integer.js ➔ setUp - Code Metrics - Inspection of "Fix links in documentation" - rochars/byte-data - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Push — master ( 567ae9...db344a )

by Rafael S.

created 2018-07-24 07:51 UTC

integer.js ➔ setUp A

↳ Parent: lib/integer.js

Complexity

Conditions	4
Paths	8

Size

Total Lines	21
Code Lines	12

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	4
eloc	12
nc	8
nop	1
dl	0
loc	21
rs	9.8
c	0
b	0
f	0

/*
 * Copyright (c) 2017-2018 Rafael da Silva Rocha.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

/**
 * @fileoverview Pack and unpack two's complement ints and unsigned ints.
 * @see https://github.com/rochars/byte-data
 */

/**
 * A class to pack and unpack two's complement ints and unsigned ints.
 */
export default class Integer {

  constructor() {
    /**
     * @type {number}
     */
    this.offset = 0;
    /**
     * @type {number}
     */
    this.realOffset_ = 0;
    /**
     * @type {number}
     * @private
     */
    this.bits_ = 0;
    /**
     * @type {number}
     * @private
     */
    this.lastByteMask_ = 0;
    /**
     * @type {number}
     * @private
     */
    this.max_ = 0;
    /**
     * @type {number}
     * @private
     */
    this.min_ = 0;
  }

  /**
   * Set up the object to start serializing/deserializing a data type..
   * @param {!Object} theType The type definition.
   */
  setUp(theType) {
    /**
     * The max number of bits used by the data.
     * @type {number}
     * @private
     */
    this.bits_ = theType.bits;
    // Set the min and max values according to the number of bits
    /** @type {number} */
    let max = Math.pow(2, this.bits_);
    if (theType.signed) {
      this.max_ = max / 2 -1;
      this.min_ = -max / 2;
    } else {
      this.max_ = max - 1;
      this.min_ = 0;
    }
    this.setLastByteMask_();
    this.offset = this.bits_ < 8 ? 1 : Math.ceil(this.bits_ / 8);
    this.realOffset_ = this.bits_ === 64 ? 4 : this.offset;
  }

  /**
   * Read one integer number from a byte buffer.
   * @param {!Uint8Array} bytes An array of bytes.
   * @param {number=} i The index to read.
   * @return {number}
   */
  read(bytes, i=0) {
    let num = 0;
    for(let x=0; x<this.realOffset_; x++) {
      num += bytes[i + x] * Math.pow(256, x);
    }
    return this.overflow_(this.sign_(num)); 
  }

  /**
   * Write one integer number to a byte buffer.
   * @param {!Uint8Array} bytes An array of bytes.
   * @param {number} num The number.
   * @param {number=} j The index being written in the byte buffer.
   * @return {number} The next index to write on the byte buffer.
   * @private
   */
  write(bytes, num, j=0) {
    j = this.writeFirstByte_(bytes, this.overflow_(num), j);
    for (let i = 2, len = this.realOffset_; i < len; i++, j++) {
      bytes[j] = Math.floor(num / Math.pow(2, ((i - 1) * 8))) & 255;
    }
    if (this.bits_ > 8) {
      bytes[j] = Math.floor(
          num / Math.pow(2, ((this.realOffset_ - 1) * 8))) & this.lastByteMask_;
      j++;

    }
    return j;
  }

  /**
   * Sign a number.
   * @param {number} num The number.
   * @return {number}
   * @private
   */
  sign_(num) {
    if (num > this.max_) {
      num -= (this.max_ * 2) + 2;
    }
    return num;
  }

  /**
   * Trows error in case of underflow or overflow.
   * @param {number} num The number.
   * @return {number}
   * @throws {Error} on overflow or underflow.
   * @private
   */
  overflow_(num) {
    if (num > this.max_) {
      throw new Error('Overflow.');
    } else if (num < this.min_) {
      throw new Error('Underflow.');
    }
    return num;
  }

  /**
   * Set the mask that should be used when writing the last byte.
   * @private
   */
  setLastByteMask_() {
    /** @type {number} */
    let r = 8 - ((((this.bits_ - 1) | 7) + 1) - this.bits_);
    this.lastByteMask_ = Math.pow(2, r > 0 ? r : 8) - 1;
  }

  /**
   * Write the first byte of a integer number.
   * @param {!Uint8Array} bytes An array of bytes.
   * @param {number} number The number.
   * @param {number} j The index being written in the byte buffer.
   * @return {number} The next index to write on the byte buffer.
   * @private
   */
  writeFirstByte_(bytes, number, j) {
    if (this.bits_ < 8) {
      bytes[j] = number < 0 ? number + Math.pow(2, this.bits_) : number;
    } else {
      bytes[j] = number & 255;
    }
    return j + 1;
  }
}


