ID3Util.js ➔ constructor - Code Metrics - Inspection of "fix unsynchronisation #107" - Zazama/node-id3 - Measure and Improve Code Quality continuously with Scrutinizer

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Push — master ( 62bfad...2b6a7f )

by Jan

created 2021-04-26 20:43 UTC

ID3Util.js ➔ constructor A

↳ Parent: src/ID3Util.js

Complexity

Conditions

Size

Total Lines	4
Code Lines	3

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
eloc	3
dl	0
loc	4
rs	10
c	0
b	0
f	0
cc	1

const iconv = require('iconv-lite')
const ID3Definitions = require('./ID3Definitions')

const ENCODINGS = [
    'ISO-8859-1', 'UTF-16', 'UTF-16BE', 'UTF-8'
]

module.exports.SplitBuffer = class SplitBuffer {
    constructor(value = null, remainder = null) {
        this.value = value
        this.remainder = remainder
    }
}

module.exports.splitNullTerminatedBuffer = function(buffer, encodingByte = 0x00) {
    let termination = { start: -1, size: 0 }
    if(encodingByte === 0x01 || encodingByte === 0x02) {
        termination.start = buffer.indexOf(Buffer.from([0x00, 0x00]))
        termination.size = 2
        if(termination.start !== -1 && buffer.length > (termination.start + termination.size)) {
            if(buffer[termination.start + termination.size] === 0x00) {
                termination.start += 1
            }
        }
    } else {
        termination.start = buffer.indexOf(0x00)
        termination.size = 1
    }

    if(termination.start === -1) {
        return new this.SplitBuffer(null, buffer.slice(0))
    }
    else if(buffer.length <= termination.start + termination.length) {
        return new this.SplitBuffer(buffer.slice(0, termination.start), null)
    } else {
        return new this.SplitBuffer(buffer.slice(0, termination.start), buffer.slice(termination.start + termination.size))
    }
}

module.exports.terminationBuffer = function(encodingByte = 0x00) {
    if(encodingByte === 0x01 || encodingByte === 0x02) {
        return Buffer.alloc(2, 0x00)
    } else {

        return Buffer.alloc(1, 0x00)
    }
}

module.exports.encodingFromStringOrByte = function(encoding) {
    if(ENCODINGS.indexOf(encoding) !== -1) {
        return encoding
    } else if(encoding > -1 && encoding < ENCODINGS.length) {
        encoding = ENCODINGS[encoding]
    } else {
        encoding = ENCODINGS[0]
    }
    return encoding
}

module.exports.stringToEncodedBuffer = function(str, encodingByte) {
    return iconv.encode(str, this.encodingFromStringOrByte(encodingByte))
}

module.exports.bufferToDecodedString = function(buffer, encodingByte) {
    return iconv.decode(buffer, this.encodingFromStringOrByte(encodingByte)).replace(/\0/g, '')
}

module.exports.getSpecOptions = function(specName, version) {
    if(version === 2) {
        if(ID3Definitions.ID3_FRAME_OPTIONS.v2[specName] && ID3Definitions.ID3_FRAME_OPTIONS.v2[specName]) {
            return ID3Definitions.ID3_FRAME_OPTIONS.v2[specName]
        }
    } else if (version === 3 || version === 4) {
        if(ID3Definitions.ID3_FRAME_OPTIONS.v3[specName] && ID3Definitions.ID3_FRAME_OPTIONS.v3[specName]) {
            return ID3Definitions.ID3_FRAME_OPTIONS.v3[specName]
        }
    }
    return {}
}

module.exports.isValidID3Header = function(buffer) {
    if(buffer.length < 10) {
        return false;
    } else if(buffer.readUIntBE(0, 3) !== 0x494433) {
        return false;
    } else if([0x02, 0x03, 0x04].indexOf(buffer[3]) === -1 || buffer[4] !== 0x00) {
        return false;
    } else if(buffer[6] & 128 === 1 || buffer[7] & 128 === 1 || buffer[8] & 128 === 1 || buffer[9] & 128 === 1) {

        return false;
    }
    return true;
};

module.exports.getFramePosition = function(buffer) {
    /* Search Buffer for valid ID3 frame */
    let framePosition = -1;
    let frameHeaderValid = false;
    do {
        framePosition = buffer.indexOf("ID3", framePosition + 1);
        if(framePosition !== -1) {
            /* It's possible that there is a "ID3" sequence without being an ID3 Frame,
             * so we need to check for validity of the next 10 bytes
             */
            frameHeaderValid = this.isValidID3Header(buffer.slice(framePosition, framePosition + 10));
        }
    } while (framePosition !== -1 && !frameHeaderValid);

    if(!frameHeaderValid) {
        return -1;
    } else {

        return framePosition;
    }
}

/**
 * @return {Buffer}
 */
module.exports.encodeSize = function(totalSize) {
    let byte_3 = totalSize & 0x7F;
    let byte_2 = (totalSize >> 7) & 0x7F;
    let byte_1 = (totalSize >> 14) & 0x7F;
    let byte_0 = (totalSize >> 21) & 0x7F;
    return Buffer.from([byte_0, byte_1, byte_2, byte_3]);
};

