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