token-types
Version:
Common token types for decoding and encoding numeric and string values
418 lines (417 loc) • 10.5 kB
JavaScript
import * as ieee754 from 'ieee754';
// Primitive types
function dv(array) {
return new DataView(array.buffer, array.byteOffset);
}
/**
* 8-bit unsigned integer
*/
export const UINT8 = {
len: 1,
get(array, offset) {
return dv(array).getUint8(offset);
},
put(array, offset, value) {
dv(array).setUint8(offset, value);
return offset + 1;
}
};
/**
* 16-bit unsigned integer, Little Endian byte order
*/
export const UINT16_LE = {
len: 2,
get(array, offset) {
return dv(array).getUint16(offset, true);
},
put(array, offset, value) {
dv(array).setUint16(offset, value, true);
return offset + 2;
}
};
/**
* 16-bit unsigned integer, Big Endian byte order
*/
export const UINT16_BE = {
len: 2,
get(array, offset) {
return dv(array).getUint16(offset);
},
put(array, offset, value) {
dv(array).setUint16(offset, value);
return offset + 2;
}
};
/**
* 24-bit unsigned integer, Little Endian byte order
*/
export const UINT24_LE = {
len: 3,
get(array, offset) {
const dataView = dv(array);
return dataView.getUint8(offset) + (dataView.getUint16(offset + 1, true) << 8);
},
put(array, offset, value) {
const dataView = dv(array);
dataView.setUint8(offset, value & 0xff);
dataView.setUint16(offset + 1, value >> 8, true);
return offset + 3;
}
};
/**
* 24-bit unsigned integer, Big Endian byte order
*/
export const UINT24_BE = {
len: 3,
get(array, offset) {
const dataView = dv(array);
return (dataView.getUint16(offset) << 8) + dataView.getUint8(offset + 2);
},
put(array, offset, value) {
const dataView = dv(array);
dataView.setUint16(offset, value >> 8);
dataView.setUint8(offset + 2, value & 0xff);
return offset + 3;
}
};
/**
* 32-bit unsigned integer, Little Endian byte order
*/
export const UINT32_LE = {
len: 4,
get(array, offset) {
return dv(array).getUint32(offset, true);
},
put(array, offset, value) {
dv(array).setUint32(offset, value, true);
return offset + 4;
}
};
/**
* 32-bit unsigned integer, Big Endian byte order
*/
export const UINT32_BE = {
len: 4,
get(array, offset) {
return dv(array).getUint32(offset);
},
put(array, offset, value) {
dv(array).setUint32(offset, value);
return offset + 4;
}
};
/**
* 8-bit signed integer
*/
export const INT8 = {
len: 1,
get(array, offset) {
return dv(array).getInt8(offset);
},
put(array, offset, value) {
dv(array).setInt8(offset, value);
return offset + 1;
}
};
/**
* 16-bit signed integer, Big Endian byte order
*/
export const INT16_BE = {
len: 2,
get(array, offset) {
return dv(array).getInt16(offset);
},
put(array, offset, value) {
dv(array).setInt16(offset, value);
return offset + 2;
}
};
/**
* 16-bit signed integer, Little Endian byte order
*/
export const INT16_LE = {
len: 2,
get(array, offset) {
return dv(array).getInt16(offset, true);
},
put(array, offset, value) {
dv(array).setInt16(offset, value, true);
return offset + 2;
}
};
/**
* 24-bit signed integer, Little Endian byte order
*/
export const INT24_LE = {
len: 3,
get(array, offset) {
const unsigned = UINT24_LE.get(array, offset);
return unsigned > 0x7fffff ? unsigned - 0x1000000 : unsigned;
},
put(array, offset, value) {
const dataView = dv(array);
dataView.setUint8(offset, value & 0xff);
dataView.setUint16(offset + 1, value >> 8, true);
return offset + 3;
}
};
/**
* 24-bit signed integer, Big Endian byte order
*/
export const INT24_BE = {
len: 3,
get(array, offset) {
const unsigned = UINT24_BE.get(array, offset);
return unsigned > 0x7fffff ? unsigned - 0x1000000 : unsigned;
},
put(array, offset, value) {
const dataView = dv(array);
dataView.setUint16(offset, value >> 8);
dataView.setUint8(offset + 2, value & 0xff);
return offset + 3;
}
};
/**
* 32-bit signed integer, Big Endian byte order
*/
export const INT32_BE = {
len: 4,
get(array, offset) {
return dv(array).getInt32(offset);
},
put(array, offset, value) {
dv(array).setInt32(offset, value);
return offset + 4;
}
};
/**
* 32-bit signed integer, Big Endian byte order
*/
export const INT32_LE = {
len: 4,
get(array, offset) {
return dv(array).getInt32(offset, true);
},
put(array, offset, value) {
dv(array).setInt32(offset, value, true);
return offset + 4;
}
};
/**
* 64-bit unsigned integer, Little Endian byte order
*/
export const UINT64_LE = {
len: 8,
get(array, offset) {
return dv(array).getBigUint64(offset, true);
},
put(array, offset, value) {
dv(array).setBigUint64(offset, value, true);
return offset + 8;
}
};
/**
* 64-bit signed integer, Little Endian byte order
*/
