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XCrashReport : Exception Handling and Crash Reporting - Part 4

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Add basic exception handling and crash reporting to your application
// XZip.cpp  Version 1.1
//
// Authors:      Mark Adler et al. (see below)
//
// Modified by:  Lucian Wischik
//               lu@wischik.com
//
// Version 1.0   - Turned C files into just a single CPP file
//               - Made them compile cleanly as C++ files
//               - Gave them simpler APIs
//               - Added the ability to zip/unzip directly in memory without 
//                 any intermediate files
// 
// Modified by:  Hans Dietrich
//               hdietrich2@hotmail.com
//
// Version 1.1:  - Added Unicode support to CreateZip() and ZipAdd()
//               - Changed file names to avoid conflicts with Lucian's files
//
///////////////////////////////////////////////////////////////////////////////
//
// Lucian Wischik's comments:
// --------------------------
// THIS FILE is almost entirely based upon code by Info-ZIP.
// It has been modified by Lucian Wischik.
// The original code may be found at http://www.info-zip.org
// The original copyright text follows.
//
///////////////////////////////////////////////////////////////////////////////
//
// Original authors' comments:
// ---------------------------
// This is version 2002-Feb-16 of the Info-ZIP copyright and license. The 
// definitive version of this document should be available at 
// ftp://ftp.info-zip.org/pub/infozip/license.html indefinitely.
// 
// Copyright (c) 1990-2002 Info-ZIP.  All rights reserved.
//
// For the purposes of this copyright and license, "Info-ZIP" is defined as
// the following set of individuals:
//
//   Mark Adler, John Bush, Karl Davis, Harald Denker, Jean-Michel Dubois,
//   Jean-loup Gailly, Hunter Goatley, Ian Gorman, Chris Herborth, Dirk Haase,
//   Greg Hartwig, Robert Heath, Jonathan Hudson, Paul Kienitz, 
//   David Kirschbaum, Johnny Lee, Onno van der Linden, Igor Mandrichenko, 
//   Steve P. Miller, Sergio Monesi, Keith Owens, George Petrov, Greg Roelofs, 
//   Kai Uwe Rommel, Steve Salisbury, Dave Smith, Christian Spieler, 
//   Antoine Verheijen, Paul von Behren, Rich Wales, Mike White
//
// This software is provided "as is", without warranty of any kind, express
// or implied.  In no event shall Info-ZIP or its contributors be held liable
// for any direct, indirect, incidental, special or consequential damages
// arising out of the use of or inability to use this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
//    1. Redistributions of source code must retain the above copyright notice,
//       definition, disclaimer, and this list of conditions.
//
//    2. Redistributions in binary form (compiled executables) must reproduce 
//       the above copyright notice, definition, disclaimer, and this list of 
//       conditions in documentation and/or other materials provided with the 
//       distribution. The sole exception to this condition is redistribution 
//       of a standard UnZipSFX binary as part of a self-extracting archive; 
//       that is permitted without inclusion of this license, as long as the 
//       normal UnZipSFX banner has not been removed from the binary or disabled.
//
//    3. Altered versions--including, but not limited to, ports to new 
//       operating systems, existing ports with new graphical interfaces, and 
//       dynamic, shared, or static library versions--must be plainly marked 
//       as such and must not be misrepresented as being the original source.  
//       Such altered versions also must not be misrepresented as being 
//       Info-ZIP releases--including, but not limited to, labeling of the 
//       altered versions with the names "Info-ZIP" (or any variation thereof, 
//       including, but not limited to, different capitalizations), 
//       "Pocket UnZip", "WiZ" or "MacZip" without the explicit permission of 
//       Info-ZIP.  Such altered versions are further prohibited from 
//       misrepresentative use of the Zip-Bugs or Info-ZIP e-mail addresses or 
//       of the Info-ZIP URL(s).
//
//    4. Info-ZIP retains the right to use the names "Info-ZIP", "Zip", "UnZip",
//       "UnZipSFX", "WiZ", "Pocket UnZip", "Pocket Zip", and "MacZip" for its 
//       own source and binary releases.
//
///////////////////////////////////////////////////////////////////////////////

#define STRICT
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <time.h>
#include "xzip.h"


typedef unsigned char uch;      // unsigned 8-bit value
typedef unsigned short ush;     // unsigned 16-bit value
typedef unsigned long ulg;      // unsigned 32-bit value
typedef size_t extent;          // file size
typedef unsigned Pos;   // must be at least 32 bits
typedef unsigned IPos; // A Pos is an index in the character window. Pos is used only for parameter passing

