[Twisted-Python] Information on new endpoints API?

[Albert Brandl]

On Tue, Jun 14, 2011 at 07:37:50PM -0400, Glyph Lefkowitz wrote:
> This is the most important point to take away, and I agree with it.  As much as
> possible, code should interact with endpoints as parameters.  If you need to
> pass something around, pass the endpoint or the service itself, not the string
> or the parameters used to construct it.

Granted.

> This then begs the question: where does "debug_mode()"'s result come from?

Actually, there is no `debug_mode()` function, but we rewrite the 
configuration file before deploying it. It contains some blocks like

# DEV_START
GPS_PORT = "tcp:1049"
...
# DEV_END

and

# PROD_START
# GPS_PORT = "SERIAL:/dev/ttyS2:baudrate=4800"
# ...
# PROD_END

The deployment script removes all lines between "# DEV_START" and "# DEV_END" 
and removes the comments between "# PROD_START" and "# PROD_END". This allows 
us to guarantee that development features (e.g. a manhole, a different kind 
of database, TCP-based stubs for serial devices like the GPS-receiver) do not 
"leak" into the production environment.

> Presumably someone had to indicate a boolean to this code somehow.  It would
> be simpler for whoever was supplying the value for debug_mode to just supply a
> value for the endpoint string description instead.  And if it's OK to hard-code
> the debug_mode boolean, why not just hard-code the string?

That's how it's implemented.

Best regards,
-- 
Albert Brandl
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