firehol/netdata

// SPDX-License-Identifier: GPL-3.0-or-later

package scrape

import "sync"

type throttledCaller struct {
    limit chan struct{}
    wg    sync.WaitGroup
}

func newThrottledCaller(limit int) *throttledCaller {
    if limit <= 0 {
        panic("limit must be > 0")
    }
    return &throttledCaller{limit: make(chan struct{}, limit)}
}

func (t *throttledCaller) call(job func()) {
    t.wg.Add(1)
    go func() {
        defer t.wg.Done()
        t.limit <- struct{}{}
        defer func() {
            <-t.limit
        }()
        job()
    }()
}

func (t *throttledCaller) wait() {
    t.wg.Wait()
}