/**
 * @return {Buffer}
 */
module.exports.decodeSize = function(hSize) {
    return (hSize[0] << 21) + (hSize[1] << 14) + (hSize[2] << 7) + hSize[3];
};

module.exports.getFrameSize = function(buffer, decode, ID3Version) {
    let decodeBytes
    if(ID3Version > 2) {
        decodeBytes = [buffer[4], buffer[5], buffer[6], buffer[7]]
    } else {
        decodeBytes = [buffer[3], buffer[4], buffer[5]]
    }
    if(decode) {
        return this.decodeSize(Buffer.from(decodeBytes))
    } else {

        return Buffer.from(decodeBytes).readUIntBE(0, decodeBytes.length)
    }
}

module.exports.parseTagHeaderFlags = function(header) {
    if(!(header instanceof Buffer && header.length >= 10)) {
        return {}
    }
    const version = header[3]
    const flagsByte = header[5]
    if(version === 3) {
        return {
            unsynchronisation: !!(flagsByte & 128),
            extendedHeader: !!(flagsByte & 64),
            experimentalIndicator: !!(flagsByte & 32)
        }
    }
    if(version === 4) {
        return {
            unsynchronisation: !!(flagsByte & 128),
            extendedHeader: !!(flagsByte & 64),
            experimentalIndicator: !!(flagsByte & 32),
            footerPresent: !!(flagsByte & 16)
        }
    }
    return {}
}

module.exports.parseFrameHeaderFlags = function(header, ID3Version) {
    if(!(header instanceof Buffer && header.length === 10)) {
        return {}
    }
    const flagsFirstByte = header[8]
    const flagsSecondByte = header[9]
    if(ID3Version === 3) {

        return {
            tagAlterPreservation: !!(flagsFirstByte & 128),
            fileAlterPreservation: !!(flagsFirstByte & 64),
            readOnly: !!(flagsFirstByte & 32),
            compression: !!(flagsSecondByte & 128),
            encryption: !!(flagsSecondByte & 64),
            groupingIdentity: !!(flagsSecondByte & 32)
        }
    }
    if(ID3Version === 4) {

        return {
            tagAlterPreservation: !!(flagsFirstByte & 64),
            fileAlterPreservation: !!(flagsFirstByte & 32),
            readOnly: !!(flagsFirstByte & 16),
            groupingIdentity: !!(flagsSecondByte & 64),
            compression: !!(flagsSecondByte & 8),
            encryption: !!(flagsSecondByte & 4),
            unsynchronisation: !!(flagsSecondByte & 2),
            dataLengthIndicator: !!(flagsSecondByte & 1)
        }
    }
    return {}
}

module.exports.processUnsynchronisedBuffer = function(buffer) {
    const newDataArr = []
    if(buffer.length > 0) {
        newDataArr.push(buffer[0])
    }
    for(let i = 1; i < buffer.length; i++) {
        if(buffer[i - 1] === 0xFF && buffer[i] === 0x00)
            continue
if (a > 0)
    b = 42;
        newDataArr.push(buffer[i])
    }
    return Buffer.from(newDataArr)
}


