From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
Provide an interface for the application to iterate over all the entries
in the traceeval histogram.
traceeval_iterator_get() - acquire an iterator for the given traceeval
traceveal_iterator_put() - release the iterator
traceeval_iterator_sort() - sort the iterator for a given key/value
traceeval_iterator_next() - return the keys of the next entry in the
traceeval
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
include/traceeval-hist.h | 7 ++
src/eval-local.h | 11 ++
src/histograms.c | 258 ++++++++++++++++++++++++++++++++++++++-
3 files changed, 275 insertions(+), 1 deletion(-)
diff --git a/include/traceeval-hist.h b/include/traceeval-hist.h
index 164d34c0fa81..e8a7981ac2c0 100644
--- a/include/traceeval-hist.h
+++ b/include/traceeval-hist.h
@@ -163,4 +163,11 @@ unsigned long long traceeval_stat_min(struct traceeval_stat *stat);
unsigned long long traceeval_stat_total(struct traceeval_stat *stat);
unsigned long long traceeval_stat_count(struct traceeval_stat *stat);
+struct traceeval_iterator *traceeval_iterator_get(struct traceeval *teval);
+void traceeval_iterator_put(struct traceeval_iterator *iter);
+int traceeval_iterator_sort(struct traceeval_iterator *iter, const char *sort_field,
+ int level, bool ascending);
+int traceeval_iterator_next(struct traceeval_iterator *iter,
+ const union traceeval_data **keys);
+
#endif /* __LIBTRACEEVAL_HIST_H__ */
diff --git a/src/eval-local.h b/src/eval-local.h
index ed2e8abc9b63..5c3918f17cc1 100644
--- a/src/eval-local.h
+++ b/src/eval-local.h
@@ -70,6 +70,17 @@ struct traceeval {
size_t nr_val_types;
};
+struct traceeval_iterator {
+ struct traceeval *teval;
+ struct entry **entries;
+ struct traceeval_type **sort;
+ bool *direction;
+ size_t nr_entries;
+ size_t nr_sort;
+ size_t next;
+ bool needs_sort;
+};
+
extern struct hash_table *hash_alloc(void);
extern void hash_free(struct hash_table *hash);
extern void hash_add(struct hash_table *hash, struct hash_item *item, unsigned key);
diff --git a/src/histograms.c b/src/histograms.c
index 592e9c5f78a4..c4ff632b4f87 100644
--- a/src/histograms.c
+++ b/src/histograms.c
@@ -37,7 +37,7 @@ static void print_err(const char *fmt, ...)
*/
static int compare_traceeval_data(struct traceeval *teval,
struct traceeval_type *type,
- union traceeval_data *orig,
+ const union traceeval_data *orig,
const union traceeval_data *copy)
{
int i;
@@ -903,3 +903,259 @@ int traceeval_insert(struct traceeval *teval,
else
return update_entry(teval, entry, vals);
}
+
+/**
+ * traceeval_iterator_put - release a given iterator
+ * @iter: The iterartor to release
+ *
+ * Frees the resources of an @iter that was created by
+ * traceeval_iterator_get().
+ */
+void traceeval_iterator_put(struct traceeval_iterator *iter)
+{
+ if (!iter)
+ return;
+
+ free(iter->direction);
+ free(iter->entries);
+ free(iter->sort);
+ free(iter);
+}
+
+/**
+ * traceeval_iterator_get - get a handle to iterate over a given traceeval
+ * @teval: The traceeval handle to iterate over
+ *
+ * Returns a handle to iterate over the given @teval. Must be freed with
+ * traceeval_iterator_put(). It can be used with traceeval_iterator_next()
+ * to retrieve the keys of the next entry in @teval.
+ *
+ * Use traceeval_iterator_sort() to specify the order of the entries
+ * returned by traceeval_iterator_next().
+ *
+ * Returns an allocated iterator on success, and NULL on failure.
+ */
+struct traceeval_iterator *traceeval_iterator_get(struct traceeval *teval)
+{
+ struct traceeval_iterator *iter;
+ struct hash_table *hist = teval->hist;
+ struct hash_iter *hiter;
+ struct hash_item *item;
+ int i;
+
+ iter = calloc(1, sizeof(*iter));
+ if (!iter)
+ return NULL;
+
+ iter->teval = teval;
+ iter->nr_entries = hash_nr_items(hist);
+ iter->entries = calloc(iter->nr_entries, sizeof(*iter->entries));
+ if (!iter->entries) {
+ free(iter);
+ return NULL;
+ }
+
+ for (i = 0, hiter = hash_iter_start(hist); (item = hash_iter_next(hiter)); i++) {
+ struct entry *entry = container_of(item, struct entry, hash);
+
+ iter->entries[i] = entry;
+ }
+
+ /* Loop must match entries */
+ if (i != iter->nr_entries) {
+ traceeval_iterator_put(iter);
+ return NULL;
+ }
+
+ return iter;
+}
+
+static struct traceeval_type *find_sort_type(struct traceeval *teval,
+ const char *name)
+{
+ struct traceeval_type *type;
+ int i;
+
+ /* Check values first, and then keys */
+ for (i = 0; i < teval->nr_val_types; i++) {
+ type = &teval->val_types[i];
+
+ if (strcmp(type->name, name) == 0)
+ return type;
+ }
+
+ for (i = 0; i < teval->nr_key_types; i++) {
+ type = &teval->key_types[i];
+
+ if (strcmp(type->name, name) == 0)
+ return type;
+ }
+
+ return NULL;
+}
+
+/**
+ * traceeval_iterator_sort - sort the entries that an iterator will return
+ * @iter: The iterator to specify the sort order of the entries
+ * @sort_field: The name of the key or value to sort with.
