fix(http): avoid closing stream multiple times (#2535)

* fix(http): avoid closing stream multiple times

closes #2533

* use different signal than empty vec

.changes/http-controller-multiple-close.md

@@ -0,0 +1,7 @@
+---
+"http": "patch"
+"http-js": "patch"
+---
+
+Fix `fetch` occasionally throwing an error due to trying to close the underline stream twice.
+

plugins/http/api-iife.js

@@ -1 +1 @@
-if("__TAURI__"in window){var __TAURI_PLUGIN_HTTP__=function(e){"use strict";function t(e,t,r,n){if("function"==typeof t||!t.has(e))throw new TypeError("Cannot read private member from an object whose class did not declare it");return"m"===r?n:"a"===r?n.call(e):n?n.value:t.get(e)}function r(e,t,r,n,s){if("function"==typeof t||!t.has(e))throw new TypeError("Cannot write private member to an object whose class did not declare it");return t.set(e,r),r}var n,s,a;"function"==typeof SuppressedError&&SuppressedError;const i="__TAURI_TO_IPC_KEY__";class o{constructor(){this.__TAURI_CHANNEL_MARKER__=!0,n.set(this,(()=>{})),s.set(this,0),a.set(this,[]),this.id=function(e,t=!1){return window.__TAURI_INTERNALS__.transformCallback(e,t)}((({message:e,id:i})=>{if(i==t(this,s,"f"))for(t(this,n,"f").call(this,e),r(this,s,t(this,s,"f")+1);t(this,s,"f")in t(this,a,"f");){const e=t(this,a,"f")[t(this,s,"f")];t(this,n,"f").call(this,e),delete t(this,a,"f")[t(this,s,"f")],r(this,s,t(this,s,"f")+1)}else t(this,a,"f")[i]=e}))}set onmessage(e){r(this,n,e)}get onmessage(){return t(this,n,"f")}[(n=new WeakMap,s=new WeakMap,a=new WeakMap,i)](){return`__CHANNEL__:${this.id}`}toJSON(){return this[i]()}}async function c(e,t={},r){return window.__TAURI_INTERNALS__.invoke(e,t,r)}const d="Request cancelled";return e.fetch=async function(e,t){const r=t?.signal;if(r?.aborted)throw new Error(d);const n=t?.maxRedirections,s=t?.connectTimeout,a=t?.proxy,i=t?.danger;t&&(delete t.maxRedirections,delete t.connectTimeout,delete t.proxy,delete t.danger);const h=t?.headers?t.headers instanceof Headers?t.headers:new Headers(t.headers):new Headers,f=new Request(e,t),_=await f.arrayBuffer(),u=0!==_.byteLength?Array.from(new Uint8Array(_)):null;for(const[e,t]of f.headers)h.get(e)||h.set(e,t);const l=(h instanceof Headers?Array.from(h.entries()):Array.isArray(h)?h:Object.entries(h)).map((([e,t])=>[e,"string"==typeof t?t:t.toString()]));if(r?.aborted)throw new Error(d);const w=await c("plugin:http|fetch",{clientConfig:{method:f.method,url:f.url,headers:l,data:u,maxRedirections:n,connectTimeout:s,proxy:a,danger:i}}),p=()=>c("plugin:http|fetch_cancel",{rid:w});if(r?.aborted)throw p(),new Error(d);r?.addEventListener("abort",(()=>{p()}));const{status:y,statusText:m,url:T,headers:g,rid:A}=await c("plugin:http|fetch_send",{rid:w}),R=new ReadableStream({start:e=>{const t=new o;t.onmessage=t=>{r?.aborted?e.error(d):(t instanceof ArrayBuffer?0!=t.byteLength:0!=t.length)?e.enqueue(new Uint8Array(t)):e.close()},c("plugin:http|fetch_read_body",{rid:A,streamChannel:t}).catch((t=>{e.error(t)}))}}),b=new Response(R,{status:y,statusText:m});return Object.defineProperty(b,"url",{value:T}),Object.defineProperty(b,"headers",{value:new Headers(g)}),b},e}({});Object.defineProperty(window.__TAURI__,"http",{value:__TAURI_PLUGIN_HTTP__})}
+if("__TAURI__"in window){var __TAURI_PLUGIN_HTTP__=function(e){"use strict";function t(e,t,r,n){if("function"==typeof t||!t.has(e))throw new TypeError("Cannot read private member from an object whose class did not declare it");return"m"===r?n:"a"===r?n.call(e):n?n.value:t.get(e)}function r(e,t,r,n,s){if("function"==typeof t||!t.has(e))throw new TypeError("Cannot write private member to an object whose class did not declare it");return t.set(e,r),r}var n,s,a;"function"==typeof SuppressedError&&SuppressedError;const i="__TAURI_TO_IPC_KEY__";class o{constructor(){this.__TAURI_CHANNEL_MARKER__=!0,n.set(this,(()=>{})),s.set(this,0),a.set(this,[]),this.id=function(e,t=!1){return window.__TAURI_INTERNALS__.transformCallback(e,t)}((({message:e,id:i})=>{if(i==t(this,s,"f"))for(t(this,n,"f").call(this,e),r(this,s,t(this,s,"f")+1);t(this,s,"f")in t(this,a,"f");){const e=t(this,a,"f")[t(this,s,"f")];t(this,n,"f").call(this,e),delete t(this,a,"f")[t(this,s,"f")],r(this,s,t(this,s,"f")+1)}else t(this,a,"f")[i]=e}))}set onmessage(e){r(this,n,e)}get onmessage(){return t(this,n,"f")}[(n=new WeakMap,s=new WeakMap,a=new WeakMap,i)](){return`__CHANNEL__:${this.id}`}toJSON(){return this[i]()}}async function c(e,t={},r){return window.__TAURI_INTERNALS__.invoke(e,t,r)}const d="Request cancelled";return e.fetch=async function(e,t){const r=t?.signal;if(r?.aborted)throw new Error(d);const n=t?.maxRedirections,s=t?.connectTimeout,a=t?.proxy,i=t?.danger;t&&(delete t.maxRedirections,delete t.connectTimeout,delete t.proxy,delete t.danger);const h=t?.headers?t.headers instanceof Headers?t.headers:new Headers(t.headers):new Headers,f=new Request(e,t),_=await f.arrayBuffer(),u=0!==_.byteLength?Array.from(new Uint8Array(_)):null;for(const[e,t]of f.headers)h.get(e)||h.set(e,t);const l=(h instanceof Headers?Array.from(h.entries()):Array.isArray(h)?h:Object.entries(h)).map((([e,t])=>[e,"string"==typeof t?t:t.toString()]));if(r?.aborted)throw new Error(d);const w=await c("plugin:http|fetch",{clientConfig:{method:f.method,url:f.url,headers:l,data:u,maxRedirections:n,connectTimeout:s,proxy:a,danger:i}}),p=()=>c("plugin:http|fetch_cancel",{rid:w});if(r?.aborted)throw p(),new Error(d);r?.addEventListener("abort",(()=>{p()}));const{status:y,statusText:m,url:T,headers:g,rid:b}=await c("plugin:http|fetch_send",{rid:w}),A=new ReadableStream({start:e=>{const t=new o;t.onmessage=t=>{if(r?.aborted)return void e.error(d);const n=new Uint8Array(t),s=n[n.byteLength-1],a=n.slice(0,n.byteLength-1);1!=s?e.enqueue(a):e.close()},c("plugin:http|fetch_read_body",{rid:b,streamChannel:t}).catch((t=>{e.error(t)}))}}),R=new Response(A,{status:y,statusText:m});return Object.defineProperty(R,"url",{value:T}),Object.defineProperty(R,"headers",{value:new Headers(g)}),R},e}({});Object.defineProperty(window.__TAURI__,"http",{value:__TAURI_PLUGIN_HTTP__})}