1		const iconv = require('iconv-lite')
2		const ID3Definitions = require('./ID3Definitions')
3
4		const ENCODINGS = [
5		'ISO-8859-1', 'UTF-16', 'UTF-16BE', 'UTF-8'
6		]
7
8		module.exports.SplitBuffer = class SplitBuffer {
9		constructor(value = null, remainder = null) {
10		this.value = value
11		this.remainder = remainder
12		}
13		}
14
15		module.exports.splitNullTerminatedBuffer = function(buffer, encodingByte = 0x00) {
16		let termination = { start: -1, size: 0 }
17		if(encodingByte === 0x01 \|\| encodingByte === 0x02) {
18		termination.start = buffer.indexOf(Buffer.from([0x00, 0x00]))
19		termination.size = 2
20		if(termination.start !== -1 && buffer.length > (termination.start + termination.size)) {
21		if(buffer[termination.start + termination.size] === 0x00) {
22		termination.start += 1
23		}
24		}
25		} else {
26		termination.start = buffer.indexOf(0x00)
27		termination.size = 1
28		}
29
30		if(termination.start === -1) {
31		return new this.SplitBuffer(null, buffer.slice(0))
32		}
33		else if(buffer.length <= termination.start + termination.length) {
34		return new this.SplitBuffer(buffer.slice(0, termination.start), null)
35		} else {
36		return new this.SplitBuffer(buffer.slice(0, termination.start), buffer.slice(termination.start + termination.size))
37		}
38		}
39
40		module.exports.terminationBuffer = function(encodingByte = 0x00) {
41		if(encodingByte === 0x01 \|\| encodingByte === 0x02) {
42		return Buffer.alloc(2, 0x00)
43		} else {
		0 ignored issues – show Comprehensibility introduced 2021-03-18 21:25 UTC by Report Bug Copy Issue Report `else` is not necessary here since all `if` branches return, consider removing it to reduce nesting and make code more readable. Loading history...
44		return Buffer.alloc(1, 0x00)
45		}
46		}
47
48		module.exports.encodingFromStringOrByte = function(encoding) {
49		if(ENCODINGS.indexOf(encoding) !== -1) {
50		return encoding
51		} else if(encoding > -1 && encoding < ENCODINGS.length) {
52		encoding = ENCODINGS[encoding]
53		} else {
54		encoding = ENCODINGS[0]
55		}
56		return encoding
57		}
58
59		module.exports.stringToEncodedBuffer = function(str, encodingByte) {
60		return iconv.encode(str, this.encodingFromStringOrByte(encodingByte))
61		}
62
63		module.exports.bufferToDecodedString = function(buffer, encodingByte) {
64		return iconv.decode(buffer, this.encodingFromStringOrByte(encodingByte)).replace(/\0/g, '')
65		}
66
67		module.exports.getSpecOptions = function(specName, version) {
68		if(version === 2) {
69		if(ID3Definitions.ID3_FRAME_OPTIONS.v2[specName] && ID3Definitions.ID3_FRAME_OPTIONS.v2[specName]) {
70		return ID3Definitions.ID3_FRAME_OPTIONS.v2[specName]
71		}
72		} else if (version === 3 \|\| version === 4) {
73		if(ID3Definitions.ID3_FRAME_OPTIONS.v3[specName] && ID3Definitions.ID3_FRAME_OPTIONS.v3[specName]) {
74		return ID3Definitions.ID3_FRAME_OPTIONS.v3[specName]
75		}
76		}
77		return {}
78		}
79
80		module.exports.isValidID3Header = function(buffer) {
81		if(buffer.length < 10) {
82		return false;
83		} else if(buffer.readUIntBE(0, 3) !== 0x494433) {
84		return false;
85		} else if([0x02, 0x03, 0x04].indexOf(buffer[3]) === -1 \|\| buffer[4] !== 0x00) {
86		return false;
87		} else if(buffer[6] & 128 === 1 \|\| buffer[7] & 128 === 1 \|\| buffer[8] & 128 === 1 \|\| buffer[9] & 128 === 1) {
		0 ignored issues – show introduced 2021-03-18 21:25 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...
88		return false;
89		}
90		return true;
91		};
92
93		module.exports.getFramePosition = function(buffer) {
94		/* Search Buffer for valid ID3 frame */
95		let framePosition = -1;
96		let frameHeaderValid = false;
97		do {
98		framePosition = buffer.indexOf("ID3", framePosition + 1);
99		if(framePosition !== -1) {
100		/* It's possible that there is a "ID3" sequence without being an ID3 Frame,
101		* so we need to check for validity of the next 10 bytes
102		*/
103		frameHeaderValid = this.isValidID3Header(buffer.slice(framePosition, framePosition + 10));
104		}
105		} while (framePosition !== -1 && !frameHeaderValid);
106
107		if(!frameHeaderValid) {
108		return -1;
109		} else {
		0 ignored issues – show Comprehensibility introduced 2021-03-18 21:25 UTC by Report Bug Copy Issue Report `else` is not necessary here since all `if` branches return, consider removing it to reduce nesting and make code more readable. Loading history...
110		return framePosition;
111		}
112		}
113
114		/**
115		* @return {Buffer}
116		*/
117		module.exports.encodeSize = function(totalSize) {
