LU-3692 api: More flexible logging API.

Allow applications to register their own logging callback instead of
writing every log message to stderr/stdout. Registered callbacks are
global to the process, just like the log level.

Signed-off-by: Henri Doreau <henri.doreau@cea.fr>
Change-Id: I5ccfd1e24f1786408ce67b2cd87d53443bcd028a
Reviewed-on: http://review.whamcloud.com/7572
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/include/lustre/lustre_user.h b/lustre/include/lustre/lustre_user.h
index 5c9e0a7..5f47ada 100644 (file)
--- a/lustre/include/lustre/lustre_user.h
+++ b/lustre/include/lustre/lustre_user.h
@@ -47,6 +47,7 @@
  */
 
 #ifndef __KERNEL__
  */
 
 #ifndef __KERNEL__

+#include <stdio.h>

 #include <libcfs/posix/posix-types.h>
 #endif
 #include <lustre/ll_fiemap.h>
 #include <libcfs/posix/posix-types.h>
 #endif
 #include <lustre/ll_fiemap.h>

diff --git a/lustre/include/lustre/lustreapi.h b/lustre/include/lustre/lustreapi.h
index 3212bfe..3eb04a5 100644 (file)
--- a/lustre/include/lustre/lustreapi.h
+++ b/lustre/include/lustre/lustreapi.h
@@ -42,9 +42,11 @@
  * @{
  */
 
  * @{
  */
 

+#include <stdarg.h>

 #include <lustre/lustre_user.h>
 
 #include <lustre/lustre_user.h>
 

-typedef void (*llapi_cb_t)(char *obd_type_name, char *obd_name, char *obd_uuid, void *args);
+typedef void (*llapi_cb_t)(char *obd_type_name, char *obd_name, char *obd_uuid,
+                          void *args);

 
 /* lustreapi message severity level */
 enum llapi_message_level {
 
 /* lustreapi message severity level */
 enum llapi_message_level {


@@ -58,17 +60,23 @@ enum llapi_message_level {
         LLAPI_MSG_MAX
 };
 
         LLAPI_MSG_MAX
 };
 

+typedef void (*llapi_log_callback_t)(enum llapi_message_level level, int err,
+                                    const char *fmt, va_list ap);
+
+

 /* the bottom three bits reserved for llapi_message_level */
 #define LLAPI_MSG_MASK          0x00000007
 #define LLAPI_MSG_NO_ERRNO      0x00000010
 
 extern void llapi_msg_set_level(int level);
 /* the bottom three bits reserved for llapi_message_level */
 #define LLAPI_MSG_MASK          0x00000007
 #define LLAPI_MSG_NO_ERRNO      0x00000010
 
 extern void llapi_msg_set_level(int level);

+extern llapi_log_callback_t llapi_error_callback_set(llapi_log_callback_t cb);
+extern llapi_log_callback_t llapi_info_callback_set(llapi_log_callback_t cb);

 
 

-void llapi_error(int level, int rc, const char *fmt, ...)
+void llapi_error(enum llapi_message_level level, int err, const char *fmt, ...)

        __attribute__((__format__(__printf__, 3, 4)));
 #define llapi_err_noerrno(level, fmt, a...)                    \
        llapi_error((level) | LLAPI_MSG_NO_ERRNO, 0, fmt, ## a)
        __attribute__((__format__(__printf__, 3, 4)));
 #define llapi_err_noerrno(level, fmt, a...)                    \
        llapi_error((level) | LLAPI_MSG_NO_ERRNO, 0, fmt, ## a)

-void llapi_printf(int level, const char *fmt, ...)
+void llapi_printf(enum llapi_message_level level, const char *fmt, ...)

