Node message store

A Node application that writes User messages to a binary file and reads them back as a stream. Each message is prefixed with its encoded length, so one file can hold many messages.

The full source is in packages/protobuf-example.

Schema

Create proto/example.proto:

syntax = "proto3";
package example;

message User {
  string first_name = 1;
  string last_name = 2;
  bool active = 3;
  repeated string locations = 4;
}

Generate TypeScript with the same setup from Getting started. For import path and target settings, see Plugin options.

Add a user

sizeDelimitedEncode() returns bytes you can append to a file.

import { appendFileSync } from "node:fs";
import { create } from "@bufbuild/protobuf";
import { sizeDelimitedEncode } from "@bufbuild/protobuf/wire";
import { UserSchema } from "./gen/example_pb";

const user = create(UserSchema, {
  firstName: "Homer",
  lastName: "Simpson",
  active: true,
  locations: ["Springfield"],
});

appendFileSync("users.binpb", sizeDelimitedEncode(UserSchema, user));

List users

sizeDelimitedDecodeStream() parses one message at a time from a Node stream.

import { createReadStream } from "node:fs";
import { sizeDelimitedDecodeStream } from "@bufbuild/protobuf/wire";
import { UserSchema } from "./gen/example_pb";

const stream = createReadStream("users.binpb");

for await (const user of sizeDelimitedDecodeStream(UserSchema, stream)) {
  console.log(`${user.firstName} ${user.lastName}`);
}

For single-message binary serialization, use toBinary() and fromBinary() instead. See Serialization for both formats.