[PATCH v5 05/16] ref-filter: introduce format_ref_array_item()

[Karthik Nayak <karthik.188@gmail.com>]

To allow column display, we will need to first render the output in a
string list to allow print_columns() to compute the proper size of
each column before starting the actual output. Introduce the function
format_ref_array_item() that does the formatting of a ref_array_item
to an strbuf.

show_ref_array_item() is kept as a convenience wrapper around it which
obtains the strbuf and prints it the standard output.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
---
 ref-filter.c | 16 ++++++++++++----
 ref-filter.h |  3 +++
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/ref-filter.c b/ref-filter.c
index fcb3353..da2b9ee 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -1813,10 +1813,10 @@ static void append_literal(const char *cp, const char *ep, struct ref_formatting
 	}
 }
 
-void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
+void format_ref_array_item(struct ref_array_item *info, const char *format,
+			   int quote_style, struct strbuf *final_buf)
 {
 	const char *cp, *sp, *ep;
-	struct strbuf *final_buf;
 	struct ref_formatting_state state = REF_FORMATTING_STATE_INIT;
 
 	state.quote_style = quote_style;
@@ -1846,9 +1846,17 @@ void show_ref_array_item(struct ref_array_item *info, const char *format, int qu
 	}
 	if (state.stack->prev)
 		die(_("format: %%(end) atom missing"));
-	final_buf = &state.stack->output;
-	fwrite(final_buf->buf, 1, final_buf->len, stdout);
+	strbuf_addbuf(final_buf, &state.stack->output);
 	pop_stack_element(&state.stack);
+}
+
+void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
+{
+	struct strbuf final_buf = STRBUF_INIT;
+
+	format_ref_array_item(info, format, quote_style, &final_buf);
+	fwrite(final_buf.buf, 1, final_buf.len, stdout);
+	strbuf_release(&final_buf);
 	putchar('\n');
 }
 
diff --git a/ref-filter.h b/ref-filter.h
index 4aea594..0014b92 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -98,6 +98,9 @@ int parse_ref_filter_atom(const char *atom, const char *ep);
 int verify_ref_format(const char *format);
 /*  Sort the given ref_array as per the ref_sorting provided */
 void ref_array_sort(struct ref_sorting *sort, struct ref_array *array);
+/*  Based on the given format and quote_style, fill the strbuf */
+void format_ref_array_item(struct ref_array_item *info, const char *format,
+			   int quote_style, struct strbuf *final_buf);
 /*  Print the ref using the given format and quote_style */
 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style);
 /*  Callback function for parsing the sort option */
-- 
2.8.0