object-name: re-use "struct strbuf" in show_ambiguous_object()

Reduce the allocations done by show_ambiguous_object() by moving the
"desc" strbuf into the "struct ambiguous_output" introduced in the
preceding commit.

This doesn't matter for optimization purposes, but since we're
accumulating a "struct strbuf advice" anyway let's follow that pattern
and add a "struct strbuf sb", we can then strbuf_reset() it rather
than calling strbuf_release() for each call to
show_ambiguous_object().

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/object-name.c b/object-name.c
index 6154e1ec6f858f28a37f3600d49b0c4b97f7276e..61b58a2f2927a34210d74f9c29a0dfe867401695 100644 (file)
--- a/object-name.c
+++ b/object-name.c
@@ -354,6 +354,7 @@ static int init_object_disambiguation(struct repository *r,
 struct ambiguous_output {
        const struct disambiguate_state *ds;
        struct strbuf advice;
+       struct strbuf sb;
 };
 
 static int show_ambiguous_object(const struct object_id *oid, void *data)
@@ -361,7 +362,7 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
        struct ambiguous_output *state = data;
        const struct disambiguate_state *ds = state->ds;
        struct strbuf *advice = &state->advice;
-       struct strbuf desc = STRBUF_INIT;
+       struct strbuf *sb = &state->sb;
        int type;
        const char *hash;
 
@@ -377,7 +378,7 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
                 * output shown when we cannot look up or parse the
                 * object in question. E.g. "deadbeef [bad object]".
                 */
-               strbuf_addf(&desc, _("%s [bad object]"), hash);
+               strbuf_addf(sb, _("%s [bad object]"), hash);
                goto out;
        }
 
@@ -402,8 +403,8 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
                 *
                 *    "deadbeef commit 2021-01-01 - Some Commit Message"
                 */
-               strbuf_addf(&desc, _("%s commit %s - %s"),
-                           hash, date.buf, msg.buf);
+               strbuf_addf(sb, _("%s commit %s - %s"), hash, date.buf,
+                           msg.buf);
 
                strbuf_release(&date);
                strbuf_release(&msg);
@@ -423,7 +424,7 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
                         * The third argument is the "tag" string
                         * from object.c.
                         */
-                       strbuf_addf(&desc, _("%s tag %s - %s"), hash,
+                       strbuf_addf(sb, _("%s tag %s - %s"), hash,
                                    show_date(tag->date, 0, DATE_MODE(SHORT)),
                                    tag->tag);
                } else {
@@ -434,7 +435,7 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
                         *
                         *    "deadbeef [bad tag, could not parse it]"
                         */
-                       strbuf_addf(&desc, _("%s [bad tag, could not parse it]"),
+                       strbuf_addf(sb, _("%s [bad tag, could not parse it]"),
                                    hash);
                }
        } else if (type == OBJ_TREE) {
@@ -442,13 +443,13 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
                 * TRANSLATORS: This is a line of ambiguous <type>
                 * object output. E.g. "deadbeef tree".
                 */
-               strbuf_addf(&desc, _("%s tree"), hash);
+               strbuf_addf(sb, _("%s tree"), hash);
        } else if (type == OBJ_BLOB) {
                /*
                 * TRANSLATORS: This is a line of ambiguous <type>
                 * object output. E.g. "deadbeef blob".
                 */
-               strbuf_addf(&desc, _("%s blob"), hash);
+               strbuf_addf(sb, _("%s blob"), hash);
        }
 
 
@@ -459,9 +460,9 @@ out:
         * you'll probably want to swap the "%s" and leading " " space
         * around.
         */
-       strbuf_addf(advice, _("  %s\n"), desc.buf);
+       strbuf_addf(advice, _("  %s\n"), sb->buf);
 
-       strbuf_release(&desc);
+       strbuf_reset(sb);
        return 0;
 }
 
@@ -560,6 +561,7 @@ static enum get_oid_result get_short_oid(struct repository *r,
                struct oid_array collect = OID_ARRAY_INIT;
                struct ambiguous_output out = {
                        .ds = &ds,
+                       .sb = STRBUF_INIT,
                        .advice = STRBUF_INIT,
                };
 
@@ -589,6 +591,7 @@ static enum get_oid_result get_short_oid(struct repository *r,
 
                oid_array_clear(&collect);
                strbuf_release(&out.advice);
+               strbuf_release(&out.sb);
        }
 
        return status;