chore(example): http server example

Adds an example project in ./examples that demonstrates hosting an
instance of Hold This as a HTTP server.

Author: gregdaynes

README.md

@@ -8,6 +8,7 @@ It is designed to be used in a single-threaded synchronous environment.
 [Examples](#examples)
 - [No Config](#no-config-setup)
 - [File Backed](#file-backed-store)
+- [HTTP Server](#http-server)
 - [WebSocket Server](#websocket-server)
 - [Data Serialization](#data-serialization)
 - [TTL / Expiring Records](#ttl-%2F-expiring-records)
@@ -103,6 +104,42 @@ const holder = holder({ location: './holder.sqlite', enableWAL: false })
 _Performed on Macbook Pro M1 with 16 GB Memory_
 
 
+### HTTP Server
+
+Because Hold This is based on SQLite3, it does not support a native network connection.
+We can achieve a networked, multi-connection instance by wrapping Hold This in a HTTP Server.
+
+>[!CAUTION]
+>This is not a production ready example. Security, and failure modes must be considered, but are outside the scope of the example.
+
+```js
+import { createServer } from 'node:http'
+import Hold from 'hold-this'
+
+const server = createServer()
+server.holder = Hold()
+
+server.on('request', (req, res) => {
+	let body = ''
+	req.on('data', (chunk) => { body += chunk })
+
+	req.on('end', () => {
+		const parsedBody = JSON.parse(body)
+
+		const { cmd, topic, key, value, options } = parsedBody
+		const data = server.holder[cmd](topic, key, value, options)
+
+		res.writeHead(200, { 'Content-Type': 'application/json' })
+		res.end(JSON.stringify(data))
+	})
+})
+
+server.listen(3000)
+```
+
+_The complete example including client and benchmarks can be found in [examples/http](examples/http)_
+
+
 ### WebSocket Server
 
 Because Hold This is based on SQLite3, it does not support a native network connection.

examples/http/README.md

@@ -0,0 +1,28 @@
+Hold This Example: HTTP
+=======================
+
+This is an example application that runs Hold This behind an HTTP server.
+
+>[!CAUTION]
+>This is not a production ready example. Security, and failure modes must be considered, but are outside the scope of the example.
+
+>[!NOTE]
+>This example depends on the package `autocannon` to benchmark the server.
+>
+>Requires Node 22.0.0
+>- import.meta.filename
+
+Getting Started
+---------------
+
+1. Install dependency
+
+		npm install
+
+2. Run Example
+
+		npm start
+
+3. Run Benchmark
+
+		npm run test:bench

examples/http/bench.js

@@ -0,0 +1,27 @@
+import { stdout } from 'node:process'
+import autocannon from 'autocannon'
+import { Server } from './index.js'
+
+const server = Server()
+
+server.holder.set('http', 'foo', 'bar')
+
+autocannon({
+  url: 'http://localhost:3000',
+  connections: 10,
+  pipelining: 10,
+  duration: 10,
+  method: 'POST',
+  headers: {
+    'Content-Type': 'application/json'
+  },
+  body: JSON.stringify({
+    cmd: 'get', topic: 'http', key: 'test'
+  })
+
+}, (err, result) => {
+  if (err) throw err
+
+  stdout.write(autocannon.printResult(result))
+  server.close()
+})

examples/http/index.js

@@ -0,0 +1,78 @@
+import { createServer } from 'node:http'
+import Hold from 'hold-this'
+
+/**
+ * Creates a HTTP server decorated with an instance of the data store
+ *
+ * @param {Object} options - server options
+ * @param {number} options.port - port number to listen on
+ * @returns {http.Server}
+ * @example
+ * const server = Server()
+ */
+export function Server ({ port = 3000 } = {}) {
+  const server = createServer()
+  server.holder = Hold()
+
+  server.on('request', (req, res) => {
+    if (req.method !== 'POST') {
+      res.writeHead(405, { 'Content-Type': 'application/json' })
+      res.end('Method Not Allowed\n')
+      return false
+    }
+
+    if (req.headers['content-type'] !== 'application/json') {
+      res.writeHead(415, { 'Content-Type': 'application/json' })
+      res.end('Unsupported Media Type\n')
+      return false
+    }
+
+    let body = ''
+    req.on('data', (chunk) => { body += chunk })
+
+    req.on('end', () => {
+      const parsedBody = JSON.parse(body)
+
+      const { cmd, topic, key, value, options } = parsedBody
+      const data = server.holder[cmd](topic, key, value, options)
+
+      res.writeHead(200, { 'Content-Type': 'application/json' })
+      res.end(JSON.stringify(data))
+    })
+  })
+
+  server.listen(port)
+
+  return server
+}
+
+// When this file is run directly from node (main module)
+// setup a server, and run a test demonstrating using fetch to set and
+// get data from the server
+if (process.argv[1] === import.meta.filename) {
+  Server()
+
+  // Write the record that we'll be fetching
+  await fetch('http://localhost:3000', {
+    headers: {
+      'Content-Type': 'application/json'
+    },
+    method: 'POST',
+    body: JSON.stringify({
+      cmd: 'set', topic: 'http', key: 'test', value: 'test1'
+    })
+  })
+
+  // Fetch the record previously set
+  const response = await fetch('http://localhost:3000', {
+    headers: {
+      'Content-Type': 'application/json'
+    },
+    method: 'POST',
+    body: JSON.stringify({
+      cmd: 'get', topic: 'http', key: 'test'
+    })
+  }).then(response => response.json())
+
+  console.log(response)
+}