inflatelib.c

VXWORKS源代码

      NEEDBITS(j)
      t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
      DUMPBITS(t->bits)
      e = (uInt)(t->exop);
      if (e == 0)               /* literal */
      {
        c->sub.lit = t->base;
        Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
                 "inflate:         literal '%c'\n" :
                 "inflate:         literal 0x%02x\n", t->base));
        c->mode = LIT;
        break;
      }
      if (e & 16)               /* length */
      {
        c->sub.copy.get = e & 15;
        c->len = t->base;
        c->mode = LENEXT;
        break;
      }
      if ((e & 64) == 0)        /* next table */
      {
        c->sub.code.need = e;
        c->sub.code.tree = t->next;
        break;
      }
      if (e & 32)               /* end of block */
      {
        Tracevv((stderr, "inflate:         end of block\n"));
        c->mode = WASH;
        break;
      }
      c->mode = BADCODE;        /* invalid code */
      z->msg = (char*)"invalid literal/length code";
      r = Z_DATA_ERROR;
      LEAVE
    case LENEXT:        /* i: getting length extra (have base) */
      j = c->sub.copy.get;
      NEEDBITS(j)
      c->len += (uInt)b & inflate_mask[j];
      DUMPBITS(j)
      c->sub.code.need = c->dbits;
      c->sub.code.tree = c->dtree;
      Tracevv((stderr, "inflate:         length %u\n", c->len));
      c->mode = DIST;
    case DIST:          /* i: get distance next */
      j = c->sub.code.need;
      NEEDBITS(j)
      t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
      DUMPBITS(t->bits)
      e = (uInt)(t->exop);
      if (e & 16)               /* distance */
      {
        c->sub.copy.get = e & 15;
        c->sub.copy.dist = t->base;
        c->mode = DISTEXT;
        break;
      }
      if ((e & 64) == 0)        /* next table */
      {
        c->sub.code.need = e;
        c->sub.code.tree = t->next;
        break;
      }
      c->mode = BADCODE;        /* invalid code */
      z->msg = (char*)"invalid distance code";
      r = Z_DATA_ERROR;
      LEAVE
    case DISTEXT:       /* i: getting distance extra */
      j = c->sub.copy.get;
      NEEDBITS(j)
      c->sub.copy.dist += (uInt)b & inflate_mask[j];
      DUMPBITS(j)
      Tracevv((stderr, "inflate:         distance %u\n", c->sub.copy.dist));
      c->mode = COPY;
    case COPY:          /* o: copying bytes in window, waiting for space */
#ifndef __TURBOC__ /* Turbo C bug for following expression */
      f = (uInt)(q - s->window) < c->sub.copy.dist ?
          s->end - (c->sub.copy.dist - (q - s->window)) :
          q - c->sub.copy.dist;
#else
      f = q - c->sub.copy.dist;
      if ((uInt)(q - s->window) < c->sub.copy.dist)
        f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
#endif
      while (c->len)
      {
        NEEDOUT
        OUTBYTE(*f++)
        if (f == s->end)
          f = s->window;
        c->len--;
      }
      c->mode = START;
      break;
    case LIT:           /* o: got literal, waiting for output space */
      NEEDOUT
      OUTBYTE(c->sub.lit)
      c->mode = START;
      break;
    case WASH:          /* o: got eob, possibly more output */
      FLUSH
      if (s->read != s->write)
        LEAVE
      c->mode = END;
    case END:
      r = Z_STREAM_END;
      LEAVE
    case BADCODE:       /* x: got error */
      r = Z_DATA_ERROR;
      LEAVE
    default:
      r = Z_STREAM_ERROR;
      LEAVE
  }
}

/******************************************************************************
*
* inflate_codes_free - frees inflate codes
*
*/ 

static void inflate_codes_free
    (
    inflate_codes_statef *c,
    z_streamp z
    )
    {
    ZFREE(z, c);
    }

