[PATCH v4 4/7] perf dsos: Switch hand code to bsearch

Ian Rogers
2024-04-23T04:26:29Z

Switch to using the bsearch library function rather than having a hand
written binary search. Const-ify some static functions to avoid
compiler warnings.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/dsos.c | 46 +++++++++++++++++++++++++-----------------
1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c
index e4110438841b..23c3fe4f2abb 100644
--- a/tools/perf/util/dsos.c
+++ b/tools/perf/util/dsos.c
@@ -107,13 +107,15 @@ bool dsos__read_build_ids(struct dsos *dsos, bool with_hits)
return args.have_build_id;
}

-static int __dso__cmp_long_name(const char *long_name, struct dso_id *id, struct dso *b)
+static int __dso__cmp_long_name(const char *long_name, const struct dso_id *id,
+ const struct dso *b)
{
int rc = strcmp(long_name, b->long_name);
return rc ?: dso_id__cmp(id, &b->id);
}

-static int __dso__cmp_short_name(const char *short_name, struct dso_id *id, struct dso *b)
+static int __dso__cmp_short_name(const char *short_name, const struct dso_id *id,
+ const struct dso *b)
{
int rc = strcmp(short_name, b->short_name);
return rc ?: dso_id__cmp(id, &b->id);
@@ -133,6 +135,19 @@ static int dsos__cmp_long_name_id_short_name(const void *va, const void *vb)
return rc;
}

+struct dsos__key {
+ const char *long_name;
+ const struct dso_id *id;
+};
+
+static int dsos__cmp_key_long_name_id(const void *vkey, const void *vdso)
+{
+ const struct dsos__key *key = vkey;
+ const struct dso *dso = *((const struct dso **)vdso);
+
+ return __dso__cmp_long_name(key->long_name, key->id, dso);
+}
+
/*
* Find a matching entry and/or link current entry to RB tree.
* Either one of the dso or name parameter must be non-NULL or the
@@ -143,7 +158,11 @@ static struct dso *__dsos__find_by_longname_id(struct dsos *dsos,
struct dso_id *id,
bool write_locked)
{
- int low = 0, high = dsos->cnt - 1;
+ struct dsos__key key = {
+ .long_name = name,
+ .id = id,
+ };
+ struct dso **res;

if (!dsos->sorted) {
if (!write_locked) {
@@ -162,23 +181,12 @@ static struct dso *__dsos__find_by_longname_id(struct dsos *dsos,
dsos->sorted = true;
}

- /*
- * Find node with the matching name
- */
- while (low <= high) {
- int mid = (low + high) / 2;
- struct dso *this = dsos->dsos[mid];
- int rc = __dso__cmp_long_name(name, id, this);
+ res = bsearch(&key, dsos->dsos, dsos->cnt, sizeof(struct dso *),
+ dsos__cmp_key_long_name_id);
+ if (!res)
+ return NULL;

- if (rc == 0) {
- return dso__get(this); /* Find matching dso */
- }
- if (rc < 0)
- high = mid - 1;
- else
- low = mid + 1;
- }
- return NULL;
+ return dso__get(*res);
}

int __dsos__add(struct dsos *dsos, struct dso *dso)
--
2.44.0.769.g3c40516874-goog