Log4CL integration.

README.markdown

@@ -5,6 +5,8 @@ A Common Lisp structured logger for Fluentd.
 ## Usage
 
 ```common-lisp
+(ql:quickload :cl-fluent-logger)
+
 (defvar *logger*
   (make-instance 'fluent-logger:fluent-logger))
 
@@ -19,6 +21,18 @@ A Common Lisp structured logger for Fluentd.
                     '(("from" . "userA") ("to" . "userB")))
 ```
 
+### Log4CL Integration
+
+```common-lisp
+(ql:quickload :cl-fluent-logger/log4cl)
+
+(defvar *logger* (log:category '(cl-user)))
+(fluent-logger/log4cl:create-fluent-logger *logger* :tag "debug" :level :info)
+
+(log:info "hi")
+;-> <INFO> [17:03:33]  (cl-user) - hi
+```
+
 ## Author
 
 * Eitaro Fukamachi (e.arrows@gmail.com)

log4cl.lisp

@@ -0,0 +1,38 @@
+(defpackage #:cl-fluent-logger/log4cl
+  (:nicknames :fluent-logger/log4cl)
+  (:use #:cl)
+  (:import-from #:cl-fluent-logger
+                #:fluent-logger
+                #:send)
+  (:import-from #:log4cl)
+  (:export #:fluent-appender
+           #:create-fluent-logger))
+(in-package #:cl-fluent-logger/log4cl)
+
+(defclass fluent-appender (log4cl:appender)
+  ((logger :accessor fluent-appender-logger
+           :initarg :logger
+           :initform nil)))
+
+(defmethod initialize-instance :after ((appender fluent-appender) &rest initargs)
+  (unless (fluent-appender-logger appender)
+    (setf (fluent-appender-logger appender)
+          (apply #'make-instance 'fluent-logger :allow-other-keys t initargs))))
+
+(defmethod log4cl:appender-do-append ((appender fluent-appender) logger level log-func)
+  (declare (ignore logger))
+  (send (fluent-appender-logger appender)
+        (string-downcase (log4cl:log-level-to-string level))
+        (with-output-to-string (s) (funcall log-func s))))
+
+(defun create-fluent-logger (logger &rest initargs
+                             &key tag host port buffer-limit timeout nanosecond-precision
+                               level)
+  (declare (ignore tag host port buffer-limit timeout nanosecond-precision))
+  (log:config logger level)
+  (let* ((fluent-logger (apply #'make-instance 'fluent-logger
+                               :allow-other-keys t
+                               initargs))
+         (appender (make-instance 'fluent-appender :logger fluent-logger)))
+    (log4cl:add-appender logger appender)
+    logger))