85 lines
1.6 KiB
Go
85 lines
1.6 KiB
Go
package main
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import (
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"fmt"
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"log"
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"net"
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"sync"
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"time"
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)
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type DiscardedHost struct {
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Host string
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Tries int
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}
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type DiscardedHostHandler struct {
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mu sync.RWMutex
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port int
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hosts []*DiscardedHost
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onConnection *func(string)
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}
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func (d *DiscardedHostHandler) run() {
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for range time.Tick(time.Second) {
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d.mu.RLock()
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lst := make([]*DiscardedHost, 0, len(d.hosts))
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for _, host := range d.hosts {
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if host.Tries >= 0 && host.Tries < 5 {
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go d.testConnection(host)
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lst = append(lst, host)
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} else {
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if host.Tries > 0 {
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log.Printf("Host %s discarded after %d tries", host.Host, host.Tries)
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}
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}
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}
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d.mu.RUnlock()
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d.mu.Lock()
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d.hosts = lst
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d.mu.Unlock()
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}
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}
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func (d *DiscardedHostHandler) testConnection(host *DiscardedHost) {
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addr := fmt.Sprintf("%s:%d", host.Host, d.port)
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conn, err := net.Dial("tcp", addr)
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if err != nil {
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host.Tries++
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if host.Tries >= 5 {
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// Exceeded retry threshold; will be dropped by run loop.
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}
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} else {
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conn.Close()
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if d.onConnection != nil {
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fn := *d.onConnection
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fn(host.Host)
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}
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}
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}
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func NewDiscardedHostHandler(port int) *DiscardedHostHandler {
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ret := &DiscardedHostHandler{
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hosts: make([]*DiscardedHost, 0),
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port: port,
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}
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go ret.run()
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return ret
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}
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func (d *DiscardedHostHandler) SetReconnectHandler(fn func(string)) {
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d.onConnection = &fn
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}
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func (d *DiscardedHostHandler) AppendHost(host string) {
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d.mu.Lock()
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defer d.mu.Unlock()
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log.Printf("Adding host %s to retry list", host)
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d.hosts = append(d.hosts, &DiscardedHost{
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Host: host,
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Tries: 0,
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})
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}
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