From 3991c9b4bbcd3039bd27eb5352cddd76a6a866b8 Mon Sep 17 00:00:00 2001
From: garrettmills <garrett@glmdev.tech>
Date: Sat, 1 Aug 2020 13:59:38 -0500
Subject: [PATCH] Add support for request timeouts; timeout helper

---
 TODO.txt                     |  4 +--
 app/configs/server.config.ts |  2 ++
 lib/src/support/timeout.ts   | 48 ++++++++++++++++++++++++++++++++++++
 lib/src/unit/HttpServer.ts   | 23 +++++++++++++++--
 4 files changed, 72 insertions(+), 5 deletions(-)
 create mode 100644 lib/src/support/timeout.ts

diff --git a/TODO.txt b/TODO.txt
index 5bdecb9..264c4c6 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -22,6 +22,4 @@ unit tests
 integration tests
 documentation & docs site
 events and observables?
-no matching route handler
-request timeout
-error response handler figure out json
+error response handler figure out json - requested content type
diff --git a/app/configs/server.config.ts b/app/configs/server.config.ts
index b86707b..90f8ba1 100644
--- a/app/configs/server.config.ts
+++ b/app/configs/server.config.ts
@@ -4,6 +4,8 @@ export default {
     prefix: '/',
     allow_mount_without_prefix: false,
 
+    request_timeout: 15000, // 15 seconds
+
     powered_by: {
         enable: true,
         text: 'Daton',
diff --git a/lib/src/support/timeout.ts b/lib/src/support/timeout.ts
new file mode 100644
index 0000000..c1e71d3
--- /dev/null
+++ b/lib/src/support/timeout.ts
@@ -0,0 +1,48 @@
+export interface TimeoutSubscriber<T> {
+    on_time: (handler: (arg: T) => any) => TimeoutSubscriber<T>,
+    late: (handler: (arg: T) => any) => TimeoutSubscriber<T>,
+    timeout: (handler: () => any) => TimeoutSubscriber<T>,
+    run: () => Promise<T>,
+}
+
+export function withTimeout<T>(timeout: number, promise: Promise<T>) {
+    let on_time_handler: (arg: T) => any = (arg) => {}
+    let late_handler: (arg: T) => any = (arg) => {}
+    let timeout_handler: () => any = () => {}
+
+    const sub = {
+        on_time: handler => {
+            on_time_handler = handler
+            return sub
+        },
+        late: handler => {
+            late_handler = handler
+            return sub
+        },
+        timeout: handler => {
+            timeout_handler = handler
+            return sub
+        },
+        run: async () => {
+            let expired = false
+            let resolved = false
+            setTimeout(() => {
+                expired = true
+                if ( !resolved ) timeout_handler()
+            }, timeout)
+
+            const result: T = await promise
+            resolved = true
+
+            if ( !expired ) {
+                await on_time_handler(result)
+            } else {
+                await late_handler(result)
+            }
+
+            return result
+        }
+    } as TimeoutSubscriber<T>
+
+    return sub
+}
\ No newline at end of file
diff --git a/lib/src/unit/HttpServer.ts b/lib/src/unit/HttpServer.ts
index 91984fb..1f7dc42 100644
--- a/lib/src/unit/HttpServer.ts
+++ b/lib/src/unit/HttpServer.ts
@@ -4,6 +4,10 @@ import Kernel from '../http/kernel/Kernel.ts'
 import {Logging} from '../service/logging/Logging.ts'
 import {serve} from '../external/http.ts'
 import {Request} from '../http/Request.ts'
+import {withTimeout} from '../support/timeout.ts'
+import {http} from '../http/response/helpers.ts'
+import {HTTPStatus} from '../const/http.ts'
+import Config from './Config.ts'
 
 @Unit()
 export default class HttpServer extends LifecycleUnit {
@@ -11,6 +15,7 @@ export default class HttpServer extends LifecycleUnit {
 
     constructor(
         protected readonly kernel: Kernel,
+        protected readonly config: Config,
         protected readonly logger: Logging,
     ) {
         super()
@@ -20,10 +25,24 @@ export default class HttpServer extends LifecycleUnit {
         this._server = serve({ port: 8000 })
         this.logger.success(`HTTP/S server listening on port 8000!`)
 
+        const request_timeout: number = this.config.get('server.request_timeout', 15000)
+
         for await ( const native_request of this._server ) {
             let req: Request = this.make(Request, native_request)
-            req = await this.kernel.handle(req)
-            req.response.send()
+
+            await withTimeout(request_timeout, this.kernel.handle(req))
+                .on_time(output_req => {
+                    output_req.response.send()
+                })
+                .late(output_req => {
+                    this.logger.error(`Request timed out. Response was already sent on path: ${req.path}. Consider increasing server.request_timeout.`)
+                })
+                .timeout(async () => {
+                    const factory = http(HTTPStatus.REQUEST_TIMEOUT)
+                    const output_req = await factory.write(req)
+                    output_req.response.send()
+                })
+                .run()
         }
     }
 }