
    private final ListenHashProvider hashFunction;
    private final Long tag;

    private OutstandingListen(
        RequestResultCallback callback,
        ListenQuerySpec query,
        Long tag,
        ListenHashProvider hashFunction) {
      this.resultCallback = callback;
      this.query = query;
      this.hashFunction = hashFunction;
      this.tag = tag;
    }

    ListenQuerySpec getQuery() {
      return query;
    }

    Long getTag() {
      return this.tag;
    }

    ListenHashProvider getHashFunction() {
      return this.hashFunction;
    }

    @Override
    public String toString() {
      return query.toString() + " (Tag: " + this.tag + ")";
    }
  }

  private static class OutstandingPut {

    private String action;
    private Map request;
    private RequestResultCallback onComplete;
    private boolean sent;

    private OutstandingPut(
        String action, Map request, RequestResultCallback onComplete) {
      this.action = action;
      this.request = request;
      this.onComplete = onComplete;
    }

    String getAction() {
      return action;
    }

    Map getRequest() {
      return request;
    }

    RequestResultCallback getOnComplete() {
      return onComplete;
    }

    void markSent() {
      this.sent = true;
    }

    boolean wasSent() {
      return this.sent;
    }
  }

  private static class OutstandingDisconnect {

    private final String action;
    private final List path;
    private final Object data;
    private final RequestResultCallback onComplete;

    private OutstandingDisconnect(
        String action, List path, Object data, RequestResultCallback onComplete) {
      this.action = action;
      this.path = path;
      this.data = data;
      this.onComplete = onComplete;
    }

    public String getAction() {
      return action;
    }

    public List getPath() {
      return path;
    }

    public Object getData() {
      return data;
    }

    public RequestResultCallback getOnComplete() {
      return onComplete;
    }
  }

  interface ConnectionFactory {
    Connection newConnection(PersistentConnectionImpl delegate);
  }

  private static class DefaultConnectionFactory implements ConnectionFactory {
    @Override
    public Connection newConnection(PersistentConnectionImpl delegate) {
      return new Connection(delegate.context, delegate.hostInfo, delegate.cachedHost,
          delegate, delegate.lastSessionId);
    }
  }


}




© 2015 - 2024 Weber Informatics LLC | Privacy Policy