threads / patch / 34363

patchdiffcore-pickaxe: simplify has_changes and contains

Subject: [PATCH] diffcore-pickaxe: simplify has_changes and contains

## tl;dr

3 messages between Jul 6, 2013 and Jul 7, 2013. Diffs are folded; open one to read it.

replies: 2people: 3as markdown or json

René Scharfe· Jul 6, 2013, 13:53 UTC · lore

Halve the number of callsites of contains() to two using temporary variables, simplifying the code. While at it, get rid of the diff_options parameter, which became unused with 8fa4b09f.

Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
---
 diffcore-pickaxe.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)
Show changes to diffcore-pickaxe.c +4 −7
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index c97ac9b..401eb72 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c
@@ -131,8 +131,7 @@ static void diffcore_pickaxe_grep(struct diff_options *o)
 	return;
 }
 
-static unsigned int contains(mmfile_t *mf, struct diff_options *o,
-			     regex_t *regexp, kwset_t kws)
+static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws)
 {
 	unsigned int cnt;
 	unsigned long sz;
@@ -176,11 +175,9 @@ static int has_changes(mmfile_t *one, mmfile_t *two,
 		       struct diff_options *o,
 		       regex_t *regexp, kwset_t kws)
 {
-	if (!one)
-		return contains(two, o, regexp, kws) != 0;
-	if (!two)
-		return contains(one, o, regexp, kws) != 0;
-	return contains(one, o, regexp, kws) != contains(two, o, regexp, kws);
+	unsigned int one_contains = one ? contains(one, regexp, kws) : 0;
+	unsigned int two_contains = two ? contains(two, regexp, kws) : 0;
+	return one_contains != two_contains;
 }
 
 static int pickaxe_match(struct diff_filepair *p, struct diff_options *o,

-- 
1.8.3.2
Jeff King· Jul 7, 2013, 04:03 UTC · re: René Scharfe · lore

Re: [PATCH] diffcore-pickaxe: simplify has_changes and contains

On Sat, Jul 06, 2013 at 03:53:27PM +0200, René Scharfe wrote:
> Halve the number of callsites of contains() to two using temporary
> variables, simplifying the code.  While at it, get rid of the
> diff_options parameter, which became unused with 8fa4b09f.
There is a slight change in behavior, too:
Show 8 quoted lines
> -	if (!one)
> -		return contains(two, o, regexp, kws) != 0;
> -	if (!two)
> -		return contains(one, o, regexp, kws) != 0;
> -	return contains(one, o, regexp, kws) != contains(two, o, regexp, kws);
> +	unsigned int one_contains = one ? contains(one, regexp, kws) : 0;
> +	unsigned int two_contains = two ? contains(two, regexp, kws) : 0;
> +	return one_contains != two_contains;

Before, if (!one && !two) we would call contains(two, ...), and now we will simply assume it is zero. Which I think is an improvement, as we would have segfaulted before. I don't think it is a bug in the current code (we would not ever feed the function two NULLs), but it is nice to be more defensive.

Acked-by: Jeff King <peff@peff.net>
-Peff
Junio C Hamano· Jul 7, 2013, 17:25 UTC · re: Jeff King · lore

Re: [PATCH] diffcore-pickaxe: simplify has_changes and contains

Jeff King <peff@peff.net> writes:
Show 7 quoted lines
> Before, if (!one && !two) we would call contains(two, ...), and now we
> will simply assume it is zero. Which I think is an improvement, as we
> would have segfaulted before. I don't think it is a bug in the current
> code (we would not ever feed the function two NULLs), but it is nice to
> be more defensive.
>
> Acked-by: Jeff King <peff@peff.net>
Thanks, both.

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