degesch: slightly cut down memory usage

The worst offenders are actually OpenSSL and Lua, this is
mostly about a preventable surprise.

This is more correct because we mix escape sequences for
attributes with text, however in practice no one will use
shit-jizz with degesch.

It is also a clean-up: "struct line_char" has been almost
halved in size.  We used to use it as a cache and now we
recompute the multibyte sequence.

Of course, it'd be best to get rid of the linked list but
it would take a very long time to rewrite the algorithm.
Plus, it's not certain that it could be improved by much.

The change in "struct line_char_attrs" is merely cosmetical.

1 files changed, 25 insertions, 16 deletions

diff --git a/degesch.c b/degesch.c
index 4e58684..7063343 100644
--- a/degesch.c
+++ b/degesch.c
@@ -3413,8 +3413,8 @@ formatter_add (struct formatter *self, const char *format, ...)
 
 struct line_char_attrs
 {
-	int named;                          ///< Named attribute or -1
-	int text;                           ///< Text attributes
+	short named;                        ///< Named attribute or -1
+	short text;                         ///< Text attributes
 	int fg;                             ///< Foreground colour (-1 for default)
 	int bg;                             ///< Background colour (-1 for default)
 };
@@ -3423,18 +3423,15 @@ struct line_char
 {
 	LIST_HEADER (struct line_char)
 
-	char bytes[MB_LEN_MAX];             ///< The character
-	size_t len;                         ///< Length of the character in bytes
 	wchar_t wide;                       ///< The character as a wchar_t
 	int width;                          ///< Width of the character in cells
 	struct line_char_attrs attrs;       ///< Attributes
 };
 
 static struct line_char *
-line_char_new (const char *mb, size_t mb_len, wchar_t wc)
+line_char_new (wchar_t wc)
 {
 	struct line_char *self = xcalloc (1, sizeof *self);
-	memcpy (self->bytes, mb, (self->len = MIN (mb_len, sizeof self->bytes)));
 	self->width = wcwidth ((self->wide = wc));
 
 	// Typically various control characters
@@ -3476,7 +3473,7 @@ struct line_wrap_state
 static void
 line_wrap_flush_split (struct line_wrap_state *s, struct line_wrap_mark *before)
 {
-	struct line_char *nl = line_char_new ("\n", 1, L'\n');
+	struct line_char *nl = line_char_new (L'\n');
 	LIST_INSERT_WITH_TAIL (s->result, s->result_tail, nl, before->start);
 	s->line_used = before->used;
 }
@@ -3512,7 +3509,7 @@ static void
 line_wrap_nl (struct line_wrap_state *s)
 {
 	line_wrap_flush (s, true);
-	struct line_char *nl = line_char_new ("\n", 1, L'\n');
+	struct line_char *nl = line_char_new (L'\n');
 	LIST_APPEND_WITH_TAIL (s->result, s->result_tail, nl);
 	s->line_used = 0;
 }
@@ -3533,7 +3530,7 @@ line_wrap_tab (struct line_wrap_state *s, struct line_char *c)
 	s->line_used += tab_width;
 	while (tab_width--)
 	{
-		struct line_char *space = line_char_new (" ", 1, L' ');
+		struct line_char *space = line_char_new (L' ');
 		space->attrs = c->attrs;
 		LIST_APPEND_WITH_TAIL (s->result, s->result_tail, space);
 	}
@@ -3664,7 +3661,7 @@ explode_text (struct exploder *self, const char *text)
 		hard_assert (len != (size_t) -2 && len != (size_t) -1);
 		processed += len;
 
-		struct line_char *c = line_char_new (term + processed - len, len, wch);
+		struct line_char *c = line_char_new (wch);
 		c->attrs = self->attrs;
 		LIST_APPEND_WITH_TAIL (self->result, self->result_tail, c);
 	}
@@ -3698,6 +3695,18 @@ enum
 	FLUSH_OPT_NOWRAP = (1 << 1)         ///< Do not wrap
 };
 
+/// The input is a bunch of wide characters--respect shift state encodings
+static void
+formatter_putc (struct line_char *c, FILE *stream)
+{
+	static mbstate_t mb;
+	char buf[MB_LEN_MAX] = {};
+	size_t len = wcrtomb (buf, c ? c->wide : L'\0', &mb);
+	if (len != (size_t) -1 && len)
+		fwrite (buf, len - !c, 1, stream);
+	free (c);
+}
+
 static void
 formatter_flush (struct formatter *self, FILE *stream, int flush_opts)
 {
@@ -3707,10 +3716,8 @@ formatter_flush (struct formatter *self, FILE *stream, int flush_opts)
 	if (!is_tty && !(flush_opts & FLUSH_OPT_RAW))
 	{
 		LIST_FOR_EACH (struct line_char, c, line)
-		{
-			fwrite (c->bytes, c->len, 1, stream);
-			free (c);
-		}
+			formatter_putc (c, stream);
+		formatter_putc (NULL, stream);
 		return;
 	}
 
@@ -3726,6 +3733,8 @@ formatter_flush (struct formatter *self, FILE *stream, int flush_opts)
 		 || attrs.named != c->attrs.named
 		 || attrs.text  != c->attrs.text)
 		{
+			formatter_putc (NULL, stream);
+
 			attrs = c->attrs;
 			if (attrs.named != -1)
 				attr_printer_apply_named (&state, attrs.named);
@@ -3733,9 +3742,9 @@ formatter_flush (struct formatter *self, FILE *stream, int flush_opts)
 				attr_printer_apply (&state, attrs.text, attrs.fg, attrs.bg);
 		}
 
-		fwrite (c->bytes, c->len, 1, stream);
-		free (c);
+		formatter_putc (c, stream);
 	}
+	formatter_putc (NULL, stream);
 	attr_printer_reset (&state);
 }