index.js ➔ decode - Code Metrics - Inspection of "Distribute es5 builds" - btccom/cashaddress-js - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#1)

by thomas

created 2018-01-03 14:17 UTC

index.js ➔ decode C

↳ Parent: lib/index.js

Complexity

Conditions	12
Paths	3

Size

Total Lines

Duplication

Lines	55
Ratio	100 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	12
c	1
b	0
f	0
nc	3
nop	1
dl	55
loc	55
rs	6.8009

How to fix Long Method Complexity

'use strict';


var BigInteger = require('bigi');
var ALPHABET = 'qpzry9x8gf2tvdw0s3jn54khce6mua7l';

// pre-compute lookup table
var SEPARATOR = ':';
var CSLEN = 8;
var ALPHABET_MAP = {};
for (var z = 0; z < ALPHABET.length; z++) {
    var x = ALPHABET.charAt(z);
    if (ALPHABET_MAP[x] !== undefined) {
        throw new TypeError(x + ' is ambiguous');
    }
    ALPHABET_MAP[x] = z;
}

function polymodStep(pre) {
    var b = pre.shiftRight(35);
    var mask = BigInteger.fromHex('07ffffffff');

    var v = pre.and(mask).shiftLeft(new BigInteger('5'));

    if (b.and(new BigInteger('1')).intValue() > 0) {
        v = v.xor(BigInteger.fromHex('98f2bc8e61'));
    }
    if (b.and(new BigInteger('2')).intValue()) {
        v = v.xor(BigInteger.fromHex('79b76d99e2'));
    }
    if (b.and(new BigInteger('4')).intValue()) {
        v = v.xor(BigInteger.fromHex('f33e5fb3c4'));
    }
    if (b.and(new BigInteger('8')).intValue()) {
        v = v.xor(BigInteger.fromHex('ae2eabe2a8'));
    }
    if (b.and(new BigInteger('16')).intValue()) {
        v = v.xor(BigInteger.fromHex('1e4f43e470'));
    }

    return v;
}

function prefixChk(prefix) {
    var chk = new BigInteger('1');
    for (var i = 0; i < prefix.length; ++i) {
        var c = prefix.charCodeAt(i);

        var mixwith = new BigInteger('' + (c & 0x1f));
        chk = polymodStep(chk).xor(mixwith);
    }

    chk = polymodStep(chk);
    return chk;
}

function encode(prefix, words) {
    // too long?
    if (prefix.length + CSLEN + 1 + words.length > 90) {
        throw new TypeError('Exceeds Base32 maximum length');
    }

    prefix = prefix.toLowerCase();

    // determine chk mod
    var chk = prefixChk(prefix);
    var result = prefix + SEPARATOR;
    for (var i = 0; i < words.length; ++i) {
        var _x = words[i];
        if (_x >>> 5 !== 0) {
            throw new Error('Non 5-bit word');
        }

        chk = polymodStep(chk).xor(new BigInteger('' + _x));
        result += ALPHABET.charAt(_x);
    }

    for (var _i = 0; _i < CSLEN; ++_i) {
        chk = polymodStep(chk);
    }
    chk = chk.xor(new BigInteger('1'));
    for (var _i2 = 0; _i2 < CSLEN; ++_i2) {
        var pos = 5 * (CSLEN - 1 - _i2);
        var v2 = chk.shiftRight(new BigInteger('' + pos)).and(BigInteger.fromHex('1f'));
        result += ALPHABET.charAt(v2.toString(10));
    }

    return result;
}

function decode(str) {
    if (str.length < 8) {
        throw new TypeError(str + ' too short');
    }
    if (str.length > 90) {
        throw new TypeError(str + ' too long');
    }

