RIFFFile.readString_ - Code Metrics - Inspection of "Move WAVE format validation back to WaveFile" - rochars/wavefile - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Branch — riff-file (882407)

by Rafael S.

created 2019-08-01 08:01 UTC

RIFFFile.readString_ A

↳ Parent: RIFFFile

Complexity

Conditions

Size

Total Lines	7
Code Lines	5

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	1
eloc	5
dl	0
loc	7
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 The RIFFFile class.
 * @see https://github.com/rochars/wavefile
 */

import {unpackString, unpack} from 'byte-data';

/**
 * A class to perform low-level reading of RIFF files.
 */
export default class RIFFFile {

  constructor() {
    
    /** @type {number} */
    this.head_ = 0;
    /** @type {!Object} */
    this.uInt32_ = {bits: 32, be: false};
    /** @type {!Object} */
    this.uInt16_ = {bits: 16, be: false};
    /**
     * The container identifier.
     * 'RIFF', 'RIFX' and 'RF64' are supported.
     * @type {string}
     */
    this.container = '';
    /**
     * @type {number}
     */
    this.chunkSize = 0;
    /**
     * The format.
     * Always 'WAVE'.
     * @type {string}
     */
    this.format = '';
    /**
     * A object defining the start and end of all chunks in a wav buffer.
     * @type {!Object}
     */
    this.signature = {};
  }

  /**
   * Return the chunks in a RIFF/RIFX file.
   * @param {!Uint8Array} buffer The file bytes.
   */
  getSignature_(buffer) {
      this.head_ = 0;
      /** @type {string} */
      let chunkId = this.getChunkId_(buffer, 0);
      this.uInt32_.be = chunkId == 'RIFX';
      /** @type {string} */
      let format = unpackString(buffer, 8, 12);
      this.head_ += 4;
      this.signature = {
          chunkId: chunkId,
          chunkSize: this.getChunkSize_(buffer, 0),
          format: format,
          subChunks: this.getSubChunksIndex_(buffer)
      };
  }

  /**
    * Find a chunk by its fourCC_ in a array of RIFF chunks.
    * @param {string} chunkId The chunk fourCC_.
    * @param {boolean} multiple True if there may be multiple chunks
    *    with the same chunkId.
    * @return {Object}
    */
  findChunk_(chunkId, multiple=false) {
    /** @type {!Array<!Object>} */
    let chunks = this.signature.subChunks;
    /** @type {!Array<!Object>} */
    let chunk = [];
    for (let i=0; i<chunks.length; i++) {
      if (chunks[i].chunkId == chunkId) {
        if (multiple) {
          chunk.push(chunks[i]);
        } else {
          return chunks[i];
        }
      }
    }
    if (chunkId == 'LIST') {
      return chunk.length ? chunk : null;
    }
    return null;
  }

  /**
   * Return the sub chunks of a RIFF file.
   * @param {!Uint8Array} buffer the RIFF file bytes.
   * @return {!Array<Object>} The subchunks of a RIFF/RIFX or LIST chunk.
   * @private
   */
  getSubChunksIndex_(buffer) {
      /** @type {!Array<!Object>} */
      let chunks = [];
      /** @type {number} */
      let i = this.head_;
      while(i <= buffer.length - 8) {
          chunks.push(this.getSubChunkIndex_(buffer, i));
          i += 8 + chunks[chunks.length - 1].chunkSize;
          i = i % 2 ? i + 1 : i;
      }
      return chunks;
  }

  /**
   * Return a sub chunk from a RIFF file.
   * @param {!Uint8Array} buffer the RIFF file bytes.
   * @param {number} index The start index of the chunk.
   * @return {!Object} A subchunk of a RIFF/RIFX or LIST chunk.
   * @private
   */
  getSubChunkIndex_(buffer, index) {
      /** @type {!Object} */
      let chunk = {
          chunkId: this.getChunkId_(buffer, index),
          chunkSize: this.getChunkSize_(buffer, index),
      };
      if (chunk.chunkId == 'LIST') {
          chunk.format = unpackString(buffer, index + 8, index + 12);
          this.head_ += 4;
          chunk.subChunks = this.getSubChunksIndex_(buffer);
      } else {
          /** @type {number} */
          let realChunkSize = chunk.chunkSize % 2 ?
              chunk.chunkSize + 1 : chunk.chunkSize;
          this.head_ = index + 8 + realChunkSize;
          chunk.chunkData = {
              start: index + 8,
              end: this.head_
          };
      }
      return chunk;
  }

  /**
   * Return the fourCC_ of a chunk.
   * @param {!Uint8Array} buffer the RIFF file bytes.
   * @param {number} index The start index of the chunk.
   * @return {string} The id of the chunk.
   * @private
   */
  getChunkId_(buffer, index) {
      this.head_ += 4;
      return unpackString(buffer, index, index + 4);
  }

