[PATCH 3/3] diffcore-pickaxe: unify setup and teardown code between log -S/-G

[Junio C Hamano <gitster@pobox.com>]

The logic to decide early to do nothing and prepare the data to be
inspected are the same between has_changes() and diff_grep().
Introduce pickaxe_setup() helper to share the same code.

Similarly, introduce pickaxe_finish_filepair() to clean up after
these two functions are done with a filepair.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 diffcore-pickaxe.c | 103 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 55 insertions(+), 48 deletions(-)

diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index cadb071..ac5a28d 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c
@@ -48,6 +48,54 @@ static void pickaxe(struct diff_queue_struct *q, struct diff_options *o,
 	*q = outq;
 }
 
+static int pickaxe_setup(struct diff_filepair *p,
+			 struct diff_options *o,
+			 mmfile_t *mf_one,
+			 mmfile_t *mf_two,
+			 unsigned *what_to_free)
+{
+	struct userdiff_driver *textconv_one = NULL;
+	struct userdiff_driver *textconv_two = NULL;
+
+	if (!o->pickaxe[0])
+		return 0;
+
+	if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
+		textconv_one = get_textconv(p->one);
+		textconv_two = get_textconv(p->two);
+	}
+
+	/*
+	 * If we have an unmodified pair, we know that there is no
+	 * interesting difference and we don't even have to load the
+	 * blobs, unless textconv is in play, _and_ we are using two
+	 * different textconv filters (e.g., because a pair is an
+	 * exact rename with different textconv attributes for each
+	 * side, which might generate different content).
+	 */
+	if (textconv_one == textconv_two && diff_unmodified_pair(p))
+		return 0;
+
+	mf_one->size = fill_textconv(textconv_one, p->one, &mf_one->ptr);
+	mf_two->size = fill_textconv(textconv_two, p->two, &mf_two->ptr);
+
+	*what_to_free = (textconv_one ? 1 : 0) | (textconv_two ? 2 : 0);
+	return 1;
+}
+
+static void pickaxe_finish_filepair(struct diff_filepair *p,
+				    mmfile_t *mf_one,
+				    mmfile_t *mf_two,
+				    unsigned what_to_free)
+{
+	if (what_to_free & 1)
+		free(mf_one->ptr);
+	if (what_to_free & 2)
+		free(mf_two->ptr);
+	diff_free_filespec_data(p->one);
+	diff_free_filespec_data(p->two);
+}
+
 struct diffgrep_cb {
 	regex_t *regexp;
 	int hit;
@@ -78,25 +126,13 @@ static int diff_grep(struct diff_filepair *p, struct diff_options *o,
 		     regex_t *regexp, kwset_t kws)
 {
 	regmatch_t regmatch;
-	struct userdiff_driver *textconv_one = NULL;
-	struct userdiff_driver *textconv_two = NULL;
 	mmfile_t mf1, mf2;
+	unsigned what_to_free;
 	int hit;
 
-	if (!o->pickaxe[0])
+	if (!pickaxe_setup(p, o, &mf1, &mf2, &what_to_free))
 		return 0;
 
-	if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
-		textconv_one = get_textconv(p->one);
-		textconv_two = get_textconv(p->two);
-	}
-
-	if (textconv_one == textconv_two && diff_unmodified_pair(p))
-		return 0;
-
-	mf1.size = fill_textconv(textconv_one, p->one, &mf1.ptr);
-	mf2.size = fill_textconv(textconv_two, p->two, &mf2.ptr);
-
 	if (!DIFF_FILE_VALID(p->one)) {
 		if (!DIFF_FILE_VALID(p->two))
 			hit = 0; /* ignore unmerged */
@@ -125,12 +161,8 @@ static int diff_grep(struct diff_filepair *p, struct diff_options *o,
 			      &xpp, &xecfg);
 		hit = ecbdata.hit;
 	}
-	if (textconv_one)
-		free(mf1.ptr);
-	if (textconv_two)
-		free(mf2.ptr);
-	diff_free_filespec_data(p->one);
-	diff_free_filespec_data(p->two);
+
+	pickaxe_finish_filepair(p, &mf1, &mf2, what_to_free);
 	return hit;
 }
 
@@ -201,32 +233,13 @@ static unsigned int contains(mmfile_t *mf, struct diff_options *o,
 static int has_changes(struct diff_filepair *p, struct diff_options *o,
 		       regex_t *regexp, kwset_t kws)
 {
-	struct userdiff_driver *textconv_one = NULL;
-	struct userdiff_driver *textconv_two = NULL;
 	mmfile_t mf1, mf2;
+	unsigned what_to_free;
 	int ret;
 
-	if (!o->pickaxe[0])
-		return 0;
-
-	if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
-		textconv_one = get_textconv(p->one);
-		textconv_two = get_textconv(p->two);
-	}
-
-	/*
-	 * If we have an unmodified pair, we know that the count will be the
-	 * same and don't even have to load the blobs. Unless textconv is in
-	 * play, _and_ we are using two different textconv filters (e.g.,
-	 * because a pair is an exact rename with different textconv attributes
-	 * for each side, which might generate different content).
-	 */
-	if (textconv_one == textconv_two && diff_unmodified_pair(p))
+	if (!pickaxe_setup(p, o, &mf1, &mf2, &what_to_free))
 		return 0;
 
-	mf1.size = fill_textconv(textconv_one, p->one, &mf1.ptr);
-	mf2.size = fill_textconv(textconv_two, p->two, &mf2.ptr);
-
 	if (!DIFF_FILE_VALID(p->one)) {
 		if (!DIFF_FILE_VALID(p->two))
 			ret = 0; /* ignore unmerged */
@@ -240,13 +253,7 @@ static int has_changes(struct diff_filepair *p, struct diff_options *o,
 		ret = contains(&mf1, o, regexp, kws) !=
 		      contains(&mf2, o, regexp, kws);
 
-	if (textconv_one)
-		free(mf1.ptr);
-	if (textconv_two)
-		free(mf2.ptr);
-	diff_free_filespec_data(p->one);
-	diff_free_filespec_data(p->two);
-
+	pickaxe_finish_filepair(p, &mf1, &mf2, what_to_free);
 	return ret;
 }
 
-- 
1.8.2-588-gbf1c992