Switch to stdlib log

[Fijxu]

Closes #5413

• Kemal was upgraded to 1.7.2 (1.7.0 is the one that introduced integration with the stdlib Log)
• CONFIG.output works again (it didn't seem to work when I tested it)
• Some functions were encapsulated into modules (YoutubeJSONParser, Parser, I18n, and others) to keep the source (from where the Log function is being called) consistent for some functions.
• A macro ::Log.forf was added to add the function name to the source so we can prevent using Log.info { "fetch_channel: something" }, Log.info { "fetch_channel: something2" }, etc.

How it looks and behaves: https://asciinema.org/a/WQXsdnxcV1Hu7fOufJeMEaovZ

It's slower (~1.06x times slower) than using the old Invidious::LogHandler, but this is mostly because of heavy use of colorization. Without colorization, Log is 1.12x times faster.

With the Invidious::Logger.formatter added in this PR, it's possible to use Log.info &.emit("msg", error: "someerror", debuginfo: response.data) or something like that which may be useful for better context in the logs.

[syeopite]

Behemoth PRs like this are a bit hard to review 😅 Do you think you can split it into smaller ones?

More specifically I think the module changes mentioned here:

Some functions were encapsulated into modules (YoutubeJSONParser, Parser, I18n, and others) to keep the source (from where the Log function is being called) consistent for some functions.

Can be split off into smaller PRs that can be merged after this main migration. Having it all in one adds a bunch of noise to the primary change of switching to the stdlib logger.

In my opinion for a large-scale code migration like this having some minor issues during the midst of it like with how logs are represented isn't too big of a deal.

[syeopite]

Just a comment

If we want to squeeze some extra performance calling a function is slightly faster (1.03x on my machine) than a proc so subclassing Log::Formatter or Log::StaticFormatter will result in slightly faster performance than using the proc constructor.

I don't know if such a small gain will be worth it though

[Fijxu]

Can be split off into smaller PRs that can be merged after this main migration. Having it all in one adds a bunch of noise to the primary change of switching to the stdlib logger.

Done, that should be better ;)

[syeopite]

For consistency can you also set this as Log? A namespace collision can be prevented by changing the Log::Severity below to ::Log::Severity

[Fijxu]

I did that because I didn't know how to fix this error 😅:

...
 >  151 |                 # Sort types to avoid parsing nulls and numbers as strings
 >  152 |                 
 >  153 |                 [Log::Severity].each do |ivar_type|
 >  154 |                     if !success
 >  155 |                         begin
 >  156 |                             config.log_level = ivar_type.from_yaml(env_value)
 >  157 |                             success = true
 >  158 |                         rescue
 >  159 |                             # nop
 >  160 |                         end
 >  161 |                     end
 >  162 |                 end
 ...
 
 Error: undefined constant Log::Severity

It should be ::Log::Severity but is a passed as Log::Severity in the macro.

[SamantazFox]

I'd suggest to use the IO when using Colorize so that no intermediary string is created. The code is a bit convoluted due to the way Colorize is implemented in the standard library.

The use_color condition can also be removed, as Colorize keeps track of the enabled state (see lines 7/8 of this same file).

Finally, .each does nothing when the array is empty, thus making the if redundant. Note that in my suggestion the key=value pairs are separated by a single space, but a newline or another character might be more appropriate.

Suggested change

	message = entry.message
	severity = entry.severity
	data = entry.data
	source = entry.source
	timestamp = entry.timestamp
	io << (use_color ? timestamp.colorize(:dark_gray) : timestamp) << " "
	io << (use_color ? colorize_severity(severity) : severity.label) << " "
	io << (use_color ? source.colorize(:dark_gray) : source) << ": " if !source.empty?
	io << message
	if !data.empty?
	io << " "
	data.each do |dat|
	io << (use_color ? dat[0].to_s.colorize(:light_cyan) : dat[0].to_s)
	io << "="
	io << dat[1].to_s
	end
	end
	entry.timestamp.colorize.dark_gray.to_s(io)
	io << " "
	colorize_severity(entry.severity).to_s(io)
	io << " "
	if !entry.source.empty?
	entry.source.colorize.dark_gray.to_s(io)
	io << ": "
	end
	io << entry.message
	data.each do |dat|
	io << " "
	dat[0].colorize.light_cyan.to_s(io)
	io << "=" << dat[1]
	end