Add option to control user cache

And make it disabled by default (breaking change!).

javacord-api/src/main/java/org/javacord/api/DiscordApiBuilder.java

@@ -439,6 +439,28 @@ public DiscordApiBuilder setAllIntentsWhere(Predicate<Intent> condition) {
         return this;
     }
 
+    /**
+     * Sets whether or not the user cache should be enabled.
+     *
+     * <p>By default, the user cache is disabled.
+     *
+     * @param enabled Whether or not the user cache should be enabled.
+     * @return The current instance in order to chain call methods.
+     */
+    public DiscordApiBuilder setUserCacheEnabled(boolean enabled) {
+        delegate.setUserCacheEnabled(enabled);
+        return this;
+    }
+
+    /**
+     * Gets whether or not the user cache is enabled.
+     *
+     * @return Whether or not the user cache is enabled.
+     */
+    public boolean isUserCachedEnabled() {
+        return delegate.isUserCacheEnabled();
+    }
+
     /**
      * Retrieves the recommended shards count from the Discord API and sets it in this builder.
      * Sharding allows you to split your bot into several independent instances.

javacord-api/src/main/java/org/javacord/api/internal/DiscordApiBuilderDelegate.java

@@ -178,6 +178,22 @@ public interface DiscordApiBuilderDelegate {
      */
     void setAllIntentsWhere(Predicate<Intent> condition);
 
+    /**
+     * Sets whether or not the user cache should be enabled.
+     *
+     * <p>By default, the user cache is disabled.
+     *
+     * @param enabled Whether or not the user cache should be enabled.
+     */
+    void setUserCacheEnabled(boolean enabled);
+
+    /**
+     * Gets whether or not the user cache is enabled.
+     *
+     * @return Whether or not the user cache is enabled.
+     */
+    boolean isUserCacheEnabled();
+
     /**
      * Logs the bot in.
      *

javacord-core/src/main/java/org/javacord/core/DiscordApiBuilderDelegateImpl.java

@@ -129,6 +129,11 @@ public class DiscordApiBuilderDelegateImpl implements DiscordApiBuilderDelegate
     private Set<Intent> intents = Arrays.stream(Intent.values())
             .filter(intent -> !intent.isPrivileged()).collect(Collectors.toCollection(HashSet::new));
 
+    /**
+     * Whether the user cache should be enabled or not.
+     */
+    private boolean userCacheEnabled = false;
+
     /**
      * The globally attachable listeners to register for every created DiscordApi instance.
      */
@@ -194,7 +199,7 @@ public CompletableFuture<DiscordApi> login() {
             new DiscordApiImpl(accountType, token, currentShard.get(), totalShards.get(), intents,
                     waitForServersOnStartup, waitForUsersOnStartup, registerShutdownHook, globalRatelimiter,
                     gatewayIdentifyRatelimiter, proxySelector, proxy, proxyAuthenticator, trustAllCertificates,
-                    future, null, preparedListeners, preparedUnspecifiedListeners);
+                    future, null, preparedListeners, preparedUnspecifiedListeners, userCacheEnabled);
         }
         return future;
     }
@@ -395,6 +400,16 @@ public void setAllIntentsWhere(Predicate<Intent> condition) {
         }
     }
 
+    @Override
+    public void setUserCacheEnabled(boolean enabled) {
+        userCacheEnabled = enabled;
+    }
+
+    @Override
+    public boolean isUserCacheEnabled() {
+        return userCacheEnabled;
+    }
+
     @Override
     public CompletableFuture<Void> setRecommendedTotalShards() {
         CompletableFuture<Void> future = new CompletableFuture<>();

javacord-core/src/main/java/org/javacord/core/DiscordApiImpl.java

@@ -462,7 +462,7 @@ public DiscordApiImpl(
     ) {
         this(accountType, token, currentShard, totalShards, intents, waitForServersOnStartup, waitForUsersOnStartup,
                 true, globalRatelimiter, gatewayIdentifyRatelimiter, proxySelector, proxy, proxyAuthenticator,
-                trustAllCertificates, ready, null, Collections.emptyMap(), Collections.emptyList());
+                trustAllCertificates, ready, null, Collections.emptyMap(), Collections.emptyList(), false);
     }
 
