/* infutil.h -- types and macros common to blocks and codes * Copyright (C) 1995-1998 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. */ #ifndef _INFUTIL_H #define _INFUTIL_H #include #include "inftrees.h" #include "infcodes.h" typedef enum { TYPE, /* get type bits (3, including end bit) */ LENS, /* get lengths for stored */ STORED, /* processing stored block */ TABLE, /* get table lengths */ BTREE, /* get bit lengths tree for a dynamic block */ DTREE, /* get length, distance trees for a dynamic block */ CODES, /* processing fixed or dynamic block */ DRY, /* output remaining window bytes */ B_DONE, /* finished last block, done */ B_BAD} /* got a data error--stuck here */ inflate_block_mode; /* inflate blocks semi-private state */ struct inflate_blocks_state { /* mode */ inflate_block_mode mode; /* current inflate_block mode */ /* mode dependent information */ union { uInt left; /* if STORED, bytes left to copy */ struct { uInt table; /* table lengths (14 bits) */ uInt index; /* index into blens (or border) */ uIntf *blens; /* bit lengths of codes */ uInt bb; /* bit length tree depth */ inflate_huft *tb; /* bit length decoding tree */ } trees; /* if DTREE, decoding info for trees */ struct { inflate_codes_statef *codes; } decode; /* if CODES, current state */ } sub; /* submode */ uInt last; /* true if this block is the last block */ /* mode independent information */ uInt bitk; /* bits in bit buffer */ uLong bitb; /* bit buffer */ inflate_huft *hufts; /* single malloc for tree space */ Bytef *window; /* sliding window */ Bytef *end; /* one byte after sliding window */ Bytef *read; /* window read pointer */ Bytef *write; /* window write pointer */ check_func checkfn; /* check function */ uLong check; /* check on output */ }; /* defines for inflate input/output */ /* update pointers and return */ #define UPDBITS {s->bitb=b;s->bitk=k;} #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} #define UPDOUT {s->write=q;} #define UPDATE {UPDBITS UPDIN UPDOUT} #define LEAVE {UPDATE return zlib_inflate_flush(s,z,r);} /* get bytes and bits */ #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} #define NEEDBYTE {if(n)r=Z_OK;else LEAVE} #define NEXTBYTE (n--,*p++) #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<>=(j);k-=(j);} /* output bytes */ #define WAVAIL (uInt)(qread?s->read-q-1:s->end-q) #define LOADOUT {q=s->write;m=(uInt)WAVAIL;} #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} #define FLUSH {UPDOUT r=zlib_inflate_flush(s,z,r); LOADOUT} #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;} #define OUTBYTE(a) {*q++=(Byte)(a);m--;} /* load local pointers */ #define LOAD {LOADIN LOADOUT} /* masks for lower bits (size given to avoid silly warnings with Visual C++) */ extern uInt zlib_inflate_mask[17]; /* copy as much as possible from the sliding window to the output area */ extern int zlib_inflate_flush OF(( inflate_blocks_statef *, z_streamp , int)); /* inflate private state */ typedef enum { METHOD, /* waiting for method byte */ FLAG, /* waiting for flag byte */ DICT4, /* four dictionary check bytes to go */ DICT3, /* three dictionary check bytes to go */ DICT2, /* two dictionary check bytes to go */ DICT1, /* one dictionary check byte to go */ DICT0, /* waiting for inflateSetDictionary */ BLOCKS, /* decompressing blocks */ CHECK4, /* four check bytes to go */ CHECK3, /* three check bytes to go */ CHECK2, /* two check bytes to go */ CHECK1, /* one check byte to go */ I_DONE, /* finished check, done */ I_BAD} /* got an error--stay here */ inflate_mode; struct internal_state { /* mode */ inflate_mode mode; /* current inflate mode */ /* mode dependent information */ union { uInt method; /* if FLAGS, method byte */ struct { uLong was; /* computed check value */ uLong need; /* stream check value */ } check; /* if CHECK, check values to compare */ uInt marker; /* if BAD, inflateSync's marker bytes count */ } sub; /* submode */ /* mode independent information */ int nowrap; /* flag for no wrapper */ uInt wbits; /* log2(window size) (8..15, defaults to 15) */ inflate_blocks_statef *blocks; /* current inflate_blocks state */ }; /* inflate codes private state */ 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; 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 */ }; /* memory allocation for inflation */ struct inflate_workspace { inflate_codes_statef working_state; struct inflate_blocks_state working_blocks_state; struct internal_state internal_state; unsigned int tree_work_area_1[19]; unsigned int tree_work_area_2[288]; unsigned working_blens[258 + 0x1f + 0x1f]; inflate_huft working_hufts[MANY]; unsigned char working_window[1 << MAX_WBITS]; }; #define WS(z) ((struct inflate_workspace *)(z->workspace)) #endif