Crate ringlog

This crate provides an asynchronous logging backend that can direct logs to one or more outputs.

The core of this crate is the RingLog type, which is constructed using a builder that is specific to your logging needs. After building the RingLog, it can be registered as the global logger using the start method. You will be left with a Box<dyn Drain> which should be periodically flushed outside of any critical path. For example, in an admin thread or dedicated logging thread.

For logging to a single file, the LogBuilder type can be used to construct an RingLog which has low overhead, but directs log messages to a single Output.

A SamplingLogBuilder can be used to construct an RingLog which will filter the log messages using sampling before directing the log messages to a single Output.

A MultiLogBuilder can be used to construct an RingLog which routes log messages based on the target metadata of the log Record. If there is an RingLog registered for that specific target, then the log message will be routed to that instance of RingLog. Log messages that do not match any specific target will be routed to the default RingLog that has been added to the MultiLogBuilder. If there is no default, messages that do not match any specific target will be simply dropped.

This combination of logging types allows us to compose a logging backend which meets the application’s needs. For example, you can use a local log macro to set the target to some specific category and log those messages to a file, while letting all other log messages pass to standard out. This could allow splitting command/access/audit logs from the normal logging.

Macros

debug

Logs a message at the debug level.

error

Logs a message at the error level.

fatal

Logs a fatal error and terminates the program.

info

Logs a message at the info level.

log

The standard logging macro.

log_enabled

Determines if a message logged at the specified level in that module will be logged.

trace

Logs a message at the trace level.

warn

Logs a message at the warn level.

Structs

File

A file based output which allows rotating the current log file off to a backup location.

LogBuilder

A type to construct a basic RingLog which routes all log messages to a single Output.

Metadata

Metadata about a log message.

MetadataBuilder

Builder for Metadata.

MultiLogBuilder

A type to construct a multi-target RingLog which routes messages based on the log’s target metadata to a corresponding RingLog. Targets which do not match a specific target will be routed to the default RingLog if one is configured.

NopLogBuilder

A type to construct a basic RingLog which drops all log messages.

ParseLevelError

The type returned by from_str when the string doesn’t match any of the log levels.

Record

The “payload” of a log message.

RecordBuilder

Builder for Record.

RingLog

A type which implements an asynchronous logging backend.

SamplingLogBuilder

A type to construct a basic RingLog which routes 1 in N log messages to a single Output.

SetLoggerError

The type returned by set_logger if set_logger has already been called.

Stderr

An output that writes to stderr.

Stdout

An output that writes to stdout.

Enums

Level

An enum representing the available verbosity levels of the logger.

LevelFilter

An enum representing the available verbosity level filters of the logger.

Constants

STATIC_MAX_LEVEL

The statically resolved maximum log level.

Traits

Drain

A Drain serves to receive log messages from a queue and flush them to an Output.

Log

A trait encapsulating the operations required of a logger.

Output

An Output is a logging destination, for example, standard out or a file.

Functions

default_format

klog_format

logger

Returns a reference to the logger.

max_level

Returns the current maximum log level.

set_boxed_logger

Sets the global logger to a Box<Log>.

set_logger

Sets the global logger to a &'static Log.

set_logger_racy^⚠

A thread-unsafe version of set_logger.

set_max_level

Sets the global maximum log level.

set_max_level_racy^⚠

A thread-unsafe version of set_max_level.

Type Aliases

FormatFunction