#ifndef EOF
#define EOF (-1)
#endif


// Error return values.  The values 0..4 and 12..18 follow the conventions
// of PKZIP.   The values 4..10 are all assigned to "insufficient memory"
// by PKZIP, so the codes 5..10 are used here for other purposes.
#define ZE_MISS         -1      // used by procname(), zipbare()
#define ZE_OK           0       // success
#define ZE_EOF          2       // unexpected end of zip file
#define ZE_FORM         3       // zip file structure error
#define ZE_MEM          4       // out of memory
#define ZE_LOGIC        5       // internal logic error
#define ZE_BIG          6       // entry too large to split
#define ZE_NOTE         7       // invalid comment format
#define ZE_TEST         8       // zip test (-T) failed or out of memory
#define ZE_ABORT        9       // user interrupt or termination
#define ZE_TEMP         10      // error using a temp file
#define ZE_READ         11      // read or seek error
#define ZE_NONE         12      // nothing to do
#define ZE_NAME         13      // missing or empty zip file
#define ZE_WRITE        14      // error writing to a file
#define ZE_CREAT        15      // couldn't open to write
#define ZE_PARMS        16      // bad command line
#define ZE_OPEN         18      // could not open a specified file to read
#define ZE_MAXERR       18      // the highest error number


// internal file attribute
#define UNKNOWN (-1)
#define BINARY  0
#define ASCII   1

#define BEST -1                 // Use best method (deflation or store)
#define STORE 0                 // Store method
#define DEFLATE 8               // Deflation method

#define CRCVAL_INITIAL  0L

// MSDOS file or directory attributes
#define MSDOS_HIDDEN_ATTR 0x02
#define MSDOS_DIR_ATTR 0x10

// Lengths of headers after signatures in bytes
#define LOCHEAD 26
#define CENHEAD 42
#define ENDHEAD 18

// Definitions for extra field handling:
#define EB_HEADSIZE       4     /* length of a extra field block header */
#define EB_LEN            2     /* offset of data length field in header */
#define EB_UT_MINLEN      1     /* minimal UT field contains Flags byte */
#define EB_UT_FLAGS       0     /* byte offset of Flags field */
#define EB_UT_TIME1       1     /* byte offset of 1st time value */
#define EB_UT_FL_MTIME    (1 << 0)      /* mtime present */
#define EB_UT_FL_ATIME    (1 << 1)      /* atime present */
#define EB_UT_FL_CTIME    (1 << 2)      /* ctime present */
#define EB_UT_LEN(n)      (EB_UT_MINLEN + 4 * (n))
#define EB_L_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(3))
#define EB_C_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(1))


// Macros for writing machine integers to little-endian format
#define PUTSH(a,f) {char _putsh_c=(char)((a)&0xff); wfunc(param,&_putsh_c,1); _putsh_c=(char)((a)>>8); wfunc(param,&_putsh_c,1);}
#define PUTLG(a,f) {PUTSH((a) & 0xffff,(f)) PUTSH((a) >> 16,(f))}


// -- Structure of a ZIP file --
// Signatures for zip file information headers
#define LOCSIG     0x04034b50L
#define CENSIG     0x02014b50L
#define ENDSIG     0x06054b50L
#define EXTLOCSIG  0x08074b50L


#define MIN_MATCH  3
#define MAX_MATCH  258
// The minimum and maximum match lengths


#define WSIZE  (0x8000)
// Maximum window size = 32K. If you are really short of memory, compile
// with a smaller WSIZE but this reduces the compression ratio for files
// of size > WSIZE. WSIZE must be a power of two in the current implementation.
//

#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
// Minimum amount of lookahead, except at the end of the input file.
// See deflate.c for comments about the MIN_MATCH+1.
//

#define MAX_DIST  (WSIZE-MIN_LOOKAHEAD)
// In order to simplify the code, particularly on 16 bit machines, match
// distances are limited to MAX_DIST instead of WSIZE.
//





// ===========================================================================
// Constants
//

#define MAX_BITS 15
// All codes must not exceed MAX_BITS bits

#define MAX_BL_BITS 7
// Bit length codes must not exceed MAX_BL_BITS bits

#define LENGTH_CODES 29
// number of length codes, not counting the special END_BLOCK code

#define LITERALS  256
// number of literal bytes 0..255

#define END_BLOCK 256
// end of block literal code

#define L_CODES (LITERALS+1+LENGTH_CODES)
// number of Literal or Length codes, including the END_BLOCK code

#define D_CODES   30
// number of distance codes

#define BL_CODES  19
// number of codes used to transfer the bit lengths


#define STORED_BLOCK 0
#define STATIC_TREES 1
#define DYN_TREES    2
// The three kinds of block type

#define LIT_BUFSIZE  0x8000
#define DIST_BUFSIZE  LIT_BUFSIZE
// Sizes of match buffers for literals/lengths and distances.  There are
// 4 reasons for limiting LIT_BUFSIZE to 64K:
//   - frequencies can be kept in 16 bit counters
//   - if compression is not successful for the first block, all input data is
//     still in the window so we can still emit a stored block even when input
//     comes from standard input.  (This can also be done for all blocks if
//     LIT_BUFSIZE is not greater than 32K.)
//   - if compression is not successful for a file smaller than 64K, we can
//     even emit a stored file instead of a stored block (saving 5 bytes).
//   - creating new Huffman trees less frequently may not provide fast
//     adaptation to changes in the input data statistics. (Take for
//     example a binary file with poorly compressible code followed by
//     a highly compressible string table.) Smaller buffer sizes give
//     fast adaptation but have of course the overhead of transmitting trees
//     more frequently.
//   - I can't count above 4
// The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
// memory at the expense of compression). Some optimizations would be possible
// if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
//

#define REP_3_6      16
// repeat previous bit length 3-6 times (2 bits of repeat count)

#define REPZ_3_10    17
// repeat a zero length 3-10 times  (3 bits of repeat count)

#define REPZ_11_138  18
// repeat a zero length 11-138 times  (7 bits of repeat count)

#define HEAP_SIZE (2*L_CODES+1)
// maximum heap size


// ===========================================================================
// Local data used by the "bit string" routines.
//

#define Buf_size (8 * 2*sizeof(char))
// Number of bits used within bi_buf. (bi_buf may be implemented on
// more than 16 bits on some systems.)

