common/logging/Logger.php

   1 <?php
   2 /**
   3  * Application logger. Puts daily logs in the server's temporary directory. Log level is set in
   4  * globals as $GLOBALS["log_level"] (this is customizable in the globals file).
   5
   6  * A *nix user can run the following command to see the logs:
   7  * <code>
   8  *     > tail -f /var/www/openemr/logs/2016_11_24_application.log
   9  *     2016-11-24 20:15:07 [TRACE] \common\database\Connector - Connecting with pooled mode
  10  *     2016-11-24 20:15:07 [TRACE] \common\database\Connector - Wiring up Doctrine entities
  11  *     2016-11-24 20:15:07 [TRACE] \common\database\Connector - Creating connection
  12  *     2016-11-24 20:15:07 [INFO] \some\other\Class - Some info message
  13  *     2016-11-24 20:18:01 [WARN] \some\other\Class - Some field is missing
  14  * </code>
  15  *
  16  * @note Error level logs will also be sent to Apache error log.
  17  *
  18  * @note Application logging is sparse at the moment (will be introduced w/ the modernization project).
  19  *
  20  * Copyright (C) 2016 Matthew Vita <matthewvita48@gmail.com>
  21  *
  22  * LICENSE: This program is free software; you can redistribute it and/or
  23  * modify it under the terms of the GNU General Public License
  24  * as published by the Free Software Foundation; either version 2
  25  * of the License, or (at your option) any later version.
  26  * This program is distributed in the hope that it will be useful,
  27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  29  * GNU General Public License for more details.
  30  * You should have received a copy of the GNU General Public License
  31  * along with this program. If not, see <http://opensource.org/licenses/gpl-license.php>.
  32  *
  33  * @package OpenEMR
  34  * @author  Matthew Vita <matthewvita48@gmail.com>
  35  * @link    http://www.open-emr.org
  36  */
  37
  38 namespace common\logging;
  39
  40 class Logger {
  41     /**
  42      * The class that is associated with a log entry.
  43      */
  44     private $classContext;
  45
  46     /**
  47      * The fully qualified log file path.
  48      */
  49     private $logFile;
  50
  51     /**
  52      * Default constructor. Only continues with instance creation
  53      * if logging is enabled.
  54      *
  55      * @param $classContext - provided when a class uses the logger.
  56      */
  57     public function __construct($classContext="UnknownClassContext") {
  58         if (isset($GLOBALS["log_level"]) && $GLOBALS["log_level"] !== "OFF") {
  59             $this->classContext = $classContext;
  60             $this->determineLogFilePath();
  61         }
  62     }
  63
  64     /**
  65      * Sets the log file on the operating system's temporary directory. Format is:
  66      * [log area] + FILE_SEP + YYYY_MM_DD_application.log
  67      *
  68      * On *nix, the file will be stored in /home/current_user/openemr/ (if writable). On Windows, it will
  69      * be stored in C:\Users\current_user\openemr\ (if writable).
  70      */
  71     private function determineLogFilePath() {
  72         $fileName = date("Y_m_d") . "_application.log";
  73
  74         global $webserver_root;
  75         $currentDir = $webserver_root;
  76         $logDirName = 'logs';
  77         $combinedLogDir = $currentDir . DIRECTORY_SEPARATOR . $logDirName;
  78
  79         if (!is_dir($combinedLogDir)) {
  80             mkdir($combinedLogDir);
  81         }
  82
  83         if (is_writable($combinedLogDir)) {
  84             $this->logFile = $combinedLogDir . DIRECTORY_SEPARATOR . $fileName;
  85         } else {
  86             error_log('Can\'t write application log file to ' . $combinedLogDir);
  87         }
  88     }
  89
  90     /**
  91      * Determines if the log level is allowed by the log level in the global
  92      * configuration.
  93      *
  94      * Hierarchy/conditions:
  95      *     - TRACE (allows TRACE, DEBUG, INFO, WARN, ERROR)
  96      *     - DEBUG (allows DEBUG, INFO, WARN, ERROR)
  97      *     - INFO  (allows INFO, WARN, ERROR)
  98      *     - WARN  (allows WARN, ERROR)
  99      *     - ERROR (allows ERROR)
 100      *     - OFF   (no logs)
 101      *
 102      * @param $level the incoming log level
 103      * @return boolean that represents if log entry should be made
 104      */
 105     private function isLogLevelInDesiredHierarchy($level) {
 106         if (empty($GLOBALS["log_level"]) || $GLOBALS["log_level"] === "OFF") {
 107             return false;
 108         }
 109
 110         if ($GLOBALS["log_level"] === "TRACE") {
 111             return true;
 112         } else if ($GLOBALS["log_level"] === "DEBUG" && in_array($level, array("DEBUG", "INFO", "WARN", "ERROR"))) {
 113             return true;
 114         } else if ($GLOBALS["log_level"] === "INFO" && in_array($level, array("INFO", "WARN", "ERROR"))) {
 115             return true;
 116         } else if ($GLOBALS["log_level"] === "WARN" && in_array($level, array("WARN", "ERROR"))) {
 117             return true;
 118         } else if ($GLOBALS["log_level"] === "ERROR" && $level === "ERROR") {
 119             return true;
 120         } else {
 121             return false;
 122         }
 123     }
 124
 125     /**
 126      * Used for informational messages of the application.
 127      *
 128      * @param $message - the log message
 129      */
 130     public function info($message) {
 131         $this->log($message, "INFO");
 132     }
 133
 134     /**
 135      * Used by developers that wish to expose information that is
 136      * notable for developers.
 137      *
 138      * @param $message - the log message
 139      */
 140     public function debug($message) {
 141         $this->log($message, "DEBUG");
 142     }
 143
 144     /**
 145      * Used by developers that wish to expose information that is
 146      * notable for developers. Note this is more "noisy" than debug.
 147      *
 148      * @param $message - the log message
 149      */
 150     public function trace($message) {
 151         $this->log($message, "TRACE");
 152     }
 153
 154     /**
 155      * Used for in case of harmful conditions.
 156      *
 157      * @param $message - the log message
 158      */
 159     public function warn($message) {
 160         $this->log($message, "WARN");
 161     }
 162
 163     /**
 164      * Used for in case an error occurs and the application might continue running.
 165      *
 166      * @param $message - the log message
 167      */
 168     public function error($message) {
 169         $this->log($message, "ERROR");
 170     }
 171
 172     /**
 173      * Writes the entry to the log file. If the level is type "error", the message
 174      * will additionally go to the Apache error log.
 175      *
 176      * @param $message - the log message
 177      * @param $type - the log type
 178      */
 179     private function log($message, $type) {
 180         if ($this->isLogLevelInDesiredHierarchy($type) && !empty($this->logFile)) {
 181             $logEntry = date("Y-m-d H:i:s") . " [" . $type . "] " . $this->classContext . " - " . $message;
 182
 183             file_put_contents($this->logFile, $logEntry.PHP_EOL , FILE_APPEND | LOCK_EX);
 184
 185             if ($type === "ERROR") {
 186                 error_log($message);
 187             }
 188         }
 189     }
 190 }