Implement PreparedStmt on the Server side (#16764)

integration-test/src/main/java/org/apache/iotdb/itbase/runtime/ClusterTestStatement.java

@@ -78,6 +78,13 @@ private void updateConfig(Statement statement, int timeout) throws SQLException
     statement.setQueryTimeout(timeout);
   }
 
+  /**
+   * Executes a SQL query on all read statements in parallel.
+   *
+   * <p>Note: For PreparedStatement EXECUTE queries, use the write connection directly instead,
+   * because PreparedStatements are session-scoped and this method may route queries to different
+   * nodes where the PreparedStatement doesn't exist.
+   */
   @Override
   public ResultSet executeQuery(String sql) throws SQLException {
     return new ClusterTestResultSet(readStatements, readEndpoints, sql, queryTimeout);

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/session/ClientSession.java

@@ -33,6 +33,9 @@ public class ClientSession extends IClientSession {
 
   private final Map<Long, Set<Long>> statementIdToQueryId = new ConcurrentHashMap<>();
 
+  // Map from statement name to PreparedStatementInfo
+  private final Map<String, PreparedStatementInfo> preparedStatements = new ConcurrentHashMap<>();
+
   public ClientSession(Socket clientSocket) {
     this.clientSocket = clientSocket;
   }
@@ -103,4 +106,24 @@ public static void removeQueryId(
       }
     }
   }
+
+  @Override
+  public void addPreparedStatement(String statementName, PreparedStatementInfo info) {
+    preparedStatements.put(statementName, info);
+  }
+
+  @Override
+  public PreparedStatementInfo removePreparedStatement(String statementName) {
+    return preparedStatements.remove(statementName);
+  }
+
+  @Override
+  public PreparedStatementInfo getPreparedStatement(String statementName) {
+    return preparedStatements.get(statementName);
+  }
+
+  @Override
+  public Set<String> getPreparedStatementNames() {
+    return preparedStatements.keySet();
+  }
 }

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/session/IClientSession.java

@@ -188,6 +188,37 @@ public void setDatabaseName(@Nullable String databaseName) {
     this.databaseName = databaseName;
   }
 
+  /**
+   * Add a prepared statement to this session.
+   *
+   * @param statementName the name of the prepared statement
+   * @param info the prepared statement information
+   */
+  public abstract void addPreparedStatement(String statementName, PreparedStatementInfo info);
+
+  /**
+   * Remove a prepared statement from this session.
+   *
+   * @param statementName the name of the prepared statement
+   * @return the removed prepared statement info, or null if not found
+   */
+  public abstract PreparedStatementInfo removePreparedStatement(String statementName);
+
+  /**
+   * Get a prepared statement from this session.
+   *
+   * @param statementName the name of the prepared statement
+   * @return the prepared statement info, or null if not found
+   */
+  public abstract PreparedStatementInfo getPreparedStatement(String statementName);
+
+  /**
+   * Get all prepared statement names in this session.
+   *
+   * @return set of prepared statement names
+   */
+  public abstract Set<String> getPreparedStatementNames();
+
   public long getLastActiveTime() {
     return lastActiveTime;
   }

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/session/InternalClientSession.java

@@ -88,4 +88,28 @@ public void addQueryId(Long statementId, long queryId) {
   public void removeQueryId(Long statementId, Long queryId) {
     ClientSession.removeQueryId(statementIdToQueryId, statementId, queryId);
   }
+
+  @Override
+  public void addPreparedStatement(String statementName, PreparedStatementInfo info) {
+    throw new UnsupportedOperationException(
+        "InternalClientSession should never call PREPARE statement methods.");
+  }
+
+  @Override
+  public PreparedStatementInfo removePreparedStatement(String statementName) {
+    throw new UnsupportedOperationException(
+        "InternalClientSession should never call PREPARE statement methods.");
+  }
+
+  @Override
+  public PreparedStatementInfo getPreparedStatement(String statementName) {
+    throw new UnsupportedOperationException(
+        "InternalClientSession should never call PREPARE statement methods.");
+  }
+
+  @Override
+  public Set<String> getPreparedStatementNames() {
+    throw new UnsupportedOperationException(
+        "InternalClientSession should never call PREPARE statement methods.");
+  }
 }

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/session/MqttClientSession.java