// Output a 16 bit value to the bit stream, lower (oldest) byte first
#define PUTSHORT(state,w) \
{ if (state.bs.out_offset >= state.bs.out_size-1) \
    state.flush_outbuf(state.param,state.bs.out_buf, &state.bs.out_offset); \
  state.bs.out_buf[state.bs.out_offset++] = (char) ((w) & 0xff); \
  state.bs.out_buf[state.bs.out_offset++] = (char) ((ush)(w) >> 8); \
}

#define PUTBYTE(state,b) \
{ if (state.bs.out_offset >= state.bs.out_size) \
    state.flush_outbuf(state.param,state.bs.out_buf, &state.bs.out_offset); \
  state.bs.out_buf[state.bs.out_offset++] = (char) (b); \
}

// DEFLATE.CPP HEADER

#define HASH_BITS  15
// For portability to 16 bit machines, do not use values above 15.

#define HASH_SIZE (unsigned)(1<<HASH_BITS)
#define HASH_MASK (HASH_SIZE-1)
#define WMASK     (WSIZE-1)
// HASH_SIZE and WSIZE must be powers of two

#define NIL 0
// Tail of hash chains

#define FAST 4
#define SLOW 2
// speed options for the general purpose bit flag

#define TOO_FAR 4096
// Matches of length 3 are discarded if their distance exceeds TOO_FAR



#define EQUAL 0
// result of memcmp for equal strings


// ===========================================================================
// Local data used by the "longest match" routines.

#define H_SHIFT  ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
// Number of bits by which ins_h and del_h must be shifted at each
// input step. It must be such that after MIN_MATCH steps, the oldest
// byte no longer takes part in the hash key, that is:
//   H_SHIFT * MIN_MATCH >= HASH_BITS

#define max_insert_length  max_lazy_match
// Insert new strings in the hash table only if the match length
// is not greater than this length. This saves time but degrades compression.
// max_insert_length is used only for compression levels <= 3.



const int extra_lbits[LENGTH_CODES] // extra bits for each length code
   = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};

const int extra_dbits[D_CODES] // extra bits for each distance code
   = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};

const int extra_blbits[BL_CODES]// extra bits for each bit length code
   = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};

const uch bl_order[BL_CODES] = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
// The lengths of the bit length codes are sent in order of decreasing
// probability, to avoid transmitting the lengths for unused bit length codes.


typedef struct config {
   ush good_length; // reduce lazy search above this match length
   ush max_lazy;    // do not perform lazy search above this match length
   ush nice_length; // quit search above this match length
   ush max_chain;
} config;

// Values for max_lazy_match, good_match, nice_match and max_chain_length,
// depending on the desired pack level (0..9). The values given below have
// been tuned to exclude worst case performance for pathological files.
// Better values may be found for specific files.
//

const config configuration_table[10] = {
//  good lazy nice chain
    {0,    0,  0,    0},  // 0 store only
    {4,    4,  8,    4},  // 1 maximum speed, no lazy matches
    {4,    5, 16,    8},  // 2
    {4,    6, 32,   32},  // 3
    {4,    4, 16,   16},  // 4 lazy matches */
    {8,   16, 32,   32},  // 5
    {8,   16, 128, 128},  // 6
    {8,   32, 128, 256},  // 7
    {32, 128, 258, 1024}, // 8
    {32, 258, 258, 4096}};// 9 maximum compression */

// Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
// For deflate_fast() (levels <= 3) good is ignored and lazy has a different meaning.





// Data structure describing a single value and its code string.
typedef struct ct_data {
    union {
        ush  freq;       // frequency count
        ush  code;       // bit string
    } fc;
    union {
        ush  dad;        // father node in Huffman tree
        ush  len;        // length of bit string
    } dl;
} ct_data;

typedef struct tree_desc {
    ct_data *dyn_tree;      // the dynamic tree
    ct_data *static_tree;   // corresponding static tree or NULL
    const int *extra_bits;  // extra bits for each code or NULL
    int     extra_base;     // base index for extra_bits
    int     elems;          // max number of elements in the tree
    int     max_length;     // max bit length for the codes
    int     max_code;       // largest code with non zero frequency
} tree_desc;




class TTreeState
{ public:
  TTreeState();

  ct_data dyn_ltree[HEAP_SIZE];    // literal and length tree
  ct_data dyn_dtree[2*D_CODES+1];  // distance tree
  ct_data static_ltree[L_CODES+2]; // the static literal tree...
  // ... Since the bit lengths are imposed, there is no need for the L_CODES
  // extra codes used during heap construction. However the codes 286 and 287
  // are needed to build a canonical tree (see ct_init below).
  ct_data static_dtree[D_CODES]; // the static distance tree...
  // ... (Actually a trivial tree since all codes use 5 bits.)
  ct_data bl_tree[2*BL_CODES+1];  // Huffman tree for the bit lengths

  tree_desc l_desc;
  tree_desc d_desc;
  tree_desc bl_desc;

  ush bl_count[MAX_BITS+1];  // number of codes at each bit length for an optimal tree

  int heap[2*L_CODES+1]; // heap used to build the Huffman trees
  int heap_len;               // number of elements in the heap
  int heap_max;               // element of largest frequency
  // The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
  // The same heap array is used to build all trees.

