package async_log

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Logging library built on top of Async_unix

Install

Dune Dependency

github.com Changelog MIT License Edit opam file Versions (1)

Authors

J

Jane Street Group, LLC

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J

Jane Street developers

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sha256=2dae248d74c23aa6a1e0bc38d5b34c975eb4dfbdf32f0970641b5befd8385720

doc/async_log.kernel/Async_log_kernel/Log/index.html

Module `Async_log_kernel.Log`Source

A library for general logging.

Although this module is fully Async-safe it exposes almost no Deferreds. This is partially a design choice to minimize the impact of logging in code, and partially the result of organic design (i.e., older versions of this interface did the same thing).

A (limited) Blocking module is supplied to accommodate the portion of a program that runs outside of Async.

Sourcetype t

Sourceval sexp_of_t : t -> Sexplib0.Sexp.t

Sourceval set_level_via_param : t -> unit Core.Command.Param.t

Sets the log level via a flag, if provided.

Sourceval set_level : t -> Level.t -> unit

Messages sent at a level less than the current level will not be output.

Sourceval level : t -> Level.t

Returns the last level passed to set_level, which will be the log level checked as a threshold against the level of the next message sent.

Sourceval set_output : t -> Output.t list -> unit

Changes the output type of the log, which can be useful when daemonizing. The new output type will be applied to all subsequent messages.

Sourceval get_output : t -> Output.t list

Sourceval get_time_source : t -> Async_kernel.Synchronous_time_source.t

Changes the time source of the log, which controls the default timestamp on messages.

Sourceval set_time_source : t -> Async_kernel.Synchronous_time_source.t -> unit

Sourceval get_transform : t -> (Message_event.t -> Message_event.t) option

Changes the transform function within log. This allows you to *synchronously* change things about the message at the time that they were written.

The transform function *will not* be called if the initial message is of a level that would not currently be logged.

The transform function *will* be called if even if there are no log outputs.

Sourceval set_transform : t -> (Message_event.t -> Message_event.t) option -> unit

Sourceval get_on_error : t -> [ `Raise | `Call of Core.Error.t -> unit ]

If `Raise is given, then background errors raised by logging will be raised to the monitor that was in scope when create was called. Errors can be redirected anywhere by providing `Call f.

Sourceval set_on_error : t -> [ `Raise | `Call of Core.Error.t -> unit ] -> unit

Sourceval close : t -> unit Async_kernel.Deferred.t

Any call that writes to a log after close is called will raise.

Sourceval is_closed : t -> bool

Returns true if close has been called.

Sourceval flushed : t -> unit Async_kernel.Deferred.t

Returns a Deferred.t that is fulfilled when the last message delivered to t before the call to flushed is out the door.

val create : 
  level:Level.t ->
  output:Output.t list ->
  on_error:[ `Raise | `Call of Core.Error.t -> unit ] ->
  ?time_source:Async_kernel.Synchronous_time_source.t ->
  ?transform:(Message_event.t -> Message_event.t) ->
  unit ->
  t

Creates a new log. See set_level, set_on_error, set_output, set_time_source, and set_transform for more.

Sourceval create_null : unit -> t

Log that drops messages sent to it, as if it wrote to /dev/null

Sourceval copy : t -> t

Creates a copy of a log, which has the same settings and logs to the same outputs.

Printf-like logging for messages at each log level or raw (no level) messages. Raw messages still include a timestamp.

val raw : 
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  ('a, unit, string, unit) Core.format4 ->
  'a

val debug : 
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  ('a, unit, string, unit) Core.format4 ->
  'a

val info : 
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  ('a, unit, string, unit) Core.format4 ->
  'a

val error : 
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  ('a, unit, string, unit) Core.format4 ->
  'a

val printf : 
  ?level:Level.t ->
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  ('a, unit, string, unit) Core.format4 ->
  'a

Generalized printf-style logging.

Sexp logging for messages at each log level or raw (no level) messages. Raw messages still include a timestamp

val raw_s : 
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  Core.Sexp.t ->
  unit

val info_s : 
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  Core.Sexp.t ->
  unit

val error_s : 
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  Core.Sexp.t ->
  unit

val debug_s : 
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  Core.Sexp.t ->
  unit

val sexp : 
  ?level:Level.t ->
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  Core.Sexp.t ->
  unit

Generalized sexp-style logging.

val string : 
  ?level:Level.t ->
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  string ->
  unit

Log a string directly.

val structured_message : 
  ?level:Level.t ->
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  Ppx_log_types.Message_data.t ->
  Ppx_log_types.Message_source.t ->
  unit

Sourceval message : t -> Message.t -> unit

Log a pre-created message.

Sourceval message_event : t -> Message_event.t -> unit

val surround_s : 
  on_subsequent_errors:[ `Call of exn -> unit | `Log | `Raise ] ->
  ?level:Level.t ->
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  Core.Sexp.t ->
  (unit -> 'a Async_kernel.Deferred.t) ->
  'a Async_kernel.Deferred.t

surround t message f logs message and a UUID once before calling f and again after f returns or raises. If f raises, the second message will include the exception, and surround itself will re-raise the exception tagged with message. on_subsequent_errors is passed to the internal monitor as rest argument. As usual, the logging happens only if level exceeds the minimum level of t.

val surroundf : 
  on_subsequent_errors:[ `Call of exn -> unit | `Log | `Raise ] ->
  ?level:Level.t ->
  ?time:Core.Time_float.t ->
  ?tags:(string * string) list ->
  t ->
  ('a,
    unit,
    string,
    (unit -> 'b Async_kernel.Deferred.t) ->
    'b Async_kernel.Deferred.t)
    Core.format4 ->
  'a

Sourceval would_log : t -> Level.t option -> bool

would_log returns true if a message at the given log level would be logged if sent immediately.

This will return false if there are no outputs for the log, unless there is a transform set.

Sourcemodule For_testing : sig ... end