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std/textproto/mod.ts

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// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.// Based on https://github.com/golang/go/tree/master/src/net/textproto// Copyright 2009 The Go Authors. All rights reserved.// Use of this source code is governed by a BSD-style// license that can be found in the LICENSE file.
import type { BufReader, ReadLineResult } from "../io/buffer.ts";import { concat } from "../bytes/mod.ts";
// Constants created for DRYconst CHAR_SPACE: number = " ".charCodeAt(0);const CHAR_TAB: number = "\t".charCodeAt(0);const CHAR_COLON: number = ":".charCodeAt(0);
const WHITESPACES: Array<number> = [CHAR_SPACE, CHAR_TAB];
const decoder = new TextDecoder();
// FROM https://github.com/denoland/deno/blob/b34628a26ab0187a827aa4ebe256e23178e25d39/cli/js/web/headers.ts#L9const invalidHeaderCharRegex = /[^\t\x20-\x7e\x80-\xff]/g;
function str(buf: Uint8Array | null | undefined): string { return !buf ? "" : decoder.decode(buf);}
export class TextProtoReader { constructor(readonly r: BufReader) {}
/** readLine() reads a single line from the TextProtoReader, * eliding the final \n or \r\n from the returned string. */ async readLine(): Promise<string | null> { const s = await this.readLineSlice(); return s === null ? null : str(s); }
/** ReadMIMEHeader reads a MIME-style header from r. * The header is a sequence of possibly continued Key: Value lines * ending in a blank line. * The returned map m maps CanonicalMIMEHeaderKey(key) to a * sequence of values in the same order encountered in the input. * * For example, consider this input: * * My-Key: Value 1 * Long-Key: Even * Longer Value * My-Key: Value 2 * * Given that input, ReadMIMEHeader returns the map: * * map[string][]string{ * "My-Key": {"Value 1", "Value 2"}, * "Long-Key": {"Even Longer Value"}, * } */ async readMIMEHeader(): Promise<Headers | null> { const m = new Headers(); let line: Uint8Array | undefined;
// The first line cannot start with a leading space. let buf = await this.r.peek(1); if (buf === null) { return null; } else if (WHITESPACES.includes(buf[0])) { line = (await this.readLineSlice()) as Uint8Array; }
buf = await this.r.peek(1); if (buf === null) { throw new Deno.errors.UnexpectedEof(); } else if (WHITESPACES.includes(buf[0])) { throw new Deno.errors.InvalidData( `malformed MIME header initial line: ${str(line)}`, ); }
while (true) { const kv = await this.readLineSlice(); // readContinuedLineSlice if (kv === null) throw new Deno.errors.UnexpectedEof(); if (kv.byteLength === 0) return m;
// Key ends at first colon let i = kv.indexOf(CHAR_COLON); if (i < 0) { throw new Deno.errors.InvalidData( `malformed MIME header line: ${str(kv)}`, ); }
//let key = canonicalMIMEHeaderKey(kv.subarray(0, endKey)); const key = str(kv.subarray(0, i));
// As per RFC 7230 field-name is a token, // tokens consist of one or more chars. // We could throw `Deno.errors.InvalidData` here, // but better to be liberal in what we // accept, so if we get an empty key, skip it. if (key == "") { continue; }
// Skip initial spaces in value. i++; // skip colon while ( i < kv.byteLength && (WHITESPACES.includes(kv[i])) ) { i++; } const value = str(kv.subarray(i)).replace( invalidHeaderCharRegex, encodeURI, );
// In case of invalid header we swallow the error // example: "Audio Mode" => invalid due to space in the key try { m.append(key, value); } catch { // Pass } } }
async readLineSlice(): Promise<Uint8Array | null> { let line = new Uint8Array(0); let r: ReadLineResult | null = null;
do { r = await this.r.readLine(); // TODO(ry): // This skipSpace() is definitely misplaced, but I don't know where it // comes from nor how to fix it.
//TODO(SmashingQuasar): Kept skipSpace to preserve behavior but it should be looked into to check if it makes sense when this is used.
if (r !== null && this.skipSpace(r.line) !== 0) { line = concat(line, r.line); } } while (r !== null && r.more);
return r === null ? null : line; }
skipSpace(l: Uint8Array): number { let n = 0;
for (const val of l) { if (!WHITESPACES.includes(val)) { n++; } }
return n; }}