  uch depth[2*L_CODES+1];
  // Depth of each subtree used as tie breaker for trees of equal frequency

  uch length_code[MAX_MATCH-MIN_MATCH+1];
  // length code for each normalized match length (0 == MIN_MATCH)

  uch dist_code[512];
  // distance codes. The first 256 values correspond to the distances
  // 3 .. 258, the last 256 values correspond to the top 8 bits of
  // the 15 bit distances.

  int base_length[LENGTH_CODES];
  // First normalized length for each code (0 = MIN_MATCH)

  int base_dist[D_CODES];
  // First normalized distance for each code (0 = distance of 1)

  uch far l_buf[LIT_BUFSIZE];  // buffer for literals/lengths
  ush far d_buf[DIST_BUFSIZE]; // buffer for distances

  uch flag_buf[(LIT_BUFSIZE/8)];
  // flag_buf is a bit array distinguishing literals from lengths in
  // l_buf, and thus indicating the presence or absence of a distance.

  unsigned last_lit;    // running index in l_buf
  unsigned last_dist;   // running index in d_buf
  unsigned last_flags;  // running index in flag_buf
  uch flags;            // current flags not yet saved in flag_buf
  uch flag_bit;         // current bit used in flags
  // bits are filled in flags starting at bit 0 (least significant).
  // Note: these flags are overkill in the current code since we don't
  // take advantage of DIST_BUFSIZE == LIT_BUFSIZE.

  ulg opt_len;          // bit length of current block with optimal trees
  ulg static_len;       // bit length of current block with static trees

  ulg cmpr_bytelen;     // total byte length of compressed file
  ulg cmpr_len_bits;    // number of bits past 'cmpr_bytelen'

  ulg input_len;        // total byte length of input file
  // input_len is for debugging only since we can get it by other means.

  ush *file_type;       // pointer to UNKNOWN, BINARY or ASCII
//  int *file_method;     // pointer to DEFLATE or STORE
};

TTreeState::TTreeState()
{ tree_desc a = {dyn_ltree, static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS, 0};  l_desc = a;
  tree_desc b = {dyn_dtree, static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS, 0};  d_desc = b;
  tree_desc c = {bl_tree, NULL,       extra_blbits, 0,         BL_CODES, MAX_BL_BITS, 0};  bl_desc = c;
  last_lit=0;
  last_dist=0;
  last_flags=0;
}



class TBitState
{ public:

  int flush_flg;
  //
  unsigned bi_buf;
  // Output buffer. bits are inserted starting at the bottom (least significant
  // bits). The width of bi_buf must be at least 16 bits.
  int bi_valid;
  // Number of valid bits in bi_buf.  All bits above the last valid bit
  // are always zero.
  char *out_buf;
  // Current output buffer.
  unsigned out_offset;
  // Current offset in output buffer.
  // On 16 bit machines, the buffer is limited to 64K.
  unsigned out_size;
  // Size of current output buffer
  ulg bits_sent;   // bit length of the compressed data  only needed for debugging???
};







class TDeflateState
{ public:
  TDeflateState() {window_size=0;}

  uch    window[2L*WSIZE];
  // Sliding window. Input bytes are read into the second half of the window,
  // and move to the first half later to keep a dictionary of at least WSIZE
  // bytes. With this organization, matches are limited to a distance of
  // WSIZE-MAX_MATCH bytes, but this ensures that IO is always
  // performed with a length multiple of the block size. Also, it limits
  // the window size to 64K, which is quite useful on MSDOS.
  // To do: limit the window size to WSIZE+CBSZ if SMALL_MEM (the code would
  // be less efficient since the data would have to be copied WSIZE/CBSZ times)
  Pos    prev[WSIZE];
  // Link to older string with same hash index. To limit the size of this
  // array to 64K, this link is maintained only for the last 32K strings.
  // An index in this array is thus a window index modulo 32K.
  Pos    head[HASH_SIZE];
  // Heads of the hash chains or NIL. If your compiler thinks that
  // HASH_SIZE is a dynamic value, recompile with -DDYN_ALLOC.

  ulg window_size;
  // window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
  // input file length plus MIN_LOOKAHEAD.

  long block_start;
  // window position at the beginning of the current output block. Gets
  // negative when the window is moved backwards.

  int sliding;
  // Set to false when the input file is already in memory

  unsigned ins_h;  // hash index of string to be inserted

  unsigned int prev_length;
  // Length of the best match at previous step. Matches not greater than this
  // are discarded. This is used in the lazy match evaluation.

