Question

我有一个代码如下：

 1  sub do_leave {
 2
 3    my ($asterisk, $event) = @_;
 4    my $join_id;
 5    my $id = $astman->send_action({ Action    => 'Getvar',
 6                                    Variable  => 'join_id',
 7                                    Channel   => $event->{'Channel'},
 8                                  }, \&get_value, undef, \$join_id);
 9
10    sleep(2);
11    say "join_id is: $join_id";
12
13    my $sql = "UPDATE conference_log SET duration=(TIMESTAMPDIFF(SECOND, (SELECT start_conf), NOW())), end_conf=(NOW()) WHERE id=?";
14    my $sth = $dbh->prepare($sql);
15    $sth->execute($join_id);
16  }
17
18  sub get_value {
19    my ($ast, $resp, $ref_join_id) = @_;
20    for my $key (keys %$resp) {
21      if ($key eq "PARSED") {
22        $$ref_join_id = $resp->{$key}{"Value"};
23      }
24    }
25  }

我正在使用Asterisk::AMI模块从星号AMI获取信息。只要有人离开会议，就会调用do_leave子。我的问题是在get_value中的所有语句之后执行do_leave回调。如何在第10行之前执行get_value回调。\$join_id中的变量send_action是回调的第三个参数。我在sql语句之前需要$join_id变量。

Answer 1

对脚本进行最少的更改

sub do_leave {

  my ($asterisk, $event) = @_;
  my $join_id;

  my $sub = sub {
    get_value(@_);
    say "join_id is: $join_id";

    my $sql = "UPDATE conference_log SET duration=(TIMESTAMPDIFF(SECOND, (SELECT start_conf), NOW())), end_conf=(NOW()) WHERE id=?";
    my $sth = $dbh->prepare($sql);
    $sth->execute($join_id);
  };
  my $id = $astman->send_action({ Action    => 'Getvar',
                                  Variable  => 'join_id',
                                  Channel   => $event->{'Channel'},
                                }, $sub, undef, \$join_id);
  # sleep(2);
}

Answer 2

我没有使用Asterisk :: AMI，但我认为send_action方法采用回调方法的原因是结果是异步返回的。你不能保证需要多长时间。

快速简便的解决方案是将数据库更新放在回调函数中，如下所示：

sub do_leave {

  my ($asterisk, $event) = @_;
  my $get_value = sub {
    my ($ast, $resp, $ref_join_id) = @_;
    for my $key (keys %$resp) {
        if ($key eq "PARSED") {
            my $ref_join_id = $resp->{$key}{"Value"};
            my $sql = "UPDATE conference_log SET duration=(TIMESTAMPDIFF(SECOND, (SELECT start_conf), NOW())), end_conf=(NOW()) WHERE id=?";
            my $sth = $dbh->prepare($sql);
            $sth->execute($join_id);
        }
    }
  };

  my $id = $astman->send_action({ Action    => 'Getvar',
                                  Variable  => 'join_id',
                                  Channel   => $event->{'Channel'},
                                }, $get_value);

}

请注意，我使用了一个匿名子，分配给一个变量，它允许你在外部do_leave子和回调子之间共享变量（这称为闭包）。但是在这种情况下可能不需要，因为没有共享变量。

Perl执行星号回调的顺序？

2 个答案: