[PATCH v7 01/11] ref-filter: introduce 'ref_formatting_state'

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

Introduce 'ref_formatting_state' structure to hold values of modifier
atoms which help only in formatting. This will eventually be used by
atoms like `padright` which will be introduced in a later patch.

Helped-by: Junio C Hamano <gitster@pobox.com>
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 | 70 ++++++++++++++++++++++++++++++++++++++++++++----------------
 ref-filter.h |  5 +++++
 2 files changed, 57 insertions(+), 18 deletions(-)

diff --git a/ref-filter.c b/ref-filter.c
index 7561727..d6510a6 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -10,6 +10,8 @@
 #include "quote.h"
 #include "ref-filter.h"
 #include "revision.h"
+#include "utf8.h"
+#include "git-compat-util.h"
 
 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
 
@@ -1190,30 +1192,41 @@ 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 print_value(struct atom_value *v, int quote_style)
+static void apply_formatting_state(struct ref_formatting_state *state,
+				   const char *buf, struct strbuf *value)
 {
-	struct strbuf sb = STRBUF_INIT;
-	switch (quote_style) {
+	/* Eventually we'll format based on the ref_formatting_state */
+	strbuf_addstr(value, buf);
+}
+
+static void print_value(struct atom_value *v, struct ref_formatting_state *state)
+{
+	struct strbuf value = STRBUF_INIT;
+	struct strbuf formatted = STRBUF_INIT;
+
+	apply_formatting_state(state, v->s, &value);
+
+	switch (state->quote_style) {
 	case QUOTE_NONE:
-		fputs(v->s, stdout);
+		fputs(value.buf, stdout);
 		break;
 	case QUOTE_SHELL:
-		sq_quote_buf(&sb, v->s);
+		sq_quote_buf(&formatted, value.buf);
 		break;
 	case QUOTE_PERL:
-		perl_quote_buf(&sb, v->s);
+		perl_quote_buf(&formatted, value.buf);
 		break;
 	case QUOTE_PYTHON:
-		python_quote_buf(&sb, v->s);
+		python_quote_buf(&formatted, value.buf);
 		break;
 	case QUOTE_TCL:
-		tcl_quote_buf(&sb, v->s);
+		tcl_quote_buf(&formatted, value.buf);
 		break;
 	}
-	if (quote_style != QUOTE_NONE) {
-		fputs(sb.buf, stdout);
-		strbuf_release(&sb);
-	}
+	if (state->quote_style != QUOTE_NONE)
+		fputs(formatted.buf, stdout);
+	strbuf_release(&value);
+	strbuf_release(&formatted);
 }
 
 static int hex1(char ch)
@@ -1234,8 +1247,12 @@ static int hex2(const char *cp)
 		return -1;
 }
 
-static void emit(const char *cp, const char *ep)
+static void emit(const char *cp, const char *ep,
+		 struct ref_formatting_state *state)
 {
+	struct strbuf value = STRBUF_INIT;
+	struct strbuf format = STRBUF_INIT;
+
 	while (*cp && (!ep || cp < ep)) {
 		if (*cp == '%') {
 			if (cp[1] == '%')
@@ -1249,27 +1266,44 @@ static void emit(const char *cp, const char *ep)
 				}
 			}
 		}
-		putchar(*cp);
+		strbuf_addch(&value, *cp);
 		cp++;
 	}
+	apply_formatting_state(state, value.buf, &format);
+	fputs(format.buf, stdout);
+	strbuf_release(&format);
+	strbuf_release(&value);
+}
+
+static void store_formatting_state(struct ref_formatting_state *state,
+				   struct atom_value *atomv)
+{
+	/*  Here the 'ref_formatting_state' variable will be filled */
 }
 
 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
 {
 	const char *cp, *sp, *ep;
+	struct ref_formatting_state state;
+
+	memset(&state, 0, sizeof(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)
-			emit(cp, sp);
+			emit(cp, sp, &state);
 		get_ref_atom_value(info, parse_ref_filter_atom(sp + 2, ep), &atomv);
-		print_value(atomv, quote_style);
+		if (atomv->modifier_atom)
+			store_formatting_state(&state, atomv);
+		else
+			print_value(atomv, &state);
 	}
 	if (*cp) {
 		sp = cp + strlen(cp);
-		emit(cp, sp);
+		emit(cp, sp, &state);
 	}
 	if (need_color_reset_at_eol) {
 		struct atom_value resetv;
@@ -1278,7 +1312,7 @@ 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;
-		print_value(&resetv, quote_style);
+		print_value(&resetv, &state);
 	}
 	putchar('\n');
 }
diff --git a/ref-filter.h b/ref-filter.h
index 6bf27d8..12e6a6b 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -19,6 +19,11 @@
 struct atom_value {
 	const char *s;
 	unsigned long ul; /* used for sorting when not FIELD_STR */
+	unsigned int modifier_atom : 1; /*  atoms which act as modifiers for the next atom */
+};
+
+struct ref_formatting_state {
+	int quote_style;
 };
 
 struct ref_sorting {
-- 
2.4.6