1 /* infutil.h -- types and macros common to blocks and codes |
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2 * Copyright (C) 1995-2002 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 /* WARNING: this file should *not* be used by applications. It is |
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7 part of the implementation of the compression library and is |
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8 subject to change. Applications should only use zlib.h. |
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9 */ |
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10 |
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11 #ifndef _INFUTIL_H |
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12 #define _INFUTIL_H |
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13 |
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14 typedef enum { |
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15 TYPE, /* get type bits (3, including end bit) */ |
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16 LENS, /* get lengths for stored */ |
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17 STORED, /* processing stored block */ |
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18 TABLE, /* get table lengths */ |
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19 BTREE, /* get bit lengths tree for a dynamic block */ |
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20 DTREE, /* get length, distance trees for a dynamic block */ |
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21 CODES, /* processing fixed or dynamic block */ |
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22 DRY, /* output remaining window bytes */ |
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23 DONE, /* finished last block, done */ |
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24 BAD} /* got a data error--stuck here */ |
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25 inflate_block_mode; |
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26 |
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27 /* inflate blocks semi-private state */ |
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28 struct inflate_blocks_state { |
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29 |
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30 /* mode */ |
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31 inflate_block_mode mode; /* current inflate_block mode */ |
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32 |
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33 /* mode dependent information */ |
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34 union { |
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35 uInt left; /* if STORED, bytes left to copy */ |
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36 struct { |
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37 uInt table; /* table lengths (14 bits) */ |
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38 uInt index; /* index into blens (or border) */ |
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39 uIntf *blens; /* bit lengths of codes */ |
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40 uInt bb; /* bit length tree depth */ |
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41 inflate_huft *tb; /* bit length decoding tree */ |
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42 } trees; /* if DTREE, decoding info for trees */ |
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43 struct { |
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44 inflate_codes_statef |
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45 *codes; |
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46 } decode; /* if CODES, current state */ |
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47 } sub; /* submode */ |
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48 uInt last; /* true if this block is the last block */ |
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49 |
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50 /* mode independent information */ |
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51 uInt bitk; /* bits in bit buffer */ |
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52 uLong bitb; /* bit buffer */ |
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53 inflate_huft *hufts; /* single malloc for tree space */ |
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54 Bytef *window; /* sliding window */ |
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55 Bytef *end; /* one byte after sliding window */ |
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56 Bytef *read; /* window read pointer */ |
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57 Bytef *write; /* window write pointer */ |
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58 check_func checkfn; /* check function */ |
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59 uLong check; /* check on output */ |
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60 |
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61 }; |
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62 |
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63 |
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64 /* defines for inflate input/output */ |
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65 /* update pointers and return */ |
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66 #define UPDBITS {s->bitb=b;s->bitk=k;} |
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67 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} |
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68 #define UPDOUT {s->write=q;} |
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69 #define UPDATE {UPDBITS UPDIN UPDOUT} |
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70 #define LEAVE {UPDATE return inflate_flush(s,z,r);} |
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71 /* get bytes and bits */ |
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72 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} |
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73 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE} |
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74 #define NEXTBYTE (n--,*p++) |
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75 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} |
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76 #define DUMPBITS(j) {b>>=(j);k-=(j);} |
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77 /* output bytes */ |
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78 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q) |
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79 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;} |
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80 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} |
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81 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} |
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82 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;} |
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83 #define OUTBYTE(a) {*q++=(Byte)(a);m--;} |
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84 /* load local pointers */ |
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85 #define LOAD {LOADIN LOADOUT} |
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86 |
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87 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */ |
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88 #ifndef NO_INFLATE_MASK |
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89 local uInt inflate_mask[17]; |
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90 #endif |
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91 |
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92 /* copy as much as possible from the sliding window to the output area */ |
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93 local int inflate_flush OF(( |
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94 inflate_blocks_statef *, |
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95 z_streamp , |
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96 int)); |
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97 |
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98 #endif |
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