index.js ➔ unpack - Code Metrics - Inspection of "Update docs with v11.0" - rochars/wavefile - Measure and Improve Code Quality continuously with Scrutinizer

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Push — master ( 13b350...038bd4 )

by Rafael S.

created 2020-01-30 04:04 UTC

index.js ➔ unpack A

↳ Parent: lib/parsers/binary/index.js

Complexity

Conditions

Size

Total Lines	6
Code Lines	5

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	1
eloc	5
dl	0
loc	6
rs	10
c	0
b	0
f	0

/*
 * Copyright (c) 2017-2019 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 binary parser.
 * @see https://github.com/rochars/byte-data
 * @see https://github.com/rochars/wavefile
 */

import { endianness } from './lib/endianness';
import { pack as packUTF8, unpack as unpackUTF8 } from './lib/utf8-parser';
import { IntParser } from './lib/int-parser';
import { FloatParser } from './lib/float-parser';

/**
 * Read a string of UTF-8 characters from a byte buffer.
 * @param {!(Uint8Array|Array<number>)} buffer A byte buffer.
 * @param {number} [index=0] The buffer index to start reading.
 * @param {number} [end=buffer.length] The index to stop reading, non inclusive.
 * @return {string}
 */
export function unpackString(buffer, index=0, end=buffer.length) {
  return unpackUTF8(buffer, index, end);
}

/**
 * Write a string of UTF-8 characters as a byte buffer.
 * @param {string} str The string to pack.
 * @return {!Array<number>} The UTF-8 string bytes.
 */
export function packString(str) {
  /** @type {!Array<number>} */
  let buffer = [];
  packUTF8(str, buffer);
  return buffer;
}

/**
 * Write a string of UTF-8 characters to a byte buffer.
 * @param {string} str The string to pack.
 * @param {!(Uint8Array|Array<number>)} buffer The output buffer.
 * @param {number} [index=0] The buffer index to start writing.
 * @return {number} The next index to write in the buffer.
 */
export function packStringTo(str, buffer, index=0) {
  return packUTF8(str, buffer, index);
}

// Numbers
/**
 * Pack a array of numbers to a byte buffer.
 * All other packing functions are interfaces to this function.
 * @param {!(Array<number>|TypedArray)} values The values to pack.
 * @param {!{bits:number,
 *   fp: (boolean|undefined),
 *   signed: (boolean|undefined),
 *   be: (boolean|undefined)}} theType The type definition.
 * @param {!(Uint8Array|Array<number>)} buffer The buffer to write on.
 * @param {number} [index=0] The buffer index to start writing.
 * @return {number} The next index to write.
 * @throws {Error} If the type definition is not valid.
 */
export function packArrayTo(values, theType, buffer, index=0) {
  theType = theType || {};
  /** @type {!Object} */
  let packer = getParser_(theType.bits, theType.fp, theType.signed);
  /** @type {number} */
  let offset = Math.ceil(theType.bits / 8);
  /** @type {number} */
  let i = 0;
  /** @type {number} */
  let start = index;
  for (let valuesLen = values.length; i < valuesLen; i++) {
    index = packer.pack(buffer, values[i], index);
  }
  if (theType.be) {
    endianness(buffer, offset, start, index);
  }
  return index;
}

/**
 * Unpack a array of numbers from a byte buffer to a array or a typed array.
 * All other unpacking functions are interfaces to this function.
 * @param {!(Uint8Array|Array<number>)} buffer The byte buffer.
 * @param {!{bits:number,
 *   fp: (boolean|undefined),
 *   signed: (boolean|undefined),
 *   be: (boolean|undefined)}} theType The type definition.
 * @param {!(TypedArray|Array<number>)} output The output array or typed array.
 * @param {number} [start=0] The buffer index to start reading.
 * @param {number} [end=buffer.length] The buffer index to stop reading.
 * @throws {Error} If the type definition is not valid.
 */
export function unpackArrayTo(
    buffer, theType, output, start=0, end=buffer.length) {
  theType = theType || {};
  /** @type {!Object} */
  let parser = getParser_(theType.bits, theType.fp, theType.signed);
  // getUnpackLen_ will adjust the end index according to the size
  // of the input buffer and the byte offset or throw a error on bad
  // end index if safe=true
  end = getUnpackLen_(buffer, start, end, parser.offset);
  if (theType.be) {
    /** @type {!(Uint8Array|Array<number>)} */
    let readBuffer = copyBuffer_(buffer);
    if (theType.be) {
      endianness(readBuffer, parser.offset, start, end);
    }
    unpack_(readBuffer, output, start, end, parser);
  } else {
    unpack_(buffer, output, start, end, parser);
  }
}

