tree-walk: drop oid from traverse_info

As the previous commit shows, the presence of an oid in each level of
the traverse_info is confusing and ultimately not necessary. Let's drop
it to make it clear that it will not always be set (as well as convince
us that it's unused, and let the compiler catch any merges with other
branches that do add new uses).

Since the oid is part of name_entry, we'll actually stop embedding a
name_entry entirely, and instead just separately hold the pathname, its
length, and the mode.

This makes the resulting code slightly more verbose as we have to pass
those elements around individually. But it also makes it more clear what
each code path is going to use (and in most of the paths, we really only
care about the pathname itself).

A few of these conversions are noisier than they need to be, as they
also take the opportunity to rename "len" to "namelen" for clarity
(especially where we also have "pathlen" or "ce_len" alongside).

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

1 files changed, 29 insertions, 24 deletions

diff --git a/unpack-trees.c b/unpack-trees.c
index 50189909b8..26f971f7ff 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -632,7 +632,7 @@ static int unpack_index_entry(struct cache_entry *ce,
 	return ret;
 }
 
-static int find_cache_pos(struct traverse_info *, const struct name_entry *);
+static int find_cache_pos(struct traverse_info *, const char *p, size_t len);
 
 static void restore_cache_bottom(struct traverse_info *info, int bottom)
 {
@@ -651,7 +651,7 @@ static int switch_cache_bottom(struct traverse_info *info)
 	if (o->diff_index_cached)
 		return 0;
 	ret = o->cache_bottom;
-	pos = find_cache_pos(info->prev, &info->name);
+	pos = find_cache_pos(info->prev, info->name, info->namelen);
 
 	if (pos < -1)
 		o->cache_bottom = -2 - pos;
@@ -690,7 +690,7 @@ static int index_pos_by_traverse_info(struct name_entry *names,
 	char *name = xmalloc(len + 1 /* slash */ + 1 /* NUL */);
 	int pos;
 
-	make_traverse_path(name, info, names);
+	make_traverse_path(name, info, names->path, names->pathlen);
 	name[len++] = '/';
 	name[len] = '\0';
 	pos = index_name_pos(o->src_index, name, len);
@@ -811,7 +811,9 @@ static int traverse_trees_recursive(int n, unsigned long dirmask,
 	newinfo = *info;
 	newinfo.prev = info;
 	newinfo.pathspec = info->pathspec;
-	newinfo.name = *p;
+	newinfo.name = p->path;
+	newinfo.namelen = p->pathlen;
+	newinfo.mode = p->mode;
 	newinfo.pathlen += tree_entry_len(p) + 1;
 	newinfo.df_conflicts |= df_conflicts;
 
@@ -863,14 +865,18 @@ static int traverse_trees_recursive(int n, unsigned long dirmask,
  * itself - the caller needs to do the final check for the cache
  * entry having more data at the end!
  */
-static int do_compare_entry_piecewise(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
+static int do_compare_entry_piecewise(const struct cache_entry *ce,
+				      const struct traverse_info *info,
+				      const char *name, size_t namelen,
+				      unsigned mode)
 {
-	int len, pathlen, ce_len;
+	int pathlen, ce_len;
 	const char *ce_name;
 
 	if (info->prev) {
 		int cmp = do_compare_entry_piecewise(ce, info->prev,
-						     &info->name);
+						     info->name, info->namelen,
+						     info->mode);
 		if (cmp)
 			return cmp;
 	}
@@ -884,15 +890,15 @@ static int do_compare_entry_piecewise(const struct cache_entry *ce, const struct
 	ce_len -= pathlen;
 	ce_name = ce->name + pathlen;
 
-	len = tree_entry_len(n);
-	return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
+	return df_name_compare(ce_name, ce_len, S_IFREG, name, namelen, mode);
 }
 
 static int do_compare_entry(const struct cache_entry *ce,
 			    const struct traverse_info *info,
-			    const struct name_entry *n)
+			    const char *name, size_t namelen,
+			    unsigned mode)
 {
-	int len, pathlen, ce_len;
+	int pathlen, ce_len;
 	const char *ce_name;
 	int cmp;
 
