feat: add AsyncHttpContext

Author: targos

adonis-typings/async-http-context.ts

@@ -0,0 +1,30 @@
+/**
+ * @adonisjs/http-server
+ *
+ * (c) Harminder Virk <virk@adonisjs.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare module '@ioc:Adonis/Core/AsyncHttpContext' {
+  import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
+
+  /**
+   * Async Http context available during the lifecycle of HTTP requests
+   */
+  export interface AsyncHttpContextContract {
+    /**
+     * Returns the current HTTP context or null if called outside of a request.
+     */
+    getContext(): HttpContextContract | null
+
+    /**
+     * Returns the current HTTP context or throws if called outside of a request.
+     */
+    getContextOrFail(): HttpContextContract
+  }
+
+  const AsyncHttpContext: AsyncHttpContextContract
+  export default AsyncHttpContext
+}

adonis-typings/index.ts

@@ -7,6 +7,7 @@
  * file that was distributed with this source code.
  */
 
+/// <reference path="./async-http-context.ts" />
 /// <reference path="./container.ts" />
 /// <reference path="./context.ts" />
 /// <reference path="./http-server.ts" />

providers/HttpServerProvider.ts

@@ -10,6 +10,8 @@
 import { Exception } from '@poppinss/utils'
 import { ApplicationContract } from '@ioc:Adonis/Core/Application'
 
+import { asyncHttpContext } from '../src/AsyncHttpContext'
+
 export default class HttpServerProvider {
   constructor(protected application: ApplicationContract) {}
 
@@ -80,6 +82,13 @@ export default class HttpServerProvider {
     })
   }
 
+  /**
+   * Register the async HTTP context
+   */
+  protected registerAsyncHttpContext() {
+    this.application.container.singleton('Adonis/Core/AsyncHttpContext', () => asyncHttpContext)
+  }
+
   /**
    * Register the router. The router points to the instance of router used
    * by the middleware
@@ -98,6 +107,7 @@ export default class HttpServerProvider {
     this.registerMiddlewareStore()
     this.registerHttpServer()
     this.registerHTTPContext()
+    this.registerAsyncHttpContext()
     this.registerRouter()
   }
 }

src/AsyncHttpContext/index.ts

@@ -0,0 +1,49 @@
+/**
+ * @adonisjs/http-server
+ *
+ * (c) Harminder Virk <virk@adonisjs.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/// <reference path="../../adonis-typings/index.ts" />
+
+import { AsyncLocalStorage } from 'async_hooks'
+import { Exception } from '@poppinss/utils'
+import { AsyncHttpContextContract } from '@ioc:Adonis/Core/AsyncHttpContext'
+import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
+
+const adonisLocalStorage = new AsyncLocalStorage<InternalAsyncHttpContext>()
+
+export class InternalAsyncHttpContext {
+  constructor(private ctx: HttpContextContract) {}
+
+  public getContext() {
+    return this.ctx
+  }
+
+  public run(callback: () => any) {
+    return adonisLocalStorage.run(this, callback)
+  }
+}
+
+class AsyncHttpContext implements AsyncHttpContextContract {
+  public getContext() {
+    const store = adonisLocalStorage.getStore()
+    if (store) {
+      return store.getContext()
+    }
+    return null
+  }
+
+  public getContextOrFail() {
+    const store = adonisLocalStorage.getStore()
+    if (store) {
+      return store.getContext()
+    }
+    throw new Exception('AsyncHttpContext accessed outside of a request context')
+  }
+}
+
+export const asyncHttpContext = new AsyncHttpContext()

src/Server/index.ts

@@ -27,6 +27,7 @@ import { HttpContext } from '../HttpContext'
 import { RequestHandler } from './RequestHandler'
 import { MiddlewareStore } from '../MiddlewareStore'
 import { ExceptionManager } from './ExceptionManager'
+import { InternalAsyncHttpContext } from '../AsyncHttpContext'
 
 /**
  * Server class handles the HTTP requests by using all Adonis micro modules.
@@ -123,6 +124,13 @@ export class Server implements ServerContract {
     )
   }
 
+  /**
+   * Returns a new async HTTP context for the new request
+   */
+  private getAsyncContext(ctx: HttpContextContract): InternalAsyncHttpContext {
+    return new InternalAsyncHttpContext(ctx)
+  }
+
   /**
    * Define custom error handler to handler all errors
    * occurred during HTTP request
@@ -160,34 +168,40 @@ export class Server implements ServerContract {
 
     const requestAction = this.getProfilerRow(request)
     const ctx = this.getContext(request, response, requestAction)
+    const asyncContext = this.getAsyncContext(ctx)
 
     /*
-     * Handle request by executing hooks, request middleware stack
-     * and route handler
+     * Run everything within the async HTTP context
      */
-    try {
-      await this.handleRequest(ctx)
-    } catch (error) {
-      await this.exception.handle(error, ctx)
-    }
+    return asyncContext.run(async () => {
+      /*
+       * Handle request by executing hooks, request middleware stack
+       * and route handler
+       */
+      try {
+        await this.handleRequest(ctx)
+      } catch (error) {
+        await this.exception.handle(error, ctx)
+      }
 
-    /*
-     * Excute hooks when there are one or more hooks. The `ctx.response.finish`
-     * is intentionally inside both the `try` and `catch` blocks as a defensive
-     * measure.
-     *
-     * When we call `response.finish`, it will serialize the response body and may
-     * encouter errors while doing so and hence will be catched by the catch
-     * block.
-     */
-    try {
-      await this.hooks.executeAfter(ctx)
-      requestAction.end({ status_code: res.statusCode })
-      ctx.response.finish()
-    } catch (error) {
-      await this.exception.handle(error, ctx)
-      requestAction.end({ status_code: res.statusCode, error })
-      ctx.response.finish()
-    }
+      /*
+       * Excute hooks when there are one or more hooks. The `ctx.response.finish`
+       * is intentionally inside both the `try` and `catch` blocks as a defensive
+       * measure.
+       *
+       * When we call `response.finish`, it will serialize the response body and may
+       * encouter errors while doing so and hence will be catched by the catch
+       * block.
+       */
+      try {
+        await this.hooks.executeAfter(ctx)
+        requestAction.end({ status_code: res.statusCode })
+        ctx.response.finish()
+      } catch (error) {
+        await this.exception.handle(error, ctx)
+        requestAction.end({ status_code: res.statusCode, error })
+        ctx.response.finish()
+      }
+    })
   }
 }