contrib/blast/blast.c

48     int bitcnt;                 /* number of bits in bit buffer */
50     /* input limit error return state for bits() and decode() */
62  * Return need bits from the input stream.  This always leaves less than
63  * eight bits in the buffer.  bits() works properly for need == 0.
68  *   significant bit.  Therefore bits are dropped from the bottom of the bit
72 local int bits(struct state *s, int need)
76     /* load at least need bits into val */
83         val |= (int)(*(s->in)++) << s->bitcnt;          /* load eight bits */
88     /* drop need bits and update buffer, always zero to seven bits left */
92     /* return need bits, zeroing the bits above that */
112  * then -9 is returned after reading MAXBITS bits.
118  *   bits are pulled from the compressed data one at a time and used to
126  *   this ordering, the bits pulled during decoding are inverted to apply the
131     int len;            /* current number of bits in code */
132     int code;           /* len bits being decoded */
136     int bitbuf;         /* bits from stream */
137     int left;           /* bits left in next or left to process */
176  * count (high four bits + 1) and a code length (low four bits), generate the
187  * enough bits will resolve to a symbol.  If the return value is positive, then
250  *   byte is 4, 5, or 6 for the number of extra bits in the distance code.
262  * - If literals are uncoded, then the next eight bits are the literal, in the
264  *   no bit reversal is needed for either the length extra bits or the distance
265  *   extra bits.
286     int symbol;         /* decoded symbol, extra bits for distance */
312     static const char extra[16] = {     /* extra bits for length codes */
324     lit = bits(s, 8);
326     dict = bits(s, 8);
331         if (bits(s, 1)) {
334             len = base[symbol] + bits(s, extra[symbol]);
340             dist += bits(s, symbol);
370             symbol = lit ? decode(s, &litcode) : bits(s, 8);
407     /* return if bits() or decode() tries to read past available input */