merge-ort: add helper functions for using cached renames

If we have a usable rename cache, then we can remove from
relevant_sources all the paths that were cached;
diffcore_rename_extended() can then consider an even smaller set of
relevant_sources in its rename detection.

However, when diffcore_rename_extended() is done, we will need to take
the renames it detected and then add back in all the ones we had cached
from before.

Add helper functions for doing these two operations; the next commit
will make use of them.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/merge-ort.c b/merge-ort.c
index cc1adc74561dc1f6dfc168bd9bb9bb903ec4afaa..8e38dac3413fba6f6a6aedb2708a4c1e87fcc5b1 100644 (file)
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -2371,6 +2371,53 @@ static void resolve_diffpair_statuses(struct diff_queue_struct *q)
        }
 }
 
+MAYBE_UNUSED
+static void prune_cached_from_relevant(struct rename_info *renames,
+                                      unsigned side)
+{
+       /* Reason for this function described in add_pair() */
+       struct hashmap_iter iter;
+       struct strmap_entry *entry;
+
+       /* Remove from relevant_sources all entries in cached_pairs[side] */
+       strmap_for_each_entry(&renames->cached_pairs[side], &iter, entry) {
+               strintmap_remove(&renames->relevant_sources[side],
+                                entry->key);
+       }
+       /* Remove from relevant_sources all entries in cached_irrelevant[side] */
+       strset_for_each_entry(&renames->cached_irrelevant[side], &iter, entry) {
+               strintmap_remove(&renames->relevant_sources[side],
+                                entry->key);
+       }
+}
+
+MAYBE_UNUSED
+static void use_cached_pairs(struct merge_options *opt,
+                            struct strmap *cached_pairs,
+                            struct diff_queue_struct *pairs)
+{
+       struct hashmap_iter iter;
+       struct strmap_entry *entry;
+
+       /*
+        * Add to side_pairs all entries from renames->cached_pairs[side_index].
+        * (Info in cached_irrelevant[side_index] is not relevant here.)
+        */
+       strmap_for_each_entry(cached_pairs, &iter, entry) {
+               struct diff_filespec *one, *two;
+               const char *old_name = entry->key;
+               const char *new_name = entry->value;
+               if (!new_name)
+                       new_name = old_name;
+
+               /* We don't care about oid/mode, only filenames and status */
+               one = alloc_filespec(old_name);
+               two = alloc_filespec(new_name);
+               diff_queue(pairs, one, two);
+               pairs->queue[pairs->nr-1]->status = entry->value ? 'R' : 'D';
+       }
+}
+
 static void cache_new_pair(struct rename_info *renames,
                           int side,
                           char *old_path,