✨ request based context

Author: Mortaro

server/context.js

@@ -1,14 +1,54 @@
-const context = {}
+import { AsyncLocalStorage } from 'async_hooks'
+
+const internalContext = {}
 
 const contextProxyHandler = {
   set(target, name, value, receiver) {
-    context[name] = value
-    return Reflect.set(target, name, value, receiver)
+    const currentContext = asyncLocalStorage.getStore()
+    if (currentContext) {
+      currentContext[name] = value
+      return true
+    } else {
+      return Reflect.set(target, name, value, receiver)
+    }
   },
+  get(target, name, receiver) {
+    const currentContext = asyncLocalStorage.getStore()
+    if (currentContext) {
+      return currentContext[name]
+    } else {
+      return Reflect.get(target, name, receiver)
+    }
+  }
 }
 
+const context = new Proxy(internalContext, contextProxyHandler)
+
+const asyncLocalStorage = new AsyncLocalStorage()
+
 export function generateContext(temporary) {
-  return new Proxy({ ...context, ...temporary }, contextProxyHandler)
+  if(temporary) {
+    Object.assign(context, temporary)
+  }
+  return context
+}
+
+export function generateCurrentContext(temporary, callback) {
+  const currentContext = {...internalContext, ...temporary}
+  asyncLocalStorage.run(currentContext, () => {
+    callback(currentContext);
+  });
+}
+
+export function getCurrentContext(temporary) {
+  const currentContext = asyncLocalStorage.getStore()
+  if (!currentContext) {
+    return generateContext()
+  }
+  if(temporary) {
+    Object.assign(currentContext, temporary)
+  }
+  return currentContext
 }
 
-export default context
+export default context

server/exposeServerFunctions.js

@@ -3,18 +3,16 @@ import fs from 'fs'
 import bodyParser from 'body-parser'
 import path from 'path'
 import deserialize from '../shared/deserialize'
-import { generateContext } from './context'
+import { getCurrentContext } from './context'
 import printError from './printError'
 import registry from './registry'
-import reqres from './reqres'
 
 export default function exposeServerFunctions(server) {
   for (const method of ['get', 'post', 'put', 'patch', 'delete', 'all']) {
     const original = server[method].bind(server)
     server[method] = function (...args) {
       if (typeof args[1] === 'function' && args[1].name === '_invoke') {
         return original(args[0], bodyParser.text({ limit: server.maximumPayloadSize }), async (request, response) => {
-          reqres.set(request, response)
           const params = {}
           for (const key of Object.keys(request.params)) {
             params[key] = extractParamValue(request.params[key])
@@ -27,14 +25,12 @@ export default function exposeServerFunctions(server) {
             Object.assign(params, deserialize(payload))
           }
           try {
-            const subcontext = generateContext({ request, response, ...params })
+            const currentContext = getCurrentContext(params)
             const exposedFunction = module.hot ? registry[args[1].hash] : args[1]
-            const result = await exposedFunction(subcontext)
-            reqres.clear()
+            const result = await exposedFunction(currentContext)
             response.json(result)
           } catch (error) {
             printError(error)
-            reqres.clear()
             response.status(500).json({})
           }
         })

server/project.js

@@ -1,7 +1,7 @@
 import { ICONS } from 'nullstack/project'
 import environment from './environment'
-import reqres from './reqres'
 import worker from './worker'
+import { getCurrentContext } from './context'
 
 const project = {}
 
@@ -21,8 +21,9 @@ project.disallow = []
 project.icons = ICONS
 
 function getHost() {
-  if (reqres.request?.headers?.host) {
-    return reqres.request.headers.host
+  const currentContext = getCurrentContext()
+  if (currentContext.request?.headers?.host) {
+    return currentContext.request.headers.host
   }
   if (project.domain === 'localhost') {
     return `localhost:${process.env.NULLSTACK_SERVER_PORT}`

server/registry.js

@@ -1,7 +1,6 @@
 const registry = {}
 export default registry
-import reqres from "./reqres"
-import { generateContext } from "./context"
+import { getCurrentContext } from "./context"
 import Nullstack from '.'
 import { load } from "./lazy"
 