/**
 * Pack a number to a byte buffer.
 * @param {number} value The value.
 * @param {!{bits:number,
 *   fp: (boolean|undefined),
 *   signed: (boolean|undefined),
 *   be: (boolean|undefined)}} theType The type definition.
 * @param {!(Uint8Array|Array<number>)} buffer The byte buffer to write on.
 * @param {number} [index=0] The buffer index to write.
 * @return {number} The next index to write.
 * @throws {Error} If the type definition is not valid.
 */
export function packTo(value, theType, buffer, index=0) {
  return packArrayTo([value], theType, buffer, index);
}

/**
 * Pack a number as a array of bytes.
 * @param {number} value The number to pack.
 * @param {!{bits:number,
 *   fp: (boolean|undefined),
 *   signed: (boolean|undefined),
 *   be: (boolean|undefined)}} theType The type definition.
 * @return {!Array<number>} The packed value.
 * @throws {Error} If the type definition is not valid.
 */
export function pack(value, theType) {
  /** @type {!Array<number>} */
  let output = [];
  packTo(value, theType, output, 0);
  return output;
}

/**
 * Unpack a number from a byte buffer.
 * @param {!(Uint8Array|Array<number>)} buffer The byte buffer.
 * @param {!{bits:number,
 *   fp: (boolean|undefined),
 *   signed: (boolean|undefined),
 *   be: (boolean|undefined)}} theType The type definition.
 * @param {number} [index=0] The buffer index to read.
 * @return {number}
 * @throws {Error} If the type definition is not valid.
 */
export function unpack(buffer, theType, index=0) {
  let output = [];
  unpackArrayTo(buffer, theType, output,
    index, index + Math.ceil(theType.bits / 8));
  return output[0];
}

/**
 * Unpack a array of numbers from a byte buffer to a array or a typed array.
 * @param {!(Uint8Array|Array<number>)} buffer The byte buffer.
 * @param {!(TypedArray|Array<number>)} output The output array or typed array.
 * @param {number} start The buffer index to start reading.
 * @param {number} end The buffer index to stop reading.
 * @param {!Object} parser The parser.
 * @private
 */
function unpack_(buffer, output, start, end, parser) {
  /** @type {number} */
  let offset = parser.offset;
  for (let index = 0, j = start; j < end; j += offset, index++) {
    output[index] = parser.unpack(buffer, j);
  }
}

/**
 * Copy a byte buffer as a Array or Uint8Array.
 * @param {!(Uint8Array|Array<number>)} buffer The byte buffer.
 * @return {!(Uint8Array|Array<number>)}
 * @private
 */
function copyBuffer_(buffer) {
  return new Uint8Array(buffer);
}

/**
 * Adjust the end index according to the input buffer length and the
 * type offset.
 * @param {!(Uint8Array|Array<number>)} buffer The byte buffer.
 * @param {number} start The buffer index to start reading.
 * @param {number} end The buffer index to stop reading.
 * @param {number} offset The number of bytes used by the type.
 * @private
 */
function getUnpackLen_(buffer, start, end, offset) {
  /** @type {number} */
  let extra = (end - start) % offset;
  return end - extra;
}

/**
 * Return a parser for int, uint or fp numbers.
 * @param {number} bits The number of bits.
 * @param {boolean|undefined} fp True for fp numbers, false otherwise.
 * @param {boolean|undefined} signed True for signed ints, false otherwise.
 * @return {!Object}
 * @private
 */
function getParser_(bits, fp, signed) {
  if (fp && bits == 32) {
    return new FloatParser(8, 23);
  } else if(fp && bits == 64) {
    return new FloatParser(11, 52);
  }
  return new IntParser(bits, signed);
}


