destroy prepared statements on connection close

Author: jraymakers

api/src/DuckDBConnection.ts

@@ -5,15 +5,18 @@ import { DuckDBInstance } from './DuckDBInstance';
 import { DuckDBMaterializedResult } from './DuckDBMaterializedResult';
 import { DuckDBPendingResult } from './DuckDBPendingResult';
 import { DuckDBPreparedStatement } from './DuckDBPreparedStatement';
+import { DuckDBPreparedStatementWeakRefCollection } from './DuckDBPreparedStatementWeakRefCollection';
 import { DuckDBResult } from './DuckDBResult';
 import { DuckDBResultReader } from './DuckDBResultReader';
 import { DuckDBType } from './DuckDBType';
 import { DuckDBValue } from './values';
 
 export class DuckDBConnection {
   private readonly connection: duckdb.Connection;
+  private readonly preparedStatements: DuckDBPreparedStatementWeakRefCollection;
   constructor(connection: duckdb.Connection) {
     this.connection = connection;
+    this.preparedStatements = new DuckDBPreparedStatementWeakRefCollection();
   }
   public static async create(
     instance?: DuckDBInstance
@@ -28,6 +31,7 @@ export class DuckDBConnection {
     return this.disconnectSync();
   }
   public disconnectSync() {
+    this.preparedStatements.destroySync();
     return duckdb.disconnect_sync(this.connection);
   }
   public interrupt() {
@@ -141,9 +145,11 @@ export class DuckDBConnection {
     return prepared.startStream();
   }
   public async prepare(sql: string): Promise<DuckDBPreparedStatement> {
-    return new DuckDBPreparedStatement(
+    const prepared = new DuckDBPreparedStatement(
       await duckdb.prepare(this.connection, sql)
     );
+    this.preparedStatements.add(prepared);
+    return prepared;
   }
   public async extractStatements(
     sql: string
@@ -160,7 +166,8 @@ export class DuckDBConnection {
     return new DuckDBExtractedStatements(
       this.connection,
       extracted_statements,
-      statement_count
+      statement_count,
+      this.preparedStatements
     );
   }
   public async createAppender(

api/src/DuckDBExtractedStatements.ts

@@ -1,29 +1,37 @@
 import duckdb from '@duckdb/node-bindings';
 import { DuckDBPreparedStatement } from './DuckDBPreparedStatement';
+import { DuckDBPreparedStatementCollection } from './DuckDBPreparedStatementCollection';
 
 export class DuckDBExtractedStatements {
   private readonly connection: duckdb.Connection;
   private readonly extracted_statements: duckdb.ExtractedStatements;
   private readonly statement_count: number;
+  private readonly preparedStatements?: DuckDBPreparedStatementCollection;
   constructor(
     connection: duckdb.Connection,
     extracted_statements: duckdb.ExtractedStatements,
-    statement_count: number
+    statement_count: number,
+    preparedStatements?: DuckDBPreparedStatementCollection
   ) {
     this.connection = connection;
     this.extracted_statements = extracted_statements;
     this.statement_count = statement_count;
+    this.preparedStatements = preparedStatements;
   }
   public get count(): number {
     return this.statement_count;
   }
   public async prepare(index: number): Promise<DuckDBPreparedStatement> {
-    return new DuckDBPreparedStatement(
+    const prepared = new DuckDBPreparedStatement(
       await duckdb.prepare_extracted_statement(
         this.connection,
         this.extracted_statements,
         index
       )
     );
+    if (this.preparedStatements) {
+      this.preparedStatements.add(prepared);
+    }
+    return prepared;
   }
 }

api/src/DuckDBPreparedStatementCollection.ts

@@ -0,0 +1,5 @@
+import { DuckDBPreparedStatement } from './DuckDBPreparedStatement';
+
+export interface DuckDBPreparedStatementCollection {
+  add(prepared: DuckDBPreparedStatement): void;
+}

api/src/DuckDBPreparedStatementWeakRefCollection.ts

@@ -0,0 +1,20 @@
+import { DuckDBPreparedStatement } from './DuckDBPreparedStatement';
+import { DuckDBPreparedStatementCollection } from './DuckDBPreparedStatementCollection';
+
+export class DuckDBPreparedStatementWeakRefCollection
+  implements DuckDBPreparedStatementCollection
+{
+  preparedStatements: WeakRef<DuckDBPreparedStatement>[] = [];
+  public add(prepared: DuckDBPreparedStatement) {
+    this.preparedStatements.push(new WeakRef(prepared));
+  }
+  public destroySync() {
+    for (const preparedRef of this.preparedStatements) {
+      const prepared = preparedRef.deref();
+      if (prepared) {
+        prepared.destroySync();
+      }
+    }
+    this.preparedStatements = [];
+  }
+}

api/src/duckdb.ts

@@ -15,6 +15,7 @@ export * from './DuckDBLogicalType';
 export * from './DuckDBMaterializedResult';
 export * from './DuckDBPendingResult';
 export * from './DuckDBPreparedStatement';
+export * from './DuckDBPreparedStatementCollection';
 export * from './DuckDBResult';
 export * from './DuckDBType';
 export * from './DuckDBTypeId';