  unsigned strstart;         // start of string to insert
  unsigned match_start; // start of matching string
  int      eofile;           // flag set at end of input file
  unsigned lookahead;        // number of valid bytes ahead in window

  unsigned max_chain_length;
  // To speed up deflation, hash chains are never searched beyond this length.
  // A higher limit improves compression ratio but degrades the speed.

  unsigned int max_lazy_match;
  // Attempt to find a better match only when the current match is strictly
  // smaller than this value. This mechanism is used only for compression
  // levels >= 4.

  unsigned good_match;
  // Use a faster search when the previous match is longer than this

  int nice_match; // Stop searching when current match exceeds this
};


typedef struct iztimes {
  time_t atime,mtime,ctime;
} iztimes; // access, modify, create times

typedef struct zlist {
  ush vem, ver, flg, how;       // See central header in zipfile.c for what vem..off are
  ulg tim, crc, siz, len;
  extent nam, ext, cext, com;   // offset of ext must be >= LOCHEAD
  ush dsk, att, lflg;           // offset of lflg must be >= LOCHEAD
  ulg atx, off;
  char name[MAX_PATH];                   // File name in zip file
  char *extra;                  // Extra field (set only if ext != 0)
  char *cextra;                 // Extra in central (set only if cext != 0)
  char *comment;                // Comment (set only if com != 0)
  char iname[MAX_PATH];                  // Internal file name after cleanup
  char zname[MAX_PATH];                  // External version of internal name
  int mark;                     // Marker for files to operate on
  int trash;                    // Marker for files to delete
  int dosflag;                  // Set to force MSDOS file attributes
  struct zlist far *nxt;        // Pointer to next header in list
} TZipFileInfo;


class TState;
typedef unsigned (*READFUNC)(TState &state, char *buf,unsigned size);
typedef unsigned (*FLUSHFUNC)(void *param, const char *buf, unsigned *size);
typedef unsigned (*WRITEFUNC)(void *param, const char *buf, unsigned size);
class TState
{ public: TState() {err=0;}
  //
  void *param;
  int level; bool seekable;
  READFUNC readfunc; FLUSHFUNC flush_outbuf;
  TTreeState ts; TBitState bs; TDeflateState ds;
  const char *err;
};









void Assert(TState &state,bool cond, const char *msg)
{ if (cond) return;
  state.err=msg;
}
void __cdecl Trace(const char *x, ...) {va_list paramList; va_start(paramList, x); paramList; va_end(paramList);}
void __cdecl Tracec(bool ,const char *x, ...) {va_list paramList; va_start(paramList, x); paramList; va_end(paramList);}



// ===========================================================================
// Local (static) routines in this file.
//

void init_block     (TState &);
void pqdownheap     (TState &,ct_data *tree, int k);
void gen_bitlen     (TState &,tree_desc *desc);
void gen_codes      (TState &state,ct_data *tree, int max_code);
void build_tree     (TState &,tree_desc *desc);
void scan_tree      (TState &,ct_data *tree, int max_code);
void send_tree      (TState &state,ct_data *tree, int max_code);
int  build_bl_tree  (TState &);
void send_all_trees (TState &state,int lcodes, int dcodes, int blcodes);
void compress_block (TState &state,ct_data *ltree, ct_data *dtree);
void set_file_type  (TState &);
void send_bits      (TState &state, int value, int length);
unsigned bi_reverse (unsigned code, int len);
void bi_windup      (TState &state);
void copy_block     (TState &state,char *buf, unsigned len, int header);


#define send_code(state, c, tree) send_bits(state, tree[c].fc.code, tree[c].dl.len)
// Send a code of the given tree. c and tree must not have side effects

// alternatively...
//#define send_code(state, c, tree)
//     { if (state.verbose>1) fprintf(stderr,"\ncd %3d ",(c));
//       send_bits(state, tree[c].fc.code, tree[c].dl.len); }

#define d_code(dist) ((dist) < 256 ? state.ts.dist_code[dist] : state.ts.dist_code[256+((dist)>>7)])
// Mapping from a distance to a distance code. dist is the distance - 1 and
// must not have side effects. dist_code[256] and dist_code[257] are never used.

#define Max(a,b) (a >= b ? a : b)
/* the arguments must not have side effects */

/* ===========================================================================
 * Allocate the match buffer, initialize the various tables and save the
 * location of the internal file attribute (ascii/binary) and method
 * (DEFLATE/STORE).
 */
void ct_init(TState &state, ush *attr)
{
    int n;        /* iterates over tree elements */
    int bits;     /* bit counter */
    int length;   /* length value */
    int code;     /* code value */
    int dist;     /* distance index */

    state.ts.file_type = attr;
    //state.ts.file_method = method;
    state.ts.cmpr_bytelen = state.ts.cmpr_len_bits = 0L;
    state.ts.input_len = 0L;

    if (state.ts.static_dtree[0].dl.len != 0) return; /* ct_init already called */

    /* Initialize the mapping length (0..255) -> length code (0..28) */
    length = 0;
    for (code = 0; code < LENGTH_CODES-1; code++) {
        state.ts.base_length[code] = length;
        for (n = 0; n < (1<<extra_lbits[code]); n++) {
            state.ts.length_code[length++] = (uch)code;
        }
    }
    Assert(state,length == 256, "ct_init: length != 256");
    /* Note that the length 255 (match length 258) can be represented
     * in two different ways: code 284 + 5 bits or code 285, so we
     * overwrite length_code[255] to use the best encoding:
     */
    state.ts.length_code[length-1] = (uch)code;