118		let byte_3 = totalSize & 0x7F;
119		let byte_2 = (totalSize >> 7) & 0x7F;
120		let byte_1 = (totalSize >> 14) & 0x7F;
121		let byte_0 = (totalSize >> 21) & 0x7F;
122		return Buffer.from([byte_0, byte_1, byte_2, byte_3]);
123		};
124
125		/**
126		* @return {Buffer}
127		*/
128		module.exports.decodeSize = function(hSize) {
129		return (hSize[0] << 21) + (hSize[1] << 14) + (hSize[2] << 7) + hSize[3];
130		};
131
132		module.exports.getFrameSize = function(buffer, decode, ID3Version) {
133		let decodeBytes
134		if(ID3Version > 2) {
135		decodeBytes = [buffer[4], buffer[5], buffer[6], buffer[7]]
136		} else {
137		decodeBytes = [buffer[3], buffer[4], buffer[5]]
138		}
139		if(decode) {
140		return this.decodeSize(Buffer.from(decodeBytes))
141		} else {
		0 ignored issues – show Comprehensibility introduced 2021-03-18 21:25 UTC by Report Bug Copy Issue Report `else` is not necessary here since all `if` branches return, consider removing it to reduce nesting and make code more readable. Loading history...
142		return Buffer.from(decodeBytes).readUIntBE(0, decodeBytes.length)
143		}
144		}
145
146		module.exports.parseTagHeaderFlags = function(header) {
147		if(!(header instanceof Buffer && header.length >= 10)) {
148		return {}
149		}
150		const version = header[3]
151		const flagsByte = header[5]
152		if(version === 3) {
153		return {
154		unsynchronisation: !!(flagsByte & 128),
155		extendedHeader: !!(flagsByte & 64),
156		experimentalIndicator: !!(flagsByte & 32)
157		}
158		}
159		if(version === 4) {
160		return {
161		unsynchronisation: !!(flagsByte & 128),
162		extendedHeader: !!(flagsByte & 64),
163		experimentalIndicator: !!(flagsByte & 32),
164		footerPresent: !!(flagsByte & 16)
165		}
166		}
167		return {}
168		}
169
170		module.exports.parseFrameHeaderFlags = function(header, ID3Version) {
171		if(!(header instanceof Buffer && header.length === 10)) {
172		return {}
173		}
174		const flagsFirstByte = header[8]
175		const flagsSecondByte = header[9]
176	View Code Duplication	if(ID3Version === 3) {
		0 ignored issues – show Duplication introduced 2021-03-18 21:25 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
177		return {
178		tagAlterPreservation: !!(flagsFirstByte & 128),
179		fileAlterPreservation: !!(flagsFirstByte & 64),
180		readOnly: !!(flagsFirstByte & 32),
181		compression: !!(flagsSecondByte & 128),
182		encryption: !!(flagsSecondByte & 64),
183		groupingIdentity: !!(flagsSecondByte & 32)
184		}
185		}
186	View Code Duplication	if(ID3Version === 4) {
		0 ignored issues – show Duplication introduced 2021-03-18 21:25 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
187		return {
188		tagAlterPreservation: !!(flagsFirstByte & 64),
189		fileAlterPreservation: !!(flagsFirstByte & 32),
190		readOnly: !!(flagsFirstByte & 16),
191		groupingIdentity: !!(flagsSecondByte & 64),
192		compression: !!(flagsSecondByte & 8),
193		encryption: !!(flagsSecondByte & 4),
194		unsynchronisation: !!(flagsSecondByte & 2),
195		dataLengthIndicator: !!(flagsSecondByte & 1)
196		}
197		}
198		return {}
199		}
200
201		module.exports.processUnsynchronisedBuffer = function(buffer) {
202		const newDataArr = []
203		if(buffer.length > 0) {
204		newDataArr.push(buffer[0])
205		}
206		for(let i = 1; i < buffer.length; i++) {
207		if(buffer[i - 1] === 0xFF && buffer[i] === 0x00)
208		continue
		0 ignored issues – show Coding Style Best Practice introduced 2021-04-26 20:46 UTC by Report Bug Copy Issue Report Curly braces around statements make for more readable code and help prevent bugs when you add further statements. Consider adding curly braces around all statements when they are executed conditionally. This is optional if there is only one statement, but leaving them out can lead to unexpected behaviour if another statement is added later. Consider: if (a > 0) b = 42; If you or someone else later decides to put another statement in, only the first statement will be executed. if (a > 0) console.log("a > 0"); b = 42; In this case the statement `b = 42` will always be executed, while the logging statement will be executed conditionally. if (a > 0) { console.log("a > 0"); b = 42; } ensures that the proper code will be executed conditionally no matter how many statements are added or removed. Loading history...
209		newDataArr.push(buffer[i])
210		}
211		return Buffer.from(newDataArr)
212		}
213

Zazama / node-id3

Push — master ( 62bfad...2b6a7f )

ID3Util.js ➔ constructor A

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