#include <ltt/type.h>
#include <errno.h>
-
+#define min(a,b) (((a)<(b))?(a):(b))
gint compare_tracefile(gconstpointer a, gconstpointer b)
pos->tfc = g_array_set_size(pos->tfc, 0);
pos->ep = g_array_set_size(pos->ep, 0);
+
+ pos->timestamp = ltt_time_infinite;
for(i=0; i<num_traces;i++) {
GArray * tracefiles = self->traces[i]->tracefiles;
lttv_traceset_context_position_save(tsc, tsc->sync_position);
}
+struct seek_back_data {
+ guint first_event; /* Index of the first event in the array : we will always
+ overwrite at this position : this is a circular array.
+ */
+ guint events_found;
+ GPtrArray *array; /* array of LttvTracesetContextPositions pointers */
+};
+
+static gint seek_back_event_hook(void *hook_data, void* call_data)
+{
+ struct seek_back_data *sd = (struct seek_back_data*)hook_data;
+ LttvTracefileContext *tfc = (LttvTracefileContext*)call_data;
+ LttvTracesetContext *tsc = tfc->t_context->ts_context;
+ LttvTracesetContextPosition *pos;
+
+ if(sd->events_found < sd->array->len) {
+ pos = (LttvTracesetContextPosition*)g_ptr_array_index (sd->array,
+ sd->events_found);
+ } else {
+ pos = (LttvTracesetContextPosition*)g_ptr_array_index (sd->array,
+ sd->first_event);
+ }
+
+ lttv_traceset_context_position_save(tsc, pos);
+
+ if(sd->first_event >= sd->array->len - 1) sd->first_event = 0;
+ else sd->first_event++;
+
+ sd->events_found = min(sd->array->len, sd->events_found + 1);
+
+ return FALSE;
+}
+
+
+/* Seek back n events back from the current position.
+ *
+ * Parameters :
+ * @self The trace set context
+ * @n number of events to jump over
+ * @first_offset The initial offset value used. Hint : try about 100000ns.
+ *
+ * Return value : the number of events found (might be lower than the number
+ * requested if beginning of traceset is reached).
+ *
+ * The first search will go back first_offset and try to find the last n events
+ * matching the filter. If there are not enough, it will try to go back from the
+ * new trace point from first_offset*2, and so on, until beginning of trace or n
+ * events are found.
+ *
+ * Note : this function does not take in account the LttvFilter : use the
+ * similar function found in state.c instead.
+ *
+ * Note2 : the caller must make sure that the LttvTracesetContext does not
+ * contain any hook, as process_traceset_middle is used in this routine.
+ */
+guint lttv_process_traceset_seek_n_backward(LttvTracesetContext *self,
+ guint n, LttTime first_offset)
+{
+ guint i;
+ LttvTracesetContextPosition *next_iter_end_pos =
+ lttv_traceset_context_position_new();
+ LttvTracesetContextPosition *end_pos = lttv_traceset_context_position_new();
+ LttTime time;
+ LttTime time_offset;
+ struct seek_back_data sd;
+ LttvHooks *hooks = lttv_hooks_new();
+
+ sd.first_event = 0;
+ sd.events_found = 0;
+ sd.array = g_ptr_array_sized_new(n);
+ g_ptr_array_set_size(sd.array, n);
+ for(i=0;i<n;i++) {
+ g_ptr_array_index (sd.array, i) = lttv_traceset_context_position_new();
+ }
+
+ lttv_traceset_context_position_save(self, next_iter_end_pos);
+ /* Get the current time from which we will offset */
+ time = lttv_traceset_context_position_get_time(next_iter_end_pos);
+ /* the position saved might be end of traceset... */
+ if(ltt_time_compare(time, self->time_span.end_time) > 0) {
+ time = self->time_span.end_time;
