From: ZheNing Hu <adlternative@xxxxxxxxx>
xstrdup("") calls strdup(""), which in glibc will
call malloc(1), this means that there will have unwanted
memory allocations.
Introduce the global one-byte array ref_filter_slopbuf,
which learn from strbuf_slopbuf. let those places which
need fill strdup("") now fill ref_filter_slopbuf. This
can reduce some unnecessary memory allocation.
Mentored-by: Christian Couder <christian.couder@xxxxxxxxx>
Mentored-by: Hariom Verma <hariom18599@xxxxxxxxx>
Signed-off-by: ZheNing Hu <adlternative@xxxxxxxxx>
---
ref-filter.c | 53 ++++++++++++++++++++++++++--------------------------
1 file changed, 27 insertions(+), 26 deletions(-)
diff --git a/ref-filter.c b/ref-filter.c
index 771804c06f0..5e00dbd993a 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -25,6 +25,8 @@
#include "hashmap.h"
#include "strvec.h"
+char ref_filter_slopbuf[1];
+
static struct ref_msg {
const char *gone;
const char *ahead;
@@ -1225,7 +1227,7 @@ static const char *copy_name(const char *buf)
if (!strncmp(cp, " <", 2))
return xmemdupz(buf, cp - buf);
}
- return xstrdup("");
+ return ref_filter_slopbuf;
}
static const char *copy_email(const char *buf, struct used_atom *atom)
@@ -1233,7 +1235,7 @@ static const char *copy_email(const char *buf, struct used_atom *atom)
const char *email = strchr(buf, '<');
const char *eoemail;
if (!email)
- return xstrdup("");
+ return ref_filter_slopbuf;
switch (atom->u.email_option.option) {
case EO_RAW:
eoemail = strchr(email, '>');
@@ -1255,7 +1257,7 @@ static const char *copy_email(const char *buf, struct used_atom *atom)
}
if (!eoemail)
- return xstrdup("");
+ return ref_filter_slopbuf;
return xmemdupz(email, eoemail - email);
}
@@ -1309,7 +1311,7 @@ static void grab_date(const char *buf, struct atom_value *v, const char *atomnam
v->value = timestamp;
return;
bad:
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
v->value = 0;
}
@@ -1519,7 +1521,7 @@ static void fill_missing_values(struct atom_value *val)
for (i = 0; i < used_atom_cnt; i++) {
struct atom_value *v = &val[i];
if (v->s == NULL)
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
}
}
@@ -1594,7 +1596,7 @@ static const char *lstrip_ref_components(const char *refname, int len)
switch (*start++) {
case '\0':
free((char *)to_free);
- return xstrdup("");
+ return ref_filter_slopbuf;
case '/':
remaining--;
break;
@@ -1632,7 +1634,7 @@ static const char *rstrip_ref_components(const char *refname, int len)
char *p = strrchr(start, '/');
if (p == NULL) {
free((char *)to_free);
- return xstrdup("");
+ return ref_filter_slopbuf;
} else
p[0] = '\0';
}
@@ -1663,7 +1665,7 @@ static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
AHEAD_BEHIND_FULL) < 0) {
v->s = xstrdup(msgs.gone);
} else if (!num_ours && !num_theirs)
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
else if (!num_ours)
v->s = xstrfmt_len(&v->s_size, msgs.behind, num_theirs);
else if (!num_theirs)
@@ -1680,7 +1682,7 @@ static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
if (stat_tracking_info(branch, &num_ours, &num_theirs,
NULL, atom->u.remote_ref.push,
AHEAD_BEHIND_FULL) < 0) {
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
return;
}
if (!num_ours && !num_theirs)
@@ -1739,7 +1741,7 @@ char *get_head_description(void)
static const char *get_symref(struct used_atom *atom, struct ref_array_item *ref)
{
if (!ref->symref)
- return xstrdup("");
+ return ref_filter_slopbuf;
else
return show_ref(&atom->u.refname, ref->symref);
}
@@ -1861,7 +1863,7 @@ static char *get_worktree_path(const struct used_atom *atom, const struct ref_ar
e = hashmap_get(&(ref_to_worktree_map.map), &entry, ref->refname);
if (!e)
- return xstrdup("");
+ return ref_filter_slopbuf;
lookup_result = container_of(e, struct ref_to_worktree_entry, ent);
@@ -1884,7 +1886,7 @@ static int populate_value(struct ref_array_item *ref, struct strbuf *err)
ref->symref = resolve_refdup(ref->refname, RESOLVE_REF_READING,
NULL, NULL);
if (!ref->symref)
- ref->symref = xstrdup("");
+ ref->symref = ref_filter_slopbuf;
}
/* Fill in specials first */
@@ -1912,7 +1914,7 @@ static int populate_value(struct ref_array_item *ref, struct strbuf *err)
if (ref->kind == FILTER_REFS_BRANCHES)
v->s = get_worktree_path(atom, ref);
else
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
continue;
}
else if (atom_type == ATOM_SYMREF)
@@ -1922,7 +1924,7 @@ static int populate_value(struct ref_array_item *ref, struct strbuf *err)
/* only local branches may have an upstream */
if (!skip_prefix(ref->refname, "refs/heads/",
&branch_name)) {
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
continue;
}
branch = branch_get(branch_name);
@@ -1931,11 +1933,11 @@ static int populate_value(struct ref_array_item *ref, struct strbuf *err)
if (refname)
fill_remote_ref_details(atom, refname, branch, v);
else
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
continue;
} else if (atom_type == ATOM_PUSH && atom->u.remote_ref.push) {
const char *branch_name;
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
if (!skip_prefix(ref->refname, "refs/heads/",
&branch_name))
continue;
@@ -1948,8 +1950,6 @@ static int populate_value(struct ref_array_item *ref, struct strbuf *err)
if (!refname)
continue;
}
- /* We will definitely re-init v->s on the next line. */
- free((char *)v->s);
fill_remote_ref_details(atom, refname, branch, v);
continue;
} else if (atom_type == ATOM_COLOR) {
@@ -1962,7 +1962,7 @@ static int populate_value(struct ref_array_item *ref, struct strbuf *err)
if (ref->flag & REF_ISPACKED)
cp = copy_advance(cp, ",packed");
if (cp == buf)
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
else {
*cp = '\0';
v->s = xstrdup(buf + 1);
@@ -1979,33 +1979,33 @@ static int populate_value(struct ref_array_item *ref, struct strbuf *err)
continue;
} else if (atom_type == ATOM_ALIGN) {
v->handler = align_atom_handler;
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
continue;
} else if (atom_type == ATOM_END) {
v->handler = end_atom_handler;
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
continue;
} else if (atom_type == ATOM_IF) {
const char *s;
if (skip_prefix(name, "if:", &s))
v->s = xstrdup(s);
else
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
v->handler = if_atom_handler;
continue;
} else if (atom_type == ATOM_THEN) {
v->handler = then_atom_handler;
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
continue;
} else if (atom_type == ATOM_ELSE) {
v->handler = else_atom_handler;
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
continue;
} else if (atom_type == ATOM_REST) {
if (ref->rest)
v->s = xstrdup(ref->rest);
else
- v->s = xstrdup("");
+ v->s = ref_filter_slopbuf;
continue;
} else
continue;
@@ -2356,7 +2356,8 @@ void free_ref_array_item_value(struct ref_array_item *item)
if (item->value) {
int i;
for (i = 0; i < used_atom_cnt; i++)
- free((char *)item->value[i].s);
+ if (item->value[i].s != ref_filter_slopbuf)
+ free((char *)item->value[i].s);
free(item->value);
}
}
--
gitgitgadget
