Src/zlib-1.1.4/infcodes.c

/* infcodes.c -- process literals and length/distance pairs
 * Copyright (C) 1995-2002 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h 
 */

#include "zutil.h"
#include "inftrees.h"
#include "infblock.h"
#include "infcodes.h"
#include "infutil.h"
#include "inffast.h"

/* simplify the use of the inflate_huft type with some defines */
#define exop word.what.Exop
#define bits word.what.Bits

typedef enum {        /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
      START,    /* x: set up for LEN */
      LEN,      /* i: get length/literal/eob next */
      LENEXT,   /* i: getting length extra (have base) */
      DIST,     /* i: get distance next */
      DISTEXT,  /* i: getting distance extra */
      COPY,     /* o: copying bytes in window, waiting for space */
      LIT,      /* o: got literal, waiting for output space */
      WASH,     /* o: got eob, possibly still output waiting */
      END,      /* x: got eob and all data flushed */
      BADCODE}  /* x: got error */
inflate_codes_mode;

/* inflate codes private state */
struct inflate_codes_state {

  /* mode */
  inflate_codes_mode mode;      /* current inflate_codes mode */

  /* mode dependent information */
  uInt len;
  union {
    struct {
      inflate_huft *tree;       /* pointer into tree */
      uInt need;                /* bits needed */
    } code;             /* if LEN or DIST, where in tree */
    uInt lit;           /* if LIT, literal */
    struct {
      uInt get;                 /* bits to get for extra */
      uInt dist;                /* distance back to copy from */
    } copy;             /* if EXT or COPY, where and how much */
  } sub;                /* submode */

  /* mode independent information */
  Byte lbits;           /* ltree bits decoded per branch */
  Byte dbits;           /* dtree bits decoder per branch */
  inflate_huft *ltree;          /* literal/length/eob tree */
  inflate_huft *dtree;          /* distance tree */

};


inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
uInt bl, bd;
inflate_huft *tl;
inflate_huft *td; /* need separate declaration for Borland C++ */
z_streamp z;
{
  inflate_codes_statef *c;

  if ((c = (inflate_codes_statef *)
       ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
  {
    c->mode = START;
    c->lbits = (Byte)bl;
    c->dbits = (Byte)bd;
    c->ltree = tl;
    c->dtree = td;
    Tracev((stderr, "inflate:       codes new\n"));
  }
  return c;
}


int inflate_codes(s, z, r)
inflate_blocks_statef *s;
z_streamp z;
int r;
{
  uInt j;               /* temporary storage */
  inflate_huft *t;      /* temporary pointer */
  uInt e;               /* extra bits or operation */
  uLong b;              /* bit buffer */
  uInt k;               /* bits in bit buffer */
  Bytef *p;             /* input data pointer */
  uInt n;               /* bytes available there */
  Bytef *q;             /* output window write pointer */
  uInt m;               /* bytes to end of window or read pointer */
  Bytef *f;             /* pointer to copy strings from */
  inflate_codes_statef *c = s->sub.decode.codes;  /* codes state */

