Revert "unpack-trees: improve performance of next_cache_entry"

This reverts commit f2a454e0a5 (unpack-trees: improve performance of
next_cache_entry, 2021-11-29).

The "hint" value was originally needed to improve performance in 'git reset
-- <pathspec>' caused by 'cache_bottom' lagging behind its correct value
when using a sparse index. The 'cache_bottom' tracking has since been
corrected, removing the need for an additional "pseudo-cache_bottom"
tracking variable.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/unpack-trees.c b/unpack-trees.c
index b82c1a9705e1a09270dcb118005731421de2ab15..7f528d35cc263ad2d87444d2b9c0081ba6e1da74 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -644,24 +644,17 @@ static void mark_ce_used_same_name(struct cache_entry *ce,
        }
 }
 
-static struct cache_entry *next_cache_entry(struct unpack_trees_options *o, int *hint)
+static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
 {
        const struct index_state *index = o->src_index;
        int pos = o->cache_bottom;
 
-       if (*hint > pos)
-               pos = *hint;
-
        while (pos < index->cache_nr) {
                struct cache_entry *ce = index->cache[pos];
-               if (!(ce->ce_flags & CE_UNPACKED)) {
-                       *hint = pos + 1;
+               if (!(ce->ce_flags & CE_UNPACKED))
                        return ce;
-               }
                pos++;
        }
-
-       *hint = pos;
        return NULL;
 }
 
@@ -1409,13 +1402,12 @@ static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, str
 
        /* Are we supposed to look at the index too? */
        if (o->merge) {
-               int hint = -1;
                while (1) {
                        int cmp;
                        struct cache_entry *ce;
 
                        if (o->diff_index_cached)
-                               ce = next_cache_entry(o, &hint);
+                               ce = next_cache_entry(o);
                        else
                                ce = find_cache_entry(info, p);
 
@@ -1777,7 +1769,7 @@ static int verify_absent(const struct cache_entry *,
 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
 {
        struct repository *repo = the_repository;
-       int i, hint, ret;
+       int i, ret;
        static struct cache_entry *dfc;
        struct pattern_list pl;
        int free_pattern_list = 0;
@@ -1869,15 +1861,13 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
                info.pathspec = o->pathspec;
 
                if (o->prefix) {
-                       hint = -1;
-
                        /*
                         * Unpack existing index entries that sort before the
                         * prefix the tree is spliced into.  Note that o->merge
                         * is always true in this case.
                         */
                        while (1) {
-                               struct cache_entry *ce = next_cache_entry(o, &hint);
+                               struct cache_entry *ce = next_cache_entry(o);
                                if (!ce)
                                        break;
                                if (ce_in_traverse_path(ce, &info))
@@ -1898,9 +1888,8 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 
        /* Any left-over entries in the index? */
        if (o->merge) {
-               hint = -1;
                while (1) {
-                       struct cache_entry *ce = next_cache_entry(o, &hint);
+                       struct cache_entry *ce = next_cache_entry(o);
                        if (!ce)
                                break;
                        if (unpack_index_entry(ce, o) < 0)