Cache solid patterns

We use a small cache of size 16 for patterns created from solid colors,
e.g. cairo_set_source_rgb(). This helps with toolkits that draw many
widgets using the same colour scheme.

The cache uses a static index variable, which itself acts like a cache
of size 1, remembering the most recently used colour. So repeated
lookups for the same colour hit immediately. If that fails, the cache
is searched linearly, and if that fails too, a new pattern is created
and a random member of the cache is evicted.

1 files changed, 83 insertions, 0 deletions

diff --git a/test/solid-pattern-cache-stress.c b/test/solid-pattern-cache-stress.c
new file mode 100644
index 000000000..93e2f697f
--- /dev/null
+++ b/test/solid-pattern-cache-stress.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright ? 2007 Chris Wilson.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Chris Wilson. not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Chris Wilson makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * CHRIS WILSON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL CHRIS WILSON BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Author: Chris Wilson <chris at chris-wilson.co.uk>
+ */
+
+#include "cairo-test.h"
+
+static cairo_test_draw_function_t draw;
+
+cairo_test_t test = {
+    "solid-pattern-cache-stress",
+    "Stress the solid pattern cache and ensure it behaves",
+    0, 0,
+    draw
+};
+#include <cairo.h>
+#include <stdlib.h>
+
+#define LOOPS 10
+#define NRAND 100
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    int loop;
+    int i;
+
+    for (loop = 0; loop < LOOPS; loop++) {
+	cairo_set_source_rgb (cr, 0.0, 0.0, 0.0); /* black */
+	cairo_set_source_rgb (cr, 1.0, 0.0, 0.0); /* red */
+	cairo_set_source_rgb (cr, 0.0, 1.0, 0.0); /* green */
+	cairo_set_source_rgb (cr, 1.0, 1.0, 0.0); /* yellow */
+	cairo_set_source_rgb (cr, 0.0, 0.0, 1.0); /* blue */
+	cairo_set_source_rgb (cr, 1.0, 0.0, 1.0); /* magenta */
+	cairo_set_source_rgb (cr, 0.0, 1.0, 1.0); /* cyan */
+	cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
+
+	cairo_set_source_rgba (cr, 0.0, 0.0, 0.0, 1.0); /* black */
+	cairo_set_source_rgba (cr, 1.0, 0.0, 0.0, 1.0); /* red */
+	cairo_set_source_rgba (cr, 0.0, 1.0, 0.0, 1.0); /* green */
+	cairo_set_source_rgba (cr, 1.0, 1.0, 0.0, 1.0); /* yellow */
+	cairo_set_source_rgba (cr, 0.0, 0.0, 1.0, 1.0); /* blue */
+	cairo_set_source_rgba (cr, 1.0, 0.0, 1.0, 1.0); /* magenta */
+	cairo_set_source_rgba (cr, 0.0, 1.0, 1.0, 1.0); /* cyan */
+	cairo_set_source_rgba (cr, 1.0, 1.0, 1.0, 1.0); /* white */
+
+	for (i = 0; i < NRAND; i++)
+	    cairo_set_source_rgba (cr,
+		                   drand48 (),
+				   drand48 (),
+				   drand48 (),
+				   drand48 ());
+    }
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+int
+main (void)
+{
+    return cairo_test (&test);
+}
+