/******************************************************************************
*
* inflate_blocks_reset - resets inflate blocks
*
*/ 

static void inflate_blocks_reset(s, z, c)
inflate_blocks_statef *s;
z_streamp z;
uLong *c;
{
  if (s->checkfn != Z_NULL)
    *c = s->check;
  if (s->mode == BTREE || s->mode == DTREE)
    ZFREE(z, s->sub.trees.blens);
  if (s->mode == CODES)
  {
    inflate_codes_free(s->sub.decode.codes, z);
    inflate_trees_free(s->sub.decode.td, z);
    inflate_trees_free(s->sub.decode.tl, z);
  }
  s->mode = TYPE;
  s->bitk = 0;
  s->bitb = 0;
  s->read = s->write = s->window;
  if (s->checkfn != Z_NULL)
    z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
  Trace((stderr, "inflate:   blocks reset\n"));
}

/******************************************************************************
*
* inflate_blocks_new - allocates new inflate blocks
*
*/ 

static inflate_blocks_statef *inflate_blocks_new(z, c, w)
z_streamp z;
check_func c;
uInt w;
{
  inflate_blocks_statef *s;

  if ((s = (inflate_blocks_statef *)ZALLOC
       (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
    return s;
  if ((s->window = (Byte *)ZALLOC(z, 1, w)) == Z_NULL)
  {
    ZFREE(z, s);
    return Z_NULL;
  }
  s->end = s->window + w;
  s->checkfn = c;
  s->mode = TYPE;
  Trace((stderr, "inflate:   blocks allocated\n"));
  inflate_blocks_reset(s, z, &s->check);
  return s;
}


/******************************************************************************
*
* inflate_block - inflates a block
*/ 

static int inflate_blocks(s, z, r)
inflate_blocks_statef *s;
z_streamp z;
int r;
{
  uInt t;               /* temporary storage */
  uLong b;              /* bit buffer */
  uInt k;               /* bits in bit buffer */
  Byte *p;             /* input data pointer */
  uInt n;               /* bytes available there */
  Byte *q;             /* output window write pointer */
  uInt m;               /* bytes to end of window or read pointer */

  /* copy input/output information to locals (UPDATE macro restores) */
  LOAD

  /* process input based on current state */
  while (1) switch (s->mode)
  {
    case TYPE:
      NEEDBITS(3)
      t = (uInt)b & 7;
      s->last = t & 1;
      switch (t >> 1)
      {
        case 0:                         /* stored */
          Trace((stderr, "inflate:     stored block%s\n",
                 s->last ? " (last)" : ""));
          DUMPBITS(3)
          t = k & 7;                    /* go to byte boundary */
          DUMPBITS(t)
          s->mode = LENS;               /* get length of stored block */
          break;
        case 1:                         /* fixed */
          Trace((stderr, "inflate:     fixed codes block%s\n",
                 s->last ? " (last)" : ""));
          {
            uInt bl, bd;
            inflate_huft *tl, *td;

