Improve the lttng list feature

[lttng-tools.git] / ltt-sessiond / kernel-ctl.c

diff --git a/ltt-sessiond/kernel-ctl.c b/ltt-sessiond/kernel-ctl.c
index ef3afb714bf1bebe6b96376f484f15044f2e4555..09a3763eb835c30aaaa25fca4081f27d34aeb881 100644 (file)
--- a/ltt-sessiond/kernel-ctl.c
+++ b/ltt-sessiond/kernel-ctl.c
@@ -545,18 +545,16 @@ error:
 }
 
 /*
- *  kernel_list_events
- *
- *  Get the event list from the kernel tracer and return that list in the CTF
- *  format.
+ * Get the event list from the kernel tracer and return the number of elements.
  */
-ssize_t kernel_list_events(int tracer_fd, char **list)
+ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events)
 {
-       int fd;
-       char *buf, *line = NULL;
-       size_t nb, nbmem, total = 0;
+       int fd, pos;
+       char *event;
+       size_t nbmem, count = 0;
        ssize_t size;
        FILE *fp;
+       struct lttng_event *elist;
 
        fd = kernctl_tracepoint_list(tracer_fd);
        if (fd < 0) {
@@ -575,29 +573,29 @@ ssize_t kernel_list_events(int tracer_fd, char **list)
         * See kernel-ctl.h for explanation of this value
         */
        nbmem = KERNEL_EVENT_LIST_SIZE;
-       buf = malloc(nbmem);
+       elist = malloc(sizeof(struct lttng_event) * nbmem);
 
-       while ((size = getline(&line, &nb, fp)) != -1) {
-               if (total + size > nbmem) {
+       while ((size = fscanf(fp, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
+               if (count > nbmem) {
                        DBG("Reallocating event list from %zd to %zd bytes", nbmem,
-                                       total + size + KERNEL_EVENT_LIST_SIZE);
+                                       nbmem + KERNEL_EVENT_LIST_SIZE);
                        /* Adding the default size again */
-                       nbmem = total + size + KERNEL_EVENT_LIST_SIZE;
-                       buf = realloc(buf, nbmem);
-                       if (buf == NULL) {
+                       nbmem += KERNEL_EVENT_LIST_SIZE;
+                       elist = realloc(elist, nbmem);
+                       if (elist == NULL) {
                                perror("realloc list events");
                                goto error;
                        }
                }
-               memcpy(buf + total, line, size);
-               total += size;
+               strncpy(elist[count].name, event, strlen(event));
+               count++;
        }
 
-       *list = buf;
+       *events = elist;
 
-       DBG("Kernel list events done");
+       DBG("Kernel list events done (%ld events)", count);
 
-       return total;
+       return count;
 
 error:
        return -1;