feat: preferred connection type pg only

vertx-pg-client/src/main/java/io/vertx/pgclient/TargetServerType.java

@@ -0,0 +1,47 @@
+/*
+ * 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 io.vertx.pgclient;
+
+/**
+ * Defines the target server type when connecting to a PostgreSQL cluster with multiple hosts.
+ * This is similar to the {@code targetServerType} parameter in the PostgreSQL JDBC driver
+ * and {@code target_session_attrs} in libpq.
+ */
+public enum TargetServerType {
+
+  /**
+   * Connect to any server (default).
+   */
+  ANY,
+
+  /**
+   * Connect only to a primary (read-write) server.
+   */
+  PRIMARY,
+
+  /**
+   * Connect only to a secondary (read-only/hot standby) server.
+   */
+  SECONDARY,
+
+  /**
+   * Prefer connecting to a primary server, but fall back to a secondary if no primary is available.
+   */
+  PREFER_PRIMARY,
+
+  /**
+   * Prefer connecting to a secondary server, but fall back to a primary if no secondary is available.
+   */
+  PREFER_SECONDARY
+}

vertx-pg-client/src/main/java/io/vertx/pgclient/impl/PgPoolOptions.java

@@ -16,18 +16,30 @@
  */
 package io.vertx.pgclient.impl;
 
+import io.vertx.pgclient.PgConnectOptions;
+import io.vertx.pgclient.TargetServerType;
 import io.vertx.sqlclient.PoolOptions;
 
+import java.util.List;
+
 public class PgPoolOptions extends PoolOptions {
 
-  public PgPoolOptions(PoolOptions other) {
-    super(other);
-  }
+  private boolean pipelined;
+  private TargetServerType targetServerType = TargetServerType.ANY;
+  private List<PgConnectOptions> servers;
 
   public PgPoolOptions() {
   }
 
-  private boolean pipelined;
+  public PgPoolOptions(PoolOptions other) {
+    super(other);
+    if (other instanceof PgPoolOptions) {
+      PgPoolOptions pgOther = (PgPoolOptions) other;
+      this.pipelined = pgOther.pipelined;
+      this.targetServerType = pgOther.targetServerType;
+      this.servers = pgOther.servers;
+    }
+  }
 
   public boolean isPipelined() {
     return pipelined;
@@ -37,4 +49,22 @@ public PgPoolOptions setPipelined(boolean pipelined) {
     this.pipelined = pipelined;
     return this;
   }
+
+  public TargetServerType getTargetServerType() {
+    return targetServerType;
+  }
+
+  public PgPoolOptions setTargetServerType(TargetServerType targetServerType) {
+    this.targetServerType = targetServerType;
+    return this;
+  }
+
+  public List<PgConnectOptions> getServers() {
+    return servers;
+  }
+
+  public PgPoolOptions setServers(List<PgConnectOptions> servers) {
+    this.servers = servers;
+    return this;
+  }
 }

vertx-pg-client/src/main/java/io/vertx/pgclient/impl/PgSocketConnection.java

@@ -57,6 +57,7 @@ public class PgSocketConnection extends SocketConnectionBase {
   public int processId;
   public int secretKey;
   public PgDatabaseMetadata dbMetaData;
+  public ServerType serverType = ServerType.UNDEFINED;
   private PgConnectOptions connectOptions;
 
   public PgSocketConnection(NetSocketInternal socket,

vertx-pg-client/src/main/java/io/vertx/pgclient/impl/ServerType.java

@@ -0,0 +1,24 @@
+/*
+ * 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 io.vertx.pgclient.impl;
+
+/**
+ * Internal enum representing the detected server type of a PostgreSQL instance.
+ */
+public enum ServerType {
+
+  PRIMARY,
+  SECONDARY,
+  UNDEFINED
+}