1			/*
2			* Copyright (c) 2017-2018 Rafael da Silva Rocha.
3			*
4			* Permission is hereby granted, free of charge, to any person obtaining
5			* a copy of this software and associated documentation files (the
6			* "Software"), to deal in the Software without restriction, including
7			* without limitation the rights to use, copy, modify, merge, publish,
8			* distribute, sublicense, and/or sell copies of the Software, and to
9			* permit persons to whom the Software is furnished to do so, subject to
10			* the following conditions:
11			*
12			* The above copyright notice and this permission notice shall be
13			* included in all copies or substantial portions of the Software.
14			*
15			* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16			* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17			* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18			* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
19			* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
20			* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
21			* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22			*
23			*/
24
25			/**
26			* @fileoverview Pack and unpack two's complement ints and unsigned ints.
27			* @see https://github.com/rochars/byte-data
28			*/
29
30			/**
31			* A class to pack and unpack two's complement ints and unsigned ints.
32			*/
33			export default class Integer {
34
35			constructor() {
36			/**
37			* @type {number}
38			*/
39			this.offset = 0;
40			/**
41			* @type {number}
42			*/
43			this.realOffset_ = 0;
44			/**
45			* @type {number}
46			* @private
47			*/
48			this.bits_ = 0;
49			/**
50			* @type {number}
51			* @private
52			*/
53			this.lastByteMask_ = 0;
54			/**
55			* @type {number}
56			* @private
57			*/
58			this.max_ = 0;
59			/**
60			* @type {number}
61			* @private
62			*/
63			this.min_ = 0;
64			}
65
66			/**
67			* Set up the object to start serializing/deserializing a data type..
68			* @param {!Object} theType The type definition.
69			*/
70			setUp(theType) {
71			/**
72			* The max number of bits used by the data.
73			* @type {number}
74			* @private
75			*/
76			this.bits_ = theType.bits;
77			// Set the min and max values according to the number of bits
78			/** @type {number} */
79			let max = Math.pow(2, this.bits_);
80			if (theType.signed) {
81			this.max_ = max / 2 -1;
82			this.min_ = -max / 2;
83			} else {
84			this.max_ = max - 1;
85			this.min_ = 0;
86			}
87			this.setLastByteMask_();
88			this.offset = this.bits_ < 8 ? 1 : Math.ceil(this.bits_ / 8);
89			this.realOffset_ = this.bits_ === 64 ? 4 : this.offset;
90			}
91
92			/**
93			* Read one integer number from a byte buffer.
94			* @param {!Uint8Array} bytes An array of bytes.
95			* @param {number=} i The index to read.
96			* @return {number}
97			*/
98			read(bytes, i=0) {
99			let num = 0;
100			for(let x=0; x<this.realOffset_; x++) {
101			num += bytes[i + x] * Math.pow(256, x);
102			}
103			return this.overflow_(this.sign_(num));
104			}
105
106			/**
107			* Write one integer number to a byte buffer.
108			* @param {!Uint8Array} bytes An array of bytes.
109			* @param {number} num The number.
110			* @param {number=} j The index being written in the byte buffer.
111			* @return {number} The next index to write on the byte buffer.
112			* @private
113			*/
114			write(bytes, num, j=0) {
115			j = this.writeFirstByte_(bytes, this.overflow_(num), j);
116			for (let i = 2, len = this.realOffset_; i < len; i++, j++) {
117			bytes[j] = Math.floor(num / Math.pow(2, ((i - 1) * 8))) & 255;
118			}
119			if (this.bits_ > 8) {
120			bytes[j] = Math.floor(
121			num / Math.pow(2, ((this.realOffset_ - 1) * 8))) & this.lastByteMask_;
122			j++;
			0 ignored issues – show Complexity Coding Style introduced 2018-07-16 17:11 UTC by Report Bug Copy Issue Report You seem to be assigning a new value to the loop variable `j` here. Please check if this was indeed your intention. Even if it was, consider using another kind of loop instead. Loading history...
123			}
124			return j;
125			}
126
127			/**
128			* Sign a number.
129			* @param {number} num The number.
130			* @return {number}
131			* @private
132			*/
133			sign_(num) {
134			if (num > this.max_) {
135			num -= (this.max_ * 2) + 2;
136			}
137			return num;
138			}
139
140			/**
141			* Trows error in case of underflow or overflow.
142			* @param {number} num The number.
143			* @return {number}
144			* @throws {Error} on overflow or underflow.
145			* @private
146			*/
147			overflow_(num) {
148			if (num > this.max_) {
149			throw new Error('Overflow.');
150			} else if (num < this.min_) {
151			throw new Error('Underflow.');
152			}
153			return num;
154			}
155
156			/**
157			* Set the mask that should be used when writing the last byte.
158			* @private
159			*/
160			setLastByteMask_() {
161			/** @type {number} */
162			let r = 8 - ((((this.bits_ - 1) \| 7) + 1) - this.bits_);
163			this.lastByteMask_ = Math.pow(2, r > 0 ? r : 8) - 1;
164			}
165
166			/**
167			* Write the first byte of a integer number.
168			* @param {!Uint8Array} bytes An array of bytes.
169			* @param {number} number The number.
170			* @param {number} j The index being written in the byte buffer.
171			* @return {number} The next index to write on the byte buffer.
172			* @private
173			*/
174			writeFirstByte_(bytes, number, j) {
175			if (this.bits_ < 8) {
176			bytes[j] = number < 0 ? number + Math.pow(2, this.bits_) : number;
177			} else {
178			bytes[j] = number & 255;
179			}
180			return j + 1;
181			}
182			}
183

rochars / byte-data

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integer.js ➔ setUp A

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