@jbrowse/core/esm/util/flatqueue/index.js

JBrowse 2 core libraries used by plugins

export default class FlatQueue {
    ids = [];
    values = [];
    length = 0;
    clear() {
        this.length = 0;
    }
    push(item, priority) {
        let pos = this.length++;
        while (pos > 0) {
            const parent = (pos - 1) >> 1;
            const parentValue = this.values[parent];
            if (priority >= parentValue) {
                break;
            }
            this.ids[pos] = this.ids[parent];
            this.values[pos] = parentValue;
            pos = parent;
        }
        this.ids[pos] = item;
        this.values[pos] = priority;
    }
    pop() {
        if (this.length === 0) {
            return undefined;
        }
        const ids = this.ids;
        const values = this.values;
        const top = ids[0];
        const last = --this.length;
        if (last > 0) {
            const id = ids[last];
            const value = values[last];
            let pos = 0;
            const halfLen = last >> 1;
            while (pos < halfLen) {
                const left = (pos << 1) + 1;
                const right = left + 1;
                const child = left + (+(right < last) & +(values[right] < values[left]));
                if (values[child] >= value) {
                    break;
                }
                ids[pos] = ids[child];
                values[pos] = values[child];
                pos = child;
            }
            ids[pos] = id;
            values[pos] = value;
        }
        return top;
    }
    peek() {
        return this.length > 0 ? this.ids[0] : undefined;
    }
    peekValue() {
        return this.length > 0 ? this.values[0] : undefined;
    }
    shrink() {
        this.ids.length = this.values.length = this.length;
    }
}