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perf: optimize compareStringsNumeric

This commit is contained in:
Alexander Akait 2024-01-30 16:40:42 +03:00 committed by GitHub
parent c7fc02e857 2cd85a22ac
commit d99434a492
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GPG Key ID: B5690EEEBB952194
2 changed files with 153 additions and 23 deletions
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82
lib/util/comparators.js
View File

@ -92,32 +92,68 @@ exports.compareNumbers = compareNumbers;
* @returns {-1|0|1} compare result
*/
const compareStringsNumeric = (a, b) => {
const partsA = a.split(/(\d+)/);
const partsB = b.split(/(\d+)/);
const len = Math.min(partsA.length, partsB.length);
for (let i = 0; i < len; i++) {
const pA = partsA[i];
const pB = partsB[i];
if (i % 2 === 0) {
if (pA.length > pB.length) {
if (pA.slice(0, pB.length) > pB) return 1;
return -1;
} else if (pB.length > pA.length) {
if (pB.slice(0, pA.length) > pA) return -1;
return 1;
} else {
if (pA < pB) return -1;
if (pA > pB) return 1;
}
const aLength = a.length;
const bLength = b.length;
let aChar = 0;
let bChar = 0;
let aIsDigit = false;
let bIsDigit = false;
let i = 0;
let j = 0;
while (i < aLength && j < bLength) {
aChar = a.charCodeAt(i);
bChar = b.charCodeAt(j);
aIsDigit = aChar >= 48 && aChar <= 57;
bIsDigit = bChar >= 48 && bChar <= 57;
if (!aIsDigit && !bIsDigit) {
if (aChar < bChar) return -1;
if (aChar > bChar) return 1;
i++;
j++;
} else if (aIsDigit && !bIsDigit) {
// This segment of a is shorter than in b
return 1;
} else if (!aIsDigit && bIsDigit) {
// This segment of b is shorter than in a
return -1;
} else {
const nA = +pA;
const nB = +pB;
if (nA < nB) return -1;
if (nA > nB) return 1;
let aNumber = aChar - 48;
let bNumber = bChar - 48;
while (++i < aLength) {
aChar = a.charCodeAt(i);
if (aChar < 48 || aChar > 57) break;
aNumber = aNumber * 10 + aChar - 48;
}
while (++j < bLength) {
bChar = b.charCodeAt(j);
if (bChar < 48 || bChar > 57) break;
bNumber = bNumber * 10 + bChar - 48;
}
if (aNumber < bNumber) return -1;
if (aNumber > bNumber) return 1;
}
}
if (partsB.length < partsA.length) return 1;
if (partsB.length > partsA.length) return -1;
if (j < bLength) {
// a is shorter than b
bChar = b.charCodeAt(j);
bIsDigit = bChar >= 48 && bChar <= 57;
return bIsDigit ? -1 : 1;
}
if (i < aLength) {
// b is shorter than a
aChar = a.charCodeAt(i);
aIsDigit = aChar >= 48 && aChar <= 57;
return aIsDigit ? 1 : -1;
}
return 0;
};
exports.compareStringsNumeric = compareStringsNumeric;

94
test/compareStringsNumeric.unittest.js Normal file
View File

@ -0,0 +1,94 @@
const { compareStringsNumeric } = require("../lib/util/comparators.js");
/**
* @param {string} a string
* @param {string} b string
* @returns {-1|0|1} compare result
*/
const referenceComparer = (a, b) => {
const partsA = a.split(/(\d+)/);
const partsB = b.split(/(\d+)/);
const len = Math.min(partsA.length, partsB.length);
for (let i = 0; i < len; i++) {
const pA = partsA[i];
const pB = partsB[i];
if (i % 2 === 0) {
if (pA.length > pB.length) {
if (pA.slice(0, pB.length) > pB) return 1;
return -1;
} else if (pB.length > pA.length) {
if (pB.slice(0, pA.length) > pA) return -1;
return 1;
} else {
if (pA < pB) return -1;
if (pA > pB) return 1;
}
} else {
const nA = +pA;
const nB = +pB;
if (nA < nB) return -1;
if (nA > nB) return 1;
}
}
if (partsB.length < partsA.length) return 1;
if (partsB.length > partsA.length) return -1;
return 0;
};
describe(compareStringsNumeric.name, () => {
const testCases = [
["", "a", 1],
["a", "", -1],
["", "0", -1],
["1", "", 1],
["", "", 0],
["a", "1", -1],
["1", "a", 1],
["_", "1", -1],
["1", "_", 1],
["a", "b", -1],
["b", "a", 1],
["a", "a", 0],
["a1", "a2", -1],
["a2", "a1", 1],
["a1", "a1", 0],
["ab1", "ab2", -1],
["ab2", "ab1", 1],
["ab1", "a1", -1],
["a1", "ab1", 1],
["a1", "a10", -1],
["a10", "a1", 1],
["a1", "a01", 0],
["a1", "a1a", 1],
["a1a", "a1", -1],
["a1a", "a01a", 0],
["a1a", "a1b", -1],
["a1b", "a1a", 1],
["a1a", "a1a1", -1],
["a1a1", "a1a", 1],
["a1a1", "a1a1", 0],
["a1a1", "a1a2", -1],
["a1a2", "a1a1", 1],
["a1a1", "a1a01", 0],
["a1a1", "a1a1a", 1],
["a1a1a", "a1a1", -1],
["a1a1a", "a1a1a", 0],
["a1a1a", "a1a1b", -1],
["a1a1b", "a1a1a", 1],
["a1a1a", "a1a1a1", -1],
["a1a1a1", "a1a1a", 1],
["a1a1a1", "a1a1a1", 0],
["a1a1a1", "a1a1a2", -1],
["a1a1a2", "a1a1a1", 1],
["a1a1a1", "a1a1a01", 0],
["a1a1a1", "a1a1a1a", 1]
];
for (const testCase of testCases) {
const [a, b, expected] = testCase;
it(`returns ${expected} when comparing "${a}" to "${b}"`, () => {
expect(referenceComparer(a, b)).toBe(expected);
expect(compareStringsNumeric(a, b)).toBe(expected);
});
}
});