DMleadgen
46d973904b
Next.js website for Rocky Mountain Vending company featuring: - Product catalog with Stripe integration - Service areas and parts pages - Admin dashboard with Clerk authentication - SEO optimized pages with JSON-LD structured data Co-authored-by: Cursor <cursoragent@cursor.com>
85 lines
No EOL
2.8 KiB
Text
85 lines
No EOL
2.8 KiB
Text
// minimal implementation MurmurHash2 hash function
|
|
"use strict";
|
|
Object.defineProperty(exports, "__esModule", {
|
|
value: true
|
|
});
|
|
Object.defineProperty(exports, "BloomFilter", {
|
|
enumerable: true,
|
|
get: function() {
|
|
return BloomFilter;
|
|
}
|
|
});
|
|
function murmurhash2(str) {
|
|
let h = 0;
|
|
for(let i = 0; i < str.length; i++){
|
|
const c = str.charCodeAt(i);
|
|
h = Math.imul(h ^ c, 0x5bd1e995);
|
|
h ^= h >>> 13;
|
|
h = Math.imul(h, 0x5bd1e995);
|
|
}
|
|
return h >>> 0;
|
|
}
|
|
// default to 0.01% error rate as the filter compresses very well
|
|
const DEFAULT_ERROR_RATE = 0.0001;
|
|
class BloomFilter {
|
|
constructor(numItems, errorRate = DEFAULT_ERROR_RATE){
|
|
this.numItems = numItems;
|
|
this.errorRate = errorRate;
|
|
this.numBits = Math.ceil(-(numItems * Math.log(errorRate)) / (Math.log(2) * Math.log(2)));
|
|
this.numHashes = Math.ceil(this.numBits / numItems * Math.log(2));
|
|
this.bitArray = new Array(this.numBits).fill(0);
|
|
}
|
|
static from(items, errorRate = DEFAULT_ERROR_RATE) {
|
|
const filter = new BloomFilter(items.length, errorRate);
|
|
for (const item of items){
|
|
filter.add(item);
|
|
}
|
|
return filter;
|
|
}
|
|
export() {
|
|
const data = {
|
|
numItems: this.numItems,
|
|
errorRate: this.errorRate,
|
|
numBits: this.numBits,
|
|
numHashes: this.numHashes,
|
|
bitArray: this.bitArray
|
|
};
|
|
if (process.env.NEXT_RUNTIME === 'nodejs') {
|
|
if (this.errorRate < DEFAULT_ERROR_RATE) {
|
|
const filterData = JSON.stringify(data);
|
|
const gzipSize = require('next/dist/compiled/gzip-size').sync(filterData);
|
|
if (gzipSize > 1024) {
|
|
console.warn(`Creating filter with error rate less than 0.1% (0.001) can increase the size dramatically proceed with caution. Received error rate ${this.errorRate} resulted in size ${filterData.length} bytes, ${gzipSize} bytes (gzip)`);
|
|
}
|
|
}
|
|
}
|
|
return data;
|
|
}
|
|
import(data) {
|
|
this.numItems = data.numItems;
|
|
this.errorRate = data.errorRate;
|
|
this.numBits = data.numBits;
|
|
this.numHashes = data.numHashes;
|
|
this.bitArray = data.bitArray;
|
|
}
|
|
add(item) {
|
|
const hashValues = this.getHashValues(item);
|
|
hashValues.forEach((hash)=>{
|
|
this.bitArray[hash] = 1;
|
|
});
|
|
}
|
|
contains(item) {
|
|
const hashValues = this.getHashValues(item);
|
|
return hashValues.every((hash)=>this.bitArray[hash]);
|
|
}
|
|
getHashValues(item) {
|
|
const hashValues = [];
|
|
for(let i = 1; i <= this.numHashes; i++){
|
|
const hash = murmurhash2(`${item}${i}`) % this.numBits;
|
|
hashValues.push(hash);
|
|
}
|
|
return hashValues;
|
|
}
|
|
}
|
|
|
|
//# sourceMappingURL=bloom-filter.js.map |