ref-filter.h: add functions for filter/format & format-only

Add two new public methods to 'ref-filter.h':

* 'print_formatted_ref_array()' which, given a format specification & array
  of ref items, formats and prints the items to stdout.
* 'filter_and_format_refs()' which combines 'filter_refs()',
  'ref_array_sort()', and 'print_formatted_ref_array()' into a single
  function.

This consolidates much of the code used to filter and format refs in
'builtin/for-each-ref.c', 'builtin/tag.c', and 'builtin/branch.c', reducing
duplication and simplifying the future changes needed to optimize the filter
& format process.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

5 files changed, 68 insertions, 64 deletions

diff --git a/builtin/branch.c b/builtin/branch.c
index 49198b548e..40da31e640 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -437,8 +437,6 @@ static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sortin
 {
 	int i;
 	struct ref_array array;
-	struct strbuf out = STRBUF_INIT;
-	struct strbuf err = STRBUF_INIT;
 	int maxwidth = 0;
 	const char *remote_prefix = "";
 	char *to_free = NULL;
@@ -468,24 +466,27 @@ static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sortin
 	filter_ahead_behind(the_repository, format, &array);
 	ref_array_sort(sorting, &array);
 
-	for (i = 0; i < array.nr; i++) {
-		strbuf_reset(&err);
-		strbuf_reset(&out);
-		if (format_ref_array_item(array.items[i], format, &out, &err))
-			die("%s", err.buf);
-		if (column_active(colopts)) {
-			assert(!filter->verbose && "--column and --verbose are incompatible");
-			 /* format to a string_list to let print_columns() do its job */
+	if (column_active(colopts)) {
+		struct strbuf out = STRBUF_INIT, err = STRBUF_INIT;
+
+		assert(!filter->verbose && "--column and --verbose are incompatible");
+
+		for (i = 0; i < array.nr; i++) {
+			strbuf_reset(&err);
+			strbuf_reset(&out);
+			if (format_ref_array_item(array.items[i], format, &out, &err))
+				die("%s", err.buf);
+
+			/* format to a string_list to let print_columns() do its job */
 			string_list_append(output, out.buf);
-		} else {
-			fwrite(out.buf, 1, out.len, stdout);
-			if (out.len || !format->array_opts.omit_empty)
-				putchar('\n');
 		}
+
+		strbuf_release(&err);
+		strbuf_release(&out);
+	} else {
+		print_formatted_ref_array(&array, format);
 	}
 
-	strbuf_release(&err);
-	strbuf_release(&out);
 	ref_array_clear(&array);
 	free(to_free);
 }
diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
index 881c3ee055..1c19cd5bd3 100644
--- a/builtin/for-each-ref.c
+++ b/builtin/for-each-ref.c
@@ -19,15 +19,11 @@ static char const * const for_each_ref_usage[] = {
 
 int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 {
-	int i, total;
 	struct ref_sorting *sorting;
 	struct string_list sorting_options = STRING_LIST_INIT_DUP;
 	int icase = 0;
-	struct ref_array array;
 	struct ref_filter filter = REF_FILTER_INIT;
 	struct ref_format format = REF_FORMAT_INIT;
-	struct strbuf output = STRBUF_INIT;
-	struct strbuf err = STRBUF_INIT;
 	int from_stdin = 0;
 	struct strvec vec = STRVEC_INIT;
 
@@ -61,8 +57,6 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 		OPT_END(),
 	};
 
-	memset(&array, 0, sizeof(array));
-
 	format.format = "%(objectname) %(objecttype)\t%(refname)";
 
 	git_config(git_default_config, NULL);
@@ -104,27 +98,8 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 	}
 
 	filter.match_as_path = 1;
-	filter_refs(&array, &filter, FILTER_REFS_ALL);
-	filter_ahead_behind(the_repository, &format, &array);
-
-	ref_array_sort(sorting, &array);
-
-	total = format.array_opts.max_count;
-	if (!total || array.nr < total)
-		total = array.nr;
-	for (i = 0; i < total; i++) {
-		strbuf_reset(&err);
-		strbuf_reset(&output);
-		if (format_ref_array_item(array.items[i], &format, &output, &err))
-			die("%s", err.buf);
-		fwrite(output.buf, 1, output.len, stdout);
-		if (output.len || !format.array_opts.omit_empty)
-			putchar('\n');
-	}
+	filter_and_format_refs(&filter, FILTER_REFS_ALL, sorting, &format);
 