@@ -902,7 +908,7 @@ static int do_compare_entry(const struct cache_entry *ce,
 	 * it is quicker to use the precomputed version.
 	 */
 	if (!info->traverse_path)
-		return do_compare_entry_piecewise(ce, info, n);
+		return do_compare_entry_piecewise(ce, info, name, namelen, mode);
 
 	cmp = strncmp(ce->name, info->traverse_path, info->pathlen);
 	if (cmp)
@@ -917,13 +923,12 @@ static int do_compare_entry(const struct cache_entry *ce,
 	ce_len -= pathlen;
 	ce_name = ce->name + pathlen;
 
-	len = tree_entry_len(n);
-	return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
+	return df_name_compare(ce_name, ce_len, S_IFREG, name, namelen, mode);
 }
 
 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
 {
-	int cmp = do_compare_entry(ce, info, n);
+	int cmp = do_compare_entry(ce, info, n->path, n->pathlen, n->mode);
 	if (cmp)
 		return cmp;
 
@@ -939,7 +944,8 @@ static int ce_in_traverse_path(const struct cache_entry *ce,
 {
 	if (!info->prev)
 		return 1;
-	if (do_compare_entry(ce, info->prev, &info->name))
+	if (do_compare_entry(ce, info->prev,
+			     info->name, info->namelen, info->mode))
 		return 0;
 	/*
 	 * If ce (blob) is the same name as the path (which is a tree
@@ -964,7 +970,7 @@ static struct cache_entry *create_ce_entry(const struct traverse_info *info,
 	ce->ce_flags = create_ce_flags(stage);
 	ce->ce_namelen = len;
 	oidcpy(&ce->oid, &n->oid);
-	make_traverse_path(ce->name, info, n);
+	make_traverse_path(ce->name, info, n->path, n->pathlen);
 
 	return ce;
 }
@@ -1057,13 +1063,12 @@ static int unpack_failed(struct unpack_trees_options *o, const char *message)
  * the directory.
  */
 static int find_cache_pos(struct traverse_info *info,
-			  const struct name_entry *p)
+			  const char *p, size_t p_len)
 {
 	int pos;
 	struct unpack_trees_options *o = info->data;
 	struct index_state *index = o->src_index;
 	int pfxlen = info->pathlen;
-	int p_len = tree_entry_len(p);
 
 	for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
 		const struct cache_entry *ce = index->cache[pos];
@@ -1099,7 +1104,7 @@ static int find_cache_pos(struct traverse_info *info,
 			ce_len = ce_slash - ce_name;
 		else
 			ce_len = ce_namelen(ce) - pfxlen;
-		cmp = name_compare(p->path, p_len, ce_name, ce_len);
+		cmp = name_compare(p, p_len, ce_name, ce_len);
 		/*
 		 * Exact match; if we have a directory we need to
 		 * delay returning it.
@@ -1114,7 +1119,7 @@ static int find_cache_pos(struct traverse_info *info,
 		 * E.g.  ce_name == "t-i", and p->path == "t"; we may
 		 * have "t/a" in the index.
 		 */
-		if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
+		if (p_len < ce_len && !memcmp(ce_name, p, p_len) &&
 		    ce_name[p_len] < '/')
 			continue; /* keep looking */
 		break;
@@ -1125,7 +1130,7 @@ static int find_cache_pos(struct traverse_info *info,
 static struct cache_entry *find_cache_entry(struct traverse_info *info,
 					    const struct name_entry *p)
 {
-	int pos = find_cache_pos(info, p);
+	int pos = find_cache_pos(info, p->path, p->pathlen);
 	struct unpack_trees_options *o = info->data;
 
 	if (0 <= pos)
@@ -1138,10 +1143,10 @@ static void debug_path(struct traverse_info *info)
 {
 	if (info->prev) {
 		debug_path(info->prev);
-		if (*info->prev->name.path)
+		if (*info->prev->name)
 			putchar('/');
 	}
-	printf("%s", info->name.path);
+	printf("%s", info->name);
 }
 
 static void debug_name_entry(int i, struct name_entry *n)