+ }
+ time_offset = first_offset;
+
+ lttv_hooks_add(hooks, seek_back_event_hook, &sd, LTTV_PRIO_DEFAULT);
+
+ lttv_process_traceset_begin(self, NULL, NULL, NULL, hooks, NULL);
+
+ while(1) {
+ /* stop criteria : - n events found
+ * - time < beginning of trace */
+ if(ltt_time_compare(time, self->time_span.start_time) < 0) break;
+ if(sd.events_found == n) break;
+
+ lttv_traceset_context_position_copy(end_pos, next_iter_end_pos);
+
+ /* We must seek the traceset back to time - time_offset */
+ /* this time becomes the new reference time */
+ time = ltt_time_sub(time, time_offset);
+
+ lttv_process_traceset_seek_time(self, time);
+ lttv_traceset_context_position_save(self, next_iter_end_pos);
+
+ /* Process the traceset, calling a hook which adds events
+ * to the array, overwriting the tail. It changes first_event and
+ * events_found too. */
+ /* We would like to have a clean context here : no other hook than our's */
+
+ lttv_process_traceset_middle(self, ltt_time_infinite,
+ G_MAXUINT, end_pos);
+
+ time_offset = ltt_time_mul(time_offset, BACKWARD_SEEK_MUL);
+ }
+
+ lttv_traceset_context_position_destroy(end_pos);
+ lttv_traceset_context_position_destroy(next_iter_end_pos);
+
+ lttv_process_traceset_end(self, NULL, NULL, NULL, hooks, NULL);
+
+ if(sd.events_found > 0) {
+ /* Seek the traceset to the first event in the circular array */
+ LttvTracesetContextPosition *pos =
+ (LttvTracesetContextPosition*)g_ptr_array_index (sd.array,
+ sd.first_event);
+ g_assert(lttv_process_traceset_seek_position(self, pos) == 0);
+ }
+
+ for(i=0;i<n;i++) {
+ LttvTracesetContextPosition *pos =
+ (LttvTracesetContextPosition*)g_ptr_array_index (sd.array, i);
+ lttv_traceset_context_position_destroy(pos);
+ }
+ g_ptr_array_free(sd.array, TRUE);
+
+ lttv_hooks_destroy(hooks);
+
+ return sd.events_found;
+}
+
+
+struct seek_forward_data {
+ guint event_count; /* event counter */
+ guint n; /* requested number of events to jump over */
+};
+
+static gint seek_forward_event_hook(void *hook_data, void* call_data)
+{
+ struct seek_forward_data *sd = (struct seek_forward_data*)hook_data;
+
+ sd->event_count++;
+
+ if(sd->event_count >= sd->n)
+ return TRUE;
+ else
+ return FALSE;
+}
+
+/* Seek back n events forward from the current position
+ *
+ * Parameters :
+ * @self the trace set context
+ * @n number of events to jump over
+ *
+ * returns : the number of events jumped over (may be less than requested if end
+ * of traceset reached) */
+guint lttv_process_traceset_seek_n_forward(LttvTracesetContext *self,
+ guint n)
+{
+ struct seek_forward_data sd;
+ sd.event_count = 0;
+ sd.n = n;
+ LttvHooks *hooks = lttv_hooks_new();
+
+ lttv_hooks_add(hooks, seek_forward_event_hook, &sd, LTTV_PRIO_DEFAULT);
+
+ lttv_process_traceset_begin(self, NULL, NULL, NULL, hooks, NULL);
+
+ /* it will end on the end of traceset, or the fact that the
+ * hook returns TRUE.
+ */
+ lttv_process_traceset_middle(self, ltt_time_infinite,
+ G_MAXUINT, NULL);
+
+ /* Here, our position is either the end of traceset, or the exact position
+ * after n events : leave it like this. */
+
+ lttv_process_traceset_end(self, NULL, NULL, NULL, hooks, NULL);
+
+ lttv_hooks_destroy(hooks);
+
+ return sd.event_count;
+}
+
+
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