verbosity: Prepare hooking of log messages

Change-Id: Icfe96d2fee2d3b699dfa9105fcfe62d4eced2557
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

2 files changed, 61 insertions, 21 deletions

diff --git a/src/verbose.c b/src/verbose.c
index 2b009073..2d60dfca 100644
--- a/src/verbose.c
+++ b/src/verbose.c
@@ -21,22 +21,27 @@
 
 #include "verbose.h"
 
+#if !defined(DEFAULT_VERBOSITY)
+# define DEFAULT_VERBOSITY Verbosity_Level_Warning
+#endif
+
 int verbosity = 1;
+void (*verbose_observer)(int loglevel, const char *file, int line, const char *function, const char *fmt, va_list args);
 
-#define LEVEL(x) ((x) < 0 ? 0 : (x) > 7 ? 7 : (x))
+#define CROP_LOGLEVEL(x) ((x) < Log_Level_Emergency ? Log_Level_Emergency : (x) > Log_Level_Debug ? Log_Level_Debug : (x))
 
 #if defined(VERBOSE_WITH_SYSLOG)
 
 #include <syslog.h>
 
-void vverbose(int level, const char *file, int line, const char *function, const char *fmt, va_list args)
+static void _vverbose_(int loglevel, const char *file, int line, const char *function, const char *fmt, va_list args)
 {
 	char *p;
 
 	if (file == NULL || vasprintf(&p, fmt, args) < 0)
-		vsyslog(level, fmt, args);
+		vsyslog(loglevel, fmt, args);
 	else {
-		syslog(LEVEL(level), "%s [%s:%d, function]", p, file, line, function);
+		syslog(CROP_LOGLEVEL(loglevel), "%s [%s:%d, function]", p, file, line, function);
 		free(p);
 	}
 }
@@ -56,15 +61,15 @@ static const char *appname;
 
 static int appauthority;
 
-void vverbose(int level, const char *file, int line, const char *function, const char *fmt, va_list args)
+static void _vverbose_(int loglevel, const char *file, int line, const char *function, const char *fmt, va_list args)
 {
 	char lino[20];
 
 	if (file == NULL) {
-		sd_journal_printv(level, fmt, args);
+		sd_journal_printv(loglevel, fmt, args);
 	} else {
 		sprintf(lino, "%d", line);
-		sd_journal_printv_with_location(level, file, lino, function, fmt, args);
+		sd_journal_printv_with_location(loglevel, file, lino, function, fmt, args);
 	}
 }
 
@@ -94,13 +99,13 @@ static const char *prefixes[] = {
 	"<7> DEBUG"
 };
 
-void vverbose(int level, const char *file, int line, const char *function, const char *fmt, va_list args)
+static void _vverbose_(int loglevel, const char *file, int line, const char *function, const char *fmt, va_list args)
 {
 	int saverr = errno;
 	int tty = isatty(fileno(stderr));
 	errno = saverr;
 
-	fprintf(stderr, "%s: ", prefixes[LEVEL(level)] + (tty ? 4 : 0));
+	fprintf(stderr, "%s: ", prefixes[CROP_LOGLEVEL(loglevel)] + (tty ? 4 : 0));
 	vfprintf(stderr, fmt, args);
 	if (file != NULL && (!tty || verbosity > 2))
 		fprintf(stderr, " [%s:%d,%s]\n", file, line, function);
@@ -116,12 +121,23 @@ void verbose_set_name(const char *name, int authority)
 
 #endif
 
-void verbose(int level, const char *file, int line, const char *function, const char *fmt, ...)
+void verbose(int loglevel, const char *file, int line, const char *function, const char *fmt, ...)
 {
 	va_list ap;
 
 	va_start(ap, fmt);
-	vverbose(level, file, line, function, fmt, ap);
+	vverbose(loglevel, file, line, function, fmt, ap);
 	va_end(ap);
 }
 
