path: root/vendor/gopkg.in/olebedev/go-duktape.v3/timers.go

package duktape

import (
    "errors"
    "fmt"
    "time"
)

// DefineTimers defines `setTimeout`, `clearTimeout`, `setInterval`,
// `clearInterval` into global context.
func (d *Context) PushTimers() error {
    d.PushGlobalStash()
    // check if timers already exists
    if !d.HasPropString(-1, "timers") {
        d.PushObject()
        d.PutPropString(-2, "timers") // stash -> [ timers:{} ]
        d.Pop()

        d.PushGlobalGoFunction("setTimeout", setTimeout)
        d.PushGlobalGoFunction("setInterval", setInterval)
        d.PushGlobalGoFunction("clearTimeout", clearTimeout)
        d.PushGlobalGoFunction("clearInterval", clearTimeout)
        return nil
    } else {
        d.Pop()
        return errors.New("Timers are already defined")
    }
}

func (d *Context) FlushTimers() {
    d.PushGlobalStash()
    d.PushObject()
    d.PutPropString(-2, "timers") // stash -> [ timers:{} ]
    d.Pop()
}

func setTimeout(c *Context) int {
    id := c.pushTimer(0)
    timeout := c.ToNumber(1)
    if timeout < 1 {
        timeout = 1
    }
    go func(id float64) {
        <-time.After(time.Duration(timeout) * time.Millisecond)
        c.Lock()
        defer c.Unlock()
        if c.duk_context == nil {
            fmt.Println("[duktape] Warning!\nsetTimeout invokes callback after the context was destroyed.")
            return
        }

        // check if timer still exists
        c.putTimer(id)
        if c.GetType(-1).IsObject() {
            c.Pcall(0 /* nargs */)
        }
        c.dropTimer(id)
    }(id)
    c.PushNumber(id)
    return 1
}

func clearTimeout(c *Context) int {
    if c.GetType(0).IsNumber() {
        c.dropTimer(c.GetNumber(0))
        c.Pop()
    }
    return 0
}

func setInterval(c *Context) int {
    id := c.pushTimer(0)
    timeout := c.ToNumber(1)
    if timeout < 1 {
        timeout = 1
    }
    go func(id float64) {
        ticker := time.NewTicker(time.Duration(timeout) * time.Millisecond)
        for _ = range ticker.C {
            c.Lock()
            // check if duktape context exists
            if c.duk_context == nil {
                c.dropTimer(id)
                c.Pop()
                ticker.Stop()
                fmt.Println("[duktape] Warning!\nsetInterval invokes callback after the context was destroyed.")
                c.Unlock()
                continue
            }

            // check if timer still exists
            c.putTimer(id)
            if c.GetType(-1).IsObject() {
                c.Pcall(0 /* nargs */)
                c.Pop()
            } else {
                c.dropTimer(id)
                c.Pop()
                ticker.Stop()
            }
            c.Unlock()
        }
    }(id)
    c.PushNumber(id)
    return 1
}

func (d *Context) pushTimer(index int) float64 {
    id := d.timerIndex.get()

    d.PushGlobalStash()
    d.GetPropString(-1, "timers")
    d.PushNumber(id)
    d.Dup(index)
    d.PutProp(-3)
    d.Pop2()

    return id
}

func (d *Context) dropTimer(id float64) {
    d.PushGlobalStash()
    d.GetPropString(-1, "timers")
    d.PushNumber(id)
    d.DelProp(-2)
    d.Pop2()
}

func (d *Context) putTimer(id float64) {
    d.PushGlobalStash()           // stash -> [ ..., timers: { <id>: { func: true } } ]
    d.GetPropString(-1, "timers") // stash -> [ ..., timers: { <id>: { func: true } } }, { <id>: { func: true } ]
    d.PushNumber(id)
    d.GetProp(-2) // stash -> [ ..., timers: { <id>: { func: true } } }, { <id>: { func: true }, { func: true } ]
    d.Replace(-3)
    d.Pop()
}