shared-snippets/matlab/logging/base_logger.m

138 lines
4.5 KiB
Matlab

%
% -----------------
% Copyright © 2024 ACK Cyfronet AGH, Poland.
% -----------------
%
% BASE_LOGGER A singleton logger class for logging messages to a file.
%
% This class implements a simple logging mechanism with different log levels
% (TRACE, DEBUG, INFO, WARNING, ERROR) and writes log entries to a file.
% It follows the Singleton pattern to ensure that only one instance of the logger
% exists throughout the application.
%
% The log file is specified by the environment variable 'APP_LOG_FILE'. If
% the variable is not set, a default file 'base-logger-log.log' is used.
%
% Properties:
% fid - (private) The file identifier for the log file. This is used to write logs.
%
% Methods:
%
% getInstance() - Retrieves the singleton instance of the logger.
%
% trace(varargin) - Logs one or more messages with TRACE level.
% @param varargin The messages to log. Can be strings, numbers, or MException objects.
%
% debug(varargin) - Logs one or more messages with DEBUG level.
% @param varargin The messages to log. Can be strings, numbers, or MException objects.
%
% info(varargin) - Logs one or more messages with INFO level.
% @param varargin The messages to log. Can be strings, numbers, or MException objects.
%
% warning(varargin) - Logs one or more messages with WARNING level.
% @param varargin The messages to log. Can be strings, numbers, or MException objects.
%
% error(varargin) - Logs one or more messages with ERROR level.
% @param varargin The messages to log. Can be strings, numbers, or MException objects.
%
% delete() - Destructor method that closes the file identifier when the logger is deleted.
%
% Example Usage:
% logger = base_logger.getInstance();
% logger.info('Some info')
%
% try
% % some code causing exception
% catch err
% logger.error('An error occurred:', err);
% end
%
% See also: fopen, fclose, dbstack, fprintf
classdef base_logger < handle
properties(Access=private)
fid;
end
methods(Static, Access = public)
function obj = getInstance()
persistent instance;
if isempty(instance)
instance = base_logger();
end
obj = instance;
end
end
methods(Access=private)
function this = base_logger()
logFileName = getenv("APP_LOG_FILE");
if isempty(logFileName)
logFileName = 'base-logger-log.log';
end
this.fid = fopen(logFileName, 'a');
if this.fid == -1
error('Failed to open log file');
end
end
function log(this, level, varargin)
current_time = datestr(now, 'yyyy-mm-dd HH:MM:SS');
stack = dbstack('-completenames');
if length(stack) > 2
script_name = stack(3).name;
else
script_name = 'Unknown';
end
message = "";
for i = 1:numel(varargin)
if isa(varargin{i}, 'MException')
message = sprintf('%sError: %s\n', message, varargin{i}.message);
for j = 1:length(varargin{i}.stack)
message = sprintf('%s at %s (line %d)\n', message, varargin{i}.stack(j).name, varargin{i}.stack(j).line);
end
elseif isnumeric(varargin{i}) || isenum(varargin{i}) || islogical(varargin{i})
message = strcat(message, string(varargin{i}));
elseif ischar(varargin{i}) || isstring(varargin{i})
message = strcat(message, varargin{i});
else
message = strcat(message, 'Unsupported data type');
end
if i < numel(varargin)
message = strcat(message, ", ");
end
end
fprintf(this.fid, '%s %s %s %s\n', current_time, level, script_name, message);
end
end
methods(Access=public)
function trace(this, varargin)
this.log('TRACE', varargin{:});
end
function debug(this, varargin)
this.log('DEBUG', varargin{:});
end
function info(this, varargin)
this.log('INFO', varargin{:});
end
function warning(this, varargin)
this.log('WARNING', varargin{:});
end
function error(this, varargin)
this.log('ERROR', varargin{:});
end
function delete(this)
if this.fid ~= -1
fclose(this.fid);
end
end
end
end