@@ -76,4 +76,28 @@ public void addQueryId(Long statementId, long queryId) {
   public void removeQueryId(Long statementId, Long queryId) {
     throw new UnsupportedOperationException();
   }
+
+  @Override
+  public void addPreparedStatement(String statementName, PreparedStatementInfo info) {
+    throw new UnsupportedOperationException(
+        "MQTT client session does not support PREPARE statement.");
+  }
+
+  @Override
+  public PreparedStatementInfo removePreparedStatement(String statementName) {
+    throw new UnsupportedOperationException(
+        "MQTT client session does not support PREPARE statement.");
+  }
+
+  @Override
+  public PreparedStatementInfo getPreparedStatement(String statementName) {
+    throw new UnsupportedOperationException(
+        "MQTT client session does not support PREPARE statement.");
+  }
+
+  @Override
+  public Set<String> getPreparedStatementNames() {
+    throw new UnsupportedOperationException(
+        "MQTT client session does not support PREPARE statement.");
+  }
 }

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/session/PreparedStatementInfo.java

@@ -0,0 +1,99 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.iotdb.db.protocol.session;
+
+import org.apache.iotdb.db.queryengine.plan.relational.sql.ast.Statement;
+
+import java.util.Objects;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * Information about a prepared statement stored in a session. The AST is cached here to avoid
+ * reparsing on EXECUTE.
+ */
+public class PreparedStatementInfo {
+
+  private final String statementName;
+  private final Statement sql; // Cached AST (contains Parameter nodes)
+  private final long createTime;
+  private final long memorySizeInBytes; // Memory size allocated for this PreparedStatement
+
+  public PreparedStatementInfo(String statementName, Statement sql, long memorySizeInBytes) {
+    this.statementName = requireNonNull(statementName, "statementName is null");
+    this.sql = requireNonNull(sql, "sql is null");
+    this.createTime = System.currentTimeMillis();
+    this.memorySizeInBytes = memorySizeInBytes;
+  }
+
+  public PreparedStatementInfo(
+      String statementName, Statement sql, long createTime, long memorySizeInBytes) {
+    this.statementName = requireNonNull(statementName, "statementName is null");
+    this.sql = requireNonNull(sql, "sql is null");
+    this.createTime = createTime;
+    this.memorySizeInBytes = memorySizeInBytes;
+  }
+
+  public String getStatementName() {
+    return statementName;
+  }
+
+  public Statement getSql() {
+    return sql;
+  }
+
+  public long getCreateTime() {
+    return createTime;
+  }
+
+  public long getMemorySizeInBytes() {
+    return memorySizeInBytes;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    PreparedStatementInfo that = (PreparedStatementInfo) o;
+    return Objects.equals(statementName, that.statementName) && Objects.equals(sql, that.sql);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(statementName, sql);
+  }
+
+  @Override
+  public String toString() {
+    return "PreparedStatementInfo{"
+        + "statementName='"
+        + statementName
+        + '\''
+        + ", sql="
+        + sql
+        + ", createTime="
+        + createTime
+        + '}';
+  }
+}

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/session/RestClientSession.java

@@ -22,12 +22,17 @@
 import org.apache.iotdb.service.rpc.thrift.TSConnectionType;
 
 import java.util.Collections;
+import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 public class RestClientSession extends IClientSession {
 
   private final String clientID;
 
+  // Map from statement name to PreparedStatementInfo
+  private final Map<String, PreparedStatementInfo> preparedStatements = new ConcurrentHashMap<>();
+
   public RestClientSession(String clientID) {
     this.clientID = clientID;
   }
@@ -76,4 +81,24 @@ public void addQueryId(Long statementId, long queryId) {
   public void removeQueryId(Long statementId, Long queryId) {
     throw new UnsupportedOperationException();
   }
+
+  @Override
+  public void addPreparedStatement(String statementName, PreparedStatementInfo info) {
+    preparedStatements.put(statementName, info);
+  }
+
+  @Override
+  public PreparedStatementInfo removePreparedStatement(String statementName) {
+    return preparedStatements.remove(statementName);
+  }
+
+  @Override
+  public PreparedStatementInfo getPreparedStatement(String statementName) {
+    return preparedStatements.get(statementName);
+  }
+
+  @Override
+  public Set<String> getPreparedStatementNames() {
+    return preparedStatements.keySet();
+  }
 }

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/session/SessionManager.java

