ui/vnc-palette.c

   1 /*
   2  * QEMU VNC display driver: palette hash table
   3  *
   4  * From libvncserver/libvncserver/tight.c
   5  * Copyright (C) 2000, 2001 Const Kaplinsky.  All Rights Reserved.
   6  * Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
   7  *
   8  * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  26  * THE SOFTWARE.
  27  */
  28
  29 #include "vnc-palette.h"
  30
  31 static VncPaletteEntry *palette_find(const VncPalette *palette,
  32                                      uint32_t color, unsigned int hash)
  33 {
  34     VncPaletteEntry *entry;
  35
  36     QLIST_FOREACH(entry, &palette->table[hash], next) {
  37         if (entry->color == color) {
  38             return entry;
  39         }
  40     }
  41
  42     return NULL;
  43 }
  44
  45 static unsigned int palette_hash(uint32_t rgb, int bpp)
  46 {
  47     if (bpp == 16) {
  48         return ((unsigned int)(((rgb >> 8) + rgb) & 0xFF));
  49     } else {
  50         return ((unsigned int)(((rgb >> 16) + (rgb >> 8)) & 0xFF));
  51     }
  52 }
  53
  54 VncPalette *palette_new(size_t max, int bpp)
  55 {
  56     VncPalette *palette;
  57
  58     palette = qemu_mallocz(sizeof(*palette));
  59     palette->max = max;
  60     palette->bpp = bpp;
  61     return palette;
  62 }
  63
  64 void palette_destroy(VncPalette *palette)
  65 {
  66     int i;
  67
  68     if (palette == NULL) {
  69         return ;
  70     }
  71
  72     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
  73         VncPaletteEntry *entry = QLIST_FIRST(&palette->table[i]);
  74         while (entry) {
  75             VncPaletteEntry *tmp = QLIST_NEXT(entry, next);
  76             QLIST_REMOVE(entry, next);
  77             qemu_free(entry);
  78             entry = tmp;
  79         }
  80     }
  81
  82     qemu_free(palette);
  83 }
  84
  85 int palette_put(VncPalette *palette, uint32_t color)
  86 {
  87     unsigned int hash;
  88     unsigned int idx = palette->size;
  89     VncPaletteEntry *entry;
  90
  91     hash = palette_hash(color, palette->bpp) % VNC_PALETTE_HASH_SIZE;
  92     entry = palette_find(palette, color, hash);
  93
  94     if (!entry && palette->size >= palette->max) {
  95         return 0;
  96     }
  97     if (!entry) {
  98         VncPaletteEntry *entry;
  99
 100         entry = qemu_mallocz(sizeof(*entry));
 101         entry->color = color;
 102         entry->idx = idx;
 103         QLIST_INSERT_HEAD(&palette->table[hash], entry, next);
 104         palette->size++;
 105     }
 106     return palette->size;
 107 }
 108
 109 int palette_idx(const VncPalette *palette, uint32_t color)
 110 {
 111     VncPaletteEntry *entry;
 112     unsigned int hash;
 113
 114     hash = palette_hash(color, palette->bpp) % VNC_PALETTE_HASH_SIZE;
 115     entry = palette_find(palette, color, hash);
 116     return (entry == NULL ? -1 : entry->idx);
 117 }
 118
 119 size_t palette_size(const VncPalette *palette)
 120 {
 121     return palette->size;
 122 }
 123
 124 void palette_iter(const VncPalette *palette,
 125                   void (*iter)(int idx, uint32_t color, void *opaque),
 126                   void *opaque)
 127 {
 128     int i;
 129     VncPaletteEntry *entry;
 130
 131     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
 132         QLIST_FOREACH(entry, &palette->table[i], next) {
 133             iter(entry->idx, entry->color, opaque);
 134         }
 135     }
 136 }