[PATCH v11 03/13] ref-filter: introduce ref_formatting_state

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

Introduce ref_formatting_state which will hold the formatted
output strbuf and is used for nesting of modifier atoms.

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 | 65 ++++++++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 48 insertions(+), 17 deletions(-)

diff --git a/ref-filter.c b/ref-filter.c
index edfb1c7..3259363 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -55,6 +55,12 @@ static struct {
 	{ "color" },
 };
 
+struct ref_formatting_state {
+	struct strbuf output;
+	struct ref_formatting_state *prev;
+	int quote_style;
+};
+
 struct atom_value {
 	const char *s;
 	unsigned long ul; /* used for sorting when not FIELD_STR */
@@ -129,6 +135,26 @@ int parse_ref_filter_atom(const char *atom, const char *ep)
 	return at;
 }
 
+static struct ref_formatting_state *push_new_state(struct ref_formatting_state **state)
+{
+	struct ref_formatting_state *new_state = xcalloc(1, sizeof(struct ref_formatting_state));
+	struct ref_formatting_state *tmp = *state;
+
+	*state = new_state;
+	new_state->prev = tmp;
+	return new_state;
+}
+
+static void pop_state(struct ref_formatting_state **state)
+{
+	struct ref_formatting_state *current = *state;
+	struct ref_formatting_state *prev = current->prev;
+
+	strbuf_release(&current->output);
+	free(current);
+	*state = prev;
+}
+
 /*
  * In a format string, find the next occurrence of %(atom).
  */
@@ -1195,23 +1221,23 @@ void ref_array_sort(struct ref_sorting *sorting, struct ref_array *array)
 	qsort(array->items, array->nr, sizeof(struct ref_array_item *), compare_refs);
 }
 
-static void append_atom(struct atom_value *v, int quote_style, struct strbuf *output)
+static void append_atom(struct atom_value *v, struct ref_formatting_state *state)
 {
-	switch (quote_style) {
+	switch (state->quote_style) {
 	case QUOTE_NONE:
-		strbuf_addstr(output, v->s);
+		strbuf_addstr(&state->output, v->s);
 		break;
 	case QUOTE_SHELL:
-		sq_quote_buf(output, v->s);
+		sq_quote_buf(&state->output, v->s);
 		break;
 	case QUOTE_PERL:
-		perl_quote_buf(output, v->s);
+		perl_quote_buf(&state->output, v->s);
 		break;
 	case QUOTE_PYTHON:
-		python_quote_buf(output, v->s);
+		python_quote_buf(&state->output, v->s);
 		break;
 	case QUOTE_TCL:
-		tcl_quote_buf(output, v->s);
+		tcl_quote_buf(&state->output, v->s);
 		break;
 	}
 }
@@ -1234,7 +1260,7 @@ static int hex2(const char *cp)
 		return -1;
 }
 
-static void append_literal(const char *cp, const char *ep, struct strbuf *output)
+static void append_literal(const char *cp, const char *ep, struct ref_formatting_state *state)
 {
 	while (*cp && (!ep || cp < ep)) {
 		if (*cp == '%') {
@@ -1243,13 +1269,13 @@ static void append_literal(const char *cp, const char *ep, struct strbuf *output
 			else {
 				int ch = hex2(cp + 1);
 				if (0 <= ch) {
-					strbuf_addch(output, ch);
+					strbuf_addch(&state->output, ch);
 					cp += 3;
 					continue;
 				}
 			}
 		}
-		strbuf_addch(output, *cp);
+		strbuf_addch(&state->output, *cp);
 		cp++;
 	}
 }
@@ -1257,20 +1283,24 @@ static void append_literal(const char *cp, const char *ep, struct strbuf *output
 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
 {
 	const char *cp, *sp, *ep;
-	struct strbuf output = STRBUF_INIT;
+	struct strbuf *final_buf;
+	struct ref_formatting_state *state = NULL;
+
+	state = push_new_state(&state);
+	state->quote_style = quote_style;
 
 	for (cp = format; *cp && (sp = find_next(cp)); cp = ep + 1) {
 		struct atom_value *atomv;
 
 		ep = strchr(sp, ')');
 		if (cp < sp)
-			append_literal(cp, sp, &output);
+			append_literal(cp, sp, state);
 		get_ref_atom_value(info, parse_ref_filter_atom(sp + 2, ep), &atomv);
-		append_atom(atomv, quote_style, &output);
+		append_atom(atomv, state);
 	}
 	if (*cp) {
 		sp = cp + strlen(cp);
-		append_literal(cp, sp, &output);
+		append_literal(cp, sp, state);
 	}
 	if (need_color_reset_at_eol) {
 		struct atom_value resetv;
@@ -1279,11 +1309,12 @@ void show_ref_array_item(struct ref_array_item *info, const char *format, int qu
 		if (color_parse("reset", color) < 0)
 			die("BUG: couldn't parse 'reset' as a color");
 		resetv.s = color;
-		append_atom(&resetv, quote_style, &output);
+		append_atom(&resetv, state);
 	}
-	fwrite(output.buf, 1, output.len, stdout);
+	final_buf = &state->output;
+	fwrite(final_buf->buf, 1, final_buf->len, stdout);
+	pop_state(&state);
 	putchar('\n');
-	strbuf_release(&output);
 }
 
 /*  If no sorting option is given, use refname to sort as default */
-- 
2.5.0