paraemu/lib/base32.js

An working enviroment that provides a simplified interface for developers who want to fully parallelize node execution

(()=>{
	"use strict";
	
	const __FORMAT_CHECK = /^[0123456789ABCDEFGHIJKLMNOPQRSTUV]+$/;
	const __CHAR_MAP = '0123456789ABCDEFGHIJKLMNOPQRSTUV'.split('');
	function __BASE32_ENCODE(inputData, map=null) {
		if ( !Buffer.isBuffer(inputData) ) {
			inputData = Buffer.from(inputData);
		}
		
		if ( inputData.length < 1 ) return '';
		
		
		
		
		
		const CVT_MAP = map ? map.split('') : __CHAR_MAP;
		
		
		
		// Run complete bundles
		let encoded = '';
		let begin, loop = Math.floor(inputData.length/5);
		for (let run=0; run<loop; run++) {
			begin = run * 5;
			encoded += CVT_MAP[  inputData[begin]           >> 3];								// 0
			encoded += CVT_MAP[ (inputData[begin  ] & 0x07) << 2 | (inputData[begin+1] >> 6)];	// 1
			encoded += CVT_MAP[ (inputData[begin+1] & 0x3E) >> 1];								// 2
			encoded += CVT_MAP[ (inputData[begin+1] & 0x01) << 4 | (inputData[begin+2] >> 4)];	// 3
			encoded += CVT_MAP[ (inputData[begin+2] & 0x0F) << 1 | (inputData[begin+3] >> 7)];	// 4
			encoded += CVT_MAP[ (inputData[begin+3] & 0x7C) >> 2];								// 5
			encoded += CVT_MAP[ (inputData[begin+3] & 0x03) << 3 | (inputData[begin+4] >> 5)];	// 6
			encoded += CVT_MAP[  inputData[begin+4] & 0x1F];										// 7
		}
		
		// Run remains
		let remain = inputData.length % 5;
		if ( remain === 0 ) { return encoded; }
		
		
		begin = loop*5;
		if ( remain === 1 ) {
			encoded += CVT_MAP[  inputData[begin]           >> 3];								// 0
			encoded += CVT_MAP[ (inputData[begin  ] & 0x07) << 2];								// 1
		}
		else
		if ( remain === 2 ) {
			encoded += CVT_MAP[  inputData[begin]           >> 3];								// 0
			encoded += CVT_MAP[ (inputData[begin  ] & 0x07) << 2 | (inputData[begin+1] >> 6)];	// 1
			encoded += CVT_MAP[ (inputData[begin+1] & 0x3E) >> 1];								// 2
			encoded += CVT_MAP[ (inputData[begin+1] & 0x01) << 4];								// 3
		}
		else
		if ( remain === 3 ) {
			encoded += CVT_MAP[  inputData[begin]           >> 3];								// 0
			encoded += CVT_MAP[ (inputData[begin  ] & 0x07) << 2 | (inputData[begin+1] >> 6)];	// 1
			encoded += CVT_MAP[ (inputData[begin+1] & 0x3E) >> 1];								// 2
			encoded += CVT_MAP[ (inputData[begin+1] & 0x01) << 4 | (inputData[begin+2] >> 4)];	// 3
			encoded += CVT_MAP[ (inputData[begin+2] & 0x0F) << 1];								// 4
		}
		else
		if ( remain === 4 ) {
			encoded += CVT_MAP[  inputData[begin]           >> 3];								// 0
			encoded += CVT_MAP[ (inputData[begin  ] & 0x07) << 2 | (inputData[begin+1] >> 6)];	// 1
			encoded += CVT_MAP[ (inputData[begin+1] & 0x3E) >> 1];								// 2
			encoded += CVT_MAP[ (inputData[begin+1] & 0x01) << 4 | (inputData[begin+2] >> 4)];	// 3
			encoded += CVT_MAP[ (inputData[begin+2] & 0x0F) << 1 | (inputData[begin+3] >> 7)];	// 4
			encoded += CVT_MAP[ (inputData[begin+3] & 0x7C) >> 2];								// 5
			encoded += CVT_MAP[ (inputData[begin+3] & 0x03) << 3];								// 6
		}
		
