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[PATCH v16 02/14] ref-filter: introduce ref_formatting_state and ref_formatting_stack

From
Karthik Nayak <karthik.188@gmail.com>
Date
Sep 5, 2015, 18:52 UTC
Message-ID
<1441479135-5285-3-git-send-email-Karthik.188@gmail.com>
In-Reply-To
<1441479135-5285-1-git-send-email-Karthik.188@gmail.com>

Introduce ref_formatting_state which will hold the formatted output strbuf instead of directly printing to stdout. This will help us in creating modifier atoms which modify the format specified before printing to stdout.

Implement a stack machinery for ref_formatting_state, this allows us to push and pop elements onto the stack. Whenever we pop an element from the stack, the strbuf from that element is appended to the strbuf of the next element on the stack, this will allow us to support nesting of modifier atoms.

Rename some functions to reflect the changes made: print_value() -> append_atom() emit() -> append_literal()

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 | 78 +++++++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 59 insertions(+), 19 deletions(-)
diff --git a/ref-filter.c b/ref-filter.c
index e53c77e..432cea0 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -55,6 +55,18 @@ static struct {
 	{ "color" },
 };
 
+#define REF_FORMATTING_STATE_INIT  { 0, NULL }
+
+struct ref_formatting_stack {
+	struct ref_formatting_stack *prev;
+	struct strbuf output;
+};
+
+struct ref_formatting_state {
+	int quote_style;
+	struct ref_formatting_stack *stack;
+};
+
 struct atom_value {
 	const char *s;
 	unsigned long ul; /* used for sorting when not FIELD_STR */
@@ -129,6 +141,27 @@ int parse_ref_filter_atom(const char *atom, const char *ep)
 	return at;
 }
 
+static void push_stack_element(struct ref_formatting_stack **stack)
+{
+	struct ref_formatting_stack *s = xcalloc(1, sizeof(struct ref_formatting_stack));
+
+	strbuf_init(&s->output, 0);
+	s->prev = *stack;
+	*stack = s;
+}
+
+static void pop_stack_element(struct ref_formatting_stack **stack)
+{
+	struct ref_formatting_stack *current = *stack;
+	struct ref_formatting_stack *prev = current->prev;
+
+	if (prev)
+		strbuf_addbuf(&prev->output, &current->output);
+	strbuf_release(&current->output);
+	free(current);
+	*stack = prev;
+}
+
 /*
  * In a format string, find the next occurrence of %(atom).
  */
@@ -1195,30 +1228,27 @@ 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 append_atom(struct atom_value *v, struct ref_formatting_state *state)
 {
-	struct strbuf sb = STRBUF_INIT;
-	switch (quote_style) {
+	struct strbuf *s = &state->stack->output;
+
+	switch (state->quote_style) {
 	case QUOTE_NONE:
-		fputs(v->s, stdout);
+		strbuf_addstr(s, v->s);
 		break;
 	case QUOTE_SHELL:
-		sq_quote_buf(&sb, v->s);
+		sq_quote_buf(s, v->s);
 		break;
 	case QUOTE_PERL:
-		perl_quote_buf(&sb, v->s);
+		perl_quote_buf(s, v->s);
 		break;
 	case QUOTE_PYTHON:
-		python_quote_buf(&sb, v->s);
+		python_quote_buf(s, v->s);
 		break;
 	case QUOTE_TCL:
-		tcl_quote_buf(&sb, v->s);
+		tcl_quote_buf(s, v->s);
 		break;
 	}
-	if (quote_style != QUOTE_NONE) {
-		fputs(sb.buf, stdout);
-		strbuf_release(&sb);
-	}
 }
 
 static int hex1(char ch)
@@ -1239,8 +1269,10 @@ static int hex2(const char *cp)
 		return -1;
 }
 