export const INT64_LE = {
len: 8,
get(array, offset) {
return dv(array).getBigInt64(offset, true);
},
put(array, offset, value) {
dv(array).setBigInt64(offset, value, true);
return offset + 8;
}
};
/**
* 64-bit unsigned integer, Big Endian byte order
*/
export const UINT64_BE = {
len: 8,
get(array, offset) {
return dv(array).getBigUint64(offset);
},
put(array, offset, value) {
dv(array).setBigUint64(offset, value);
return offset + 8;
}
};
/**
* 64-bit signed integer, Big Endian byte order
*/
export const INT64_BE = {
len: 8,
get(array, offset) {
return dv(array).getBigInt64(offset);
},
put(array, offset, value) {
dv(array).setBigInt64(offset, value);
return offset + 8;
}
};
/**
* IEEE 754 16-bit (half precision) float, big endian
*/
export const Float16_BE = {
len: 2,
get(dataView, offset) {
return ieee754.read(dataView, offset, false, 10, this.len);
},
put(dataView, offset, value) {
ieee754.write(dataView, value, offset, false, 10, this.len);
return offset + this.len;
}
};
/**
* IEEE 754 16-bit (half precision) float, little endian
*/
export const Float16_LE = {
len: 2,
get(array, offset) {
return ieee754.read(array, offset, true, 10, this.len);
},
put(array, offset, value) {
ieee754.write(array, value, offset, true, 10, this.len);
return offset + this.len;
}
};
/**
* IEEE 754 32-bit (single precision) float, big endian
*/
export const Float32_BE = {
len: 4,
get(array, offset) {
return dv(array).getFloat32(offset);
},
put(array, offset, value) {
dv(array).setFloat32(offset, value);
return offset + 4;
}
};
/**
* IEEE 754 32-bit (single precision) float, little endian
*/
export const Float32_LE = {
len: 4,
get(array, offset) {
return dv(array).getFloat32(offset, true);
},
put(array, offset, value) {
dv(array).setFloat32(offset, value, true);
return offset + 4;
}
};
/**
* IEEE 754 64-bit (double precision) float, big endian
*/
export const Float64_BE = {
len: 8,
get(array, offset) {
return dv(array).getFloat64(offset);
},
put(array, offset, value) {
dv(array).setFloat64(offset, value);
return offset + 8;
}
};
/**
* IEEE 754 64-bit (double precision) float, little endian
*/
export const Float64_LE = {
len: 8,
get(array, offset) {
return dv(array).getFloat64(offset, true);
},
put(array, offset, value) {
dv(array).setFloat64(offset, value, true);
return offset + 8;
}
};
/**
* IEEE 754 80-bit (extended precision) float, big endian
*/
export const Float80_BE = {
len: 10,
get(array, offset) {
return ieee754.read(array, offset, false, 63, this.len);
},
put(array, offset, value) {
ieee754.write(array, value, offset, false, 63, this.len);
return offset + this.len;
}
};
/**
* IEEE 754 80-bit (extended precision) float, little endian
*/
export const Float80_LE = {
len: 10,
get(array, offset) {
return ieee754.read(array, offset, true, 63, this.len);
},
put(array, offset, value) {
ieee754.write(array, value, offset, true, 63, this.len);
return offset + this.len;
}
};
/**
* Ignore a given number of bytes
*/
export class IgnoreType {
/**
* @param len number of bytes to ignore
*/
constructor(len) {
this.len = len;
}
// ToDo: don't read, but skip data
get(_array, _off) {
}
}
export class Uint8ArrayType {
constructor(len) {
this.len = len;
}
get(array, offset) {
return array.subarray(offset, offset + this.len);
}
}
/**
* Consume a fixed number of bytes from the stream and return a string with a specified encoding.
* Supports all encodings supported by TextDecoder, plus 'windows-1252'.
*/
export class StringType {
constructor(len, encoding) {
this.len = len;
if (encoding && encoding.toLowerCase() === 'windows-1252') {
this.decoder = StringType.decodeWindows1252;
}
else {
const textDecoder = new TextDecoder(encoding);
this.decoder = (bytes) => textDecoder.decode(bytes);
}
}
get(data, offset = 0) {
const bytes = data.subarray(offset, offset + this.len);
return this.decoder(bytes);
}
static decodeWindows1252(bytes) {
let result = '';
for (let i = 0; i < bytes.length; i++) {
const byte = bytes[i];
result += byte < 0x80 || byte >= 0xA0
? String.fromCharCode(byte)
: StringType.win1252Map[byte - 0x80];
}
return result;
}
}
StringType.win1252Map = '\u20AC\u0081\u201A\u0192\u201E\u2026\u2020\u2021\u02C6\u2030\u0160\u2039\u0152\u008D\u017D\u008F\u0090\u2018\u2019\u201C\u201D\u2022\u2013\u2014\u02DC\u2122\u0161\u203A\u0153\u009D\u017E\u0178';
/**
* ANSI Latin 1 String using Windows-1252 (Code Page 1252)
* Windows-1252 is a superset of ISO 8859-1 / Latin-1.
*/
export class AnsiStringType extends StringType {
constructor(len) {
super(len, 'windows-1252');
}
}