list-objects: pass full pathname to callbacks

When we find a blob at "a/b/c", we currently pass this to
our show_object_fn callbacks as two components: "a/b/" and
"c". Callbacks which want the full value then call
path_name(), which concatenates the two. But this is an
inefficient interface; the path is a strbuf, and we could
simply append "c" to it temporarily, then roll back the
length, without creating a new copy.

So we could improve this by teaching the callsites of
path_name() this trick (and there are only 3). But we can
also notice that no callback actually cares about the
broken-down representation, and simply pass each callback
the full path "a/b/c" as a string. The callback code becomes
even simpler, then, as we do not have to worry about freeing
an allocated buffer, nor rolling back our modification to
the strbuf.

This is theoretically less efficient, as some callbacks
would not bother to format the final path component. But in
practice this is not measurable. Since we use the same
strbuf over and over, our work to grow it is amortized, and
we really only pay to memcpy a few bytes.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 8bbb9bd9aa9b58d75d4998f118954cebfa7493e4..a6609f19ffa2c5320eee3e2994eda1d13e922729 100644 (file)
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -2284,21 +2284,11 @@ static void show_commit(struct commit *commit, void *data)
                index_commit_for_bitmap(commit);
 }
 
-static void show_object(struct object *obj,
-                       struct strbuf *path, const char *last,
-                       void *data)
+static void show_object(struct object *obj, const char *name, void *data)
 {
-       char *name = path_name(path, last);
-
        add_preferred_base_object(name);
        add_object_entry(obj->oid.hash, obj->type, name, 0);
        obj->flags |= OBJECT_ADDED;
-
-       /*
-        * We will have generated the hash from the name,
-        * but not saved a pointer to it - we can free it
-        */
-       free((char *)name);
 }
 
 static void show_edge(struct commit *commit)
@@ -2480,8 +2470,7 @@ static int get_object_list_from_bitmap(struct rev_info *revs)
 }
 
 static void record_recent_object(struct object *obj,
-                                struct strbuf *path,
-                                const char *last,
+                                const char *name,
                                 void *data)
 {
        sha1_array_append(&recent_objects, obj->oid.hash);

diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index a92c3ca852c9788222985d991006407dfdf5a89f..275da0d647ebe147386c69683cc75f2d06105d23 100644 (file)
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -177,9 +177,7 @@ static void finish_commit(struct commit *commit, void *data)
        free_commit_buffer(commit);
 }
 
-static void finish_object(struct object *obj,
-                         struct strbuf *path, const char *name,
-                         void *cb_data)
+static void finish_object(struct object *obj, const char *name, void *cb_data)
 {
        struct rev_list_info *info = cb_data;
        if (obj->type == OBJ_BLOB && !has_object_file(&obj->oid))
@@ -188,15 +186,13 @@ static void finish_object(struct object *obj,
                parse_object(obj->oid.hash);
 }
 
-static void show_object(struct object *obj,
-                       struct strbuf *path, const char *component,
-                       void *cb_data)
+static void show_object(struct object *obj, const char *name, void *cb_data)
 {
        struct rev_list_info *info = cb_data;
-       finish_object(obj, path, component, cb_data);
+       finish_object(obj, name, cb_data);
        if (info->flags & REV_LIST_QUIET)
                return;
-       show_object_with_name(stdout, obj, path, component);
+       show_object_with_name(stdout, obj, name);
 }
 
 static void show_edge(struct commit *commit)

diff --git a/list-objects.c b/list-objects.c
index 43977665d30f545ab07c023f9abfc50c329a7818..917cc5d7c9ee04d07199f18b78342b84c0375fcd 100644 (file)
--- a/list-objects.c
+++ b/list-objects.c
@@ -16,6 +16,7 @@ static void process_blob(struct rev_info *revs,
                         void *cb_data)
 {
        struct object *obj = &blob->object;
+       size_t pathlen;
 
        if (!revs->blob_objects)
                return;
@@ -24,7 +25,11 @@ static void process_blob(struct rev_info *revs,
        if (obj->flags & (UNINTERESTING | SEEN))
                return;
        obj->flags |= SEEN;
-       show(obj, path, name, cb_data);
+
+       pathlen = path->len;
+       strbuf_addstr(path, name);
+       show(obj, path->buf, cb_data);
+       strbuf_setlen(path, pathlen);
 }
 
 /*
@@ -86,9 +91,8 @@ static void process_tree(struct rev_info *revs,
        }
 
        obj->flags |= SEEN;
-       show(obj, base, name, cb_data);
-
        strbuf_addstr(base, name);
+       show(obj, base->buf, cb_data);
        if (base->len)
                strbuf_addch(base, '/');
 