		return encoded;
	}
	
	const __REV_MAP	 = (()=>{ const MAP = {}; __CHAR_MAP.forEach((key, val)=>{ MAP[key] = val; }); return MAP; })();
	function __BASE32_DECODE(inputBase32, map=null) {
		if ( !__FORMAT_CHECK.test(inputBase32) ) {
			return null;
		}
		
		let remain = inputBase32.length % 8;
		if ( [0, 2, 4, 5, 7].indexOf(remain) < 0 ) {
			return null;
		}
		
		let decoded = Buffer.alloc(Math.floor(inputBase32.length * 5 / 8));
		
		let CVT_MAP = !map ? __REV_MAP : (()=>{ const _MAP = {}; map.split('').forEach((key, val)=>{ _MAP[key] = val; }); return _MAP; })();
		
		
		
		
		
		// Run complete bundles
		let dest, begin, loop = Math.floor(inputBase32.length/8);
		for (let run=0; run<loop; run++) {
			begin = run * 8;
			dest  = run * 5;
			decoded[dest] 	=  CVT_MAP[inputBase32[begin]] << 3 | CVT_MAP[inputBase32[begin+1]] >> 2;	// 0
			decoded[dest+1] = (CVT_MAP[inputBase32[begin+1]] & 0x03) << 6 |								// 1
							   CVT_MAP[inputBase32[begin+2]]		   << 1 |
							   CVT_MAP[inputBase32[begin+3]]		   >> 4;
			decoded[dest+2] = (CVT_MAP[inputBase32[begin+3]] & 0x0F) << 4 |								// 2
							   CVT_MAP[inputBase32[begin+4]]		   >> 1;
			decoded[dest+3] = (CVT_MAP[inputBase32[begin+4]] & 0x01) << 7 |								// 3
							   CVT_MAP[inputBase32[begin+5]]		   << 2 |
							   CVT_MAP[inputBase32[begin+6]]		   >> 3;
			decoded[dest+4] = (CVT_MAP[inputBase32[begin+6]] & 0x07) << 5 |								// 4
							   CVT_MAP[inputBase32[begin+7]];
		}
		
		if ( remain === 0 ) { return decoded; }
		
		
		
		begin = loop*8;
		dest  = loop*5;
		if ( remain >= 2 ) {
			decoded[dest] =  CVT_MAP[inputBase32[begin]] << 3 | CVT_MAP[inputBase32[begin+1]] >> 2;		// 0
		}
		
		if ( remain >= 4 ) {
			decoded[dest+1] = (CVT_MAP[inputBase32[begin+1]] & 0x03) << 6 |								// 1
							   CVT_MAP[inputBase32[begin+2]]		   << 1 |
							   CVT_MAP[inputBase32[begin+3]]		   >> 4;
		}
		
		if ( remain >= 5 ) {
			decoded[dest+2] = (CVT_MAP[inputBase32[begin+3]] & 0x0F) << 4 |								// 2
							   CVT_MAP[inputBase32[begin+4]]		   >> 1;
		}
		
		if ( remain === 7 ) {
			decoded[dest+3] = (CVT_MAP[inputBase32[begin+4]] & 0x01) << 7 |								// 3
							   CVT_MAP[inputBase32[begin+5]]		   << 2 |
							   CVT_MAP[inputBase32[begin+6]]		   >> 3;
		}
		
		return decoded;
	}
	
	module.exports = (rawData)=>{
		return __BASE32_ENCODE(rawData);
	};
	
	module.exports.encode = __BASE32_ENCODE;
	module.exports.decode = __BASE32_DECODE;
})();