WEB Session Lifecycle Observability + Bridge Recovery Drafts

Co-Authored-By: brekotis <93345790+brekotis@users.noreply.github.com>

src/web/bridge/request.js

@@ -0,0 +1,66 @@
+(()=>{'use strict';
+function create(settings){
+ const pause=(milliseconds,signal)=>new Promise((resolve,reject)=>{
+  if(signal&&signal.aborted){reject(new Error('request aborted'));return}
+  const timer=setTimeout(done,milliseconds);function done(){if(signal)signal.removeEventListener('abort',abort);resolve()}
+  function abort(){clearTimeout(timer);signal.removeEventListener('abort',abort);reject(new Error('request aborted'))}
+  if(signal)signal.addEventListener('abort',abort,{once:true});
+ });
+ const options=(method,token,body,headers,signal,keepalive)=>({
+  method,body,signal,keepalive:!!keepalive,mode:'same-origin',credentials:'omit',cache:'no-store',redirect:'error',referrerPolicy:'no-referrer',
+  headers:Object.assign(token?{Authorization:'Bearer '+token}:{},body?{'Content-Type':'application/octet-stream'}:{},headers||{})
+ });
+ function retryAfterMs(response){
+  const header=response.headers.get('Retry-After');
+  if(!header)return 0;
+  const seconds=Number(header);
+  if(Number.isFinite(seconds)&&seconds>=0)return Math.min(seconds*1000,30000);
+  const when=Date.parse(header);
+  if(Number.isFinite(when)){const delta=when-Date.now();return delta>0?Math.min(delta,30000):0}
+  return 0;
+ }
+ function retryableStatus(status){return status===408||status===429||status===502||status===503||status===504}
+ function responsePolicy(path,status){
+  if(path==='/api/v1/session'&&status===200)return {limit:8,exact:true};
+  if(path==='/api/v1/down'&&status===200)return {limit:settings.batchLimit(),exact:false};
+  return {limit:0,exact:true};
+ }
+ async function send(path,frozenOptions,remainingBudget,maxAttempts){
+  let delay=250,attempt=0,lastReason='network';maxAttempts=maxAttempts||9;
+  const initialBudget=remainingBudget?Math.min(settings.retryMs(),remainingBudget()):settings.retryMs();
+  const deadline=Date.now()+Math.max(0,initialBudget),external=frozenOptions.signal;
+  const attemptLimit=path==='/api/v1/down'?settings.longPollMs()+settings.requestMs():settings.requestMs();
+  while(attempt<maxAttempts){
+   if(settings.closed()||(external&&external.aborted))throw new Error('request aborted');
+   const remaining=Math.min(deadline-Date.now(),remainingBudget?remainingBudget():Infinity);if(remaining<=0)break;attempt++;
+   const controller=new AbortController(),abort=()=>controller.abort();
+   if(external)external.addEventListener('abort',abort,{once:true});
+   const requestOptions=Object.assign({},frozenOptions,{signal:controller.signal});
+   const timer=setTimeout(abort,Math.max(1,Math.min(attemptLimit,remaining)));
+   let response=null,wait=0;
+   try{
+    const fetched=await fetch(settings.origin()+path,requestOptions);
+    if(retryableStatus(fetched.status)){
+     lastReason='http';wait=retryAfterMs(fetched);settings.cancel(fetched);
+    }else{
+     const policy=responsePolicy(path,fetched.status);let body;
+     try{body=await settings.read(fetched,policy.limit,policy.exact,controller.signal)}
+     catch(error){controller.abort();throw settings.failure('protocol',error&&error.message)}
+     response={status:fetched.status,headers:fetched.headers,body};return response;
+    }
+   }catch(error){
+    controller.abort();
+    if(settings.closed()||(external&&external.aborted))throw error;
+    if(settings.reason(error,'')==='protocol')throw error;
+   }finally{clearTimeout(timer);if(external)external.removeEventListener('abort',abort)}
+   const after=Math.min(deadline-Date.now(),remainingBudget?remainingBudget():Infinity);if(attempt>=maxAttempts||after<=0)break;
+   settings.retrying();
+   const backoff=wait||delay+Math.floor(Math.random()*Math.max(1,delay/4));
+   await pause(Math.min(backoff,after),external);delay=Math.min(delay*2,2000);
+  }
+  throw settings.failure(lastReason,'carrier retry limit reached');
+ }
+ return Object.freeze({options,pause,send});
+}
+globalThis.TelemtBridgeRequest=Object.freeze({create});
+})();