Binary search on time-series database

btssearch.js

// inst: unix epoch
const hist = {
    "channel1": [
        { inst: 10000, id: "a" },
        { inst: 20000, id: "b" },
        { inst: 30000, id: "c" },
        { inst: 30000, id: "d" },
        { inst: 40000, id: "e" }
    ]
};

// Search ordered time-series array for any events since last.
// Results include last, in case any events were simultaneous.
const updates = (array, last) => {
    const value = obj => obj.inst;
    const search = (min, max) => {
        if (min > max) {
            return min;
        }
        const mid = Math.floor((min + max) / 2);
        const tryLater = value(array[mid]) < last;
        return tryLater ? search(mid + 1, max) : search(min, mid - 1);
    };
    return array.slice(search(0, array.length));
};

updates(hist.channel1, 30000); // returns c, d and e