  /* copy input/output information to locals (UPDATE macro restores) */
  LOAD

  /* process input and output based on current state */
  while (1) switch (c->mode)
  {             /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
    case START:         /* x: set up for LEN */
#ifndef SLOW
      if (m >= 258 && n >= 10)
      {
        UPDATE
        r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
        LOAD
        if (r != Z_OK)
        {
          c->mode = r == Z_STREAM_END ? WASH : BADCODE;
          break;
        }
      }
#endif /* !SLOW */
      c->sub.code.need = c->lbits;
      c->sub.code.tree = c->ltree;
      c->mode = LEN;
    case LEN:           /* i: get length/literal/eob next */
      j = c->sub.code.need;
      NEEDBITS(j)
      t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
      DUMPBITS(t->bits)
      e = (uInt)(t->exop);
      if (e == 0)               /* literal */
      {
        c->sub.lit = t->base;
        Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
                 "inflate:         literal '%c'\n" :
                 "inflate:         literal 0x%02x\n", t->base));
        c->mode = LIT;
        break;
      }
      if (e & 16)               /* length */
      {
        c->sub.copy.get = e & 15;
        c->len = t->base;
        c->mode = LENEXT;
        break;
      }
      if ((e & 64) == 0)        /* next table */
      {
        c->sub.code.need = e;
        c->sub.code.tree = t + t->base;
        break;
      }
      if (e & 32)               /* end of block */
      {
        Tracevv((stderr, "inflate:         end of block\n"));
        c->mode = WASH;
        break;
      }
      c->mode = BADCODE;        /* invalid code */
      z->msg = (char*)"invalid literal/length code";
      r = Z_DATA_ERROR;
      LEAVE
    case LENEXT:        /* i: getting length extra (have base) */
      j = c->sub.copy.get;
      NEEDBITS(j)
      c->len += (uInt)b & inflate_mask[j];
      DUMPBITS(j)
      c->sub.code.need = c->dbits;
      c->sub.code.tree = c->dtree;
      Tracevv((stderr, "inflate:         length %u\n", c->len));
      c->mode = DIST;
    case DIST:          /* i: get distance next */
      j = c->sub.code.need;
      NEEDBITS(j)
      t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
      DUMPBITS(t->bits)
      e = (uInt)(t->exop);
      if (e & 16)               /* distance */
      {
        c->sub.copy.get = e & 15;
        c->sub.copy.dist = t->base;
        c->mode = DISTEXT;
        break;
      }
      if ((e & 64) == 0)        /* next table */
      {
        c->sub.code.need = e;
        c->sub.code.tree = t + t->base;
        break;
      }
      c->mode = BADCODE;        /* invalid code */
      z->msg = (char*)"invalid distance code";
      r = Z_DATA_ERROR;
      LEAVE
    case DISTEXT:       /* i: getting distance extra */
      j = c->sub.copy.get;
      NEEDBITS(j)
      c->sub.copy.dist += (uInt)b & inflate_mask[j];
      DUMPBITS(j)
      Tracevv((stderr, "inflate:         distance %u\n", c->sub.copy.dist));
      c->mode = COPY;
    case COPY:          /* o: copying bytes in window, waiting for space */
      f = q - c->sub.copy.dist;
      while (f < s->window)             /* modulo window size-"while" instead */
        f += s->end - s->window;        /* of "if" handles invalid distances */
      while (c->len)
      {
        NEEDOUT
        OUTBYTE(*f++)
        if (f == s->end)
          f = s->window;
        c->len--;
      }
      c->mode = START;
      break;
    case LIT:           /* o: got literal, waiting for output space */
      NEEDOUT
      OUTBYTE(c->sub.lit)
      c->mode = START;
      break;
    case WASH:          /* o: got eob, possibly more output */
      if (k > 7)        /* return unused byte, if any */
      {
        Assert(k < 16, "inflate_codes grabbed too many bytes")
        k -= 8;
        n++;
        p--;            /* can always return one */
      }
      FLUSH
      if (s->read != s->write)
        LEAVE
      c->mode = END;
    case END:
      r = Z_STREAM_END;
      LEAVE
    case BADCODE:       /* x: got error */
      r = Z_DATA_ERROR;
      LEAVE
    default:
      r = Z_STREAM_ERROR;
      LEAVE
  }
#ifdef NEED_DUMMY_RETURN
  return Z_STREAM_ERROR;  /* Some dumb compilers complain without this */
#endif
}


