seax/frontend/fetch-event-source.js
2023-08-02 21:06:52 +03:00

2 lines
2.3 KiB
JavaScript

var m=class extends Error{};async function A(r,e,t){let n=r.getReader(),o={done:!1,value:new Uint8Array};for(;o&&!o.done;)o=await Promise.race([n.read(),new Promise((g,i)=>{setTimeout(()=>i(new Error("getBytes timed out")),t)})]),e(o.value)}function R(r){let e,t,n,o=!1;return function(i){e===void 0?(e=i,t=0,n=-1):e=L(e,i);let s=e.length,a=0;for(;t<s;){o&&(e[t]===10&&(a=++t),o=!1);let c=-1;for(;t<s&&c===-1;++t)switch(e[t]){case 58:n===-1&&(n=t-a);break;case 13:o=!0;case 10:c=t;break}if(c===-1)break;r(e.subarray(a,c),n),a=t,n=-1}a===s?e=void 0:a!==0&&(e=e.subarray(a),t-=a)}}function P(r,e,t){let n=k(),o=new TextDecoder;return function(i,s){if(i.length===0)r?.(n),n=k();else if(s>0){let a=o.decode(i.subarray(0,s)),c=s+(i[s+1]===32?2:1),p=o.decode(i.subarray(c));switch(a){case"data":n.data=n.data?n.data+`
`+p:p;break;case"event":n.event=p;break;case"id":e?.(n.id=p);break;case"retry":let l=parseInt(p,10);isNaN(l)||t?.(n.retry=l);break}}}}function L(r,e){let t=new Uint8Array(r.length+e.length);return t.set(r),t.set(e,r.length),t}function k(){return{data:"",event:"",id:"",retry:void 0}}var b="text/event-stream",N=1e3,T="last-event-id";function q(r,{signal:e,headers:t,onopen:n,onmessage:o,onclose:g,onerror:i,openWhenHidden:s,fetch:a,responseTimeout:c,...p}){return new Promise((l,M)=>{let y={...t};y.accept||(y.accept=b);let f;function w(){f.abort(),document.hidden||E()}typeof document<"u"&&!s&&document.addEventListener("visibilitychange",w);let S=N,h;function x(){typeof document<"u"&&!s&&document.removeEventListener("visibilitychange",w),clearTimeout(h),f.abort()}e?.addEventListener("abort",()=>{x(),l()});let I=a??fetch,U=n??O,v=!1;async function E(){f=new AbortController;try{let u=await Promise.race([I(r,{...p,headers:y,signal:f.signal}),new Promise((d,C)=>{setTimeout(()=>C(new Error("fetch timed out")),c)})]);if(u.status===404)throw new m("Channel reaped");if(u.status<200||u.status>=300)throw new Error(`Invalid server response: ${u.status}`);await U(u,v),v&&(v=!1),await A(u.body,R(P(o,d=>{d?y[T]=d:delete y[T]},d=>{S=d})),c),g?.(),x(),l()}catch(u){if(!f.signal.aborted)try{v=!0;let d=i?.(u)??S;clearTimeout(h),f.abort(),h=setTimeout(E,d)}catch(d){x(),M(d)}}}E()})}function O(r){let e=r.headers.get("content-type");if(!e?.startsWith(b))throw new Error(`Expected content-type to be ${b}, Actual: ${e}`)}export{b as EventStreamContentType,q as fetchEventSource};