    /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
    dist = 0;
    for (code = 0 ; code < 16; code++) {
        state.ts.base_dist[code] = dist;
        for (n = 0; n < (1<<extra_dbits[code]); n++) {
            state.ts.dist_code[dist++] = (uch)code;
        }
    }
    Assert(state,dist == 256, "ct_init: dist != 256");
    dist >>= 7; /* from now on, all distances are divided by 128 */
    for ( ; code < D_CODES; code++) {
        state.ts.base_dist[code] = dist << 7;
        for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
            state.ts.dist_code[256 + dist++] = (uch)code;
        }
    }
    Assert(state,dist == 256, "ct_init: 256+dist != 512");

    /* Construct the codes of the static literal tree */
    for (bits = 0; bits <= MAX_BITS; bits++) state.ts.bl_count[bits] = 0;
    n = 0;
    while (n <= 143) state.ts.static_ltree[n++].dl.len = 8, state.ts.bl_count[8]++;
    while (n <= 255) state.ts.static_ltree[n++].dl.len = 9, state.ts.bl_count[9]++;
    while (n <= 279) state.ts.static_ltree[n++].dl.len = 7, state.ts.bl_count[7]++;
    while (n <= 287) state.ts.static_ltree[n++].dl.len = 8, state.ts.bl_count[8]++;
    /* fc.codes 286 and 287 do not exist, but we must include them in the
     * tree construction to get a canonical Huffman tree (longest code
     * all ones)
     */
    gen_codes(state,(ct_data *)state.ts.static_ltree, L_CODES+1);

    /* The static distance tree is trivial: */
    for (n = 0; n < D_CODES; n++) {
        state.ts.static_dtree[n].dl.len = 5;
        state.ts.static_dtree[n].fc.code = (ush)bi_reverse(n, 5);
    }

    /* Initialize the first block of the first file: */
    init_block(state);
}

/* ===========================================================================
 * Initialize a new block.
 */
void init_block(TState &state)
{
    int n; /* iterates over tree elements */

    /* Initialize the trees. */
    for (n = 0; n < L_CODES;  n++) state.ts.dyn_ltree[n].fc.freq = 0;
    for (n = 0; n < D_CODES;  n++) state.ts.dyn_dtree[n].fc.freq = 0;
    for (n = 0; n < BL_CODES; n++) state.ts.bl_tree[n].fc.freq = 0;

    state.ts.dyn_ltree[END_BLOCK].fc.freq = 1;
    state.ts.opt_len = state.ts.static_len = 0L;
    state.ts.last_lit = state.ts.last_dist = state.ts.last_flags = 0;
    state.ts.flags = 0; state.ts.flag_bit = 1;
}

#define SMALLEST 1
/* Index within the heap array of least frequent node in the Huffman tree */


/* ===========================================================================
 * Remove the smallest element from the heap and recreate the heap with
 * one less element. Updates heap and heap_len.
 */
#define pqremove(tree, top) \
{\
    top = state.ts.heap[SMALLEST]; \
    state.ts.heap[SMALLEST] = state.ts.heap[state.ts.heap_len--]; \
    pqdownheap(state,tree, SMALLEST); \
}

/* ===========================================================================
 * Compares to subtrees, using the tree depth as tie breaker when
 * the subtrees have equal frequency. This minimizes the worst case length.
 */
#define smaller(tree, n, m) \
   (tree[n].fc.freq < tree[m].fc.freq || \
   (tree[n].fc.freq == tree[m].fc.freq && state.ts.depth[n] <= state.ts.depth[m]))

/* ===========================================================================
 * Restore the heap property by moving down the tree starting at node k,
 * exchanging a node with the smallest of its two sons if necessary, stopping
 * when the heap property is re-established (each father smaller than its
 * two sons).
 */
void pqdownheap(TState &state,ct_data *tree, int k)
{
    int v = state.ts.heap[k];
    int j = k << 1;  /* left son of k */
    int htemp;       /* required because of bug in SASC compiler */

    while (j <= state.ts.heap_len) {
        /* Set j to the smallest of the two sons: */
        if (j < state.ts.heap_len && smaller(tree, state.ts.heap[j+1], state.ts.heap[j])) j++;

        /* Exit if v is smaller than both sons */
        htemp = state.ts.heap[j];
        if (smaller(tree, v, htemp)) break;

        /* Exchange v with the smallest son */
        state.ts.heap[k] = htemp;
        k = j;

        /* And continue down the tree, setting j to the left son of k */
        j <<= 1;
    }
    state.ts.heap[k] = v;
}