-	strbuf_release(&err);
-	strbuf_release(&output);
-	ref_array_clear(&array);
 	ref_filter_clear(&filter);
 	ref_sorting_release(sorting);
 	strvec_clear(&vec);
diff --git a/builtin/tag.c b/builtin/tag.c
index 2d599245d4..2528d499dd 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -48,13 +48,7 @@ static int config_sign_tag = -1; /* unspecified */
 static int list_tags(struct ref_filter *filter, struct ref_sorting *sorting,
 		     struct ref_format *format)
 {
-	struct ref_array array;
-	struct strbuf output = STRBUF_INIT;
-	struct strbuf err = STRBUF_INIT;
 	char *to_free = NULL;
-	int i;
-
-	memset(&array, 0, sizeof(array));
 
 	if (filter->lines == -1)
 		filter->lines = 0;
@@ -72,23 +66,8 @@ static int list_tags(struct ref_filter *filter, struct ref_sorting *sorting,
 	if (verify_ref_format(format))
 		die(_("unable to parse format string"));
 	filter->with_commit_tag_algo = 1;
-	filter_refs(&array, filter, FILTER_REFS_TAGS);
-	filter_ahead_behind(the_repository, format, &array);
-	ref_array_sort(sorting, &array);
-
-	for (i = 0; i < array.nr; i++) {
-		strbuf_reset(&output);
-		strbuf_reset(&err);
-		if (format_ref_array_item(array.items[i], format, &output, &err))
-			die("%s", err.buf);
-		fwrite(output.buf, 1, output.len, stdout);
-		if (output.len || !format->array_opts.omit_empty)
-			putchar('\n');
-	}
+	filter_and_format_refs(filter, FILTER_REFS_TAGS, sorting, format);
 
-	strbuf_release(&err);
-	strbuf_release(&output);
-	ref_array_clear(&array);
 	free(to_free);
 
 	return 0;
diff --git a/ref-filter.c b/ref-filter.c
index 3de4cefcf5..f062bb4938 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -2939,6 +2939,18 @@ int filter_refs(struct ref_array *array, struct ref_filter *filter, unsigned int
 	return ret;
 }
 
+void filter_and_format_refs(struct ref_filter *filter, unsigned int type,
+			    struct ref_sorting *sorting,
+			    struct ref_format *format)
+{
+	struct ref_array array = { 0 };
+	filter_refs(&array, filter, type);
+	filter_ahead_behind(the_repository, format, &array);
+	ref_array_sort(sorting, &array);
+	print_formatted_ref_array(&array, format);
+	ref_array_clear(&array);
+}
+
 static int compare_detached_head(struct ref_array_item *a, struct ref_array_item *b)
 {
 	if (!(a->kind ^ b->kind))
@@ -3128,6 +3140,29 @@ int format_ref_array_item(struct ref_array_item *info,
 	return 0;
 }
 
+void print_formatted_ref_array(struct ref_array *array, struct ref_format *format)
+{
+	int total;
+	struct strbuf output = STRBUF_INIT, err = STRBUF_INIT;
+
+	total = format->array_opts.max_count;
+	if (!total || array->nr < total)
+		total = array->nr;
+	for (int i = 0; i < total; i++) {
+		strbuf_reset(&err);
+		strbuf_reset(&output);
+		if (format_ref_array_item(array->items[i], format, &output, &err))
+			die("%s", err.buf);
+		if (output.len || !format->array_opts.omit_empty) {
+			fwrite(output.buf, 1, output.len, stdout);
+			putchar('\n');
+		}
+	}
+
+	strbuf_release(&err);
+	strbuf_release(&output);
+}
+
 void pretty_print_ref(const char *name, const struct object_id *oid,
 		      struct ref_format *format)
 {
diff --git a/ref-filter.h b/ref-filter.h
index 0db3ff5288..0ce5af58ab 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -137,6 +137,14 @@ struct ref_format {
  * filtered refs in the ref_array structure.
  */
 int filter_refs(struct ref_array *array, struct ref_filter *filter, unsigned int type);
+/*
+ * Filter refs using the given ref_filter and type, sort the contents
+ * according to the given ref_sorting, format the filtered refs with the
+ * given ref_format, and print them to stdout.
+ */
+void filter_and_format_refs(struct ref_filter *filter, unsigned int type,
+			    struct ref_sorting *sorting,
+			    struct ref_format *format);
 /*  Clear all memory allocated to ref_array */
 void ref_array_clear(struct ref_array *array);
 /*  Used to verify if the given format is correct and to parse out the used atoms */
@@ -162,6 +170,12 @@ char *get_head_description(void);
 void setup_ref_filter_porcelain_msg(void);
 
 /*
+ * Print up to maxcount ref_array elements to stdout using the given
+ * ref_format.
+ */
+void print_formatted_ref_array(struct ref_array *array, struct ref_format *format);
+
+/*
  * Print a single ref, outside of any ref-filter. Note that the
  * name must be a fully qualified refname.
  */