source: trunk/poppler/freetype-2.1.10/src/gzip/inflate.c @ 2

Last change on this file since 2 was 2, checked in by Eugene Romanenko, 15 years ago

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1/* inflate.c -- zlib interface to inflate modules
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
9#define  DONE  INFLATE_DONE
10#define  BAD   INFLATE_BAD
11
12typedef enum {
13      METHOD,   /* waiting for method byte */
14      FLAG,     /* waiting for flag byte */
15      DICT4,    /* four dictionary check bytes to go */
16      DICT3,    /* three dictionary check bytes to go */
17      DICT2,    /* two dictionary check bytes to go */
18      DICT1,    /* one dictionary check byte to go */
19      DICT0,    /* waiting for inflateSetDictionary */
20      BLOCKS,   /* decompressing blocks */
21      CHECK4,   /* four check bytes to go */
22      CHECK3,   /* three check bytes to go */
23      CHECK2,   /* two check bytes to go */
24      CHECK1,   /* one check byte to go */
25      DONE,     /* finished check, done */
26      BAD}      /* got an error--stay here */
27inflate_mode;
28
29/* inflate private state */
30struct internal_state {
31
32  /* mode */
33  inflate_mode  mode;   /* current inflate mode */
34
35  /* mode dependent information */
36  union {
37    uInt method;        /* if FLAGS, method byte */
38    struct {
39      uLong was;                /* computed check value */
40      uLong need;               /* stream check value */
41    } check;            /* if CHECK, check values to compare */
42    uInt marker;        /* if BAD, inflateSync's marker bytes count */
43  } sub;        /* submode */
44
45  /* mode independent information */
46  int  nowrap;          /* flag for no wrapper */
47  uInt wbits;           /* log2(window size)  (8..15, defaults to 15) */
48  inflate_blocks_statef
49    *blocks;            /* current inflate_blocks state */
50
51};
52
53
54ZEXPORT(int) inflateReset( /* z) */
55z_streamp z )
56{
57  if (z == Z_NULL || z->state == Z_NULL)
58    return Z_STREAM_ERROR;
59  z->total_in = z->total_out = 0;
60  z->msg = Z_NULL;
61  z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
62  inflate_blocks_reset(z->state->blocks, z, Z_NULL);
63  Tracev((stderr, "inflate: reset\n"));
64  return Z_OK;
65}
66
67
68ZEXPORT(int) inflateEnd( /* z) */
69z_streamp z )
70{
71  if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
72    return Z_STREAM_ERROR;
73  if (z->state->blocks != Z_NULL)
74    inflate_blocks_free(z->state->blocks, z);
75  ZFREE(z, z->state);
76  z->state = Z_NULL;
77  Tracev((stderr, "inflate: end\n"));
78  return Z_OK;
79}
80
81
82ZEXPORT(int) inflateInit2_( /* z, w, version, stream_size) */
83z_streamp z,
84int w,
85const char *version,
86int stream_size )
87{
88  if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
89      stream_size != sizeof(z_stream))
90      return Z_VERSION_ERROR;
91
92  /* initialize state */
93  if (z == Z_NULL)
94    return Z_STREAM_ERROR;
95  z->msg = Z_NULL;
96  if (z->zalloc == Z_NULL)
97  {
98    z->zalloc = zcalloc;
99    z->opaque = (voidpf)0;
100  }
101  if (z->zfree == Z_NULL) z->zfree = zcfree;
102  if ((z->state = (struct internal_state FAR *)
103       ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
104    return Z_MEM_ERROR;
105  z->state->blocks = Z_NULL;
106
107  /* handle undocumented nowrap option (no zlib header or check) */
108  z->state->nowrap = 0;
109  if (w < 0)
110  {
111    w = - w;
112    z->state->nowrap = 1;
113  }
114
115  /* set window size */
116  if (w < 8 || w > 15)
117  {
118    inflateEnd(z);
119    return Z_STREAM_ERROR;
120  }
121  z->state->wbits = (uInt)w;
122
123  /* create inflate_blocks state */
124  if ((z->state->blocks =
125      inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
126      == Z_NULL)
127  {
128    inflateEnd(z);
129    return Z_MEM_ERROR;
130  }
131  Tracev((stderr, "inflate: allocated\n"));
132
133  /* reset state */
134  inflateReset(z);
135  return Z_OK;
136}
137
138
139
140#undef  NEEDBYTE
141#define NEEDBYTE {if(z->avail_in==0)return r;r=f;}