    // don't allow mixed case
    var lowered = str.toLowerCase();
    var uppered = str.toUpperCase();
    if (str !== lowered && str !== uppered) {
        throw new Error('Mixed-case string ' + str);
    }

    str = lowered;

    var split = str.lastIndexOf(SEPARATOR);
    if (split === -1) {
        throw new Error('No separator character for ' + str);
    }

    if (split === 0) {
        throw new Error('Missing prefix for ' + str);
    }

    var prefix = str.slice(0, split);
    var wordChars = str.slice(split + 1);
    if (wordChars.length < 6) {
        throw new Error('Data too short');
    }

    var chk = prefixChk(prefix);
    var words = [];
    for (var i = 0; i < wordChars.length; ++i) {
        var c = wordChars.charAt(i);
        var v = ALPHABET_MAP[c];
        if (v === undefined) {
            throw new Error('Unknown character ' + c);
        }

        chk = polymodStep(chk).xor(new BigInteger('' + v));
        // not in the checksum?
        if (i + CSLEN >= wordChars.length) {
            continue;
        }
        words.push(v);
    }

    if (chk.toString(10) !== '1') {
        throw new Error('Invalid checksum for ' + str);
    }

    return { prefix: prefix, words: words };
}

function convert(data, inBits, outBits, pad) {
    var value = 0;
    var bits = 0;
    var maxV = (1 << outBits) - 1;

    var result = [];
    for (var i = 0; i < data.length; ++i) {
        value = value << inBits | data[i];
        bits += inBits;

        while (bits >= outBits) {
            bits -= outBits;
            result.push(value >>> bits & maxV);
        }
    }

    if (pad) {
        if (bits > 0) {
            result.push(value << outBits - bits & maxV);
        }
    } else {
        if (bits >= inBits) {
            throw new Error('Excess padding');
        }
        if (value << outBits - bits & maxV) {

            throw new Error('Non-zero padding');
        }
    }

    return result;
}

function toWords(bytes) {
    return convert(bytes, 8, 5, true);
}

function fromWords(words) {
    return convert(words, 5, 8, false);
}

module.exports = { decode: decode, encode: encode, toWords: toWords, fromWords: fromWords };

