[PATCH v2 10/12] diff --color-moved-ws=allow-indentation-change: improve hash lookups

From

PGPhillip Wood via GitGitGadget <gitgitgadget@gmail.com>

Date

Jul 20, 2021, 10:36 UTC

Message-ID

<dd365ad115ffcf3ce5b4b14864ac3ff0ac292214.1626777394.git.gitgitgadget@gmail.com>

In-Reply-To

<pull.981.v2.git.1626777393.gitgitgadget@gmail.com>

From: Phillip Wood <phillip.wood@dunelm.org.uk>

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
---
 diff.c | 66 +++++++++++++++++-----------------------------------------
 1 file changed, 19 insertions(+), 47 deletions(-)

diff --git a/diff.c b/diff.c
index 4b5776a5a0a..f899083d028 100644
--- a/diff.c
+++ b/diff.c
@@ -850,28 +850,15 @@ static void fill_es_indent_data(struct emitted_diff_symbol *es)
 }
 
 static int compute_ws_delta(const struct emitted_diff_symbol *a,
-			    const struct emitted_diff_symbol *b,
-			    int *out)
-{
-	int a_len = a->len,
-	    b_len = b->len,
-	    a_off = a->indent_off,
-	    a_width = a->indent_width,
-	    b_off = b->indent_off,
+			    const struct emitted_diff_symbol *b)
+{
+	int a_width = a->indent_width,
 	    b_width = b->indent_width;
 
-	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
-		*out = INDENT_BLANKLINE;
-		return 1;
-	}
-
-	if (a_len - a_off != b_len - b_off ||
-	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
-		return 0;
-
-	*out = a_width - b_width;
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
+		return INDENT_BLANKLINE;
 
-	return 1;
+	return a_width - b_width;
 }
 
 static int cmp_in_block_with_wsd(const struct diff_options *o,
@@ -917,26 +904,17 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 			   const void *keydata)
 {
 	const struct diff_options *diffopt = hashmap_cmp_fn_data;
-	const struct moved_entry *a, *b;
+	const struct emitted_diff_symbol *a, *b;
 	unsigned flags = diffopt->color_moved_ws_handling
 			 & XDF_WHITESPACE_FLAGS;
 
-	a = container_of(eptr, const struct moved_entry, ent);
-	b = container_of(entry_or_key, const struct moved_entry, ent);
-
-	if (diffopt->color_moved_ws_handling &
-	    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-		/*
-		 * As there is not specific white space config given,
-		 * we'd need to check for a new block, so ignore all
-		 * white space. The setup of the white space
-		 * configuration for the next block is done else where
-		 */
-		flags |= XDF_IGNORE_WHITESPACE;
+	a = container_of(eptr, const struct moved_entry, ent)->es;
+	b = container_of(entry_or_key, const struct moved_entry, ent)->es;
 
-	return !xdiff_compare_lines(a->es->line, a->es->len,
-				    b->es->line, b->es->len,
-				    flags);
+	return !xdiff_compare_lines(a->line + a->indent_off,
+				    a->len - a->indent_off,
+				    b->line + b->indent_off,
+				    b->len - b->indent_off, flags);
 }
 
 static struct moved_entry *prepare_entry(struct diff_options *o,
@@ -945,7 +923,8 @@ static struct moved_entry *prepare_entry(struct diff_options *o,
 	struct moved_entry *ret = xmalloc(sizeof(*ret));
 	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
-	unsigned int hash = xdiff_hash_string(l->line, l->len, flags);
+	unsigned int hash = xdiff_hash_string(l->line + l->indent_off,
+					      l->len - l->indent_off, flags);
 
 	hashmap_entry_init(&ret->ent, hash);
 	ret->es = l;
@@ -1113,14 +1092,11 @@ static void mark_color_as_moved(struct diff_options *o,
 			hashmap_for_each_entry_from(hm, match, ent) {
 				ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 				if (o->color_moved_ws_handling &
-				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
-					if (compute_ws_delta(l, match->es,
-							     &pmb[pmb_nr].wsd))
-						pmb[pmb_nr++].match = match;
-				} else {
+				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+					pmb[pmb_nr].wsd = compute_ws_delta(l, match->es);
+				else
 					pmb[pmb_nr].wsd = 0;
-					pmb[pmb_nr++].match = match;
-				}
+				pmb[pmb_nr++].match = match;
 			}
 
 			if (adjust_last_block(o, n, block_length) &&
@@ -6240,10 +6216,6 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 		if (o->color_moved) {
 			struct hashmap add_lines, del_lines;
 
-			if (o->color_moved_ws_handling &
-			    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-				o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
-
 			hashmap_init(&del_lines, moved_entry_cmp, o, 0);
 			hashmap_init(&add_lines, moved_entry_cmp, o, 0);
 

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