Add compressed fonts support in the kernel.

The wsdisplay_font structure has been modified to add two new members
(zdata and zdata_len) to store compressed font data and its size. We
define compressed fonts by setting the data field to NULL and populating
the zdata and zdata_len fields.

In wsfont_lock(), we check if the selected font needs to be inflated,
and we call the newly introduced wsfont_inflate() if required.

OK kettenis@

2 files changed, 47 insertions, 2 deletions

diff --git a/sys/dev/wscons/wsconsio.h b/sys/dev/wscons/wsconsio.h
index de79bd627ff..62f0c4706c1 100644
--- a/sys/dev/wscons/wsconsio.h
+++ b/sys/dev/wscons/wsconsio.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsconsio.h,v 1.83 2017/06/15 11:48:49 fcambus Exp $ */
+/* $OpenBSD: wsconsio.h,v 1.84 2017/08/18 20:19:36 fcambus Exp $ */
 /* $NetBSD: wsconsio.h,v 1.74 2005/04/28 07:15:44 martin Exp $ */
 
 /*
@@ -514,6 +514,8 @@ struct wsdisplay_font {
 #define	WSDISPLAY_FONTORDER_R2L		2
 	void *cookie;
 	void *data;
+	void *zdata;
+	u_int zdata_len;
 };
 #define WSDISPLAYIO_LDFONT	_IOW ('W', 77, struct wsdisplay_font)
 #define	WSDISPLAYIO_LSFONT	_IOWR('W', 78, struct wsdisplay_font)
diff --git a/sys/dev/wsfont/wsfont.c b/sys/dev/wsfont/wsfont.c
index 24eec85d56b..e4d41c37274 100644
--- a/sys/dev/wsfont/wsfont.c
+++ b/sys/dev/wsfont/wsfont.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: wsfont.c,v 1.49 2017/08/17 20:21:53 kettenis Exp $ */
+/*	$OpenBSD: wsfont.c,v 1.50 2017/08/18 20:19:36 fcambus Exp $ */
 /*	$NetBSD: wsfont.c,v 1.17 2001/02/07 13:59:24 ad Exp $	*/
 
 /*-
@@ -40,6 +40,8 @@
 #include <dev/wscons/wsconsio.h>
 #include <dev/wsfont/wsfont.h>
 
+#include <lib/libz/zlib.h>
+
 #include "wsfont_glue.h"	/* NRASOPS_ROTATION */
 
 #undef HAVE_FONT
@@ -155,6 +157,7 @@ static const u_char reverse[256] = {
 #endif
 
 static struct font *wsfont_find0(int);
+static int wsfont_inflate(struct wsdisplay_font *);
 
 #ifdef INCLUDE_FONT_BIT_ENDIANNESS_SWAP_CODE
 
@@ -528,6 +531,12 @@ wsfont_lock(int cookie, struct wsdisplay_font **ptr, int bitorder,
 	s = splhigh();
 
 	if ((ent = wsfont_find0(cookie)) != NULL) {
+		/* Decompress font data if necessary */
+		if (ent->font->data == NULL &&
+		    ent->font->zdata && ent->font->zdata_len)
+			if (wsfont_inflate(ent->font))
+				return -1;
+
 		if (bitorder && bitorder != ent->font->bitorder) {
 #ifdef INCLUDE_FONT_BIT_ENDIANNESS_SWAP_CODE
 			if (ent->lockcount) {
@@ -753,3 +762,37 @@ wsfont_map_unichar(struct wsdisplay_font *font, int c)
 
 	return (-1);
 }
+
+/*
+ * Inflate a compressed font
+ */
+static int
+wsfont_inflate(struct wsdisplay_font *font) {
+	int fontdata_len = font->fontheight * font->stride * font->numchars;
+	z_stream zstream;
+
+	font->data = malloc(fontdata_len, M_DEVBUF, M_WAITOK);
+	if (font->data == NULL)
+		return ENOMEM;
+
+	memset(&zstream, 0, sizeof(zstream));
+	zstream.next_in = font->zdata;
+	zstream.avail_in = font->zdata_len;
+	zstream.next_out = font->data;
+	zstream.avail_out = fontdata_len;
+	zstream.opaque = Z_NULL;
+
+	if (inflateInit(&zstream) != Z_OK)
+		return -1;
+
+	if (inflate(&zstream, Z_FINISH) != Z_STREAM_END)
+		return -1;
+
+	if (inflateEnd(&zstream) != Z_OK)
+		return -1;
+
+	if (zstream.total_out != fontdata_len)
+		return -1;
+
+	return 0;
+}