mhtml-stream/dist/mhtml.esm.min.js

Zero dependency stream MHTML parser

var D=L;var g=[],Y=[],f=typeof Uint8Array!=="undefined"?Uint8Array:Array,P="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";for(Z=0,F=P.length;Z<F;++Z)g[Z]=P[Z],Y[P.charCodeAt(Z)]=Z;var Z,F;Y[45]=62;Y[95]=63;function m(G){var K=G.length;if(K%4>0)throw new Error("Invalid string. Length must be a multiple of 4");var J=G.indexOf("=");if(J===-1)J=K;var M=J===K?0:4-J%4;return[J,M]}function v(G,K,J){return(K+J)*3/4-J}function L(G){var K,J=m(G),M=J[0],R=J[1],U=new f(v(G,M,R)),V=0,W=R>0?M-4:M,X;for(X=0;X<W;X+=4)K=Y[G.charCodeAt(X)]<<18|Y[G.charCodeAt(X+1)]<<12|Y[G.charCodeAt(X+2)]<<6|Y[G.charCodeAt(X+3)],U[V++]=K>>16&255,U[V++]=K>>8&255,U[V++]=K&255;if(R===2)K=Y[G.charCodeAt(X)]<<2|Y[G.charCodeAt(X+1)]>>4,U[V++]=K&255;if(R===1)K=Y[G.charCodeAt(X)]<<10|Y[G.charCodeAt(X+1)]<<4|Y[G.charCodeAt(X+2)]>>2,U[V++]=K>>8&255,U[V++]=K&255;return U}class S{#G=new Map;[Symbol.iterator](){return this.entries()}append(G,K){let J=this.#G.get(G);if(J===void 0)this.#G.set(G,[K]);else J.push(K)}*entries(G=", "){for(let[K,J]of this.#G.entries())yield[K,J.join(G)]}*entriesAll(){for(let[G,K]of this.#G.entries())for(let J of K)yield[G,J]}get(G,K=", "){let J=this.#G.get(G);if(J===void 0)return null;else return J.join(K)}getAll(G){return this.#G.get(G)??[]}has(G){return this.#G.has(G)}keys(){return this.#G.keys()}*values(G=", "){for(let K of this.#G.values())yield K.join(G)}*valuesAll(){for(let G of this.#G.values())yield*G}}function _(G,K){if(G.length!==K.length)return!1;else if(G.byteOffset%4===K.byteOffset%4){let J=(4-G.byteOffset%4)%4,M=Math.floor((G.byteLength-J)/4),R=J+M*4,U=new Uint32Array(G.buffer,G.byteOffset+J,M),V=new Uint32Array(K.buffer,K.byteOffset+J,M);for(let W=0;W<J;++W)if(G[W]!==K[W])return!1;for(let W=0;W<M;++W)if(U[W]!==V[W])return!1;for(let W=R;W<G.length;++W)if(G[W]!==K[W])return!1;return!0}else{for(let J of G.keys())if(G[J]!==K[J])return!1;return!0}}function h(G,K){return G.findIndex((J,M)=>{if(J!==K[0]||M+K.length>G.length)return!1;else{for(let R=1;R<K.length;++R)if(G[M+R]!==K[R])return!1;return!0}})}async function*Q(G,K){let J=new Uint8Array(0);for await(let M of G){J=J.length?E([J,M]):M;let R;while((R=h(J,K))!==-1)yield J.subarray(0,R),J=J.subarray(R+K.length)}yield J}function E(G){let K=G.reduce((R,U)=>R+U.length,0),J=new Uint8Array(K),M=0;for(let R of G)J.set(R,M),M+=R.length;return J}async function O(G){let K=[];for await(let J of G)K.push(J);return E(K)}var k=new Uint8Array([10]);async function*T(G,K=k){for await(let J of G){let M=new Uint8Array(J.length+K.length),R=!1,U=0;for(let V=0;V<J.length;++V){let W=J[V];if(W>=128)throw new Error(`got non-ascii character when decoding quoted printable: ${W}`);if(W!==61)M[U++]=W;else{let X=J[++V];if(X===void 0)R=!0;else{let z=J[++V];if(z===void 0)throw new Error("quoted printable escape (=) was not followed by two bytes");let $=parseInt(String.fromCharCode(X),16);$*=16,$+=parseInt(String.fromCharCode(z),16),M[U++]=$}}}if(!R)M.set(K,U),U+=K.length;yield M.subarray(0,U)}}var y=new TextDecoder;async function*C(G){for await(let K of G)yield D(y.decode(K))}async function*j(G){for await(let K of G)yield K}function A(){throw new Error("binary transfer-encoding is explicitly not supported and trying to add an implementation will likely result in unexpected results, but if you want to ignore anyway, set binary to `decode8bit`")}var I=new TextEncoder,B=new TextDecoder;function b(G){let K=new Uint8Array(G.length),J=0;for(let M=0;M<G.length;++M){let R=G.charCodeAt(M),U;if(R>=128)throw new Error(`got non-ascii character when decoding q-quoted word: "${G}"`);else if(R===95)U=32;else if(R===61)U=parseInt(G[++M],16),U*=16,U+=parseInt(G[++M],16);else U=R;K[J++]=U}return K.subarray(0,J)}var p=/^=\?([^?\s]+)\?([BQ])\?([^?\s]+)\?=$/;function H(G){let K=p.exec(G);if(K){let[,J,M,R]=K,U;if(M==="Q")U=b(R);else U=D(R);return new TextDecoder(J).decode(U)}else return G}async function c(G){let K=new S,J="",M="";for(;;){let{done:R,value:U}=await G.next();if(R)throw new Error("didn't find an empty line to signify the end of header parsing");let V=B.decode(U);if(/^\s/.test(V))M+=H(V.substring(1));else{if(J)K.append(J,M);if(V){let W=V.indexOf(": ");if(W===-1)throw new Error(`header line didn't have key-value delimiter: "${V}"`);J=V.slice(0,W),M=H(V.slice(W+2))}else return K}}}var u=new Map([["7bit",j],["base64",C],["quoted-printable",T],["8bit",j],["binary",A]]);function s(G){let K=G.get("Content-Type");if(K===null)throw new Error(`first headers didn't contain a content type: ${JSON.stringify(Object.fromEntries(G))}`);let J=void 0,M=!1;for(let V of K.split(/;\s*/))if(V.startsWith("multipart/"))M=!0;else if(V.startsWith("boundary=")){if(J=V.slice(9),J.startsWith('"')&&J.endsWith('"'))J=J.slice(1,-1)}if(!M||J===void 0)throw new Error("first content type header didn't contain 'multipart/...' and a boundary string");let R=I.encode(`--${J}`),U=I.encode(`--${J}--`);return[R,U]}async function*e(G,{decoderOverrides:K=new Map}={}){let J=new Map([...u.entries(),...K.entries()]),M=new Uint8Array([13,10]),R=Q(G,M),U=null,V=!0;while(V){let W=await c(R),[X,z]=U??(U=s(W)),$=W.get("Content-Transfer-Encoding")??"7bit",q=J.get($);if(q===void 0)throw new Error(`unhandled encoding type: ${$}`);let w=await O(q({[Symbol.asyncIterator](){return{async next(){let{done:x,value:N}=await R.next();if(x)throw new Error(`stream didn't end with the appropriate termination boundary: ${B.decode(z)}`);else if(_(N,X))return{done:!0,value:void 0};else if(_(N,z))return V=!1,{done:!0,value:void 0};else return{value:N}}}}}));yield{headers:W,content:w}}}export{e as parseMhtml};