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// Modified version of maxogden/binary-split// Copyright (c) 2016 Max Ogden// Licensed under the BSD-2-Clause license
// TODO: Move to separate module
import { concatUint8Arrays } from 'https://ghuc.cc/qwtel/typed-array-utils/index.ts';
const mkFirstMatch = (matcher: Uint8Array) => (buf: Uint8Array, offset: number) => {  if (offset >= buf.length) return -1  let i  for (i = offset; i < buf.length; i++) {    if (buf[i] === matcher[0]) {      if (matcher.length > 1) {        let fullMatch = true        let j, k;        for (j = i, k = 0; j < i + matcher.length; j++, k++) {          if (buf[j] !== matcher[k]) {            fullMatch = false            break          }        }        if (fullMatch) return j - matcher.length      } else {        break      }    }  }
  const idx = i + matcher.length - 1  return idx}
const NL = new Uint8Array([10]) // new TextEncoder().encode('\n');
export class BinarySplitStream extends TransformStream<Uint8Array, Uint8Array> {  constructor(splitOn: string | Uint8Array = NL) {    const matcher = typeof splitOn === 'string'       ? new TextEncoder().encode(splitOn)       : splitOn;    let offset = 0;    let lastMatch = 0;    let buffered: Uint8Array | undefined    let firstMatch: ReturnType<typeof mkFirstMatch>;    super({      start() {        offset = 0;        lastMatch = 0;        buffered = undefined;        firstMatch = mkFirstMatch(matcher)      },      transform(chunk, controller) {        let buf: Uint8Array        if (buffered) {          buf = concatUint8Arrays(buffered, chunk)          offset = buffered.byteLength          buffered = undefined        } else {          buf = chunk        }
        while (true) {          const idx = firstMatch(buf, offset - matcher.byteLength + 1)          if (idx !== -1 && idx < buf.byteLength) {            controller.enqueue(buf.subarray(lastMatch, idx))            offset = idx + matcher.byteLength            lastMatch = offset          } else {            buffered = buf.subarray(lastMatch)            break          }        }      },      flush(controller) {        if (buffered) controller.enqueue(buffered)      },    })  }}
export class SplitStream extends TransformStream<string, string> {  constructor(splitOn: string | RegExp = /\r?\n/) {    const matcher = typeof splitOn === 'string'       ? new RegExp(splitOn)      : splitOn;    let offset = 0;    let lastMatch = 0;    let lastLen = 0;    let buffered: string | undefined    let firstMatch: (buf: string, offset: number) => [number, number];    super({      start() {        offset = 0;        lastMatch = 0;        lastLen = 0;        buffered = undefined;        firstMatch = (buf, offset) => {          const match = matcher.exec(buf.substring(offset))          return match ? [match.index, match[0].length] : [-1, 0]        }      },      transform(chunk, controller) {        let buf: string        if (buffered) {          buf = buffered + chunk          offset = buffered.length          buffered = undefined        } else {          buf = chunk        }
        while (true) {          const [idx, len] = firstMatch(buf, offset - lastLen + 1)          if (idx !== -1 && idx < buf.length) {            controller.enqueue(buf.substring(lastMatch, idx))            offset = idx + len            lastMatch = offset            lastLen = len          } else {            buffered = buf.substring(lastMatch)            break          }        }      },      flush(controller) {        if (buffered) controller.enqueue(buffered)      },    })  }}