/* ===========================================================================
 * Compute the optimal bit lengths for a tree and update the total bit length
 * for the current block.
 * IN assertion: the fields freq and dad are set, heap[heap_max] and
 *    above are the tree nodes sorted by increasing frequency.
 * OUT assertions: the field len is set to the optimal bit length, the
 *     array bl_count contains the frequencies for each bit length.
 *     The length opt_len is updated; static_len is also updated if stree is
 *     not null.
 */
void gen_bitlen(TState &state,tree_desc *desc)
{
    ct_data *tree  = desc->dyn_tree;
    const int *extra     = desc->extra_bits;
    int base            = desc->extra_base;
    int max_code        = desc->max_code;
    int max_length      = desc->max_length;
    ct_data *stree = desc->static_tree;
    int h;              /* heap index */
    int n, m;           /* iterate over the tree elements */
    int bits;           /* bit length */
    int xbits;          /* extra bits */
    ush f;              /* frequency */
    int overflow = 0;   /* number of elements with bit length too large */

    for (bits = 0; bits <= MAX_BITS; bits++) state.ts.bl_count[bits] = 0;

    /* In a first pass, compute the optimal bit lengths (which may
     * overflow in the case of the bit length tree).
     */
    tree[state.ts.heap[state.ts.heap_max]].dl.len = 0; /* root of the heap */

    for (h = state.ts.heap_max+1; h < HEAP_SIZE; h++) {
        n = state.ts.heap[h];
        bits = tree[tree[n].dl.dad].dl.len + 1;
        if (bits > max_length) bits = max_length, overflow++;
        tree[n].dl.len = (ush)bits;
        /* We overwrite tree[n].dl.dad which is no longer needed */

        if (n > max_code) continue; /* not a leaf node */

        state.ts.bl_count[bits]++;
        xbits = 0;
        if (n >= base) xbits = extra[n-base];
        f = tree[n].fc.freq;
        state.ts.opt_len += (ulg)f * (bits + xbits);
        if (stree) state.ts.static_len += (ulg)f * (stree[n].dl.len + xbits);
    }
    if (overflow == 0) return;

    Trace("\nbit length overflow\n");
    /* This happens for example on obj2 and pic of the Calgary corpus */

    /* Find the first bit length which could increase: */
    do {
        bits = max_length-1;
        while (state.ts.bl_count[bits] == 0) bits--;
        state.ts.bl_count[bits]--;           /* move one leaf down the tree */
        state.ts.bl_count[bits+1] += (ush)2; /* move one overflow item as its brother */
        state.ts.bl_count[max_length]--;
        /* The brother of the overflow item also moves one step up,
         * but this does not affect bl_count[max_length]
         */
        overflow -= 2;
    } while (overflow > 0);

    /* Now recompute all bit lengths, scanning in increasing frequency.
     * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
     * lengths instead of fixing only the wrong ones. This idea is taken
     * from 'ar' written by Haruhiko Okumura.)
     */
    for (bits = max_length; bits != 0; bits--) {
        n = state.ts.bl_count[bits];
        while (n != 0) {
            m = state.ts.heap[--h];
            if (m > max_code) continue;
            if (tree[m].dl.len != (ush)bits) {
                Trace("code %d bits %d->%d\n", m, tree[m].dl.len, bits);
                state.ts.opt_len += ((long)bits-(long)tree[m].dl.len)*(long)tree[m].fc.freq;
                tree[m].dl.len = (ush)bits;
            }
            n--;
        }
    }
}

/* ===========================================================================
 * Generate the codes for a given tree and bit counts (which need not be
 * optimal).
 * IN assertion: the array bl_count contains the bit length statistics for
 * the given tree and the field len is set for all tree elements.
 * OUT assertion: the field code is set for all tree elements of non
 *     zero code length.
 */
void gen_codes (TState &state, ct_data *tree, int max_code)
{
    ush next_code[MAX_BITS+1]; /* next code value for each bit length */
    ush code = 0;              /* running code value */
    int bits;                  /* bit index */
    int n;                     /* code index */

    /* The distribution counts are first used to generate the code values
     * without bit reversal.
     */
    for (bits = 1; bits <= MAX_BITS; bits++) {
        next_code[bits] = code = (ush)((code + state.ts.bl_count[bits-1]) << 1);
    }
    /* Check that the bit counts in bl_count are consistent. The last code
     * must be all ones.
     */
    Assert(state,code + state.ts.bl_count[MAX_BITS]-1 == (1<< ((ush) MAX_BITS)) - 1,
            "inconsistent bit counts");
    Trace("\ngen_codes: max_code %d ", max_code);

    for (n = 0;  n <= max_code; n++) {
        int len = tree[n].dl.len;
        if (len == 0) continue;
        /* Now reverse the bits */
        tree[n].fc.code = (ush)bi_reverse(next_code[len]++, len);

        //Tracec(tree != state.ts.static_ltree, "\nn %3d %c l %2d c %4x (%x) ", n, (isgraph(n) ? n : ' '), len, tree[n].fc.code, next_code[len]-1);
    }
}