142
143#undef  NEXTBYTE
144#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
145
146
147ZEXPORT(int) inflate( /* z, f) */
148z_streamp z,
149int f )
150{
151  int r;
152  uInt b;
153
154  if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
155    return Z_STREAM_ERROR;
156  f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
157  r = Z_BUF_ERROR;
158  while (1) switch (z->state->mode)
159  {
160    case METHOD:
161      NEEDBYTE
162      if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
163      {
164        z->state->mode = BAD;
165        z->msg = (char*)"unknown compression method";
166        z->state->sub.marker = 5;       /* can't try inflateSync */
167        break;
168      }
169      if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
170      {
171        z->state->mode = BAD;
172        z->msg = (char*)"invalid window size";
173        z->state->sub.marker = 5;       /* can't try inflateSync */
174        break;
175      }
176      z->state->mode = FLAG;
177    case FLAG:
178      NEEDBYTE
179      b = NEXTBYTE;
180      if (((z->state->sub.method << 8) + b) % 31)
181      {
182        z->state->mode = BAD;
183        z->msg = (char*)"incorrect header check";
184        z->state->sub.marker = 5;       /* can't try inflateSync */
185        break;
186      }
187      Tracev((stderr, "inflate: zlib header ok\n"));
188      if (!(b & PRESET_DICT))
189      {
190        z->state->mode = BLOCKS;
191        break;
192      }
193      z->state->mode = DICT4;
194    case DICT4:
195      NEEDBYTE
196      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
197      z->state->mode = DICT3;
198    case DICT3:
199      NEEDBYTE
200      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
201      z->state->mode = DICT2;
202    case DICT2:
203      NEEDBYTE
204      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
205      z->state->mode = DICT1;
206    case DICT1:
207      NEEDBYTE
208      z->state->sub.check.need += (uLong)NEXTBYTE;
209      z->adler = z->state->sub.check.need;
210      z->state->mode = DICT0;
211      return Z_NEED_DICT;
212    case DICT0:
213      z->state->mode = BAD;
214      z->msg = (char*)"need dictionary";
215      z->state->sub.marker = 0;       /* can try inflateSync */
216      return Z_STREAM_ERROR;
217    case BLOCKS:
218      r = inflate_blocks(z->state->blocks, z, r);
219      if (r == Z_DATA_ERROR)
220      {
221        z->state->mode = BAD;
222        z->state->sub.marker = 0;       /* can try inflateSync */
223        break;
224      }
225      if (r == Z_OK)
226        r = f;
227      if (r != Z_STREAM_END)
228        return r;
229      r = f;
230      inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
231      if (z->state->nowrap)
232      {
233        z->state->mode = DONE;
234        break;
235      }
236      z->state->mode = CHECK4;
237    case CHECK4:
238      NEEDBYTE
239      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
240      z->state->mode = CHECK3;
241    case CHECK3:
242      NEEDBYTE
243      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
244      z->state->mode = CHECK2;
245    case CHECK2:
246      NEEDBYTE
247      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
248      z->state->mode = CHECK1;
249    case CHECK1:
250      NEEDBYTE
251      z->state->sub.check.need += (uLong)NEXTBYTE;
252
253      if (z->state->sub.check.was != z->state->sub.check.need)
254      {
255        z->state->mode = BAD;
256        z->msg = (char*)"incorrect data check";
257        z->state->sub.marker = 5;       /* can't try inflateSync */
258        break;
259      }
260      Tracev((stderr, "inflate: zlib check ok\n"));
261      z->state->mode = DONE;
262    case DONE:
263      return Z_STREAM_END;
264    case BAD:
265      return Z_DATA_ERROR;
266    default:
267      return Z_STREAM_ERROR;
268  }
269#ifdef NEED_DUMMY_RETURN
270  return Z_STREAM_ERROR;  /* Some dumb compilers complain without this */
271#endif
272}
273
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