src/zlib/infcodes.c

/* infcodes.c -- process literals and length/distance pairs
 * Copyright (C) 1995-1998 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 */

};

#if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
inflate_codes_statef* inflate_codes_new(uInt bl, uInt bd, inflate_huft* tl, inflate_huft* td, z_streamp z)
#else
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;
#endif
{
  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;
}

#if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
int inflate_codes(inflate_blocks_statef* s, z_streamp z, int r)
#else
int inflate_codes(s, z, r)
inflate_blocks_statef *s;
z_streamp z;
int r;
#endif
{
  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 */
#ifndef __TURBOC__ /* Turbo C bug for following expression */
      f = (uInt)(q - s->window) < c->sub.copy.dist ?
          s->end - (c->sub.copy.dist - (q - s->window)) :
          q - c->sub.copy.dist;
#else
      f = q - c->sub.copy.dist;
      if ((uInt)(q - s->window) < c->sub.copy.dist)
        f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
#endif
      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 */
      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
}

#if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
void inflate_codes_free(inflate_codes_statef* c, z_streamp z)
#else
void inflate_codes_free(c, z)
inflate_codes_statef *c;
z_streamp z;
#endif
{
  ZFREE(z, c);
  Tracev((stderr, "inflate:       codes free\n"));
}
Commit	Line	Data
	1	/* infcodes.c -- process literals and length/distance pairs
	2	* Copyright (C) 1995-1998 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	#if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
	59	inflate_codes_statef* inflate_codes_new(uInt bl, uInt bd, inflate_huft* tl, inflate_huft* td, z_streamp z)
	60	#else
	61	inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
	62	uInt bl, bd;
	63	inflate_huft *tl;
	64	inflate_huft td; / need separate declaration for Borland C++ */
	65	z_streamp z;
	66	#endif
	67	{
	68	inflate_codes_statef *c;
	69
	70	if ((c = (inflate_codes_statef *)
	71	ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
	72	{
	73	c->mode = START;
	74	c->lbits = (Byte)bl;
	75	c->dbits = (Byte)bd;
	76	c->ltree = tl;
	77	c->dtree = td;
	78	Tracev((stderr, "inflate: codes new\n"));
	79	}
	80	return c;
	81	}
	82
	83	#if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
	84	int inflate_codes(inflate_blocks_statef* s, z_streamp z, int r)
	85	#else
	86	int inflate_codes(s, z, r)
	87	inflate_blocks_statef *s;
	88	z_streamp z;
	89	int r;
	90	#endif
	91	{
	92	uInt j; /* temporary storage */
	93	inflate_huft t; / temporary pointer */
	94	uInt e; /* extra bits or operation */
	95	uLong b; /* bit buffer */
	96	uInt k; /* bits in bit buffer */
	97	Bytef p; / input data pointer */
	98	uInt n; /* bytes available there */
	99	Bytef q; / output window write pointer */
	100	uInt m; /* bytes to end of window or read pointer */
	101	Bytef f; / pointer to copy strings from */
	102	inflate_codes_statef c = s->sub.decode.codes; / codes state */
	103
	104	/* copy input/output information to locals (UPDATE macro restores) */
	105	LOAD
	106
	107	/* process input and output based on current state */
	108	while (1) switch (c->mode)
	109	{ /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
	110	case START: /* x: set up for LEN */
	111	#ifndef SLOW
	112	if (m >= 258 && n >= 10)
	113	{
	114	UPDATE
	115	r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
	116	LOAD
	117	if (r != Z_OK)
	118	{
	119	c->mode = r == Z_STREAM_END ? WASH : BADCODE;
	120	break;
	121	}
	122	}
	123	#endif /* !SLOW */
