vnc: tight: stop using qdict for palette stuff

Profiling with callgrind seems to show that a lot of time is spent
in the palette code (mostly due to memory allocation and qdict to int
conversion).

This patch adds a VncPalette implementation. The palette is stored
in a hash table, like qdict, but which does way less memory allocations,
and doesn't suffer from the QObject overhead.

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/ui/vnc-palette.h b/ui/vnc-palette.h
new file mode 100644
index 0000000000..d0645ebde8
--- /dev/null
+++ b/ui/vnc-palette.h
@@ -0,0 +1,63 @@
+/*
+ * QEMU VNC display driver: palette hash table
+ *
+ * From libvncserver/libvncserver/tight.c
+ * Copyright (C) 2000, 2001 Const Kaplinsky.  All Rights Reserved.
+ * Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
+ *
+ * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef VNC_PALETTE_H
+#define VNC_PALETTE_H
+
+#include "qlist.h"
+#include "qemu-queue.h"
+#include <stdint.h>
+
+#define VNC_PALETTE_HASH_SIZE 256
+
+typedef struct VncPaletteEntry {
+    int idx;
+    uint32_t color;
+    QLIST_ENTRY(VncPaletteEntry) next;
+} VncPaletteEntry;
+
+typedef struct VncPalette {
+    QObject_HEAD;
+    size_t size;
+    size_t max;
+    int bpp;
+    QLIST_HEAD(,VncPaletteEntry) table[VNC_PALETTE_HASH_SIZE];
+} VncPalette;
+
+VncPalette *palette_new(size_t max, int bpp);
+void palette_destroy(VncPalette *palette);
+
+int palette_put(VncPalette *palette, uint32_t color);
+int palette_idx(const VncPalette *palette, uint32_t color);
+size_t palette_size(const VncPalette *palette);
+
+void palette_iter(const VncPalette *palette,
+                  void (*iter)(int idx, uint32_t color, void *opaque),
+                  void *opaque);
+
+#endif /* VNC_PALETTE_H */