log: Fixes

Drop the timestamp caching because it doesn't seem useful.
Use gettimeofday() to obtain system time.
Add null checks to both contstructor and destructor.
Drop the flushing and set line buffering instead.
Remove weston_log_print(), it only wraps vfprintf anyways.

src/log.c

@@ -24,6 +24,7 @@
 #include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/time.h>
 #include <time.h>
 
 #include <wayland-server.h>
@@ -33,36 +34,19 @@
 
 static FILE *weston_logfile = NULL;
 
-static char cached_timestamp[21];
-static int cached_tv_sec = 0;
-
 static int weston_log_timestamp(void)
 {
-	struct timespec tp;
-	unsigned int time;
-
-	clock_gettime(CLOCK_REALTIME, &tp);
-	time = (tp.tv_sec * 1000000L) + (tp.tv_nsec / 1000);
+	struct timeval tv;
+	struct tm *brokendown_time;
+	char string[128];
 
-	if (cached_tv_sec != tp.tv_sec) {
-		char string[26];
-		struct tm *lt = localtime(&tp.tv_sec);
+	gettimeofday(&tv, NULL);
 
-		cached_tv_sec = tp.tv_sec;
+	brokendown_time = localtime(&tv.tv_sec);
 
-		strftime (string,24,"%Y-%m-%d %H:%M:%S", lt);
-		strncpy (cached_timestamp, string, 20);
-	}
-
-	return fprintf(weston_logfile, "[%s.%03u] ", cached_timestamp, tp.tv_nsec/1000000);
-}
+	strftime(string, sizeof string, "%Y-%m-%d %H:%M:%S", brokendown_time);
 
-static int weston_log_print(const char *fmt, va_list arg)
-{
-	int l;
-	l = vfprintf(weston_logfile, fmt, arg);
-	fflush(weston_logfile);
-	return l;
+	return fprintf(weston_logfile, "[%s.%03li] ", string, tv.tv_usec/1000);
 }
 
 static void
@@ -70,7 +54,7 @@ custom_handler(const char *fmt, va_list arg)
 {
 	weston_log_timestamp();
 	fprintf(weston_logfile, "libwayland: ");
-	weston_log_print(fmt, arg);
+	vfprintf(weston_logfile, fmt, arg);
 }
 
 void
@@ -78,15 +62,19 @@ weston_log_file_open(const char *filename)
 {
 	wl_log_set_handler_server(custom_handler);
 
-	weston_logfile = fopen(filename, "a");
+	if (filename != NULL)
+		weston_logfile = fopen(filename, "a");
+
 	if (weston_logfile == NULL)
 		weston_logfile = stderr;
+	else
+		setvbuf(weston_logfile, NULL, _IOLBF, 256);
 }
 
 void
 weston_log_file_close()
 {
-	if (weston_logfile != stderr)
+	if ((weston_logfile != stderr) && (weston_logfile != NULL))
 		fclose(weston_logfile);
 	weston_logfile = stderr;
 }
@@ -98,7 +86,7 @@ weston_log(const char *fmt, ...)
 	va_list argp;
 	va_start(argp, fmt);
 	l = weston_log_timestamp();
-	l += weston_log_print(fmt, argp);
+	l += vfprintf(weston_logfile, fmt, argp);
 	va_end(argp);
 	return l;
 }
@@ -109,7 +97,7 @@ weston_log_continue(const char *fmt, ...)
 	int l;
 	va_list argp;
 	va_start(argp, fmt);
-	l = weston_log_print(fmt, argp);
+	l = vfprintf(weston_logfile, fmt, argp);
 	va_end(argp);
 	return l;
 }

src/log.h

@@ -20,8 +20,8 @@
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#ifndef _WAYLAND_SYSTEM_LOG_H_
-#define _WAYLAND_SYSTEM_LOG_H_
+#ifndef _WESTON_LOG_H_
+#define _WESTON_LOG_H_
 
 void weston_log_file_open(const char *filename);
 void weston_log_file_close(void);