+ * @level: The level of sorting (0 for first order, 1 for second, ...)
+ * @ascending: If the sort should go forward or backward.
+ *
+ * The iterator has a list of entries to produce with traceeval_iterator_next().
+ * This function specifies what the order of the output of that function will
+ * be. Note, whenever this function is called, it resets the @iter so that
+ * the traceveal_iterator_next() will start from the beginning again.
+ *
+ * In other words, be very careful to ever call this function in a middle
+ * of a loop that is using traceeval_iterator_next(), otherwise you may end
+ * up in an infinite loop!
+ *
+ * The @level specifies the level of sorting. That is, for @level = 0,
+ * it will decide the main sorting of the @iter. For @level = 1, it will
+ * be the tie breaker for two entries that are equal for the @level = 0
+ * sort. @level = 2, will be the tie breaker for @level = 1, and so on.
+ *
+ * Note, if traceeval_iterator_next() is called, and there's a missing @level,
+ * it will fail. That is, if this function is called once with @level = 0 and
+ * againg with @level = 2, but never with @level = 1, the call to
+ * traceeval_iterator_next() will fail.
+ *
+ * If this function is called multiple times with the same @level, then the
+ * last call will define the what that @level will do.
+ *
+ * The @ascending will determine if "smaller" items go first if true, and
+ * "larger" items go first if false.
+ *
+ * Return 0 on success and -1 on failure.
+ */
+int traceeval_iterator_sort(struct traceeval_iterator *iter, const char *sort_field,
+ int level, bool ascending)
+{
+ bool *direction = iter->direction;
+ struct traceeval_type **sort = iter->sort;
+ struct traceeval_type *type;
+ int num_levels = level + 1;
+
+ type = find_sort_type(iter->teval, sort_field);
+ if (!type)
+ return -1;
+
+ /* pointer and dynamic types must have a cmp function */
+ switch (type->type) {
+ case TRACEEVAL_TYPE_POINTER:
+ case TRACEEVAL_TYPE_DYNAMIC:
+ if (!type->cmp)
+ return -1;
+ break;
+ default:
+ break;
+ }
+
+ if (num_levels > iter->nr_sort) {
+ sort = realloc(sort, sizeof(*sort) * num_levels);
+ if (!sort)
+ return -1;
+
+ iter->sort = sort;
+
+ direction = realloc(direction, sizeof(*direction) * num_levels);
+ if (!direction)
+ return -1;
+
+ iter->direction = direction;
+
+ /* Make sure the newly allocated contain NULL */
+ for (int i = iter->nr_sort; i < num_levels; i++)
+ sort[i] = NULL;
+
+ iter->nr_sort = level + 1;
+ }
+
+ sort[level] = type;
+ direction[level] = ascending;
+ iter->needs_sort = true;
+ return 0;
+}
+
+static int iter_cmp(const void *A, const void *B, void *data)
+{
+ struct traceeval_iterator *iter = data;
+ struct traceeval *teval = iter->teval;
+ const struct entry *a = *((const struct entry **)A);
+ const struct entry *b = *((const struct entry **)B);
+ int ret;
+
+ for (int i = 0; i < iter->nr_sort; i++) {
+ struct traceeval_type *type;
+ union traceeval_data *dataA;
+ union traceeval_data *dataB;
+
+ type = iter->sort[i];
+
+ if (type->flags & TRACEEVAL_FL_KEY) {
+ dataA = &a->keys[type->index];
+ dataB = &b->keys[type->index];
+ } else {
+ dataA = &a->vals[type->index];
+ dataB = &b->vals[type->index];
+ }
+
+ ret = compare_traceeval_data(teval, type, dataA, dataB);
+
+ if (ret)
+ return iter->direction[i] ? ret : ret * -1;
+ }
+
+ return 0;
+}
+
+static int sort_iter(struct traceeval_iterator *iter)
+{
+ int i;
+
+ /* Make sure all levels are filled */
+ for (i = 0; i < iter->nr_sort; i++) {
+ if (!iter->sort[i])
+ return -1;
+ }
+
+ qsort_r(iter->entries, iter->nr_entries, sizeof(*iter->entries),
+ iter_cmp, iter);
+
+ iter->needs_sort = false;
+ iter->next = 0;
+
+ return 0;
+}
+
+/**
+ * traceeval_iterator_next - retrieve the next entry from an iterator
+ * @iter: The iterator to retrieve the next entry from
+ * @keys: The returned keys of the next entry (if exists)
+ *
+ * This returns the keys for the next entry in the traceeval being
+ * iterated over by @iter. If there are no more entries, 0 is returned
+ * and @keys are untouched.
+ *
+ * Returns 1 if another entry is returned, or 0 if not (or negative on error)
+ */
+int traceeval_iterator_next(struct traceeval_iterator *iter,
+ const union traceeval_data **keys)
+{
+ struct entry *entry;
+ int ret;
+
+ if (iter->needs_sort) {
+ ret = sort_iter(iter);
+ if (ret < 0)
+ return ret;
+ iter->next = 0;
+ }
+
+ if (iter->next >= iter->nr_entries)
+ return 0;
+
+ entry = iter->entries[iter->next++];
+ *keys = entry->keys;
+ return 1;
+}
--
2.40.1
|