plugins/http/guest-js/index.ts

@@ -239,19 +239,17 @@ export async function fetch(
           return
         }
 
-        // close when the signal to close (an empty chunk)
-        // is sent from the IPC.
-        if (
-          res instanceof ArrayBuffer ? res.byteLength == 0 : res.length == 0
-        ) {
+        const resUint8 = new Uint8Array(res)
+        const lastByte = resUint8[resUint8.byteLength - 1]
+        const actualRes = resUint8.slice(0, resUint8.byteLength - 1)
+
+        // close when the signal to close (last byte is 1) is sent from the IPC.
+        if (lastByte == 1) {
           controller.close()
           return
         }
 
-        // the content conversion (like .text(), .json(), etc.) in Response
-        // must have Uint8Array as its content, else it will
-        // have untraceable error that's hard to debug.
-        controller.enqueue(new Uint8Array(res))
+        controller.enqueue(actualRes)
       }
 
       // run a non-blocking body stream fetch
@@ -269,12 +267,11 @@ export async function fetch(
     statusText
   })
 
-  // url and headers are read only properties
-  // but seems like we can set them like this
+  // Set `Response` properties that are ignored by the
+  // constructor, like url and some headers
   //
-  // we define theme like this, because using `Response`
-  // constructor, it removes url and some headers
-  // like `set-cookie` headers
+  // Since url and headers are read only properties
+  // this is the only way to set them.
   Object.defineProperty(res, 'url', { value: url })
   Object.defineProperty(res, 'headers', {
     value: new Headers(responseHeaders)

plugins/http/src/commands.rs

@@ -426,11 +426,14 @@ pub async fn fetch_read_body<R: Runtime>(
 
     // send response through IPC channel
     while let Some(chunk) = res.chunk().await? {
-        stream_channel.send(tauri::ipc::InvokeResponseBody::Raw(chunk.to_vec()))?;
+        let mut chunk = chunk.to_vec();
+        // append 0 to indicate we are not done yet
+        chunk.push(0);
+        stream_channel.send(tauri::ipc::InvokeResponseBody::Raw(chunk))?;
     }
 
-    // send empty vector when done
-    stream_channel.send(tauri::ipc::InvokeResponseBody::Raw(Vec::new()))?;
+    // send 1 to indicate we are done
+    stream_channel.send(tauri::ipc::InvokeResponseBody::Raw(vec![1]))?;
 
     Ok(())
 }