@splitsoftware/splitio-commons/cjs/utils/lang/binarySearch.js

Split JavaScript SDK common components

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.binarySearch = void 0;
/**
 * Searches the index of the specified `value` inside an ordered array of `items` using the binary search algorithm.
 *
 * @param items - the array to be searched
 * @param value - the value to be searched for
 * @returns integer number between 0 and `items.length`. This value is the index of the search value,
 * if it is contained in the array, or the index at which the value should be inserted to keep the array ordered.
 */
function binarySearch(items, value) {
    var startIndex = 0;
    var stopIndex = items.length - 1;
    var middle = Math.floor((stopIndex + startIndex) / 2);
    var minIndex = startIndex;
    var maxIndex = stopIndex;
    while (items[middle] !== value && startIndex < stopIndex) {
        // adjust search area
        if (value < items[middle]) {
            stopIndex = middle - 1;
        }
        else if (value > items[middle]) {
            startIndex = middle + 1;
        }
        // recalculate middle
        middle = Math.floor((stopIndex + startIndex) / 2);
    }
    // correct if middle is out of range
    if (middle < minIndex) {
        middle = minIndex;
    }
    else if (middle > maxIndex) {
        middle = maxIndex;
    }
    // we want to always return based on strict minor comparation
    if (value < items[middle] && middle > minIndex) {
        return middle - 1;
    }
    return middle;
}
exports.binarySearch = binarySearch;