        __attribute__((__format__(__printf__, 2, 3)));
 
 extern int llapi_file_create(const char *name, unsigned long long stripe_size,
        __attribute__((__format__(__printf__, 2, 3)));
 
 extern int llapi_file_create(const char *name, unsigned long long stripe_size,

diff --git a/lustre/utils/liblustreapi.c b/lustre/utils/liblustreapi.c
index 3051bdf..7b470f3 100644 (file)
--- a/lustre/utils/liblustreapi.c
+++ b/lustre/utils/liblustreapi.c
@@ -130,41 +130,90 @@ void llapi_msg_set_level(int level)
                 llapi_msg_level = level;
 }
 
                 llapi_msg_level = level;
 }
 

-/* llapi_error will preserve errno */
-void llapi_error(int level, int _rc, const char *fmt, ...)
+static void error_callback_default(enum llapi_message_level level, int err,
+                                  const char *fmt, va_list ap)
+{
+       vfprintf(stderr, fmt, ap);
+       if (level & LLAPI_MSG_NO_ERRNO)
+               fprintf(stderr, "\n");
+       else
+               fprintf(stderr, ": %s (%d)\n", strerror(err), err);
+}
+
+static void info_callback_default(enum llapi_message_level level, int err,
+                                 const char *fmt, va_list ap)

 {
 {

-        va_list args;
-        int tmp_errno = errno;
-        /* to protect using errno as _rc argument */
-        int rc = abs(_rc);
+       vfprintf(stdout, fmt, ap);
+}

 
 

-        if ((level & LLAPI_MSG_MASK) > llapi_msg_level)
-                return;
+static llapi_log_callback_t llapi_error_callback = error_callback_default;
+static llapi_log_callback_t llapi_info_callback = info_callback_default;

 
 

-        va_start(args, fmt);
-        vfprintf(stderr, fmt, args);
-        va_end(args);

 
 

-        if (level & LLAPI_MSG_NO_ERRNO)
-                fprintf(stderr, "\n");
-        else
-                fprintf(stderr, ": %s (%d)\n", strerror(rc), rc);
-        errno = tmp_errno;
+/* llapi_error will preserve errno */
+void llapi_error(enum llapi_message_level level, int err, const char *fmt, ...)
+{
+       va_list  args;
+       int      tmp_errno = errno;
+
+       if ((level & LLAPI_MSG_MASK) > llapi_msg_level)
+               return;
+
+       va_start(args, fmt);
+       llapi_error_callback(level, abs(err), fmt, args);
+       va_end(args);
+       errno = tmp_errno;

 }
 
 /* llapi_printf will preserve errno */
 }
 
 /* llapi_printf will preserve errno */

-void llapi_printf(int level, const char *fmt, ...)
+void llapi_printf(enum llapi_message_level level, const char *fmt, ...)

 {
 {

-        va_list args;
-        int tmp_errno = errno;
+       va_list  args;
+       int      tmp_errno = errno;
+
+       if ((level & LLAPI_MSG_MASK) > llapi_msg_level)
+               return;
+
+       va_start(args, fmt);
+       llapi_info_callback(level, 0, fmt, args);
+       va_end(args);
+       errno = tmp_errno;
+}

 
 

-        if ((level & LLAPI_MSG_MASK) > llapi_msg_level)
-                return;
+/**
+ * Set a custom error logging function. Passing in NULL will reset the logging
+ * callback to its default value.
+ *
+ * This function returns the value of the old callback.
+ */
+llapi_log_callback_t llapi_error_callback_set(llapi_log_callback_t cb)
+{
+       llapi_log_callback_t    old = llapi_error_callback;
+
+       if (cb != NULL)
+               llapi_error_callback = cb;
+       else
+               llapi_error_callback = error_callback_default;
+
+       return old;
+}
+
+/**
+ * Set a custom info logging function. Passing in NULL will reset the logging
+ * callback to its default value.
+ *
+ * This function returns the value of the old callback.
+ */
+llapi_log_callback_t llapi_info_callback_set(llapi_log_callback_t cb)
+{
+       llapi_log_callback_t    old = llapi_info_callback;
+
+       if (cb != NULL)
+               llapi_info_callback = cb;
+       else
+               llapi_info_callback = info_callback_default;

 
 

-        va_start(args, fmt);
-        vfprintf(stdout, fmt, args);
-        va_end(args);
-        errno = tmp_errno;
+       return old;

 }
 
 /**
 }
 
 /**