void inflate_codes_free(c, z)
inflate_codes_statef *c;
z_streamp z;
{
  ZFREE(z, c);
  Tracev((stderr, "inflate:       codes free\n"));
}
1	rabbi	77	/* infcodes.c -- process literals and length/distance pairs
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 "inftrees.h"
8			#include "infblock.h"
9			#include "infcodes.h"
10			#include "infutil.h"
11			#include "inffast.h"
12
13			/* simplify the use of the inflate_huft type with some defines */
14			#define exop word.what.Exop
15			#define bits word.what.Bits
16
17			typedef enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
18			START, /* x: set up for LEN */
19			LEN, /* i: get length/literal/eob next */
20			LENEXT, /* i: getting length extra (have base) */
21			DIST, /* i: get distance next */
22			DISTEXT, /* i: getting distance extra */
23			COPY, /* o: copying bytes in window, waiting for space */
24			LIT, /* o: got literal, waiting for output space */
25			WASH, /* o: got eob, possibly still output waiting */
26			END, /* x: got eob and all data flushed */
27			BADCODE} /* x: got error */
28			inflate_codes_mode;
29
30			/* inflate codes private state */
31			struct inflate_codes_state {
32
33			/* mode */
34			inflate_codes_mode mode; /* current inflate_codes mode */
35
36			/* mode dependent information */
37			uInt len;
38			union {
39			struct {
40			inflate_huft tree; / pointer into tree */
41			uInt need; /* bits needed */
42			} code; /* if LEN or DIST, where in tree */
43			uInt lit; /* if LIT, literal */
44			struct {
45			uInt get; /* bits to get for extra */
46			uInt dist; /* distance back to copy from */
47			} copy; /* if EXT or COPY, where and how much */
48			} sub; /* submode */
49
50			/* mode independent information */
51			Byte lbits; /* ltree bits decoded per branch */
52			Byte dbits; /* dtree bits decoder per branch */
53			inflate_huft ltree; / literal/length/eob tree */
54			inflate_huft dtree; / distance tree */
55
56			};
57
58
59			inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
60			uInt bl, bd;
61			inflate_huft *tl;
62			inflate_huft td; / need separate declaration for Borland C++ */
63			z_streamp z;
64			{
65			inflate_codes_statef *c;
66
67			if ((c = (inflate_codes_statef *)
68			ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
69			{
70			c->mode = START;
71			c->lbits = (Byte)bl;
72			c->dbits = (Byte)bd;
73			c->ltree = tl;
74			c->dtree = td;
75			Tracev((stderr, "inflate: codes new\n"));
76			}
77			return c;
78			}
79
80
81			int inflate_codes(s, z, r)
82			inflate_blocks_statef *s;
83			z_streamp z;
84			int r;
85			{
86			uInt j; /* temporary storage */
87			inflate_huft t; / temporary pointer */
88			uInt e; /* extra bits or operation */
89			uLong b; /* bit buffer */
90			uInt k; /* bits in bit buffer */
91			Bytef p; / input data pointer */
92			uInt n; /* bytes available there */
93			Bytef q; / output window write pointer */
94			uInt m; /* bytes to end of window or read pointer */
95			Bytef f; / pointer to copy strings from */
96			inflate_codes_statef c = s->sub.decode.codes; / codes state */
97
98			/* copy input/output information to locals (UPDATE macro restores) */
99			LOAD
100
101			/* process input and output based on current state */
102			while (1) switch (c->mode)
103			{ /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
104			case START: /* x: set up for LEN */
105			#ifndef SLOW
106			if (m >= 258 && n >= 10)
107			{
108			UPDATE
109			r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
110			LOAD
111			if (r != Z_OK)
112			{
113			c->mode = r == Z_STREAM_END ? WASH : BADCODE;
114			break;
115			}
116			}
117			#endif /* !SLOW */
