pstcache.c

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/* -*- c-basic-offset: 8 -*-
   rdesktop: A Remote Desktop Protocol client.
   Persistent Bitmap Cache routines
   Copyright (C) Jeroen Meijer 2004-2005
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License along
   with this program; if not, write to the Free Software Foundation, Inc.,
   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
 
#include "rdesktop.h"
 
#define MAX_CELL_SIZE       0x1000  /* pixels */
 
#define IS_PERSISTENT(id) (id < 8 && This->pstcache_fd[id] > 0)
 
const uint8 zero_key[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
 
 
/* Update mru stamp/index for a bitmap */
void
pstcache_touch_bitmap(RDPCLIENT * This, uint8 cache_id, uint16 cache_idx, uint32 stamp)
{
    int fd;
 
    if (!IS_PERSISTENT(cache_id) || cache_idx >= BMPCACHE2_NUM_PSTCELLS)
        return;
 
    fd = This->pstcache_fd[cache_id];
    rd_lseek_file(fd, 12 + cache_idx * (This->pstcache_Bpp * MAX_CELL_SIZE + sizeof(CELLHEADER)));
    rd_write_file(fd, &stamp, sizeof(stamp));
}
 
/* Load a bitmap from the persistent cache */
BOOL
pstcache_load_bitmap(RDPCLIENT * This, uint8 cache_id, uint16 cache_idx)
{
    uint8 *celldata;
    int fd;
    CELLHEADER cellhdr;
    HBITMAP bitmap;
 
    if (!This->bitmap_cache_persist_enable)
        return False;
 
    if (!IS_PERSISTENT(cache_id) || cache_idx >= BMPCACHE2_NUM_PSTCELLS)
        return False;
 
    fd = This->pstcache_fd[cache_id];
    rd_lseek_file(fd, cache_idx * (This->pstcache_Bpp * MAX_CELL_SIZE + sizeof(CELLHEADER)));
    rd_read_file(fd, &cellhdr, sizeof(CELLHEADER));
    celldata = (uint8 *) malloc(cellhdr.length);
 
    if(celldata == NULL)
        return False;
 
    rd_read_file(fd, celldata, cellhdr.length);
 
    bitmap = ui_create_bitmap(This, cellhdr.width, cellhdr.height, celldata);
    DEBUG(("Load bitmap from disk: id=%d, idx=%d, bmp=0x%x)\n", cache_id, cache_idx, bitmap));
    cache_put_bitmap(This, cache_id, cache_idx, bitmap);
 
    free(celldata);
    return True;
}
 
/* Store a bitmap in the persistent cache */
BOOL
pstcache_save_bitmap(RDPCLIENT * This, uint8 cache_id, uint16 cache_idx, uint8 * key,
             uint8 width, uint8 height, uint16 length, uint8 * data)
{
    int fd;
    CELLHEADER cellhdr;
 
    if (!IS_PERSISTENT(cache_id) || cache_idx >= BMPCACHE2_NUM_PSTCELLS)
        return False;
 
    memcpy(cellhdr.key, key, sizeof(HASH_KEY));
    cellhdr.width = width;
    cellhdr.height = height;
    cellhdr.length = length;
    cellhdr.stamp = 0;
 
    fd = This->pstcache_fd[cache_id];
    rd_lseek_file(fd, cache_idx * (This->pstcache_Bpp * MAX_CELL_SIZE + sizeof(CELLHEADER)));
    rd_write_file(fd, &cellhdr, sizeof(CELLHEADER));
    rd_write_file(fd, data, length);
 
    return True;
}
 
/* List the bitmap keys from the persistent cache file */
int
pstcache_enumerate(RDPCLIENT * This, uint8 id, HASH_KEY * keylist)
{
    int fd, n;
    uint16 idx;
    sint16 mru_idx[0xa00];
    uint32 mru_stamp[0xa00];
    CELLHEADER cellhdr;
 
    if (!(This->bitmap_cache && This->bitmap_cache_persist_enable && IS_PERSISTENT(id)))
        return 0;
 
    /* The server disconnects if the bitmap cache content is sent more than once */
    if (This->pstcache_enumerated)
        return 0;
 
    DEBUG_RDP5(("Persistent bitmap cache enumeration... "));
    for (idx = 0; idx < BMPCACHE2_NUM_PSTCELLS; idx++)
    {
        fd = This->pstcache_fd[id];
        rd_lseek_file(fd, idx * (This->pstcache_Bpp * MAX_CELL_SIZE + sizeof(CELLHEADER)));
        if (rd_read_file(fd, &cellhdr, sizeof(CELLHEADER)) <= 0)
            break;
 
        if (memcmp(cellhdr.key, zero_key, sizeof(HASH_KEY)) != 0)
        {
            memcpy(keylist[idx], cellhdr.key, sizeof(HASH_KEY));
 
            /* Pre-cache (not possible for 8 bit colour depth cause it needs a colourmap) */
            if (This->bitmap_cache_precache && cellhdr.stamp && This->server_depth > 8)
                pstcache_load_bitmap(This, id, idx);
 
            /* Sort by stamp */
            for (n = idx; n > 0 && cellhdr.stamp < mru_stamp[n - 1]; n--)
            {
                mru_idx[n] = mru_idx[n - 1];
                mru_stamp[n] = mru_stamp[n - 1];
            }
 
            mru_idx[n] = idx;
            mru_stamp[n] = cellhdr.stamp;
        }
        else
        {
            break;
        }
    }
 
    DEBUG_RDP5(("%d cached bitmaps.\n", idx));
 
    cache_rebuild_bmpcache_linked_list(This, id, mru_idx, idx);
    This->pstcache_enumerated = True;
    return idx;
}
 
/* initialise the persistent bitmap cache */
BOOL
pstcache_init(RDPCLIENT * This, uint8 cache_id)
{
    int fd;
    char filename[256];
 
    if (This->pstcache_enumerated)
        return True;
 
    This->pstcache_fd[cache_id] = 0;
 
    if (!(This->bitmap_cache && This->bitmap_cache_persist_enable))
        return False;
 
    if (!rd_pstcache_mkdir())
    {
        DEBUG(("failed to get/make cache directory!\n"));
        return False;
    }
 
    This->pstcache_Bpp = (This->server_depth + 7) / 8;
    sprintf(filename, "cache/pstcache_%d_%d", cache_id, This->pstcache_Bpp);
    DEBUG(("persistent bitmap cache file: %s\n", filename));
 
    fd = rd_open_file(filename);
    if (fd == -1)
        return False;
 
    if (!rd_lock_file(fd, 0, 0))
    {
        warning("Persistent bitmap caching is disabled. (The file is already in use)\n");
        rd_close_file(fd);
        return False;
    }
 
    This->pstcache_fd[cache_id] = fd;
    return True;
}