TypeScript: Add confirmed reads config (#3247)

# Description of Changes

Adds a way to configure the DbConnection to use confirmed reads.


# Expected complexity level and risk

1

# Testing

Still figuring out...

Author: kim

crates/bindings-typescript/src/sdk/db_connection_builder.ts

@@ -20,6 +20,7 @@ export class DbConnectionBuilder<
   #emitter: EventEmitter<ConnectionEvent> = new EventEmitter();
   #compression: 'gzip' | 'none' = 'gzip';
   #lightMode: boolean = false;
+  #confirmedReads?: boolean;
   #createWSFn: typeof WebsocketDecompressAdapter.createWebSocketFn;
 
   /**
@@ -107,6 +108,31 @@ export class DbConnectionBuilder<
     return this;
   }
 
+  /**
+   * Sets the connection to use confirmed reads.
+   *
+   * When enabled, the server will send query results only after they are
+   * confirmed to be durable.
+   *
+   * What durable means depends on the server configuration: a single node
+   * server may consider a transaction durable once it is `fsync`'ed to disk,
+   * whereas a cluster may require that some number of replicas have
+   * acknowledge that they have stored the transactions.
+   *
+   * Note that enabling confirmed reads will increase the latency between a
+   * reducer call and the corresponding subscription update arriving at the
+   * client.
+   *
+   * If this method is not called, not preference is sent to the server, and
+   * the server will choose the default.
+   *
+   * @param confirmedReads `true` to enable confirmed reads, `false` to disable.
+   */
+  withConfirmedReads(confirmedReads: boolean): this {
+    this.#confirmedReads = confirmedReads;
+    return this;
+  }
+
   /**
    * Register a callback to be invoked upon authentication with the database.
    *
@@ -228,6 +254,7 @@ export class DbConnectionBuilder<
         emitter: this.#emitter,
         compression: this.#compression,
         lightMode: this.#lightMode,
+        confirmedReads: this.#confirmedReads,
         createWSFn: this.#createWSFn,
         remoteModule: this.remoteModule,
       })

crates/bindings-typescript/src/sdk/db_connection_impl.ts

@@ -100,6 +100,7 @@ type DbConnectionConfig = {
   createWSFn: typeof WebsocketDecompressAdapter.createWebSocketFn;
   compression: 'gzip' | 'none';
   lightMode: boolean;
+  confirmedReads?: boolean;
 };
 
 export class DbConnectionImpl<
@@ -177,6 +178,7 @@ export class DbConnectionImpl<
     createWSFn,
     compression,
     lightMode,
+    confirmedReads,
   }: DbConnectionConfig) {
     stdbLogger('info', 'Connecting to SpacetimeDB WS...');
 
@@ -212,6 +214,7 @@ export class DbConnectionImpl<
       authToken: token,
       compression: compression,
       lightMode: lightMode,
+      confirmedReads: confirmedReads,
     })
       .then(v => {
         this.ws = v;

crates/bindings-typescript/src/sdk/websocket_decompress_adapter.ts

@@ -73,13 +73,15 @@ export class WebsocketDecompressAdapter {
     authToken,
     compression,
     lightMode,
+    confirmedReads,
   }: {
     url: URL;
     wsProtocol: string;
     nameOrAddress: string;
     authToken?: string;
     compression: 'gzip' | 'none';
     lightMode: boolean;
+    confirmedReads?: boolean;
   }): Promise<WebsocketDecompressAdapter> {
     const headers = new Headers();
 
@@ -115,6 +117,9 @@ export class WebsocketDecompressAdapter {
     if (lightMode) {
       databaseUrl.searchParams.set('light', 'true');
     }
+    if (confirmedReads !== undefined) {
+      databaseUrl.searchParams.set('confirmed', confirmedReads.toString());
+    }
 
     const ws = new WS(databaseUrl.toString(), wsProtocol);