@@ -34,10 +33,9 @@ function bindStaticProps(klass) {
             return klass[propName].call(klass, ...args)
           }
           const params = args[0] || {}
-          const { request, response } = reqres
-          const subcontext = generateContext({ request, response, ...params })
+          const currentContext = getCurrentContext(params)
           await load(klass.hash)
-          return klass[propName].call(klass, subcontext)
+          return klass[propName].call(klass, currentContext)
         }
         if (module.hot) {
           _invoke.hash = klass[prop].hash

server/reqres.js

@@ -3,7 +3,7 @@ import express from 'express'
 import path from 'path'
 import deserialize from '../shared/deserialize'
 import prefix from '../shared/prefix'
-import context, { generateContext } from './context'
+import context, { getCurrentContext, generateCurrentContext } from './context'
 import emulatePrerender from './emulatePrerender'
 import environment from './environment'
 import exposeServerFunctions from './exposeServerFunctions'
@@ -13,7 +13,6 @@ import generateManifest from './manifest'
 import { prerender } from './prerender'
 import printError from './printError'
 import registry from './registry'
-import reqres from './reqres'
 import generateRobots from './robots'
 import template from './template'
 import { generateServiceWorker } from './worker'
@@ -31,7 +30,9 @@ server.use(async (request, response, next) => {
     typeof context.start === 'function' && (await context.start())
     contextStarted = true
   }
-  next()
+  generateCurrentContext({request, response}, () => {
+    next()
+  })
 })
 
 emulatePrerender(server)
@@ -120,7 +121,6 @@ server.start = function () {
 
   server.all(`/${prefix}/:hash/:methodName.json`, async (request, response) => {
     const payload = request.method === 'GET' ? request.query.payload : request.body
-    reqres.set(request, response)
     const args = deserialize(payload)
     const { hash, methodName } = request.params
     const [invokerHash, boundHash] = hash.split('-')
@@ -137,25 +137,22 @@ server.start = function () {
     const method = registry[key]
     if (method !== undefined) {
       try {
-        const subcontext = generateContext({ request, response, ...args })
-        const result = await method.call(boundKlass, subcontext)
-        reqres.clear()
+        const currentContext = getCurrentContext(args)
+        console.log({currentContext})
+        const result = await method.call(boundKlass, currentContext)
         response.json({ result })
       } catch (error) {
         printError(error)
-        reqres.clear()
         response.status(500).json({})
       }
     } else {
-      reqres.clear()
       response.status(404).json({})
     }
   })
 
   if (module.hot) {
     server.all(`/${prefix}/:version/:hash/:methodName.json`, async (request, response) => {
       const payload = request.method === 'GET' ? request.query.payload : request.body
-      reqres.set(request, response)
       const args = deserialize(payload)
       const { version, hash, methodName } = request.params
       const [invokerHash, boundHash] = hash.split('-')
@@ -178,17 +175,15 @@ server.start = function () {
         const method = registry[key]
         if (method !== undefined) {
           try {
-            const subcontext = generateContext({ request, response, ...args })
-            const result = await method.call(boundKlass, subcontext)
-            reqres.clear()
+            console.log("DEVY")
+            const currentContext = getCurrentContext(args)
+            const result = await method.call(boundKlass, currentContext)
             response.json({ result })
           } catch (error) {
             printError(error)
-            reqres.clear()
             response.status(500).json({})
           }
         } else {
-          reqres.clear()
           response.status(404).json({})
         }
       }
@@ -210,15 +205,11 @@ server.start = function () {
     if (request.originalUrl.split('?')[0].indexOf('.') > -1) {
       return next()
     }
-    reqres.set(request, response)
     const scope = await prerender(request, response)
     if (!response.headersSent) {
       const status = scope.context.page.status
       const html = template(scope)
-      reqres.clear()
       response.status(status).send(html)
-    } else {
-      reqres.clear()
     }
   })
 

server/server.js

@@ -73,6 +73,11 @@ context.startIncrementalValue = 0
 
 setExternalRoute(context.server)
 
+context.server.use((request, response, next) => {
+  context.url = request.originalUrl
+  next()
+})
+
 context.start = async function () {
   await ContextProject.start(context)
   await ContextSecrets.start(context)

tests/server.js

@@ -21,7 +21,10 @@ class ServerFunctions extends Nullstack {
     this.count = await this.getCountAsOne()
   }
 
-  static async getCount({ to }) {
+  static async getCount(context) {
+    const { to, url } = context
+    console.log({url})
+    setInterval(() => console.log("SERVERF:", context.url), 1000)
     return to
   }