25 lines
495 B
Go
25 lines
495 B
Go
package main
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import (
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"context"
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"net/http"
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"time"
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"github.com/RomiChan/syncx"
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)
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var canUseIPv6 = syncx.Lazy[bool]{Init: func() bool {
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ctx, cancel := context.WithTimeout(context.Background(), 4*time.Second)
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defer cancel()
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req, err := http.NewRequestWithContext(ctx, "GET", "http://v6.ipv6-test.com/json/widgetdata.php?callback=?", nil)
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if err != nil {
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return false
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}
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resp, err := http.DefaultClient.Do(req)
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if err != nil {
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return false
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}
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_ = resp.Body.Close()
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return true
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}}
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