     /**
@@ -509,7 +509,7 @@ private DiscordApiImpl(
             Dns dns) {
         this(accountType, token, currentShard, totalShards, intents, waitForServersOnStartup, waitForUsersOnStartup,
                 true, globalRatelimiter, gatewayIdentifyRatelimiter, proxySelector, proxy, proxyAuthenticator,
-                trustAllCertificates, ready, dns, Collections.emptyMap(), Collections.emptyList());
+                trustAllCertificates, ready, dns, Collections.emptyMap(), Collections.emptyList(), false);
     }
 
     /**
@@ -532,13 +532,14 @@ private DiscordApiImpl(
      *                                      websocket.
      * @param proxyAuthenticator            The authenticator that should be used to authenticate against proxies that
      *                                      require it.
-     * @param trustAllCertificates           Whether to trust all SSL certificates.
+     * @param trustAllCertificates          Whether to trust all SSL certificates.
      * @param ready                         The future which will be completed when the connection to Discord was
      *                                      successful.
      * @param dns                           The DNS instance to use in the OkHttp client. This should only be used in
      *                                      testing.
      * @param listenerSourceMap             The functions to create listeners for pre-registration.
-     * @param unspecifiedListeners           The listeners of unspecified types to pre-register.
+     * @param unspecifiedListeners          The listeners of unspecified types to pre-register.
+     * @param userCacheEnabled              Whether or not the user cache should be enabled.
      */
     @SuppressWarnings("unchecked")
     public DiscordApiImpl(
@@ -561,7 +562,9 @@ public DiscordApiImpl(
             Map<Class<? extends GloballyAttachableListener>,
                     List<Function<DiscordApi,GloballyAttachableListener>>
                     > listenerSourceMap,
-            List<Function<DiscordApi, GloballyAttachableListener>> unspecifiedListeners) {
+            List<Function<DiscordApi, GloballyAttachableListener>> unspecifiedListeners,
+            boolean userCacheEnabled
+    ) {
         this.accountType = accountType;
         this.token = token;
         this.currentShard = currentShard;
@@ -575,7 +578,7 @@ public DiscordApiImpl(
         this.proxyAuthenticator = proxyAuthenticator;
         this.trustAllCertificates = trustAllCertificates;
         this.intents = intents;
-        userCacheEnabled = intents.contains(Intent.GUILD_MEMBERS);
+        this.userCacheEnabled = userCacheEnabled;
         this.reconnectDelayProvider = x ->
                 (int) Math.round(Math.pow(x, 1.5) - (1 / (1 / (0.1 * x) + 1)) * Math.pow(x, 1.5));
 
@@ -940,6 +943,9 @@ public void removeChannelFromCache(long channelId) {
      * @param member The member to add.
      */
     public void addMemberToCacheOrReplaceExisting(Member member) {
+        if (!isUserCacheEnabled()) {
+            return;
+        }
         entityCache.getAndUpdate(cache -> {
             Member oldMember = cache.getMemberCache()
                     .getMemberByIdAndServer(member.getId(), member.getServer().getId())

javacord-core/src/main/java/org/javacord/core/entity/server/ServerImpl.java

@@ -420,10 +420,8 @@ && getMembers().size() < getMemberCount()
                         .orElse(null);
 
                 if (user == null) {
-                    // In theory, every user in "presences" should also be in "members", but Discord is weird
-                    // sometimes. This happens very rarely, but when it happens, we should ignore the presence.
+                    // Ignore rouge presences.
                     // It might be a similar issue than https://github.com/discordapp/discord-api-docs/issues/855
-                    logger.debug("Found rogue presence. Ignoring it. ({})", presenceJson);
                     continue;
                 }