Batch RPC requests 2 (#1303)

* WIP Batch RPC requests

* Lint warnings

* Match responses by ID

* Review Comments

* Lint

* Update packages/tendermint-rpc/src/rpcclients/httpbatchclient.spec.ts

Co-authored-by: Simon Warta <2603011+webmaster128@users.noreply.github.com>

* Update packages/tendermint-rpc/src/rpcclients/httpbatchclient.ts

Co-authored-by: Simon Warta <2603011+webmaster128@users.noreply.github.com>

* Update packages/tendermint-rpc/src/rpcclients/httpbatchclient.ts

Co-authored-by: Simon Warta <2603011+webmaster128@users.noreply.github.com>

* review updates

* lint

* check falsy values

* CHANGELOG & export

* Update CHANGELOG.md

Co-authored-by: Simon Warta <2603011+webmaster128@users.noreply.github.com>

* Update CHANGELOG.md

Co-authored-by: Simon Warta <2603011+webmaster128@users.noreply.github.com>

* yarn format-text

* Fix linter issues

* Test batchSizeLimit for safe integer and improve error message

* Move changelog to Unreleased section

Co-authored-by: codehans <94654388+codehans@users.noreply.github.com>

CHANGELOG.md

@@ -6,6 +6,11 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Added
+
+- @cosmjs/tendermint-rpc: Add `HttpBatchClient`, which implements `RpcClient`,
+  supporting batch RPC requests ([#1300]).
+
 ## [0.29.2] - 2022-10-13
 
 ### Added
@@ -19,6 +24,8 @@ and this project adheres to
 - @cosmjs/stargate: Add missing `{is,}MsgBeginRedelegateEncodeObject`,
   `{is,MsgCreateValidatorEncodeObject}` and `{is,MsgEditValidatorEncodeObject}`.
 
+[#1300]: https://github.com/cosmos/cosmjs/pull/1300
+
 ### Fixed
 
 - @cosmjs/cosmwasm-stargate: Use type `JsonObject = any` for smart query

packages/tendermint-rpc/src/rpcclients/httpbatchclient.spec.ts

@@ -0,0 +1,91 @@
+/* eslint-disable @typescript-eslint/naming-convention */
+import { createJsonRpcRequest } from "../jsonrpc";
+import { defaultInstance } from "../testutil.spec";
+import { HttpBatchClient } from "./httpbatchclient";
+import { http } from "./httpclient";
+
+function pendingWithoutTendermint(): void {
+  if (!process.env.TENDERMINT_ENABLED) {
+    pending("Set TENDERMINT_ENABLED to enable Tendermint RPC tests");
+  }
+}
+
+function pendingWithoutHttpServer(): void {
+  if (!process.env.HTTPSERVER_ENABLED) {
+    pending("Set HTTPSERVER_ENABLED to enable HTTP tests");
+  }
+}
+
+const tendermintUrl = defaultInstance.url;
+const echoUrl = "http://localhost:5555/echo_headers";
+
+describe("http", () => {
+  it("can send a health request", async () => {
+    pendingWithoutTendermint();
+    const response = await http("POST", `http://${tendermintUrl}`, undefined, createJsonRpcRequest("health"));
+    expect(response).toEqual(jasmine.objectContaining({ jsonrpc: "2.0" }));
+  });
+
+  it("errors for non-open port", async () => {
+    await expectAsync(
+      http("POST", `http://localhost:56745`, undefined, createJsonRpcRequest("health")),
+    ).toBeRejectedWithError(/(ECONNREFUSED|Failed to fetch)/i);
+  });
+
+  it("can send custom headers", async () => {
+    pendingWithoutHttpServer();
+    // Without custom headers
+    const response1 = await http("POST", echoUrl, undefined, createJsonRpcRequest("health"));
+    expect(response1).toEqual({
+      request_headers: jasmine.objectContaining({
+        // Basic headers from http client
+        Accept: jasmine.any(String),
+        "Content-Length": jasmine.any(String),
+        "Content-Type": "application/json",
+        Host: jasmine.any(String),
+        "User-Agent": jasmine.any(String),
+      }),
+    });
+
+    // With custom headers
+    const response2 = await http(
+      "POST",
+      echoUrl,
+      { foo: "bar123", Authorization: "Basic Z3Vlc3Q6bm9QYXNzMTIz" },
+      createJsonRpcRequest("health"),
+    );
+    expect(response2).toEqual({
+      request_headers: jasmine.objectContaining({
+        // Basic headers from http client
+        "Content-Length": jasmine.any(String),
+        "Content-Type": "application/json",
+        Host: jasmine.any(String),
+        "User-Agent": jasmine.any(String),
+        // Custom headers
+        foo: "bar123",
+        Authorization: "Basic Z3Vlc3Q6bm9QYXNzMTIz",
+      }),
+    });
+  });
+});
+
+describe("HttpBatchClient", () => {
+  it("can make a simple call", async () => {
+    pendingWithoutTendermint();
+    const client = new HttpBatchClient(tendermintUrl);
+
+    const healthResponse = await client.execute(createJsonRpcRequest("health"));
+    expect(healthResponse.result).toEqual({});
+
+    const statusResponse = await client.execute(createJsonRpcRequest("status"));
+    expect(statusResponse.result).toBeTruthy();
+    expect(statusResponse.result.node_info).toBeTruthy();
+
+    await client
+      .execute(createJsonRpcRequest("no-such-method"))
+      .then(() => fail("must not resolve"))
+      .catch((error) => expect(error).toBeTruthy());
+
+    client.disconnect();
+  });
+});

