This adds the Func log method to log using an anonymous function
only if the level is currently enabled.
The use case is for when you don't own an object and therefore can't
create your own marshaller but need to do some translation prior to
logging.
For example, this:
msg := log.Debug()
if msg.Enabled() {
msg.Str("complicated_thing", makeBinaryThingLoggable(thing))
}
msg.Msg("Sending complicated thing")
Turns into this:
log.Debug().
Func(func(e *Event) { e.Str("complicated_thing", makeBinaryThingLoggable(thing)) }).
Msg("Sending complicated thing")
As per https://github.com/rs/zerolog/issues/9 and to offer a different approach from https://github.com/rs/zerolog/pull/11 and https://github.com/rs/zerolog/pull/35 this PR introduces custom error serialization with sane defaults without breaking the existing APIs.
This is just a first draft and is missing tests. Also, a bit of code duplication which I feel could be reduced but it serves to get the idea across.
It provides global error marshalling by exposing a `var ErrorMarshalFunc func(error) interface{}` in zerolog package that by default is a function that returns the passed argument. It should be overriden if you require custom error marshalling.
Then in every function that accept error or array of errors `ErrorMarshalFunc` is called on the error and then the result of it is processed like this:
- if it implements `LogObjectMarshaler`, serialize it as an object
- if it is a string serialize as a string
- if it is an error, serialize as a string with the result of `Error()`
- else serialize it as an interface
The side effect of this change is that the encoders don't need the `AppendError/s` methods anymore, as the errors are serialized directly to other types.
Low-level optimizations to help the compiler generate better code
when logging is disabled. Measured improvement is ~30% on amd64
(from 21 ns/op to 16 ns/op).
Tim Hockin
Marcus Watkins
Tabitha
Dan Gillis
Eugene
Chris Camel
Dima
CrazyMax
Veselkov Konstantin
wangyuehong
Mike Camp
Soloman Weng
Olivier Poitrey
anthony
Dušan Kasan
Ravi Raju
Max Wolter
Rodrigo Coelho
Giovanni Bajo