1			/*
2			* Copyright (c) 2017-2019 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 binary parser.
27			* @see https://github.com/rochars/byte-data
28			* @see https://github.com/rochars/wavefile
29			*/
30
31			import { endianness } from './lib/endianness';
32			import { pack as packUTF8, unpack as unpackUTF8 } from './lib/utf8-parser';
33			import { IntParser } from './lib/int-parser';
34			import { FloatParser } from './lib/float-parser';
35
36			/**
37			* Read a string of UTF-8 characters from a byte buffer.
38			* @param {!(Uint8Array\|Array<number>)} buffer A byte buffer.
39			* @param {number} [index=0] The buffer index to start reading.
40			* @param {number} [end=buffer.length] The index to stop reading, non inclusive.
41			* @return {string}
42			*/
43			export function unpackString(buffer, index=0, end=buffer.length) {
44			return unpackUTF8(buffer, index, end);
45			}
46
47			/**
48			* Write a string of UTF-8 characters as a byte buffer.
49			* @param {string} str The string to pack.
50			* @return {!Array<number>} The UTF-8 string bytes.
51			*/
52			export function packString(str) {
53			/** @type {!Array<number>} */
54			let buffer = [];
55			packUTF8(str, buffer);
56			return buffer;
57			}
58
59			/**
60			* Write a string of UTF-8 characters to a byte buffer.
61			* @param {string} str The string to pack.
62			* @param {!(Uint8Array\|Array<number>)} buffer The output buffer.
63			* @param {number} [index=0] The buffer index to start writing.
64			* @return {number} The next index to write in the buffer.
65			*/
66			export function packStringTo(str, buffer, index=0) {
67			return packUTF8(str, buffer, index);
68			}
69
70			// Numbers
71			/**
72			* Pack a array of numbers to a byte buffer.
73			* All other packing functions are interfaces to this function.
74			* @param {!(Array<number>\|TypedArray)} values The values to pack.
75			* @param {!{bits:number,
76			* fp: (boolean\|undefined),
77			* signed: (boolean\|undefined),
78			* be: (boolean\|undefined)}} theType The type definition.
79			* @param {!(Uint8Array\|Array<number>)} buffer The buffer to write on.
80			* @param {number} [index=0] The buffer index to start writing.
81			* @return {number} The next index to write.
82			* @throws {Error} If the type definition is not valid.
83			*/
84			export function packArrayTo(values, theType, buffer, index=0) {
85			theType = theType \|\| {};
86			/** @type {!Object} */
87			let packer = getParser_(theType.bits, theType.fp, theType.signed);
88			/** @type {number} */
89			let offset = Math.ceil(theType.bits / 8);
90			/** @type {number} */
91			let i = 0;
92			/** @type {number} */
93			let start = index;
94			for (let valuesLen = values.length; i < valuesLen; i++) {
95			index = packer.pack(buffer, values[i], index);
96			}
97			if (theType.be) {
98			endianness(buffer, offset, start, index);
99			}
100			return index;
101			}
102
103			/**
104			* Unpack a array of numbers from a byte buffer to a array or a typed array.
105			* All other unpacking functions are interfaces to this function.
106			* @param {!(Uint8Array\|Array<number>)} buffer The byte buffer.
107			* @param {!{bits:number,
108			* fp: (boolean\|undefined),
109			* signed: (boolean\|undefined),
110			* be: (boolean\|undefined)}} theType The type definition.
111			* @param {!(TypedArray\|Array<number>)} output The output array or typed array.
112			* @param {number} [start=0] The buffer index to start reading.
113			* @param {number} [end=buffer.length] The buffer index to stop reading.
114			* @throws {Error} If the type definition is not valid.
115			*/
116			export function unpackArrayTo(
117			buffer, theType, output, start=0, end=buffer.length) {
118			theType = theType \|\| {};
119			/** @type {!Object} */
120			let parser = getParser_(theType.bits, theType.fp, theType.signed);
121			// getUnpackLen_ will adjust the end index according to the size
122			// of the input buffer and the byte offset or throw a error on bad
123			// end index if safe=true
124			end = getUnpackLen_(buffer, start, end, parser.offset);
125			if (theType.be) {
126			/** @type {!(Uint8Array\|Array<number>)} */
127			let readBuffer = copyBuffer_(buffer);
128			if (theType.be) {
129			endianness(readBuffer, parser.offset, start, end);
130			}