118			c->sub.code.need = c->lbits;
119			c->sub.code.tree = c->ltree;
120			c->mode = LEN;
121			case LEN: /* i: get length/literal/eob next */
122			j = c->sub.code.need;
123			NEEDBITS(j)
124			t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
125			DUMPBITS(t->bits)
126			e = (uInt)(t->exop);
127			if (e == 0) /* literal */
128			{
129			c->sub.lit = t->base;
130			Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
131			"inflate: literal '%c'\n" :
132			"inflate: literal 0x%02x\n", t->base));
133			c->mode = LIT;
134			break;
135			}
136			if (e & 16) /* length */
137			{
138			c->sub.copy.get = e & 15;
139			c->len = t->base;
140			c->mode = LENEXT;
141			break;
142			}
143			if ((e & 64) == 0) /* next table */
144			{
145			c->sub.code.need = e;
146			c->sub.code.tree = t + t->base;
147			break;
148			}
149			if (e & 32) /* end of block */
150			{
151			Tracevv((stderr, "inflate: end of block\n"));
152			c->mode = WASH;
153			break;
154			}
155			c->mode = BADCODE; /* invalid code */
156			z->msg = (char*)"invalid literal/length code";
157			r = Z_DATA_ERROR;
158			LEAVE
159			case LENEXT: /* i: getting length extra (have base) */
160			j = c->sub.copy.get;
161			NEEDBITS(j)
162			c->len += (uInt)b & inflate_mask[j];
163			DUMPBITS(j)
164			c->sub.code.need = c->dbits;
165			c->sub.code.tree = c->dtree;
166			Tracevv((stderr, "inflate: length %u\n", c->len));
167			c->mode = DIST;
168			case DIST: /* i: get distance next */
169			j = c->sub.code.need;
170			NEEDBITS(j)
171			t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
172			DUMPBITS(t->bits)
173			e = (uInt)(t->exop);
174			if (e & 16) /* distance */
175			{
176			c->sub.copy.get = e & 15;
177			c->sub.copy.dist = t->base;
178			c->mode = DISTEXT;
179			break;
180			}
181			if ((e & 64) == 0) /* next table */
182			{
183			c->sub.code.need = e;
184			c->sub.code.tree = t + t->base;
185			break;
186			}
187			c->mode = BADCODE; /* invalid code */
188			z->msg = (char*)"invalid distance code";
189			r = Z_DATA_ERROR;
190			LEAVE
191			case DISTEXT: /* i: getting distance extra */
192			j = c->sub.copy.get;
193			NEEDBITS(j)
194			c->sub.copy.dist += (uInt)b & inflate_mask[j];
195			DUMPBITS(j)
196			Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
197			c->mode = COPY;
198			case COPY: /* o: copying bytes in window, waiting for space */
199			f = q - c->sub.copy.dist;
200			while (f < s->window) /* modulo window size-"while" instead */
201			f += s->end - s->window; /* of "if" handles invalid distances */
202			while (c->len)
203			{
204			NEEDOUT
205			OUTBYTE(*f++)
206			if (f == s->end)
207			f = s->window;
208			c->len--;
209			}
210			c->mode = START;
211			break;
212			case LIT: /* o: got literal, waiting for output space */
213			NEEDOUT
214			OUTBYTE(c->sub.lit)
215			c->mode = START;
216			break;
217			case WASH: /* o: got eob, possibly more output */
218			if (k > 7) /* return unused byte, if any */
219			{
220			Assert(k < 16, "inflate_codes grabbed too many bytes")
221			k -= 8;
222			n++;
223			p--; /* can always return one */
224			}
225			FLUSH
226			if (s->read != s->write)
227			LEAVE
228			c->mode = END;
229			case END:
230			r = Z_STREAM_END;
231			LEAVE
232			case BADCODE: /* x: got error */
233			r = Z_DATA_ERROR;
234			LEAVE
235			default:
236			r = Z_STREAM_ERROR;
237			LEAVE
238			}
239			#ifdef NEED_DUMMY_RETURN
240			return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
241			#endif
242			}
243
244
245			void inflate_codes_free(c, z)
246			inflate_codes_statef *c;
247			z_streamp z;
248			{
249			ZFREE(z, c);
250			Tracev((stderr, "inflate: codes free\n"));
251			}