packages/tendermint-rpc/src/rpcclients/httpbatchclient.ts

@@ -0,0 +1,93 @@
+import {
+  isJsonRpcErrorResponse,
+  JsonRpcRequest,
+  JsonRpcSuccessResponse,
+  parseJsonRpcResponse,
+} from "@cosmjs/json-rpc";
+
+import { http, HttpEndpoint } from "./httpclient";
+import { hasProtocol, RpcClient } from "./rpcclient";
+
+export interface HttpBatchClientOptions {
+  dispatchInterval: number;
+  batchSizeLimit: number;
+}
+
+export const defaultHttpBatchClientOptions: HttpBatchClientOptions = {
+  dispatchInterval: 20,
+  batchSizeLimit: 20,
+};
+
+export class HttpBatchClient implements RpcClient {
+  protected readonly url: string;
+  protected readonly headers: Record<string, string> | undefined;
+  protected readonly options: HttpBatchClientOptions;
+  private timer?: NodeJS.Timer;
+
+  private readonly queue: Array<{
+    request: JsonRpcRequest;
+    resolve: (a: JsonRpcSuccessResponse) => void;
+    reject: (a: Error) => void;
+  }> = [];
+
+  public constructor(
+    endpoint: string | HttpEndpoint,
+    options: HttpBatchClientOptions = defaultHttpBatchClientOptions,
+  ) {
+    this.options = options;
+    if (typeof endpoint === "string") {
+      // accept host.name:port and assume http protocol
+      this.url = hasProtocol(endpoint) ? endpoint : "http://" + endpoint;
+    } else {
+      this.url = endpoint.url;
+      this.headers = endpoint.headers;
+    }
+    this.timer = setInterval(() => this.tick(), options.dispatchInterval);
+    this.validate();
+  }
+
+  public disconnect(): void {
+    this.timer && clearInterval(this.timer);
+    this.timer = undefined;
+  }
+
+  public async execute(request: JsonRpcRequest): Promise<JsonRpcSuccessResponse> {
+    return new Promise((resolve, reject) => {
+      this.queue.push({ request, resolve, reject });
+    });
+  }
+
+  private validate(): void {
+    if (
+      !this.options.batchSizeLimit ||
+      !Number.isSafeInteger(this.options.batchSizeLimit) ||
+      this.options.batchSizeLimit < 1
+    ) {
+      throw new Error("batchSizeLimit must be a safe integer >= 1");
+    }
+  }
+
+  private async tick(): Promise<void> {
+    // Avoid race conditions
+    const queue = this.queue.splice(0, this.options.batchSizeLimit);
+
+    if (!queue.length) return;
+
+    const request = queue.map((s) => s.request);
+    const raw = await http("POST", this.url, this.headers, request);
+    // Requests with a single entry return as an object
+    const arr = Array.isArray(raw) ? raw : [raw];
+
+    arr.forEach((el) => {
+      const req = queue.find((s) => s.request.id === el.id);
+      if (!req) return;
+      const { reject, resolve } = req;
+      const response = parseJsonRpcResponse(el);
+      if (isJsonRpcErrorResponse(response)) {
+        reject(new Error(JSON.stringify(response.error)));
+      } else {
+        resolve(response);
+      }
+    });
+  }
+}

packages/tendermint-rpc/src/rpcclients/index.ts

@@ -1,5 +1,6 @@
 // This folder contains Tendermint-specific RPC clients
 
+export { defaultHttpBatchClientOptions, HttpBatchClient } from "./httpbatchclient";
 export { HttpClient, HttpEndpoint } from "./httpclient";
 export { instanceOfRpcStreamingClient, RpcClient, RpcStreamingClient, SubscriptionEvent } from "./rpcclient";
 export { WebsocketClient } from "./websocketclient";