Summary:
* Now each Log related function has a variant that takes an additional
argument indicating its log level, which is one of the following:
- DEBUG, INFO, WARN, ERROR, FATAL.
* To ensure backward-compatibility, old version Log functions are kept
unchanged.
* Logger now has a member variable indicating its log level. Any incoming
Log request which log level is lower than Logger's log level will not
be output.
* The output of the newer version Log will be prefixed by its log level.
Test Plan:
Add a LogType test in auto_roll_logger_test.cc
= Sample log output =
2014/02/11-00:03:07.683895 7feded179840 [DEBUG] this is the message to be written to the log file!!
2014/02/11-00:03:07.683898 7feded179840 [INFO] this is the message to be written to the log file!!
2014/02/11-00:03:07.683900 7feded179840 [WARN] this is the message to be written to the log file!!
2014/02/11-00:03:07.683903 7feded179840 [ERROR] this is the message to be written to the log file!!
2014/02/11-00:03:07.683906 7feded179840 [FATAL] this is the message to be written to the log file!!
Reviewers: dhruba, xjin, kailiu
Reviewed By: kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16071
ccaedd16d4