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 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 13 14 /* And'ing with mask[n] masks the lower n bits */ 15 uInt inflate_mask[17] = { 16 0x0000, 17 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 18 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 19 }; 20 21 22 /* copy as much as possible from the sliding window to the output area */ 23 int inflate_flush(s, z, r) 24 inflate_blocks_statef *s; 25 z_streamp z; 26 int r; 27 { 28 uInt n; 29 Bytef *p; 30 Bytef *q; 31 32 /* local copies of source and destination pointers */ 33 p = z->next_out; 34 q = s->read; 35 36 /* compute number of bytes to copy as far as end of window */ 37 n = (uInt)((q <= s->write ? s->write : s->end) - q); 38 if (n > z->avail_out) n = z->avail_out; 39 if (n && r == Z_BUF_ERROR) r = Z_OK; 40 41 /* update counters */ 42 z->avail_out -= n; 43 z->total_out += n; 44 45 /* update check information */ 46 if (s->checkfn != Z_NULL) 47 z->adler = s->check = (*s->checkfn)(s->check, q, n); 48 49 /* copy as far as end of window */ 50 zmemcpy(p, q, n); 51 p += n; 52 q += n; 53 54 /* see if more to copy at beginning of window */ 55 if (q == s->end) 56 { 57 /* wrap pointers */ 58 q = s->window; 59 if (s->write == s->end) 60 s->write = s->window; 61 62 /* compute bytes to copy */ 63 n = (uInt)(s->write - q); 64 if (n > z->avail_out) n = z->avail_out; 65 if (n && r == Z_BUF_ERROR) r = Z_OK; 66 67 /* update counters */ 68 z->avail_out -= n; 69 z->total_out += n; 70 71 /* update check information */ 72 if (s->checkfn != Z_NULL) 73 z->adler = s->check = (*s->checkfn)(s->check, q, n); 74 75 /* copy */ 76 zmemcpy(p, q, n); 77 p += n; 78 q += n; 79 } 80 81 /* update pointers */ 82 z->next_out = p; 83 s->read = q; 84 85 /* done */ 86 return r; 87 } 88