1 /* inflate_p.h -- Private inline functions and macros shared with more than one deflate method 2 * 3 */ 4 5 #ifndef INFLATE_P_H 6 #define INFLATE_P_H 7 8 /* 9 * Macros shared by inflate() and inflateBack() 10 */ 11 12 /* check function to use adler32() for zlib or crc32() for gzip */ 13 #ifdef GUNZIP 14 # define UPDATE(check, buf, len) \ 15 (state->flags ? PREFIX(crc32)(check, buf, len) : functable.adler32(check, buf, len)) 16 #else 17 # define UPDATE(check, buf, len) functable.adler32(check, buf, len) 18 #endif 19 20 /* check macros for header crc */ 21 #ifdef GUNZIP 22 # define CRC2(check, word) \ 23 do { \ 24 hbuf[0] = (unsigned char)(word); \ 25 hbuf[1] = (unsigned char)((word) >> 8); \ 26 check = PREFIX(crc32)(check, hbuf, 2); \ 27 } while (0) 28 29 # define CRC4(check, word) \ 30 do { \ 31 hbuf[0] = (unsigned char)(word); \ 32 hbuf[1] = (unsigned char)((word) >> 8); \ 33 hbuf[2] = (unsigned char)((word) >> 16); \ 34 hbuf[3] = (unsigned char)((word) >> 24); \ 35 check = PREFIX(crc32)(check, hbuf, 4); \ 36 } while (0) 37 #endif 38 39 /* Load registers with state in inflate() for speed */ 40 #define LOAD() \ 41 do { \ 42 put = strm->next_out; \ 43 left = strm->avail_out; \ 44 next = strm->next_in; \ 45 have = strm->avail_in; \ 46 hold = state->hold; \ 47 bits = state->bits; \ 48 } while (0) 49 50 /* Restore state from registers in inflate() */ 51 #define RESTORE() \ 52 do { \ 53 strm->next_out = put; \ 54 strm->avail_out = left; \ 55 strm->next_in = (z_const unsigned char *)next; \ 56 strm->avail_in = have; \ 57 state->hold = hold; \ 58 state->bits = bits; \ 59 } while (0) 60 61 /* Clear the input bit accumulator */ 62 #define INITBITS() \ 63 do { \ 64 hold = 0; \ 65 bits = 0; \ 66 } while (0) 67 68 /* Ensure that there is at least n bits in the bit accumulator. If there is 69 not enough available input to do that, then return from inflate()/inflateBack(). */ 70 #define NEEDBITS(n) \ 71 do { \ 72 while (bits < (unsigned)(n)) \ 73 PULLBYTE(); \ 74 } while (0) 75 76 /* Return the low n bits of the bit accumulator (n < 16) */ 77 #define BITS(n) \ 78 (hold & ((1U << (unsigned)(n)) - 1)) 79 80 /* Remove n bits from the bit accumulator */ 81 #define DROPBITS(n) \ 82 do { \ 83 hold >>= (n); \ 84 bits -= (unsigned)(n); \ 85 } while (0) 86 87 /* Remove zero to seven bits as needed to go to a byte boundary */ 88 #define BYTEBITS() \ 89 do { \ 90 hold >>= bits & 7; \ 91 bits -= bits & 7; \ 92 } while (0) 93 94 #endif 95 96 /* Set mode=BAD and prepare error message */ 97 #define SET_BAD(errmsg) \ 98 do { \ 99 state->mode = BAD; \ 100 strm->msg = (char *)errmsg; \ 101 } while (0) 102