  /**
   * Return the size of a chunk.
   * @param {!Uint8Array} buffer the RIFF file bytes.
   * @param {number} index The start index of the chunk.
   * @return {number} The size of the chunk without the id and size fields.
   * @private
   */
  getChunkSize_(buffer, index) {
      this.head_ += 4;
      return unpack(buffer, this.uInt32_, index + 4);
  }

  /**
   * Read the RIFF chunk a wave file.
   * @param {!Uint8Array} bytes A wav buffer.
   * @throws {Error} If no 'RIFF' chunk is found.
   * @private
   */
  readRIFFChunk_(bytes) {
    this.head_ = 0;
    this.container = this.readString_(bytes, 4);
    if (['RIFF', 'RIFX', 'RF64'].indexOf(this.container) === -1) {
      throw Error('Not a supported format.');
    }
    this.uInt16_.be = this.container === 'RIFX';
    this.uInt32_.be = this.uInt16_.be;
    this.chunkSize = this.read_(bytes, this.uInt32_);
  }

  /**
   * Read bytes as a ZSTR string.
   * @param {!Uint8Array} bytes The bytes.
   * @param {number} index the index to start reading.
   * @return {string} The string.
   * @private
   */
  readZSTR_(bytes, index=0) {
    for (let i = index; i < bytes.length; i++) {
      this.head_++;
      if (bytes[i] === 0) {
        break;
      }
    }
    return unpackString(bytes, index, this.head_ - 1);
  }

  /**
   * Read bytes as a string from a RIFF chunk.
   * @param {!Uint8Array} bytes The bytes.
   * @param {number} maxSize the max size of the string.
   * @return {string} The string.
   * @private
   */
  readString_(bytes, maxSize) {
    /** @type {string} */
    let str = '';
    str = unpackString(bytes, this.head_, this.head_ + maxSize);
    this.head_ += maxSize;
    return str;
  }

  /**
   * Read a number from a chunk.
   * @param {!Uint8Array} bytes The chunk bytes.
   * @param {!Object} bdType The type definition.
   * @return {number} The number.
   * @private
   */
  read_(bytes, bdType) {
    /** @type {number} */
    let size = bdType.bits / 8;
    /** @type {number} */
    let value = unpack(bytes, bdType, this.head_);
    this.head_ += size;
    return value;
  }
}


