Crate tui_logger

Logger with smart widget for the tui crate.

Demo of the widget

Documentation

Documentation

Features

• [X] Logger implementation for the log crate
• [X] Logger enable/disable detection uses fast, collision free hash table
• [ ] Collision free hash table algorithm to be done. Currently use a big table
• [X] Hot logger code only copies enabled log messages with timestamp into a circular buffer
• [X] Widgets/move_message() retrieve captured log messages from hot circular buffer
• [X] Lost message detection of overwritten logs messages in circular buffer
• [X] Log filtering performed on log-target
• [X] Simple Widgets to view the logs and select Debuglevel of target
• [X] Smart Widget with dynamic event dispatcher for termion events (see demo code)
• [X] Logging of enabled logs to file

Smart Widget

Smart widget consists of two widgets. Left is the target selector widget and on the right side the logging messages view scrolling up.

The target selector widget looks like this:

It controls:

• Capturing of log messages by the logger
• Selection of levels for display in the logging message view

The target selector widget consists of two columns:

• Code EWIDT: E stands for Error, W for Warn, Info, Debug and Trace.
  • Inverted characters (EWIDT) are enabled log levels in the view
  • Normal characters show enabled capturing of a log level per target
  • If any of EWIDT are not shown, then the respective log level is not captured
• Target of the log events can be defined in the log e.g. warn!(target: "demo", "Log message");

Smart Widget Key Commands

KEY	ACTION
h	Toggles target selector widget
UP	Select previous target in target selector widget
DOWN	Select next target in target selector widget
LEFT	Reduce SHOWN (!) log messages by one level
RIGHT	Increase SHOWN (!) log messages by one level
-	Reduce CAPTURED (!) log messages by one level
+	Increase CAPTURED (!) log messages by one level
SPACE	Toggles hiding of targets, which have logfilter set to off

Basic usage to initialize logger-system:

extern crate log;
extern crate tui_logger;

use log::LevelFilter; 
use tui_logger::*;
 
fn main() {
    // Early initialization of the logger
 
    // Set max_log_level to Trace
    init_logger(LevelFilter::Trace).unwrap();
 
    // Set default level for unknown targets to Trace
    set_default_level(LevelFilter::Trace);
 
    // code....
}

For use of the widget please check examples/demo.rs

Structs

CircularBuffer	CircularBuffer is used to store the last elements of an endless sequence. Oldest elements will be overwritten. The implementation focus on speed. So memory allocations are avoided.
Dispatcher	Dispatcher is used to dispatch any event to a dynamically built chain of handlers. The dispatch is a one-shot event. After an event is successfully processed, the dispatch chain is emptied.
LevelConfig	LevelConfig stores the relation target->LevelFilter in a hash table.
TuiLoggerSmartWidget	The Smart Widget combines the TuiLoggerWidget and the TuiLoggerTargetWidget into a nice combo, where the TuiLoggerTargetWidget can be shown/hidden.
TuiLoggerTargetWidget	This is the definition for the TuiLoggerTargetWidget, which allows configuration of the logger system and selection of log messages. It implements the EventListener trait, because it can enter event handlers to the dispatcher for the key commands.
TuiLoggerWidget	The TuiLoggerWidget shows the logging messages in an endless scrolling view. It is controlled by a TuiWidgetState for selected events.
TuiWidgetState	This struct contains the shared state of a TuiLoggerWidget and a TuiLoggerTargetWidget.

Traits

EventListener

The EventListener Trait is only a standard way to implement a tui widget, which can listen to events.

Functions

init_logger	Init the logger and record with log crate.
move_events	Move events from hot circular buffer to the main one. If defined, log records will be written to file.
set_default_level	Set default levelfilter for unknown targets of the logger
set_hot_buffer_depth	Set the depth of the hot buffer in order to avoid message loss
set_level_for_target	Set levelfilter for a specific target in the logger
set_log_file	Define filename for logging.