1	View Code Duplication	'use strict';
		0 ignored issues – show Duplication introduced 2018-01-03 14:10 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
2
3		var BigInteger = require('bigi');
4		var ALPHABET = 'qpzry9x8gf2tvdw0s3jn54khce6mua7l';
5
6		// pre-compute lookup table
7		var SEPARATOR = ':';
8		var CSLEN = 8;
9		var ALPHABET_MAP = {};
10		for (var z = 0; z < ALPHABET.length; z++) {
11		var x = ALPHABET.charAt(z);
12		if (ALPHABET_MAP[x] !== undefined) {
13		throw new TypeError(x + ' is ambiguous');
14		}
15		ALPHABET_MAP[x] = z;
16		}
17
18		function polymodStep(pre) {
19		var b = pre.shiftRight(35);
20		var mask = BigInteger.fromHex('07ffffffff');
21
22		var v = pre.and(mask).shiftLeft(new BigInteger('5'));
23
24		if (b.and(new BigInteger('1')).intValue() > 0) {
25		v = v.xor(BigInteger.fromHex('98f2bc8e61'));
26		}
27		if (b.and(new BigInteger('2')).intValue()) {
28		v = v.xor(BigInteger.fromHex('79b76d99e2'));
29		}
30		if (b.and(new BigInteger('4')).intValue()) {
31		v = v.xor(BigInteger.fromHex('f33e5fb3c4'));
32		}
33		if (b.and(new BigInteger('8')).intValue()) {
34		v = v.xor(BigInteger.fromHex('ae2eabe2a8'));
35		}
36		if (b.and(new BigInteger('16')).intValue()) {
37		v = v.xor(BigInteger.fromHex('1e4f43e470'));
38		}
39
40		return v;
41		}
42
43		function prefixChk(prefix) {
44		var chk = new BigInteger('1');
45		for (var i = 0; i < prefix.length; ++i) {
46		var c = prefix.charCodeAt(i);
47
48		var mixwith = new BigInteger('' + (c & 0x1f));
49		chk = polymodStep(chk).xor(mixwith);
50		}
51
52		chk = polymodStep(chk);
53		return chk;
54		}
55
56		function encode(prefix, words) {
57		// too long?
58		if (prefix.length + CSLEN + 1 + words.length > 90) {
59		throw new TypeError('Exceeds Base32 maximum length');
60		}
61
62		prefix = prefix.toLowerCase();
63
64		// determine chk mod
65		var chk = prefixChk(prefix);
66		var result = prefix + SEPARATOR;
67		for (var i = 0; i < words.length; ++i) {
68		var _x = words[i];
69		if (_x >>> 5 !== 0) {
70		throw new Error('Non 5-bit word');
71		}
72
73		chk = polymodStep(chk).xor(new BigInteger('' + _x));
74		result += ALPHABET.charAt(_x);
75		}
76
77		for (var _i = 0; _i < CSLEN; ++_i) {
78		chk = polymodStep(chk);
79		}
80		chk = chk.xor(new BigInteger('1'));
81		for (var _i2 = 0; _i2 < CSLEN; ++_i2) {
82		var pos = 5 * (CSLEN - 1 - _i2);
83		var v2 = chk.shiftRight(new BigInteger('' + pos)).and(BigInteger.fromHex('1f'));
84		result += ALPHABET.charAt(v2.toString(10));
85		}
86
87		return result;
88		}
89
90		function decode(str) {
91		if (str.length < 8) {
92		throw new TypeError(str + ' too short');
93		}
94		if (str.length > 90) {
95		throw new TypeError(str + ' too long');
96		}
97
98		// don't allow mixed case
99		var lowered = str.toLowerCase();
100		var uppered = str.toUpperCase();
101		if (str !== lowered && str !== uppered) {
102		throw new Error('Mixed-case string ' + str);
103		}
104
105		str = lowered;
106
107		var split = str.lastIndexOf(SEPARATOR);
108		if (split === -1) {
109		throw new Error('No separator character for ' + str);
110		}
111
112		if (split === 0) {
113		throw new Error('Missing prefix for ' + str);
114		}
115
116		var prefix = str.slice(0, split);
117		var wordChars = str.slice(split + 1);
118		if (wordChars.length < 6) {
119		throw new Error('Data too short');
120		}
121
122		var chk = prefixChk(prefix);
123		var words = [];
124		for (var i = 0; i < wordChars.length; ++i) {
125		var c = wordChars.charAt(i);
126		var v = ALPHABET_MAP[c];
127		if (v === undefined) {
128		throw new Error('Unknown character ' + c);
129		}
130
131		chk = polymodStep(chk).xor(new BigInteger('' + v));
132		// not in the checksum?
133		if (i + CSLEN >= wordChars.length) {
134		continue;
135		}
136		words.push(v);
137		}
138
139		if (chk.toString(10) !== '1') {
140		throw new Error('Invalid checksum for ' + str);
141		}
142
143		return { prefix: prefix, words: words };
144		}
145
146		function convert(data, inBits, outBits, pad) {
147		var value = 0;
148		var bits = 0;
149		var maxV = (1 << outBits) - 1;
150
151		var result = [];
152		for (var i = 0; i < data.length; ++i) {
153		value = value << inBits \| data[i];
154		bits += inBits;
155
156		while (bits >= outBits) {
157		bits -= outBits;
158		result.push(value >>> bits & maxV);
159		}
160		}
161
162		if (pad) {
163		if (bits > 0) {
164		result.push(value << outBits - bits & maxV);
165		}
166		} else {
167		if (bits >= inBits) {
168		throw new Error('Excess padding');
169		}
170		if (value << outBits - bits & maxV) {
		0 ignored issues – show introduced 2018-01-03 13:38 UTC by Report Bug Copy Issue Report You have used a bitwise operator `&` in a condition. Did you maybe want to use the logical operator `&&` Loading history...
171		throw new Error('Non-zero padding');
172		}
173		}
174
175		return result;
176		}
177
178		function toWords(bytes) {
179		return convert(bytes, 8, 5, true);
180		}
181
182		function fromWords(words) {
183		return convert(words, 5, 8, false);
184		}
185
186		module.exports = { decode: decode, encode: encode, toWords: toWords, fromWords: fromWords };

btccom / cashaddress-js

Pull Request — master (#1)

index.js ➔ decode C

Complexity

Size

Duplication

Importance

How to fix Long Method Complexity

Long Method

Complexity

Duplication Side-by-Side

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