pulseplot/lib/hexbuffer.js

Pulse data viewer JS library

/**
    @file Hexbuffer JS.

    @author Christian W. Zuckschwerdt <zany@triq.net>
    @copyright Christian W. Zuckschwerdt, 2020
    @license
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 2 of the License, or
    (at your option) any later version.
*/

function dec2hex(i, w = 2) {
    i = Math.round(i)
    return (i + 0x10000).toString(16).substr(-w).toUpperCase()
}

export class Hexbuffer {
    constructor(line = '') {
        this.fromString(line)
    }
    fromString(s) {
        this.line = s.replace(/\s/g, '')
        this.index = 0
    }

    hasNibble() {
        return this.index + 1 <= this.line.length
    }
    hasByte() {
        return this.index + 2 <= this.line.length
    }
    hasWord() {
        return this.index + 4 <= this.line.length
    }

    peekNibble() {
        return parseInt(this.line.substr(this.index, 1), 16)
    }
    peekByte() {
        return parseInt(this.line.substr(this.index, 2), 16)
    }
    peekWord() {
        return parseInt(this.line.substr(this.index, 4), 16)
    }

    getNibble() {
        const r = parseInt(this.line.substr(this.index, 1), 16)
        this.index += 1
        return r
    }
    getByte() {
        const r = parseInt(this.line.substr(this.index, 2), 16)
        this.index += 2
        return r
    }
    getWord() {
        const r = parseInt(this.line.substr(this.index, 4), 16)
        this.index += 4
        return r
    }

    pushNibble(v) {
        this.line += dec2hex(v, 1)
    }
    pushByte(v) {
        this.line += dec2hex(v, 2)
    }
    pushWord(v) {
        this.line += dec2hex(v, 4)
    }
}