Log to a memory buffer

An Appender that Buffers LogEvents in-memory and and redirects them to other Appenders once certain conditions are met.

Fields

appenders, set_appenders()

Like for a Logger. Buffered events will be passed on to these Appenders once a flush is triggered

flush_on_exit, set_flush_on_exit(x)

TRUE or FALSE: Whether the buffer should be flushed when the Appender is garbage collected (f.e when you close R)

flush_on_rotate, set_flush_on_rotate

TRUE or FALSE: Whether the buffer should be flushed when the Buffer is full (f.e when you close R). Setting this to off can have slightly negative performance impacts.

See also

LayoutFormat

Other Appenders: AppenderConsole, AppenderFileRotatingDate, AppenderFileRotatingTime, AppenderFileRotating, AppenderFile, AppenderTable, Appender

Super classes

lgr::Filterable -> lgr::Appender -> lgr::AppenderMemory -> AppenderBuffer

Methods

Public methods

• AppenderBuffer$new()

• AppenderBuffer$flush()

• AppenderBuffer$clear()

• AppenderBuffer$set_appenders()

• AppenderBuffer$add_appender()

• AppenderBuffer$remove_appender()

• AppenderBuffer$format()

Inherited methods

• lgr::Filterable$add_filter()
• lgr::Filterable$filter()
• lgr::Filterable$remove_filter()
• lgr::Filterable$set_filters()
• lgr::Appender$set_layout()
• lgr::Appender$set_threshold()
• lgr::AppenderMemory$append()
• lgr::AppenderMemory$set_buffer_size()
• lgr::AppenderMemory$set_flush_on_exit()
• lgr::AppenderMemory$set_flush_on_rotate()
• lgr::AppenderMemory$set_flush_threshold()
• lgr::AppenderMemory$set_should_flush()
• lgr::AppenderMemory$show()

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Method new()

The Layout for this Appender is used only to format console output of its $show() method.

Usage

AppenderBuffer$new(
  threshold = NA_integer_,
  layout = LayoutFormat$new(fmt = "%L [%t] %m", timestamp_fmt = "%H:%M:%S",
    colors = getOption("lgr.colors")),
  appenders = NULL,
  buffer_size = 1000,
  flush_threshold = NULL,
  flush_on_exit = TRUE,
  flush_on_rotate = TRUE,
  should_flush = NULL,
  filters = NULL
)

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Method flush()

Sends the buffer's contents to all attached Appenders and then clears the Buffer

Usage

AppenderBuffer$flush()

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Method clear()

Clears the buffer, discarding all buffered Events

Usage

AppenderBuffer$clear()

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Method set_appenders()

Exactly like A Logger, an AppenderBuffer can have an arbitrary amount of Appenders attached. When the buffer is flushed, the buffered events are dispatched to these Appenders.

Usage

AppenderBuffer$set_appenders(x)

Arguments

x

single Appender or a list thereof. Appenders control the output of a Logger. Be aware that a Logger also inherits the Appenders of its ancestors (see vignette("lgr", package = "lgr") for more info about Logger inheritance).

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Method add_appender()

Add an Appender to the AppenderBuffer

Add or remove an Appender. Supplying a name is optional but recommended. After adding an Appender with appender$add_appender(AppenderConsole$new(), name = "console") you can refer to it via appender$appenders$console. remove_appender() can remove an Appender by position or name.

Usage

AppenderBuffer$add_appender(appender, name = NULL)

Arguments

appender

a single Appender

name

a character scalar. Optional but recommended.

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Method remove_appender()

remove an appender

Usage

AppenderBuffer$remove_appender(pos)

Arguments

pos

integer index or character name of the Appender(s) to remove

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Method format()

Usage

AppenderBuffer$format(...)