Merge pull request #17074 from alexkuz/patch-2

Optimize numberHash.js

lib/util/numberHash.js

@@ -68,42 +68,32 @@ module.exports = (str, range) => {
 	for (let i = 0; i < str.length; i++) {
 		// Get the character code.
 		const c = str.charCodeAt(i);
+
 		// For each 32-bit integer used to store the hash value
-		for (let j = 0; j < COUNT; j++) {
-			// Get the index of the previous 32-bit integer.
-			const p = (j + COUNT - 1) % COUNT;
-			// Add the character code to the current hash value and multiply by the prime number.
-			arr[j] = (arr[j] + c * primes[j] + arr[p]) & SAFE_PART;
-		}
+		// add the character code to the current hash value and multiply by the prime number and
+		// add the previous 32-bit integer.
+		arr[0] = (arr[0] + c * primes[0] + arr[3]) & SAFE_PART;
+		arr[1] = (arr[1] + c * primes[1] + arr[0]) & SAFE_PART;
+		arr[2] = (arr[2] + c * primes[2] + arr[1]) & SAFE_PART;
+		arr[3] = (arr[3] + c * primes[3] + arr[2]) & SAFE_PART;
 
 		// For each 32-bit integer used to store the hash value
-		for (let j = 0; j < COUNT; j++) {
-			// Get the index of the next 32-bit integer.
-			const q = arr[j] % COUNT;
-			// XOR the current hash value with the value of the next 32-bit integer.
-			arr[j] = arr[j] ^ (arr[q] >> 1);
-		}
+		// XOR the current hash value with the value of the next 32-bit integer.
+		arr[0] = arr[0] ^ (arr[arr[0] % COUNT] >> 1);
+		arr[1] = arr[1] ^ (arr[arr[1] % COUNT] >> 1);
+		arr[2] = arr[2] ^ (arr[arr[2] % COUNT] >> 1);
+		arr[3] = arr[3] ^ (arr[arr[3] % COUNT] >> 1);
 	}
 
 	if (range <= SAFE_PART) {
-		let sum = 0;
-		// For each 32-bit integer used to store the hash value
-		for (let j = 0; j < COUNT; j++) {
-			// Add the value of the current 32-bit integer to the sum.
-			sum = (sum + arr[j]) % range;
-		}
-		return sum;
+		return (arr[0] + arr[1] + arr[2] + arr[3]) % range;
 	} else {
-		let sum1 = 0;
-		let sum2 = 0;
 		// Calculate the range extension.
 		const rangeExt = Math.floor(range / SAFE_LIMIT);
-		for (let j = 0; j < COUNT; j += 2) {
-			sum1 = (sum1 + arr[j]) & SAFE_PART;
-		}
-		for (let j = 1; j < COUNT; j += 2) {
-			sum2 = (sum2 + arr[j]) % rangeExt;
-		}
+
+		const sum1 = (arr[0] + arr[2]) & SAFE_PART;
+		const sum2 = (arr[0] + arr[2]) % rangeExt;
+
 		return (sum2 * SAFE_LIMIT + sum1) % range;
 	}
 };