perl - 如何使用 AnyEvent::HTTP 仅获取页面的一部分？

Question

只需要读取页面的一部分（n 字节）并关闭连接，如何在 AnyEvent::HTTP 上执行此操作？

Answer 1

on_body当块到达时被重复调用。返回 false fromon_body将终止下载。

sub my_http_request {
   my $cb = pop;
   my ($method, $url, %args) = @_;

   croak("Unsupported: on_body")          if $args{on_body};
   croak("Unsupported: want_body_handle") if $args{want_body_handle};

   my $max_to_read = delete($args{max_to_read});

   my $data;
   return http_request(
      $method => $url,
      %args,
      on_body => sub {
         #my ($chunk, $headers) = @_;
         $data .= $_[0];
         return !defined($max_to_read) || length($data) < $max_to_read;
      },
      sub {
         my (undef, $headers) = @_;
         $cb->($data, $headers);
      },
   );
}

---

使用my_http_requestlike http_request，除了它接受一个可选max_to_read参数。

例如，

my $cb = AnyEvent->condvar();
my_http_request(
   GET => 'http://...',
   ...
   max_to_read => ...,
   $cb,
);

my ($data, $headers) = $cb->recv();

例如，

my $done = AnyEvent->condvar();
my_http_request(
   GET => 'http://...',
   ...
   max_to_read => ...,
   sub {
      my ($data, $headers) = @_;
      ...
      $done->send();
   },
);

$done->recv();