/* inflate.h -- internal inflate state definition
 * Copyright (C) 1995-2004 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* WARNING: this file should *not* be used by applications. It is
   part of the implementation of the compression library and is
   subject to change. Applications should only use zlib.h.
 */

/* define NO_GZIP when compiling if you want to disable gzip header and
   trailer decoding by inflate().  NO_GZIP would be used to avoid linking in
   the crc code when it is not needed.  For shared libraries, gzip decoding
   should be left enabled. */
#ifndef NO_GZIP
#  define GUNZIP
#endif

/* Possible inflate modes between inflate() calls */
typedef enum {
    HEAD,       /* i: waiting for magic header */
    FLAGS,      /* i: waiting for method and flags (gzip) */
    TIME,       /* i: waiting for modification time (gzip) */
    OS,	 /* i: waiting for extra flags and operating system (gzip) */
    EXLEN,      /* i: waiting for extra length (gzip) */
    EXTRA,      /* i: waiting for extra bytes (gzip) */
    NAME,       /* i: waiting for end of file name (gzip) */
    COMMENT,    /* i: waiting for end of comment (gzip) */
    HCRC,       /* i: waiting for header crc (gzip) */
    DICTID,     /* i: waiting for dictionary check value */
    DICT,       /* waiting for inflateSetDictionary() call */
	TYPE,       /* i: waiting for type bits, including last-flag bit */
	TYPEDO,     /* i: same, but skip check to exit inflate on new block */
	STORED,     /* i: waiting for stored size (length and complement) */
	COPY,       /* i/o: waiting for input or output to copy stored block */
	TABLE,      /* i: waiting for dynamic block table lengths */
	LENLENS,    /* i: waiting for code length code lengths */
	CODELENS,   /* i: waiting for length/lit and distance code lengths */
	    LEN,	/* i: waiting for length/lit code */
	    LENEXT,     /* i: waiting for length extra bits */
	    DIST,       /* i: waiting for distance code */
	    DISTEXT,    /* i: waiting for distance extra bits */
	    MATCH,      /* o: waiting for output space to copy string */
	    LIT,	/* o: waiting for output space to write literal */
    CHECK,      /* i: waiting for 32-bit check value */
    LENGTH,     /* i: waiting for 32-bit length (gzip) */
    DONE,       /* finished check, done -- remain here until reset */
    BAD,	/* got a data error -- remain here until reset */
    MEM,	/* got an inflate() memory error -- remain here until reset */
    SYNC	/* looking for synchronization bytes to restart inflate() */
} inflate_mode;

/*
    State transitions between above modes -

    (most modes can go to the BAD or MEM mode -- not shown for clarity)

    Process header:
	HEAD -> (gzip) or (zlib)
	(gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME
	NAME -> COMMENT -> HCRC -> TYPE
	(zlib) -> DICTID or TYPE
	DICTID -> DICT -> TYPE
    Read deflate blocks:
	    TYPE -> STORED or TABLE or LEN or CHECK
	    STORED -> COPY -> TYPE
	    TABLE -> LENLENS -> CODELENS -> LEN
    Read deflate codes:
		LEN -> LENEXT or LIT or TYPE
		LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
		LIT -> LEN
    Process trailer:
	CHECK -> LENGTH -> DONE
 */

/* state maintained between inflate() calls.  Approximately 7K bytes. */
struct inflate_state {
    inflate_mode mode;	  /* current inflate mode */
    int last;		   /* true if processing last block */
    int wrap;		   /* bit 0 true for zlib, bit 1 true for gzip */
    int havedict;	       /* true if dictionary provided */
    int flags;		  /* gzip header method and flags (0 if zlib) */
    unsigned dmax;	      /* zlib header max distance (INFLATE_STRICT) */
    unsigned long check;	/* protected copy of check value */
    unsigned long total;	/* protected copy of output count */
    gz_headerp head;	    /* where to save gzip header information */
	/* sliding window */
    unsigned wbits;	     /* log base 2 of requested window size */
    unsigned wsize;	     /* window size or zero if not using window */
    unsigned whave;	     /* valid bytes in the window */
    unsigned write;	     /* window write index */
    unsigned char FAR *window;  /* allocated sliding window, if needed */
	/* bit accumulator */
    unsigned long hold;	 /* input bit accumulator */
    unsigned bits;	      /* number of bits in "in" */
	/* for string and stored block copying */
    unsigned length;	    /* literal or length of data to copy */
    unsigned offset;	    /* distance back to copy string from */
	/* for table and code decoding */
    unsigned extra;	     /* extra bits needed */
	/* fixed and dynamic code tables */
    code const FAR *lencode;    /* starting table for length/literal codes */
    code const FAR *distcode;   /* starting table for distance codes */
    unsigned lenbits;	   /* index bits for lencode */
    unsigned distbits;	  /* index bits for distcode */
	/* dynamic table building */
    unsigned ncode;	     /* number of code length code lengths */
    unsigned nlen;	      /* number of length code lengths */
    unsigned ndist;	     /* number of distance code lengths */
    unsigned have;	      /* number of code lengths in lens[] */
    code FAR *next;	     /* next available space in codes[] */
    unsigned short lens[320];   /* temporary storage for code lengths */
    unsigned short work[288];   /* work area for code table building */
    code codes[ENOUGH];	 /* space for code tables */
};
