From: Ken Collins <pine29@...>
Date: 2005-01-12T06:25:15+09:00
Subject: Re: question about YAML over sockets

Thanks, _why, that change works for me. 

As a Ruby noob, it's a beautiful thing to see that major contributors to
the language are accessible and eager to help. Thanks again. 


On Wed, 12 Jan 2005 06:03:53 +0900, "why the lucky stiff"
<ruby-talk@whytheluckystiff.net> said:
> Ken Collins (pine29@myfastmail.com) wrote:
> > > > As far as I can tell, YAML.load will not return until the sender closes
> > > > the socket. Is this true? If true, is this desirable?
> > > > 
> > > If you need to have YAML.load return before you've closed the socket, 
> > > send a pause indicator "\n...\n".  YAML.load will return and you can 
> > > read further documents from the same IO.
> > > 
> > > _why
> > 
> > I tried sending the pause indicator using a variety of plausible IO
> > methods (write, print, puts, etc.) but without success. The receiver
> > listed below prints the data but only after five seconds. 
> > 
> 
> The YAML loader tries to read enough to fill its buffer.  It might be
> better to use IO#readline.  The only way to do this for now is to
> overload IO#read so it will read a line at a time.
> 
> Here's a replacement receiver:
> 
>   require "socket"
>   require "yaml"
>   
>   socket = TCPSocket.new("localhost", 5555)
>   class << socket
>       alias _read read
>       def read( len )
>           readline
>       end
>   end
>   data = YAML.load(socket)
>   p data
> 
> Also, the parser isn't stopping at the pause indicator properly and is
> requiring an additional newline.
> 
> Here's a replacement sender:
> 
>   data = { 'a' => [1,2,3], 'b' => 43 }
>   server = TCPServer.new("localhost", 5555)
>   socket = server.accept
>   YAML.dump(data, socket)
>   socket.write "\n...\n\n"
>   sleep 5
> 
> Stream parsing like this is totally untested.   Time to remedy the
> situation.
> 
> _why
>