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 The RIFFFile class.
27			* @see https://github.com/rochars/wavefile
28			*/
29
30			import {unpackString, unpack} from 'byte-data';
31
32			/**
33			* A class to perform low-level reading of RIFF files.
34			*/
35			export default class RIFFFile {
36
37			constructor() {
38
39			/** @type {number} */
40			this.head_ = 0;
41			/** @type {!Object} */
42			this.uInt32_ = {bits: 32, be: false};
43			/** @type {!Object} */
44			this.uInt16_ = {bits: 16, be: false};
45			/**
46			* The container identifier.
47			* 'RIFF', 'RIFX' and 'RF64' are supported.
48			* @type {string}
49			*/
50			this.container = '';
51			/**
52			* @type {number}
53			*/
54			this.chunkSize = 0;
55			/**
56			* The format.
57			* Always 'WAVE'.
58			* @type {string}
59			*/
60			this.format = '';
61			/**
62			* A object defining the start and end of all chunks in a wav buffer.
63			* @type {!Object}
64			*/
65			this.signature = {};
66			}
67
68			/**
69			* Return the chunks in a RIFF/RIFX file.
70			* @param {!Uint8Array} buffer The file bytes.
71			*/
72			getSignature_(buffer) {
73			this.head_ = 0;
74			/** @type {string} */
75			let chunkId = this.getChunkId_(buffer, 0);
76			this.uInt32_.be = chunkId == 'RIFX';
77			/** @type {string} */
78			let format = unpackString(buffer, 8, 12);
79			this.head_ += 4;
80			this.signature = {
81			chunkId: chunkId,
82			chunkSize: this.getChunkSize_(buffer, 0),
83			format: format,
84			subChunks: this.getSubChunksIndex_(buffer)
85			};
86			}
87
88			/**
89			* Find a chunk by its fourCC_ in a array of RIFF chunks.
90			* @param {string} chunkId The chunk fourCC_.
91			* @param {boolean} multiple True if there may be multiple chunks
92			* with the same chunkId.
93			* @return {Object}
94			*/
95			findChunk_(chunkId, multiple=false) {
96			/** @type {!Array<!Object>} */
97			let chunks = this.signature.subChunks;
98			/** @type {!Array<!Object>} */
99			let chunk = [];
100			for (let i=0; i<chunks.length; i++) {
101			if (chunks[i].chunkId == chunkId) {
102			if (multiple) {
103			chunk.push(chunks[i]);
104			} else {
105			return chunks[i];
106			}
107			}
108			}
109			if (chunkId == 'LIST') {
110			return chunk.length ? chunk : null;
111			}
112			return null;
113			}
114
115			/**
116			* Return the sub chunks of a RIFF file.
117			* @param {!Uint8Array} buffer the RIFF file bytes.
118			* @return {!Array<Object>} The subchunks of a RIFF/RIFX or LIST chunk.
119			* @private
120			*/
121			getSubChunksIndex_(buffer) {
122			/** @type {!Array<!Object>} */
123			let chunks = [];
124			/** @type {number} */
125			let i = this.head_;
126			while(i <= buffer.length - 8) {
127			chunks.push(this.getSubChunkIndex_(buffer, i));
128			i += 8 + chunks[chunks.length - 1].chunkSize;
129			i = i % 2 ? i + 1 : i;
130			}
131			return chunks;
132			}
133
134			/**
135			* Return a sub chunk from a RIFF file.
136			* @param {!Uint8Array} buffer the RIFF file bytes.
137			* @param {number} index The start index of the chunk.
138			* @return {!Object} A subchunk of a RIFF/RIFX or LIST chunk.
139			* @private
140			*/
141			getSubChunkIndex_(buffer, index) {
142			/** @type {!Object} */
143			let chunk = {
144			chunkId: this.getChunkId_(buffer, index),
145			chunkSize: this.getChunkSize_(buffer, index),
146			};
147			if (chunk.chunkId == 'LIST') {
148			chunk.format = unpackString(buffer, index + 8, index + 12);
149			this.head_ += 4;
150			chunk.subChunks = this.getSubChunksIndex_(buffer);
151			} else {
152			/** @type {number} */
153			let realChunkSize = chunk.chunkSize % 2 ?
154			chunk.chunkSize + 1 : chunk.chunkSize;
155			this.head_ = index + 8 + realChunkSize;
156			chunk.chunkData = {
157			start: index + 8,
158			end: this.head_
159			};
160			}
161			return chunk;
162			}
163
164			/**
165			* Return the fourCC_ of a chunk.
166			* @param {!Uint8Array} buffer the RIFF file bytes.
167			* @param {number} index The start index of the chunk.
168			* @return {string} The id of the chunk.
169			* @private
170			*/
171			getChunkId_(buffer, index) {
172			this.head_ += 4;
173			return unpackString(buffer, index, index + 4);
174			}
175
176			/**
177			* Return the size of a chunk.
178			* @param {!Uint8Array} buffer the RIFF file bytes.
179			* @param {number} index The start index of the chunk.
180			* @return {number} The size of the chunk without the id and size fields.
181			* @private
182			*/
183			getChunkSize_(buffer, index) {
184			this.head_ += 4;
185			return unpack(buffer, this.uInt32_, index + 4);
186			}
187
188			/**
189			* Read the RIFF chunk a wave file.
190			* @param {!Uint8Array} bytes A wav buffer.
191			* @throws {Error} If no 'RIFF' chunk is found.
192			* @private
193			*/
194			readRIFFChunk_(bytes) {
195			this.head_ = 0;
196			this.container = this.readString_(bytes, 4);
197			if (['RIFF', 'RIFX', 'RF64'].indexOf(this.container) === -1) {
198			throw Error('Not a supported format.');
199			}
200			this.uInt16_.be = this.container === 'RIFX';
201			this.uInt32_.be = this.uInt16_.be;
202			this.chunkSize = this.read_(bytes, this.uInt32_);
203			}
204
205			/**
206			* Read bytes as a ZSTR string.
207			* @param {!Uint8Array} bytes The bytes.
208			* @param {number} index the index to start reading.
209			* @return {string} The string.
210			* @private
211			*/
212			readZSTR_(bytes, index=0) {
213			for (let i = index; i < bytes.length; i++) {
214			this.head_++;
215			if (bytes[i] === 0) {
216			break;
217			}
218			}
219			return unpackString(bytes, index, this.head_ - 1);
220			}
221
222			/**
223			* Read bytes as a string from a RIFF chunk.
224			* @param {!Uint8Array} bytes The bytes.
225			* @param {number} maxSize the max size of the string.
226			* @return {string} The string.
227			* @private
228			*/
229			readString_(bytes, maxSize) {
230			/** @type {string} */
231			let str = '';
232			str = unpackString(bytes, this.head_, this.head_ + maxSize);
233			this.head_ += maxSize;
234			return str;
235			}
236
237			/**
238			* Read a number from a chunk.
239			* @param {!Uint8Array} bytes The chunk bytes.
240			* @param {!Object} bdType The type definition.
241			* @return {number} The number.
242			* @private
243			*/
244			read_(bytes, bdType) {
245			/** @type {number} */
246			let size = bdType.bits / 8;
247			/** @type {number} */
248			let value = unpack(bytes, bdType, this.head_);
249			this.head_ += size;
250			return value;
251			}
252			}
253

rochars / wavefile

Branch — riff-file (882407)

RIFFFile.readString_ A

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