@@ -207,7 +211,7 @@ void traverse_commit_list(struct rev_info *revs,
                        continue;
                if (obj->type == OBJ_TAG) {
                        obj->flags |= SEEN;
-                       show_object(obj, NULL, name, data);
+                       show_object(obj, name, data);
                        continue;
                }
                if (!path)
@@ -219,7 +223,7 @@ void traverse_commit_list(struct rev_info *revs,
                }
                if (obj->type == OBJ_BLOB) {
                        process_blob(revs, (struct blob *)obj, show_object,
-                                    NULL, path, data);
+                                    &base, path, data);
                        continue;
                }
                die("unknown pending object %s (%s)",

diff --git a/list-objects.h b/list-objects.h
index 69c4c7de6efef0e6faa21a10438ea362b151e623..0cebf8585cb179ae46fd8238eaf2b2162739bbaa 100644 (file)
--- a/list-objects.h
+++ b/list-objects.h
@@ -2,7 +2,7 @@
 #define LIST_OBJECTS_H
 
 typedef void (*show_commit_fn)(struct commit *, void *);
-typedef void (*show_object_fn)(struct object *, struct strbuf *, const char *, void *);
+typedef void (*show_object_fn)(struct object *, const char *, void *);
 void traverse_commit_list(struct rev_info *, show_commit_fn, show_object_fn, void *);
 
 typedef void (*show_edge_fn)(struct commit *);

diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c
index 65ed3425b33f435c92163d3347f167766c5d8595..c30bcd06cbd516eb04e9b55b27b5f091ede61439 100644 (file)
--- a/pack-bitmap-write.c
+++ b/pack-bitmap-write.c
@@ -148,8 +148,7 @@ static uint32_t find_object_pos(const unsigned char *sha1)
        return entry->in_pack_pos;
 }
 
-static void show_object(struct object *object, struct strbuf *path,
-                       const char *last, void *data)
+static void show_object(struct object *object, const char *name, void *data)
 {
        struct bitmap *base = data;
        bitmap_set(base, find_object_pos(object->oid.hash));

diff --git a/pack-bitmap.c b/pack-bitmap.c
index 51f790e7ce10d4e570fd909c97268c40929a61e7..b949e517167dbac6c4c347e0a2cbdf8ca2dabbcf 100644 (file)
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -414,19 +414,15 @@ static int ext_index_add_object(struct object *object, const char *name)
        return bitmap_pos + bitmap_git.pack->num_objects;
 }
 
-static void show_object(struct object *object, struct strbuf *path,
-                       const char *last, void *data)
+static void show_object(struct object *object, const char *name, void *data)
 {
        struct bitmap *base = data;
        int bitmap_pos;
 
        bitmap_pos = bitmap_position(object->oid.hash);
 
-       if (bitmap_pos < 0) {
-               char *name = path_name(path, last);
+       if (bitmap_pos < 0)
                bitmap_pos = ext_index_add_object(object, name);
-               free(name);
-       }
 
        bitmap_set(base, bitmap_pos);
 }
@@ -894,9 +890,8 @@ struct bitmap_test_data {
        size_t seen;
 };
 
-static void test_show_object(struct object *object,
-                            struct strbuf *path,
-                            const char *last, void *data)
+static void test_show_object(struct object *object, const char *name,
+                            void *data)
 {
        struct bitmap_test_data *tdata = data;
        int bitmap_pos;

diff --git a/reachable.c b/reachable.c
index e60f08d2f0418471cf8253b48cf7fc8d4d3a894d..ed352018964ef2260f5da51239800bbcc816ad1b 100644 (file)
--- a/reachable.c
+++ b/reachable.c
@@ -43,15 +43,14 @@ static int add_one_ref(const char *path, const struct object_id *oid,
  * The traversal will have already marked us as SEEN, so we
  * only need to handle any progress reporting here.
  */
-static void mark_object(struct object *obj, struct strbuf *path,
-                       const char *name, void *data)
+static void mark_object(struct object *obj, const char *name, void *data)
 {
        update_progress(data);
 }
 
 static void mark_commit(struct commit *c, void *data)
 {
-       mark_object(&c->object, NULL, NULL, data);
+       mark_object(&c->object, NULL, data);
 }
 
 struct recent_data {

diff --git a/revision.c b/revision.c
index 3c847818164481f655d2dc822ffa5ade184a3058..82f3ca44b3e3dba8bdd487be04bd66b862fefa4c 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -25,27 +25,14 @@ volatile show_early_output_fn_t show_early_output;
 static const char *term_bad;
 static const char *term_good;
 
-char *path_name(struct strbuf *path, const char *name)
+void show_object_with_name(FILE *out, struct object *obj, const char *name)
 {
-       struct strbuf ret = STRBUF_INIT;
-       if (path)
-               strbuf_addbuf(&ret, path);
-       strbuf_addstr(&ret, name);
-       return strbuf_detach(&ret, NULL);
-}
-
-void show_object_with_name(FILE *out, struct object *obj,
-                          struct strbuf *path, const char *component)
-{
-       char *name = path_name(path, component);
-       char *p;
+       const char *p;
 
        fprintf(out, "%s ", oid_to_hex(&obj->oid));
        for (p = name; *p && *p != '\n'; p++)
                fputc(*p, out);
        fputc('\n', out);
-
-       free(name);
 }
 
 static void mark_blob_uninteresting(struct blob *blob)

diff --git a/revision.h b/revision.h
index 7beab15248f696a165a51cbe683000d3ede85939..dca0d381715cf5bc6888587feaec989012f51252 100644 (file)
--- a/revision.h
+++ b/revision.h
@@ -259,8 +259,7 @@ extern void mark_tree_uninteresting(struct tree *tree);
 
 char *path_name(struct strbuf *path, const char *name);
 
-extern void show_object_with_name(FILE *, struct object *,
-                                 struct strbuf *, const char *);
+extern void show_object_with_name(FILE *, struct object *, const char *);
 
 extern void add_pending_object(struct rev_info *revs,
                               struct object *obj, const char *name);