@@ -40,6 +40,7 @@
 import org.apache.iotdb.db.protocol.thrift.OperationType;
 import org.apache.iotdb.db.queryengine.common.ConnectionInfo;
 import org.apache.iotdb.db.queryengine.common.SessionInfo;
+import org.apache.iotdb.db.queryengine.plan.execution.config.session.PreparedStatementMemoryManager;
 import org.apache.iotdb.db.storageengine.dataregion.read.control.QueryResourceManager;
 import org.apache.iotdb.db.utils.DataNodeAuthUtils;
 import org.apache.iotdb.metrics.utils.MetricLevel;
@@ -276,6 +277,7 @@
   }
 
   private void releaseSessionResource(IClientSession session, LongConsumer releaseQueryResource) {
+    // Release query resources
     Iterable<Long> statementIds = session.getStatementIds();
     if (statementIds != null) {
       for (Long statementId : statementIds) {
@@ -287,6 +289,17 @@
         }
       }
     }
+
+    // Release PreparedStatement memory resources
+    try {
+      PreparedStatementMemoryManager.getInstance().releaseAllForSession(session);
+    } catch (Exception e) {
+      LOGGER.warn(
+          "Failed to release PreparedStatement resources for session {}: {}",
+          session,
+          e.getMessage(),
+          e);
+    }
   }
 
   public TSStatus closeOperation(
@@ -295,6 +308,7 @@
       long statementId,
       boolean haveStatementId,
       boolean haveSetQueryId,
+      String preparedStatementName,
       LongConsumer releaseByQueryId) {
     if (!checkLogin(session)) {
       return RpcUtils.getStatus(
@@ -307,7 +321,7 @@
         if (haveSetQueryId) {
           this.closeDataset(session, statementId, queryId, releaseByQueryId);
         } else {
-          this.closeStatement(session, statementId, releaseByQueryId);
+          this.closeStatement(session, statementId, preparedStatementName, releaseByQueryId);
         }
         return RpcUtils.getStatus(TSStatusCode.SUCCESS_STATUS);
       } else {
@@ -342,14 +356,35 @@
   }
 
   public void closeStatement(
-      IClientSession session, long statementId, LongConsumer releaseByQueryId) {
+      IClientSession session,
+      long statementId,
+      String preparedStatementName,
+      LongConsumer releaseByQueryId) {
     Set<Long> queryIdSet = session.removeStatementId(statementId);
     if (queryIdSet != null) {
       for (Long queryId : queryIdSet) {
         releaseByQueryId.accept(queryId);
       }
     }
-    session.removeStatementId(statementId);
+
+    // If preparedStatementName is provided, release the prepared statement resources
+    if (preparedStatementName != null && !preparedStatementName.isEmpty()) {
+      try {
+        PreparedStatementInfo removedInfo = session.removePreparedStatement(preparedStatementName);
+        if (removedInfo != null) {
+          // Release the memory allocated for this PreparedStatement
+          PreparedStatementMemoryManager.getInstance().release(removedInfo.getMemorySizeInBytes());
+        }
+      } catch (Exception e) {
+        LOGGER.warn(
+            "Failed to release PreparedStatement '{}' resources when closing statement {} for session {}: {}",
+            preparedStatementName,
+            statementId,
+            session,
+            e.getMessage(),
+            e);
+      }
+    }
   }
 
   public long requestQueryId(IClientSession session, Long statementId) {

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/thrift/handler/BaseServerContextHandler.java

@@ -71,6 +71,7 @@ public ServerContext createContext(TProtocol in, TProtocol out) {
 
   public void deleteContext(ServerContext context, TProtocol in, TProtocol out) {
     getSessionManager().removeCurrSession();
+
     if (context != null && factory != null) {
       ((JudgableServerContext) context).whenDisconnect();
     }

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/thrift/impl/ClientRPCServiceImpl.java

@@ -297,7 +297,7 @@
     relationSqlParser = new SqlParser();
   }
 
   private TSExecuteStatementResp executeStatementInternal(
       TSExecuteStatementReq req, SelectResult setResult) {
     boolean finished = false;
     Long statementId = req.getStatementId();
@@ -1445,6 +1445,7 @@
         req.statementId,
         req.isSetStatementId(),
         req.isSetQueryId(),
+        req.isSetPreparedStatementName() ? req.getPreparedStatementName() : null,
         COORDINATOR::cleanupQueryExecution);
   }