1 /* inflate_util.c -- data and routines common to blocks and codes 2 * Copyright (C) 1995-2002 Mark Adler 3 * For conditions of distribution and use, see copyright notice in zlib.h 4 */ 5 6 #include "zutil.h" 7 #include "infblock.h" 8 #include "inftrees.h" 9 #include "infcodes.h" 10 #include "infutil.h" 11 12 13 /* And'ing with mask[n] masks the lower n bits */ 14 local const uInt inflate_mask[17] = { 15 0x0000, 16 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 17 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 18 }; 19 20 21 /* copy as much as possible from the sliding window to the output area */ 22 local int inflate_flush( /* s, z, r) */ 23 inflate_blocks_statef *s, 24 z_streamp z, 25 int r ) 26 { 27 uInt n; 28 Bytef *p; 29 Bytef *q; 30 31 /* local copies of source and destination pointers */ 32 p = z->next_out; 33 q = s->read; 34 35 /* compute number of bytes to copy as far as end of window */ 36 n = (uInt)((q <= s->write ? s->write : s->end) - q); 37 if (n > z->avail_out) n = z->avail_out; 38 if (n && r == Z_BUF_ERROR) r = Z_OK; 39 40 /* update counters */ 41 z->avail_out -= n; 42 z->total_out += n; 43 44 /* update check information */ 45 if (s->checkfn != Z_NULL) 46 z->adler = s->check = (*s->checkfn)(s->check, q, n); 47 48 /* copy as far as end of window */ 49 zmemcpy(p, q, n); 50 p += n; 51 q += n; 52 53 /* see if more to copy at beginning of window */ 54 if (q == s->end) 55 { 56 /* wrap pointers */ 57 q = s->window; 58 if (s->write == s->end) 59 s->write = s->window; 60 61 /* compute bytes to copy */ 62 n = (uInt)(s->write - q); 63 if (n > z->avail_out) n = z->avail_out; 64 if (n && r == Z_BUF_ERROR) r = Z_OK; 65 66 /* update counters */ 67 z->avail_out -= n; 68 z->total_out += n; 69 70 /* update check information */ 71 if (s->checkfn != Z_NULL) 72 z->adler = s->check = (*s->checkfn)(s->check, q, n); 73 74 /* copy */ 75 zmemcpy(p, q, n); 76 p += n; 77 q += n; 78 } 79 80 /* update pointers */ 81 z->next_out = p; 82 s->read = q; 83 84 /* done */ 85 return r; 86 } 87
