1534341 - [mozlog] Allow passing messages down to formatters

Status: RESOLVED FIXED

(Testing :: Mozbase, enhancement, P3)

Description

[James Graham [:jgraham]]

mozlog has a message passing system that can be used to configure handlers by calling send_message [1]. If the handler has a handle_message function registred for that kind of message then it will processs the message. This allows configuring handlers without having to know which handlers are actually present since the client code can just send whatever configuration messages it likes without worrying about whether anyone would recieve them.

Some handlers support a formatter that generates log messages and it would be good to configure those at runtime as well using a similar system. So the user would be able to dos something like mozlog.send_message("grouping_formatter", "show_logs", True) to set some configuration on that formatter if it happens to be in use.

I think the implementation here is just to update the StreamHandler and any other handler that has a formatter property to forward any messages they recieve down to the formatter after they have handled them.

[1] https://searchfox.org/mozilla-central/source/testing/mozbase/mozlog/mozlog/structuredlog.py#196

Comment 1

[Nikki Sharpley [:nikkis]]

StreamHandler inherits from BaseHandler, which has a similar method to send_message in handle_message, already allowing topic, command and args to be set. It has the additional attribute of formatter. In the case there is a formatter, do want the result of handle_message (i.e. rv), passed through self.formatter before being returned?
I hope I'm understanding this correctly!
Thanks!

Comment 2

[James Graham [:jgraham]]

Yes, that sounds exactly correct.

Comment 3

[Nikki Sharpley [:nikkis]]

Attachment: [mozlog] Allow passing messages down to formatters (Bug 1534341)

This addition allows formatters to be configured by sending a message.

For example, the show_logs attribute has been added to the GroupingFormatter
to allow switching on/off the display of all log messages at runtime.
A generic handle_message method was added to the BaseFormatter to allow
attributes to be configured, with optional arguments for those that require
it.

An additional log(data) method has been implemented on the GroupingFormatter
that checks self.show_logs, and if True, displays all messages regardless of
failure or success, with component, level and stack.

A test may be required to ensure this is behaving as expected.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c05f29dd14f5
[mozlog] Allow passing messages down to formatters r=jgraham

Comment 5

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/c05f29dd14f5