/* 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 */
};
