[PATCH v9 5/6] diff-lib: refactor out diff_change logic

From: Calvin Wan <calvinwan@google.com>
To: git@vger.kernel.org
Cc: Calvin Wan <calvinwan@google.com>,
	avarab@gmail.com, chooglen@google.com, newren@gmail.com,
	jonathantanmy@google.com, phillip.wood123@gmail.com
Subject: [PATCH v9 5/6] diff-lib: refactor out diff_change logic
Date: Thu,  2 Mar 2023 22:02:50 +0000	[thread overview]
Message-ID: <20230302220251.1474923-5-calvinwan@google.com> (raw)
In-Reply-To: <20230302215237.1473444-1-calvinwan@google.com>

In run_diff_files, there is logic that records the diff and updates
relevant bits at the end of each entry iteration. Refactor out that
logic into a helper function so a future patch can call it.

Signed-off-by: Calvin Wan <calvinwan@google.com>
---
 diff-lib.c | 48 +++++++++++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 17 deletions(-)

diff --git a/diff-lib.c b/diff-lib.c
index dec040c366..744ae98a69 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -88,6 +88,34 @@ static int match_stat_with_submodule(struct diff_options *diffopt,
 	return changed;
 }
 
+/**
+ * Records diff_change if there is a change in the entry from run_diff_files.
+ * If there is no change, then the cache entry is marked CE_UPTODATE and
+ * CE_FSMONITOR_VALID. If there is no change and the find_copies_harder flag
+ * is not set, then the function returns early.
+ */
+static void record_file_diff(struct diff_options *options, unsigned newmode,
+			     unsigned dirty_submodule, int changed,
+			     struct index_state *istate,
+			     struct cache_entry *ce)
+{
+	unsigned int oldmode;
+	const struct object_id *old_oid, *new_oid;
+
+	if (!changed && !dirty_submodule) {
+		ce_mark_uptodate(ce);
+		mark_fsmonitor_valid(istate, ce);
+		if (!options->flags.find_copies_harder)
+			return;
+	}
+	oldmode = ce->ce_mode;
+	old_oid = &ce->oid;
+	new_oid = changed ? null_oid() : &ce->oid;
+	diff_change(options, oldmode, newmode, old_oid, new_oid,
+		    !is_null_oid(old_oid), !is_null_oid(new_oid),
+		    ce->name, 0, dirty_submodule);
+}
+
 int run_diff_files(struct rev_info *revs, unsigned int option)
 {
 	int entries, i;
@@ -105,11 +133,10 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 		diff_unmerged_stage = 2;
 	entries = istate->cache_nr;
 	for (i = 0; i < entries; i++) {
-		unsigned int oldmode, newmode;
+		unsigned int newmode;
 		struct cache_entry *ce = istate->cache[i];
 		int changed;
 		unsigned dirty_submodule = 0;
-		const struct object_id *old_oid, *new_oid;
 
 		if (diff_can_quit_early(&revs->diffopt))
 			break;
@@ -245,21 +272,8 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 			newmode = ce_mode_from_stat(ce, st.st_mode);
 		}
 
-		if (!changed && !dirty_submodule) {
-			ce_mark_uptodate(ce);
-			mark_fsmonitor_valid(istate, ce);
-			if (!revs->diffopt.flags.find_copies_harder)
-				continue;
-		}
-		oldmode = ce->ce_mode;
-		old_oid = &ce->oid;
-		new_oid = changed ? null_oid() : &ce->oid;
-		diff_change(&revs->diffopt, oldmode, newmode,
-			    old_oid, new_oid,
-			    !is_null_oid(old_oid),
-			    !is_null_oid(new_oid),
-			    ce->name, 0, dirty_submodule);
-
+		record_file_diff(&revs->diffopt, newmode, dirty_submodule,
+				 changed, istate, ce);
 	}
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);
-- 
2.40.0.rc0.216.gc4246ad0f0-goog