131			unpack_(readBuffer, output, start, end, parser);
132			} else {
133			unpack_(buffer, output, start, end, parser);
134			}
135			}
136
137			/**
138			* Pack a number to a byte buffer.
139			* @param {number} value The value.
140			* @param {!{bits:number,
141			* fp: (boolean\|undefined),
142			* signed: (boolean\|undefined),
143			* be: (boolean\|undefined)}} theType The type definition.
144			* @param {!(Uint8Array\|Array<number>)} buffer The byte buffer to write on.
145			* @param {number} [index=0] The buffer index to write.
146			* @return {number} The next index to write.
147			* @throws {Error} If the type definition is not valid.
148			*/
149			export function packTo(value, theType, buffer, index=0) {
150			return packArrayTo([value], theType, buffer, index);
151			}
152
153			/**
154			* Pack a number as a array of bytes.
155			* @param {number} value The number to pack.
156			* @param {!{bits:number,
157			* fp: (boolean\|undefined),
158			* signed: (boolean\|undefined),
159			* be: (boolean\|undefined)}} theType The type definition.
160			* @return {!Array<number>} The packed value.
161			* @throws {Error} If the type definition is not valid.
162			*/
163			export function pack(value, theType) {
164			/** @type {!Array<number>} */
165			let output = [];
166			packTo(value, theType, output, 0);
167			return output;
168			}
169
170			/**
171			* Unpack a number from a byte buffer.
172			* @param {!(Uint8Array\|Array<number>)} buffer The byte buffer.
173			* @param {!{bits:number,
174			* fp: (boolean\|undefined),
175			* signed: (boolean\|undefined),
176			* be: (boolean\|undefined)}} theType The type definition.
177			* @param {number} [index=0] The buffer index to read.
178			* @return {number}
179			* @throws {Error} If the type definition is not valid.
180			*/
181			export function unpack(buffer, theType, index=0) {
182			let output = [];
183			unpackArrayTo(buffer, theType, output,
184			index, index + Math.ceil(theType.bits / 8));
185			return output[0];
186			}
187
188			/**
189			* Unpack a array of numbers from a byte buffer to a array or a typed array.
190			* @param {!(Uint8Array\|Array<number>)} buffer The byte buffer.
191			* @param {!(TypedArray\|Array<number>)} output The output array or typed array.
192			* @param {number} start The buffer index to start reading.
193			* @param {number} end The buffer index to stop reading.
194			* @param {!Object} parser The parser.
195			* @private
196			*/
197			function unpack_(buffer, output, start, end, parser) {
198			/** @type {number} */
199			let offset = parser.offset;
200			for (let index = 0, j = start; j < end; j += offset, index++) {
201			output[index] = parser.unpack(buffer, j);
202			}
203			}
204
205			/**
206			* Copy a byte buffer as a Array or Uint8Array.
207			* @param {!(Uint8Array\|Array<number>)} buffer The byte buffer.
208			* @return {!(Uint8Array\|Array<number>)}
209			* @private
210			*/
211			function copyBuffer_(buffer) {
212			return new Uint8Array(buffer);
213			}
214
215			/**
216			* Adjust the end index according to the input buffer length and the
217			* type offset.
218			* @param {!(Uint8Array\|Array<number>)} buffer The byte buffer.
219			* @param {number} start The buffer index to start reading.
220			* @param {number} end The buffer index to stop reading.
221			* @param {number} offset The number of bytes used by the type.
222			* @private
223			*/
224			function getUnpackLen_(buffer, start, end, offset) {
225			/** @type {number} */
226			let extra = (end - start) % offset;
227			return end - extra;
228			}
229
230			/**
231			* Return a parser for int, uint or fp numbers.
232			* @param {number} bits The number of bits.
233			* @param {boolean\|undefined} fp True for fp numbers, false otherwise.
234			* @param {boolean\|undefined} signed True for signed ints, false otherwise.
235			* @return {!Object}
236			* @private
237			*/
238			function getParser_(bits, fp, signed) {
239			if (fp && bits == 32) {
240			return new FloatParser(8, 23);
241			} else if(fp && bits == 64) {
242			return new FloatParser(11, 52);
243			}
244			return new IntParser(bits, signed);
245			}
246

rochars / wavefile

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index.js ➔ unpack A

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