	124	c->sub.code.need = c->lbits;
	125	c->sub.code.tree = c->ltree;
	126	c->mode = LEN;
	127	case LEN: /* i: get length/literal/eob next */
	128	j = c->sub.code.need;
	129	NEEDBITS(j)
	130	t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
	131	DUMPBITS(t->bits)
	132	e = (uInt)(t->exop);
	133	if (e == 0) /* literal */
	134	{
	135	c->sub.lit = t->base;
	136	Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
	137	"inflate: literal '%c'\n" :
	138	"inflate: literal 0x%02x\n", t->base));
	139	c->mode = LIT;
	140	break;
	141	}
	142	if (e & 16) /* length */
	143	{
	144	c->sub.copy.get = e & 15;
	145	c->len = t->base;
	146	c->mode = LENEXT;
	147	break;
	148	}
	149	if ((e & 64) == 0) /* next table */
	150	{
	151	c->sub.code.need = e;
	152	c->sub.code.tree = t + t->base;
	153	break;
	154	}
	155	if (e & 32) /* end of block */
	156	{
	157	Tracevv((stderr, "inflate: end of block\n"));
	158	c->mode = WASH;
	159	break;
	160	}
	161	c->mode = BADCODE; /* invalid code */
	162	z->msg = (char*)"invalid literal/length code";
	163	r = Z_DATA_ERROR;
	164	LEAVE
	165	case LENEXT: /* i: getting length extra (have base) */
	166	j = c->sub.copy.get;
	167	NEEDBITS(j)
	168	c->len += (uInt)b & inflate_mask[j];
	169	DUMPBITS(j)
	170	c->sub.code.need = c->dbits;
	171	c->sub.code.tree = c->dtree;
	172	Tracevv((stderr, "inflate: length %u\n", c->len));
	173	c->mode = DIST;
	174	case DIST: /* i: get distance next */
	175	j = c->sub.code.need;
	176	NEEDBITS(j)
	177	t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
	178	DUMPBITS(t->bits)
	179	e = (uInt)(t->exop);
	180	if (e & 16) /* distance */
	181	{
	182	c->sub.copy.get = e & 15;
	183	c->sub.copy.dist = t->base;
	184	c->mode = DISTEXT;
	185	break;
	186	}
	187	if ((e & 64) == 0) /* next table */
	188	{
	189	c->sub.code.need = e;
	190	c->sub.code.tree = t + t->base;
	191	break;
	192	}
	193	c->mode = BADCODE; /* invalid code */
	194	z->msg = (char*)"invalid distance code";
	195	r = Z_DATA_ERROR;
	196	LEAVE
	197	case DISTEXT: /* i: getting distance extra */
	198	j = c->sub.copy.get;
	199	NEEDBITS(j)
	200	c->sub.copy.dist += (uInt)b & inflate_mask[j];
	201	DUMPBITS(j)
	202	Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
	203	c->mode = COPY;
	204	case COPY: /* o: copying bytes in window, waiting for space */
	205	#ifndef __TURBOC__ /* Turbo C bug for following expression */
	206	f = (uInt)(q - s->window) < c->sub.copy.dist ?
	207	s->end - (c->sub.copy.dist - (q - s->window)) :
	208	q - c->sub.copy.dist;
	209	#else
	210	f = q - c->sub.copy.dist;
	211	if ((uInt)(q - s->window) < c->sub.copy.dist)
	212	f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
	213	#endif
	214	while (c->len)
	215	{
	216	NEEDOUT
	217	OUTBYTE(*f++)
	218	if (f == s->end)
	219	f = s->window;
	220	c->len--;
	221	}
	222	c->mode = START;
	223	break;
	224	case LIT: /* o: got literal, waiting for output space */
	225	NEEDOUT
	226	OUTBYTE(c->sub.lit)
	227	c->mode = START;
	228	break;
	229	case WASH: /* o: got eob, possibly more output */
	230	FLUSH
	231	if (s->read != s->write)
	232	LEAVE
	233	c->mode = END;
	234	case END:
	235	r = Z_STREAM_END;
	236	LEAVE
	237	case BADCODE: /* x: got error */
	238	r = Z_DATA_ERROR;
	239	LEAVE
	240	default:
	241	r = Z_STREAM_ERROR;
	242	LEAVE
	243	}
	244	#ifdef NEED_DUMMY_RETURN
	245	return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
	246	#endif
	247	}
	248
	249	#if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
	250	void inflate_codes_free(inflate_codes_statef* c, z_streamp z)
	251	#else
	252	void inflate_codes_free(c, z)
	253	inflate_codes_statef *c;
	254	z_streamp z;
	255	#endif
	256	{
	257	ZFREE(z, c);
	258	Tracev((stderr, "inflate: codes free\n"));
	259	}