            inflate_trees_fixed(&bl, &bd, &tl, &td);
            s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
            if (s->sub.decode.codes == Z_NULL)
            {
              r = Z_MEM_ERROR;
              LEAVE
            }
            s->sub.decode.tl = Z_NULL;  /* don't try to free these */
            s->sub.decode.td = Z_NULL;
          }
          DUMPBITS(3)
          s->mode = CODES;
          break;
        case 2:                         /* dynamic */
          Trace((stderr, "inflate:     dynamic codes block%s\n",
                 s->last ? " (last)" : ""));
          DUMPBITS(3)
          s->mode = TABLE;
          break;
        case 3:                         /* illegal */
          DUMPBITS(3)
          s->mode = BAD;
          z->msg = (char*)"invalid block type";
          r = Z_DATA_ERROR;
          LEAVE
      }
      break;
    case LENS:
      NEEDBITS(32)
      if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
      {
        s->mode = BAD;
        z->msg = (char*)"invalid stored block lengths";
        r = Z_DATA_ERROR;
        LEAVE
      }
      s->sub.left = (uInt)b & 0xffff;
      b = k = 0;                      /* dump bits */
      Tracev((stderr, "inflate:       stored length %u\n", s->sub.left));
      s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
      break;
    case STORED:
      if (n == 0)
        LEAVE
      NEEDOUT
      t = s->sub.left;
      if (t > n) t = n;
      if (t > m) t = m;
      memcpy(q, p, t);
      p += t;  n -= t;
      q += t;  m -= t;
      if ((s->sub.left -= t) != 0)
        break;
      Tracev((stderr, "inflate:       stored end, %lu total out\n",
              z->total_out + (q >= s->read ? q - s->read :
              (s->end - s->read) + (q - s->window))));
      s->mode = s->last ? DRY : TYPE;
      break;
    case TABLE:
      NEEDBITS(14)
      s->sub.trees.table = t = (uInt)b & 0x3fff;
      if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
      {
        s->mode = BAD;
        z->msg = (char*)"too many length or distance symbols";
        r = Z_DATA_ERROR;
        LEAVE
      }
      t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
      if (t < 19)
        t = 19;
      if ((s->sub.trees.blens = (uInt*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
      {
        r = Z_MEM_ERROR;
        LEAVE
      }
      DUMPBITS(14)
      s->sub.trees.index = 0;
      Tracev((stderr, "inflate:       table sizes ok\n"));
      s->mode = BTREE;
    case BTREE:
      while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
      {
        NEEDBITS(3)
        s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
        DUMPBITS(3)
      }
      while (s->sub.trees.index < 19)
        s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
      s->sub.trees.bb = 7;
      t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
                             &s->sub.trees.tb, z);
      if (t != Z_OK)
      {
        r = t;
        if (r == Z_DATA_ERROR)
          s->mode = BAD;
        LEAVE
      }
      s->sub.trees.index = 0;
      Tracev((stderr, "inflate:       bits tree ok\n"));
      s->mode = DTREE;
    case DTREE:
      while (t = s->sub.trees.table,
             s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
      {
        inflate_huft *h;
        uInt i, j, c;

        t = s->sub.trees.bb;
        NEEDBITS(t)
        h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
        t = h->word.what.Bits;
        c = h->more.Base;
        if (c < 16)
        {
          DUMPBITS(t)
          s->sub.trees.blens[s->sub.trees.index++] = c;
        }
        else /* c == 16..18 */
        {
          i = c == 18 ? 7 : c - 14;
          j = c == 18 ? 11 : 3;
          NEEDBITS(t + i)
          DUMPBITS(t)
          j += (uInt)b & inflate_mask[i];
          DUMPBITS(i)
          i = s->sub.trees.index;
          t = s->sub.trees.table;
          if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
              (c == 16 && i < 1))
          {
            s->mode = BAD;
            z->msg = (char*)"invalid bit length repeat";
            r = Z_DATA_ERROR;
            LEAVE
          }
          c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
          do {
            s->sub.trees.blens[i++] = c;
          } while (--j);
          s->sub.trees.index = i;
        }
      }
      inflate_trees_free(s->sub.trees.tb, z);
      s->sub.trees.tb = Z_NULL;
      {
        uInt bl, bd;
        inflate_huft *tl, *td;
        inflate_codes_statef *c;

        bl = 9;         /* must be <= 9 for lookahead assumptions */
        bd = 6;         /* must be <= 9 for lookahead assumptions */
        t = s->sub.trees.table;
        t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
                                  s->sub.trees.blens, &bl, &bd, &tl, &td, z);
        if (t != Z_OK)
        {
          if (t == (uInt)Z_DATA_ERROR)
            s->mode = BAD;
          r = t;
          LEAVE
        }
        Tracev((stderr, "inflate:       trees ok, %d * %d bytes used\n",
              inflate_hufts, sizeof(inflate_huft)));
        if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
        {
          inflate_trees_free(td, z);
          inflate_trees_free(tl, z);
          r = Z_MEM_ERROR;
          LEAVE
        }
        ZFREE(z, s->sub.trees.blens);
        s->sub.decode.codes = c;
        s->sub.decode.tl = tl;
        s->sub.decode.td = td;
      }
      s->mode = CODES;
    case CODES:
      UPDATE
      if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
        return