-static void emit(const char *cp, const char *ep)
+static void append_literal(const char *cp, const char *ep, struct ref_formatting_state *state)
 {
+	struct strbuf *s = &state->stack->output;
+
 	while (*cp && (!ep || cp < ep)) {
 		if (*cp == '%') {
 			if (cp[1] == '%')
@@ -1248,13 +1280,13 @@ static void emit(const char *cp, const char *ep)
 			else {
 				int ch = hex2(cp + 1);
 				if (0 <= ch) {
-					putchar(ch);
+					strbuf_addch(s, ch);
 					cp += 3;
 					continue;
 				}
 			}
 		}
-		putchar(*cp);
+		strbuf_addch(s, *cp);
 		cp++;
 	}
 }
@@ -1262,19 +1294,24 @@ static void emit(const char *cp, const char *ep)
 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
 {
 	const char *cp, *sp, *ep;
+	struct strbuf *final_buf;
+	struct ref_formatting_state state = REF_FORMATTING_STATE_INIT;
+
+	state.quote_style = quote_style;
+	push_stack_element(&state.stack);
 
 	for (cp = format; *cp && (sp = find_next(cp)); cp = ep + 1) {
 		struct atom_value *atomv;
 
 		ep = strchr(sp, ')');
 		if (cp < sp)
-			emit(cp, sp);
+			append_literal(cp, sp, &state);
 		get_ref_atom_value(info, parse_ref_filter_atom(sp + 2, ep), &atomv);
-		print_value(atomv, quote_style);
+		append_atom(atomv, &state);
 	}
 	if (*cp) {
 		sp = cp + strlen(cp);
-		emit(cp, sp);
+		append_literal(cp, sp, &state);
 	}
 	if (need_color_reset_at_eol) {
 		struct atom_value resetv;
@@ -1283,8 +1320,11 @@ 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);
+		append_atom(&resetv, &state);
 	}
+	final_buf = &state.stack->output;
+	fwrite(final_buf->buf, 1, final_buf->len, stdout);
+	pop_stack_element(&state.stack);
 	putchar('\n');
 }
 

-- 
2.5.1
Previous: Karthik NayakNext: Karthik Nayak
Message 3 of 30 in “port tag.c to use ref-filter APIs”
  1. 00/14 port tag.c to use ref-filter APIsKarthik Nayak, Sep 5, 2015
  2. 01/14 ref-filter: move `struct atom_value` to ref-filter.cKarthik Nayak, Sep 5, 2015
  3. 02/14 ref-filter: introduce ref_formatting_state and ref_formatting_stackKarthik Nayak, Sep 5, 2015
  4. 03/14 utf8: add function to align a string into given strbufKarthik Nayak, Sep 5, 2015
  5. 04/14 ref-filter: introduce handler function for each atomKarthik Nayak, Sep 5, 2015
  6. 05/14 ref-filter: introduce match_atom_name()Karthik Nayak, Sep 5, 2015
  7. Eric SunshineSep 6, 2015
  8. Karthik NayakSep 7, 2015
  9. 06/14 ref-filter: implement an `align` atomKarthik Nayak, Sep 5, 2015
  10. Eric SunshineSep 6, 2015
  11. Karthik NayakSep 7, 2015
  12. 07/14 ref-filter: add option to filter out tags, branches and remotesKarthik Nayak, Sep 5, 2015
  13. 08/14 ref-filter: add support for %(contents:lines=X)Karthik Nayak, Sep 5, 2015
  14. 09/14 ref-filter: add support to sort by versionKarthik Nayak, Sep 5, 2015
  15. 10/14 ref-filter: add option to match literal patternKarthik Nayak, Sep 5, 2015
  16. 11/14 tag.c: use 'ref-filter' data structuresKarthik Nayak, Sep 5, 2015
  17. 12/14 tag.c: use 'ref-filter' APIsKarthik Nayak, Sep 5, 2015
  18. 13/14 tag.c: implement '--format' optionKarthik Nayak, Sep 5, 2015
  19. 14/14 tag.c: implement '--merged' and '--no-merged' optionsKarthik Nayak, Sep 5, 2015
  20. Matthieu MoySep 6, 2015
  21. Karthik NayakSep 6, 2015
  22. Junio C HamanoSep 7, 2015
  23. Matthieu MoySep 7, 2015
  24. Karthik NayakSep 7, 2015
  25. Matthieu MoySep 7, 2015
  26. Karthik NayakSep 8, 2015
  27. Junio C HamanoSep 8, 2015
  28. Karthik NayakSep 9, 2015
  29. Junio C HamanoSep 9, 2015
  30. Junio C HamanoSep 8, 2015

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