static void qemu_spice_create_update(SimpleSpiceDisplay *ssd) { static const int blksize = 32; int blocks = (surface_width(ssd->ds) + blksize - 1) / blksize; int dirty_top[blocks]; int y, yoff, x, xoff, blk, bw; int bpp = surface_bytes_per_pixel(ssd->ds); uint8_t *guest, *mirror; if (qemu_spice_rect_is_empty(&ssd->dirty)) { return; }; for (blk = 0; blk < blocks; blk++) { dirty_top[blk] = -1; } guest = surface_data(ssd->ds); mirror = (void *)pixman_image_get_data(ssd->mirror); for (y = ssd->dirty.top; y < ssd->dirty.bottom; y++) { yoff = y * surface_stride(ssd->ds); for (x = ssd->dirty.left; x < ssd->dirty.right; x += blksize) { xoff = x * bpp; blk = x / blksize; bw = MIN(blksize, ssd->dirty.right - x); if (memcmp(guest + yoff + xoff, mirror + yoff + xoff, bw * bpp) == 0) { if (dirty_top[blk] != -1) { QXLRect update = { .top = dirty_top[blk], .bottom = y, .left = x, .right = x + bw, }; qemu_spice_create_one_update(ssd, &update); dirty_top[blk] = -1; } } else { if (dirty_top[blk] == -1) { dirty_top[blk] = y; } } } } for (x = ssd->dirty.left; x < ssd->dirty.right; x += blksize) { blk = x / blksize; bw = MIN(blksize, ssd->dirty.right - x); if (dirty_top[blk] != -1) { QXLRect update = { .top = dirty_top[blk], .bottom = ssd->dirty.bottom, .left = x, .right = x + bw, }; qemu_spice_create_one_update(ssd, &update); dirty_top[blk] = -1; } } memset(&ssd->dirty, 0, sizeof(ssd->dirty)); }