depot.c

   1 /*
   2  * depot.c
   3  * Copyright (C) 1998-2002 A.J. van Os; Released under GPL
   4  *
   5  * Description:
   6  * Functions to compute the depot offset
   7  */
   8
   9 #include "antiword.h"
  10
  11 #define SIZE_RATIO      (BIG_BLOCK_SIZE/SMALL_BLOCK_SIZE)
  12
  13 static ULONG    *aulSmallBlockList = NULL;
  14 static size_t   tSmallBlockListLen = 0;
  15
  16
  17 /*
  18  * vDestroySmallBlockList - destroy the small block list
  19  */
  20 void
  21 vDestroySmallBlockList(void)
  22 {
  23         DBG_MSG("vDestroySmallBlockList");
  24
  25         aulSmallBlockList = xfree(aulSmallBlockList);
  26         tSmallBlockListLen = 0;
  27 } /* end of vDestroySmalBlockList */
  28
  29 /*
  30  * vCreateSmallBlockList - create the small block list
  31  *
  32  * returns: TRUE when successful, otherwise FALSE
  33  */
  34 BOOL
  35 bCreateSmallBlockList(ULONG ulStartblock, const ULONG *aulBBD, size_t tBBDLen)
  36 {
  37         ULONG   ulTmp;
  38         size_t  tSize;
  39         int     iIndex;
  40
  41         fail(aulSmallBlockList != NULL);
  42         fail(tSmallBlockListLen != 0);
  43         fail(ulStartblock > MAX_BLOCKNUMBER && ulStartblock != END_OF_CHAIN);
  44         fail(aulBBD == NULL);
  45         fail(tBBDLen == 0);
  46
  47         /* Find the length of the small block list */
  48         for (tSmallBlockListLen = 0, ulTmp = ulStartblock;
  49              tSmallBlockListLen < tBBDLen && ulTmp != END_OF_CHAIN;
  50              tSmallBlockListLen++, ulTmp = aulBBD[ulTmp]) {
  51                 if (ulTmp >= (ULONG)tBBDLen) {
  52                         DBG_DEC(ulTmp);
  53                         DBG_DEC(tBBDLen);
  54                         werr(1, "The Big Block Depot is damaged");
  55                 }
  56         }
  57         DBG_DEC(tSmallBlockListLen);
  58
  59         if (tSmallBlockListLen == 0) {
  60                 /* There is no small block list */
  61                 fail(ulStartblock != END_OF_CHAIN);
  62                 aulSmallBlockList = NULL;
  63                 return TRUE;
  64         }
  65
  66         /* Create the small block list */
  67         tSize = tSmallBlockListLen * sizeof(ULONG);
  68         aulSmallBlockList = xmalloc(tSize);
  69         for (iIndex = 0, ulTmp = ulStartblock;
  70              iIndex < (int)tBBDLen && ulTmp != END_OF_CHAIN;
  71              iIndex++, ulTmp = aulBBD[ulTmp]) {
  72                 if (ulTmp >= (ULONG)tBBDLen) {
  73                         DBG_DEC(ulTmp);
  74                         DBG_DEC(tBBDLen);
  75                         werr(1, "The Big Block Depot is damaged");
  76                 }
  77                 aulSmallBlockList[iIndex] = ulTmp;
  78                 NO_DBG_DEC(aulSmallBlockList[iIndex]);
  79         }
  80         return TRUE;
  81 } /* end of bCreateSmallBlockList */
  82
  83 /*
  84  * ulDepotOffset - get the depot offset the block list
  85  */
  86 ULONG
  87 ulDepotOffset(ULONG ulIndex, size_t tBlockSize)
  88 {
  89         ULONG   ulTmp;
  90         size_t  tTmp;
  91
  92         fail(ulIndex >= ULONG_MAX / BIG_BLOCK_SIZE);
  93
  94         switch (tBlockSize) {
  95         case BIG_BLOCK_SIZE:
  96                 return (ulIndex + 1) * BIG_BLOCK_SIZE;
  97         case SMALL_BLOCK_SIZE:
  98                 tTmp = (size_t)(ulIndex / SIZE_RATIO);
  99                 ulTmp = ulIndex % SIZE_RATIO;
 100                 if (aulSmallBlockList == NULL ||
 101                     tTmp >= tSmallBlockListLen) {
 102                         DBG_HEX(aulSmallBlockList);
 103                         DBG_DEC(tSmallBlockListLen);
 104                         DBG_DEC(tTmp);
 105                         return 0;
 106                 }
 107                 return ((aulSmallBlockList[tTmp] + 1) * SIZE_RATIO +
 108                                 ulTmp) * SMALL_BLOCK_SIZE;
 109         default:
 110                 DBG_DEC(tBlockSize);
 111                 DBG_FIXME();
 112                 return 0;
 113         }
 114 } /* end of ulDepotOffset */