use format printf style to write to tracefd instead of using write syscall.

add a static buffer to trace() instead of always allocating from the heap.

Signed-off-by: Vincent Hanquez <vincent@xensource.com>

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 6afde0ae80710a82eae4854f277c9a0496ce3d5f..b55731fe16b88e85d90dfdc1b657b5b3a7f1a643 100644 (file)
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -174,11 +174,38 @@ static char *sockmsg_string(enum xsd_sockmsg_type type)
        }
 }
 
+void trace(const char *fmt, ...)
+{
+       va_list arglist;
+       char *str;
+       char sbuf[1024];
+       int ret;
+
+       if (tracefd < 0)
+               return;
+
+       /* try to use a static buffer */
+       va_start(arglist, fmt);
+       ret = vsnprintf(sbuf, 1024, fmt, arglist);
+       va_end(arglist);
+
+       if (ret <= 1024) {
+               write(tracefd, sbuf, ret);
+               return;
+       }
+
+       /* fail back to dynamic allocation */
+       va_start(arglist, fmt);
+       str = talloc_vasprintf(NULL, fmt, arglist);
+       va_end(arglist);
+       write(tracefd, str, strlen(str));
+       talloc_free(str);
+}
+
 static void trace_io(const struct connection *conn,
                     const char *prefix,
                     const struct buffered_data *data)
 {
-       char string[64];
        unsigned int i;
        time_t now;
        struct tm *tm;
@@ -189,62 +216,25 @@ static void trace_io(const struct connection *conn,
        now = time(NULL);
        tm = localtime(&now);
 
-       write(tracefd, prefix, strlen(prefix));
-       sprintf(string, " %p %02d:%02d:%02d ", conn, tm->tm_hour, tm->tm_min,
-               tm->tm_sec);
-       write(tracefd, string, strlen(string));
-       write(tracefd, sockmsg_string(data->hdr.msg.type),
-             strlen(sockmsg_string(data->hdr.msg.type)));
-       write(tracefd, " (", 2);
-       for (i = 0; i < data->hdr.msg.len; i++) {
-               if (data->buffer[i] == '\0')
-                       write(tracefd, " ", 1);
-               else
-                       write(tracefd, data->buffer + i, 1);
-       }
-       write(tracefd, ")\n", 2);
+       trace("%s %p %02d:%02d:%02d %s (", prefix, conn,
+             tm->tm_hour, tm->tm_min, tm->tm_sec,
+             sockmsg_string(data->hdr.msg.type));
+       
+       for (i = 0; i < data->hdr.msg.len; i++)
+               trace("%c", (data->buffer[i] != '\0') ? data->buffer[i] : ' ');
+       trace(")\n");
 }
 
 void trace_create(const void *data, const char *type)
 {
-       char string[64];
-       if (tracefd < 0)
-               return;
-
-       write(tracefd, "CREATE ", strlen("CREATE "));
-       write(tracefd, type, strlen(type));
-       sprintf(string, " %p\n", data);
-       write(tracefd, string, strlen(string));
+       trace("CREATE %s %p\n", type, data);
 }
 
 void trace_destroy(const void *data, const char *type)
 {
-       char string[64];
-       if (tracefd < 0)
-               return;
-
-       write(tracefd, "DESTROY ", strlen("DESTROY "));
-       write(tracefd, type, strlen(type));
-       sprintf(string, " %p\n", data);
-       write(tracefd, string, strlen(string));
+       trace("DESTROY %s %p\n", type, data);
 }
 
-void trace(const char *fmt, ...)
-{
-       va_list arglist;
-       char *str;
-
-       if (tracefd < 0)
-               return;
-
-       va_start(arglist, fmt);
-       str = talloc_vasprintf(NULL, fmt, arglist);
-       va_end(arglist);
-       write(tracefd, str, strlen(str));
-       talloc_free(str);
-}
-
-
 /**
  * Signal handler for SIGHUP, which requests that the trace log is reopened
  * (in the main loop).  A single byte is written to reopen_log_pipe, to awaken
@@ -268,7 +258,7 @@ static void reopen_log()
                if (tracefd < 0)
                        perror("Could not open tracefile");
                else
-                       write(tracefd, "\n***\n", strlen("\n***\n"));
+                       trace("\n***\n");
        }
 }