dynatrace-cordova-outsystems-plugin/node_modules/parse5/lib/tokenizer/preprocessor.js

This plugin gives you the ability to use the Dynatrace instrumentation in your hybrid application (Cordova, Ionic, ..). It uses the Mobile Agent, the JavaScript Agent and the Javascript Bridge. The Mobile Agent will give you all device specific values con

'use strict';

const unicode = require('../common/unicode');
const ERR = require('../common/error-codes');

//Aliases
const $ = unicode.CODE_POINTS;

//Const
const DEFAULT_BUFFER_WATERLINE = 1 << 16;

//Preprocessor
//NOTE: HTML input preprocessing
//(see: http://www.whatwg.org/specs/web-apps/current-work/multipage/parsing.html#preprocessing-the-input-stream)
class Preprocessor {
    constructor() {
        this.html = null;

        this.pos = -1;
        this.lastGapPos = -1;
        this.lastCharPos = -1;

        this.gapStack = [];

        this.skipNextNewLine = false;

        this.lastChunkWritten = false;
        this.endOfChunkHit = false;
        this.bufferWaterline = DEFAULT_BUFFER_WATERLINE;
    }

    _err() {
        // NOTE: err reporting is noop by default. Enabled by mixin.
    }

    _addGap() {
        this.gapStack.push(this.lastGapPos);
        this.lastGapPos = this.pos;
    }

    _processSurrogate(cp) {
        //NOTE: try to peek a surrogate pair
        if (this.pos !== this.lastCharPos) {
            const nextCp = this.html.charCodeAt(this.pos + 1);

            if (unicode.isSurrogatePair(nextCp)) {
                //NOTE: we have a surrogate pair. Peek pair character and recalculate code point.
                this.pos++;

                //NOTE: add gap that should be avoided during retreat
                this._addGap();

                return unicode.getSurrogatePairCodePoint(cp, nextCp);
            }
        }

        //NOTE: we are at the end of a chunk, therefore we can't infer surrogate pair yet.
        else if (!this.lastChunkWritten) {
            this.endOfChunkHit = true;
            return $.EOF;
        }

        //NOTE: isolated surrogate
        this._err(ERR.surrogateInInputStream);

        return cp;
    }

    dropParsedChunk() {
        if (this.pos > this.bufferWaterline) {
            this.lastCharPos -= this.pos;
            this.html = this.html.substring(this.pos);
            this.pos = 0;
            this.lastGapPos = -1;
            this.gapStack = [];
        }
    }

    write(chunk, isLastChunk) {
        if (this.html) {
            this.html += chunk;
        } else {
            this.html = chunk;
        }

        this.lastCharPos = this.html.length - 1;
        this.endOfChunkHit = false;
        this.lastChunkWritten = isLastChunk;
    }

    insertHtmlAtCurrentPos(chunk) {
        this.html = this.html.substring(0, this.pos + 1) + chunk + this.html.substring(this.pos + 1, this.html.length);

        this.lastCharPos = this.html.length - 1;
        this.endOfChunkHit = false;
    }

    advance() {
        this.pos++;

        if (this.pos > this.lastCharPos) {
            this.endOfChunkHit = !this.lastChunkWritten;
            return $.EOF;
        }

        let cp = this.html.charCodeAt(this.pos);

        //NOTE: any U+000A LINE FEED (LF) characters that immediately follow a U+000D CARRIAGE RETURN (CR) character
        //must be ignored.
        if (this.skipNextNewLine && cp === $.LINE_FEED) {
            this.skipNextNewLine = false;
            this._addGap();
            return this.advance();
        }

        //NOTE: all U+000D CARRIAGE RETURN (CR) characters must be converted to U+000A LINE FEED (LF) characters
        if (cp === $.CARRIAGE_RETURN) {
            this.skipNextNewLine = true;
            return $.LINE_FEED;
        }

        this.skipNextNewLine = false;

        if (unicode.isSurrogate(cp)) {
            cp = this._processSurrogate(cp);
        }

        //OPTIMIZATION: first check if code point is in the common allowed
        //range (ASCII alphanumeric, whitespaces, big chunk of BMP)
        //before going into detailed performance cost validation.
        const isCommonValidRange =
            (cp > 0x1f && cp < 0x7f) || cp === $.LINE_FEED || cp === $.CARRIAGE_RETURN || (cp > 0x9f && cp < 0xfdd0);

        if (!isCommonValidRange) {
            this._checkForProblematicCharacters(cp);
        }

        return cp;
    }

    _checkForProblematicCharacters(cp) {
        if (unicode.isControlCodePoint(cp)) {
            this._err(ERR.controlCharacterInInputStream);
        } else if (unicode.isUndefinedCodePoint(cp)) {
            this._err(ERR.noncharacterInInputStream);
        }
    }

    retreat() {
        if (this.pos === this.lastGapPos) {
            this.lastGapPos = this.gapStack.pop();
            this.pos--;
        }

        this.pos--;
    }
}

module.exports = Preprocessor;