/* $NetBSD: inflate.c,v 1.5 2003/03/25 22:48:44 mycroft Exp $ */

/* inflate.c -- zlib interface to inflate modules
 * Copyright (C) 1995-2002 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h 
 */

#include "zutil.h"
#include "infblock.h"

struct inflate_blocks_state {int dummy;}; /* for buggy compilers */

typedef enum {
      BLOCKS,   /* decompressing blocks */
      DONE,     /* finished check, done */
      BAD}      /* got an error--stay here */
inflate_mode;

/* inflate private state */
struct internal_state {

  /* mode */
  inflate_mode  mode;   /* current inflate mode */

  /* mode independent information */
  uInt wbits;           /* log2(window size)  (8..15, defaults to 15) */
  inflate_blocks_statef 
    *blocks;            /* current inflate_blocks state */

};


int ZEXPORT inflateReset(z)
z_streamp z;
{
  if (z == Z_NULL || z->state == Z_NULL)
    return Z_STREAM_ERROR;
  z->total_in = z->total_out = 0;
  z->msg = Z_NULL;
  z->state->mode = BLOCKS;
  inflate_blocks_reset(z->state->blocks, z, Z_NULL);
  Tracev((stderr, "inflate: reset\n"));
  return Z_OK;
}


int ZEXPORT inflateEnd(z)
z_streamp z;
{
  if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
    return Z_STREAM_ERROR;
  if (z->state->blocks != Z_NULL)
    inflate_blocks_free(z->state->blocks, z);
  ZFREE(z, z->state);
  z->state = Z_NULL;
  Tracev((stderr, "inflate: end\n"));
  return Z_OK;
}


int ZEXPORT inflateInit2_(z, w, version, stream_size)
z_streamp z;
int w;
const char *version;
int stream_size;
{
  if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
      stream_size != sizeof(z_stream))
      return Z_VERSION_ERROR;

  /* initialize state */
  if (z == Z_NULL)
    return Z_STREAM_ERROR;
  z->msg = Z_NULL;
  if (z->zalloc == Z_NULL)
  {
    z->zalloc = zcalloc;
    z->opaque = (voidpf)0;
  }
  if (z->zfree == Z_NULL) z->zfree = zcfree;
  if ((z->state = (struct internal_state FAR *)
       ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
    return Z_MEM_ERROR;
  z->state->blocks = Z_NULL;

  /* handle undocumented nowrap option (no zlib header or check) */
  if (w < 0)
    w = - w;
  else
    return Z_STREAM_ERROR;

  /* set window size */
  if (w < 8 || w > 15)
  {
    inflateEnd(z);
    return Z_STREAM_ERROR;
  }
  z->state->wbits = (uInt)w;

  /* create inflate_blocks state */
  if ((z->state->blocks =
      inflate_blocks_new(z, Z_NULL, (uInt)1 << w))
      == Z_NULL)
  {
    inflateEnd(z);
    return Z_MEM_ERROR;
  }
  Tracev((stderr, "inflate: allocated\n"));

  /* reset state */
  inflateReset(z);
  return Z_OK;
}


int ZEXPORT inflateInit_(z, version, stream_size)
z_streamp z;
const char *version;
int stream_size;
{
  return inflateInit2_(z, -DEF_WBITS, version, stream_size);
}


#define NEEDBYTE {if(z->avail_in==0)return r;r=f;}
#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)

int ZEXPORT inflate(z, f)
z_streamp z;
int f;
{
  int r;

  if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
    return Z_STREAM_ERROR;
  f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
  r = Z_BUF_ERROR;
  while (1) switch (z->state->mode)
  {
    case BLOCKS:
      r = inflate_blocks(z->state->blocks, z, r);
      if (r == Z_DATA_ERROR)
      {
        z->state->mode = BAD;
        break;
      }
      if (r == Z_OK)
        r = f;
      if (r != Z_STREAM_END)
        return r;
      r = f;
      inflate_blocks_reset(z->state->blocks, z, Z_NULL);
      z->state->mode = DONE;
    case DONE:
      return Z_STREAM_END;
    case BAD:
      return Z_DATA_ERROR;
    default:
      return Z_STREAM_ERROR;
  }
#ifdef NEED_DUMMY_RETURN
  return Z_STREAM_ERROR;  /* Some dumb compilers complain without this */
#endif
}