+void vverbose(int loglevel, const char *file, int line, const char *function, const char *fmt, va_list args)
+{
+	if (verbose_observer) {
+		va_list ap;
+		va_copy(ap, args);
+		verbose_observer(loglevel, file, line, function, fmt, ap);
+		va_end(ap);
+	}
+	_vverbose_(loglevel, file, line, function, fmt, args);
+}
+
diff --git a/src/verbose.h b/src/verbose.h
index 6bedc323..8b605796 100644
--- a/src/verbose.h
+++ b/src/verbose.h
@@ -34,10 +34,19 @@
 */
 extern int verbosity;
 
+enum verbosity_levels
+{
+	Verbosity_Level_Error = 0,
+	Verbosity_Level_Warning = 1,
+	Verbosity_Level_Notice = 1,
+	Verbosity_Level_Info = 2,
+	Verbosity_Level_Debug = 3
+};
+
 extern void verbose_set_name(const char *name, int authority);
 
 /*
- Level is defined by syslog standard:
+ Log level is defined by syslog standard:
        KERN_EMERG             0        System is unusable
        KERN_ALERT             1        Action must be taken immediately
        KERN_CRIT              2        Critical conditions
@@ -47,14 +56,29 @@ extern void verbose_set_name(const char *name, int authority);
        KERN_INFO              6        Informational
        KERN_DEBUG             7        Debug-level messages
 */
-extern void verbose(int level, const char *file, int line, const char *function, const char *fmt, ...) __attribute__((format(printf, 5, 6)));
-extern void vverbose(int level, const char *file, int line, const char *function, const char *fmt, va_list args);
 
-# define ERROR(...)   do{if(verbosity>=0)verbose(3,__FILE__,__LINE__,__func__,__VA_ARGS__);}while(0)
-# define WARNING(...) do{if(verbosity>=1)verbose(4,__FILE__,__LINE__,__func__,__VA_ARGS__);}while(0)
-# define NOTICE(...)  do{if(verbosity>=1)verbose(5,__FILE__,__LINE__,__func__,__VA_ARGS__);}while(0)
-# define INFO(...)    do{if(verbosity>=2)verbose(6,__FILE__,__LINE__,__func__,__VA_ARGS__);}while(0)
-# define DEBUG(...)   do{if(verbosity>=3)verbose(7,__FILE__,__LINE__,__func__,__VA_ARGS__);}while(0)
-# define LOGUSER(app) verbose_set_name(app,0)
-# define LOGAUTH(app) verbose_set_name(app,1)
+enum log_levels
+{
+	Log_Level_Emergency = 0,
+	Log_Level_Alert = 1,
+	Log_Level_Critical = 2,
+	Log_Level_Error = 3,
+	Log_Level_Warning = 4,
+	Log_Level_Notice = 5,
+	Log_Level_Info = 6,
+	Log_Level_Debug = 7
+};
+
+extern void verbose(int loglevel, const char *file, int line, const char *function, const char *fmt, ...) __attribute__((format(printf, 5, 6)));
+extern void vverbose(int loglevel, const char *file, int line, const char *function, const char *fmt, va_list args);
+
+# define _VERBOSE_(vlvl,llvl,...)  do{ if (verbosity >= vlvl) verbose(llvl, __FILE__, __LINE__, __func__, __VA_ARGS__); } while(0)
+# define ERROR(...)                _VERBOSE_(Verbosity_Level_Error, Log_Level_Error, __VA_ARGS__)
+# define WARNING(...)              _VERBOSE_(Verbosity_Level_Warning, Log_Level_Warning, __VA_ARGS__)
+# define NOTICE(...)               _VERBOSE_(Verbosity_Level_Notice, Log_Level_Notice, __VA_ARGS__)
+# define INFO(...)                 _VERBOSE_(Verbosity_Level_Info, Log_Level_Info, __VA_ARGS__)
+# define DEBUG(...)                _VERBOSE_(Verbosity_Level_Debug, Log_Level_Debug, __VA_ARGS__)
+# define LOGUSER(app)              verbose_set_name(app,0)
+# define LOGAUTH(app)              verbose_set_name(app,1)
 
+extern void (*verbose_observer)(int loglevel, const char *file, int line, const char *function, const char *fmt, va_list args);