89 lines
1.3 KiB
Go
89 lines
1.3 KiB
Go
// Package externalcmd allows to launch external commands.
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package externalcmd
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import (
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"errors"
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"strings"
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"time"
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)
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const (
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restartPause = 5 * time.Second
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)
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var errTerminated = errors.New("terminated")
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// Environment is a Cmd environment.
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type Environment map[string]string
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// Cmd is an external command.
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type Cmd struct {
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pool *Pool
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cmdstr string
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restart bool
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env Environment
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onExit func(error)
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// in
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terminate chan struct{}
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}
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// NewCmd allocates a Cmd.
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func NewCmd(
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pool *Pool,
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cmdstr string,
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restart bool,
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env Environment,
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onExit func(error),
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) *Cmd {
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// replace variables in both Linux and Windows, in order to allow using the
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// same commands on both of them.
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for key, val := range env {
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cmdstr = strings.ReplaceAll(cmdstr, "$"+key, val)
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}
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e := &Cmd{
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pool: pool,
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cmdstr: cmdstr,
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restart: restart,
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env: env,
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onExit: onExit,
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terminate: make(chan struct{}),
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}
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pool.wg.Add(1)
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go e.run()
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return e
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}
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// Close closes the command. It doesn't wait for the command to exit.
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func (e *Cmd) Close() {
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close(e.terminate)
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}
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func (e *Cmd) run() {
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defer e.pool.wg.Done()
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for {
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err := e.runOSSpecific()
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if err == errTerminated {
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return
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}
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e.onExit(err)
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if !e.restart {
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<-e.terminate
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return
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}
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select {
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case <-time.After(restartPause):
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case <-e.terminate:
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return
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}
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}
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}
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