/* ===========================================================================
 * Construct one Huffman tree and assigns the code bit strings and lengths.
 * Update the total bit length for the current block.
 * IN assertion: the field freq is set for all tree elements.
 * OUT assertions: the fields len and code are set to the optimal bit length
 *     and corresponding code. The length opt_len is updated; static_len is
 *     also updated if stree is not null. The field max_code is set.
 */
void build_tree(TState &state,tree_desc *desc)
{
    ct_data *tree   = desc->dyn_tree;
    ct_data *stree  = desc->static_tree;
    int elems            = desc->elems;
    int n, m;          /* iterate over heap elements */
    int max_code = -1; /* largest code with non zero frequency */
    int node = elems;  /* next internal node of the tree */

    /* Construct the initial heap, with least frequent element in
     * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
     * heap[0] is not used.
     */
    state.ts.heap_len = 0, state.ts.heap_max = HEAP_SIZE;

    for (n = 0; n < elems; n++) {
        if (tree[n].fc.freq != 0) {
            state.ts.heap[++state.ts.heap_len] = max_code = n;
            state.ts.depth[n] = 0;
        } else {
            tree[n].dl.len = 0;
        }
    }

    /* The pkzip format requires that at least one distance code exists,
     * and that at least one bit should be sent even if there is only one
     * possible code. So to avoid special checks later on we force at least
     * two codes of non zero frequency.
     */
    while (state.ts.heap_len < 2) {
        int newcp = state.ts.heap[++state.ts.heap_len] = (max_code < 2 ? ++max_code : 0);
        tree[newcp].fc.freq = 1;
        state.ts.depth[newcp] = 0;
        state.ts.opt_len--; if (stree) state.ts.static_len -= stree[newcp].dl.len;
        /* new is 0 or 1 so it does not have extra bits */
    }
    desc->max_code = max_code;

    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
     * establish sub-heaps of increasing lengths:
     */
    for (n = state.ts.heap_len/2; n >= 1; n--) pqdownheap(state,tree, n);

    /* Construct the Huffman tree by repeatedly combining the least two
     * frequent nodes.
     */
    do {
        pqremove(tree, n);   /* n = node of least frequency */
        m = state.ts.heap[SMALLEST];  /* m = node of next least frequency */

        state.ts.heap[--state.ts.heap_max] = n; /* keep the nodes sorted by frequency */
        state.ts.heap[--state.ts.heap_max] = m;

        /* Create a new node father of n and m */
        tree[node].fc.freq = (ush)(tree[n].fc.freq + tree[m].fc.freq);
        state.ts.depth[node] = (uch) (Max(state.ts.depth[n], state.ts.depth[m]) + 1);
        tree[n].dl.dad = tree[m].dl.dad = (ush)node;
        /* and insert the new node in the heap */
        state.ts.heap[SMALLEST] = node++;
        pqdownheap(state,tree, SMALLEST);

    } while (state.ts.heap_len >= 2);

    state.ts.heap[--state.ts.heap_max] = state.ts.heap[SMALLEST];

    /* At this point, the fields freq and dad are set. We can now
     * generate the bit lengths.
     */
    gen_bitlen(state,(tree_desc *)desc);

    /* The field len is now set, we can generate the bit codes */
    gen_codes (state,(ct_data *)tree, max_code);
}

/* ===========================================================================
 * Scan a literal or distance tree to determine the frequencies of the codes
 * in the bit length tree. Updates opt_len to take into account the repeat
 * counts. (The contribution of the bit length codes will be added later
 * during the construction of bl_tree.)
 */
void scan_tree (TState &state,ct_data *tree, int max_code)
{
    int n;                     /* iterates over all tree elements */
    int prevlen = -1;          /* last emitted length */
    int curlen;                /* length of current code */
    int nextlen = tree[0].dl.len; /* length of next code */
    int count = 0;             /* repeat count of the current code */
    int max_count = 7;         /* max repeat count */
    int min_count = 4;         /* min repeat count */

    if (nextlen == 0) max_count = 138, min_count = 3;
    tree[max_code+1].dl.len = (ush)-1; /* guard */

    for (n = 0; n <= max_code; n++) {
        curlen = nextlen; nextlen = tree[n+1].dl.len;
        if (++count < max_count && curlen == nextlen) {
            continue;
        } else if (count < min_count) {
            state.ts.bl_tree[curlen].fc.freq = (ush)(state.ts.bl_tree[curlen].fc.freq + count);
        } else if (curlen != 0) {
            if (curlen != prevlen) state.ts.bl_tree[curlen].fc.freq++;
            state.ts.bl_tree[REP_3_6].fc.freq++;
        } else if (count <= 10) {
            state.ts.bl_tree[REPZ_3_10].fc.freq++;
        } else {
            state.ts.bl_tree[REPZ_11_138].fc.freq++;
        }
        count = 0; prevlen = curlen;
        if (nextlen == 0) {
            max_count = 138, min_count = 3;
        } else if (curlen == nextlen) {
            max_count = 6, min_count = 3;
        } else {
            max_count = 7, min_count = 4;
        }
    }
}

/* ===========================================================================
 * Send a literal or distance tree in compressed form, using the codes in
 * bl_tree.
 */
void send_tree (TState &state, ct_data *tree, int max_code)
{
    int n;                     /* iterates over all tree elements */
    int prevlen = -1;          /* last emitted length */
    int curlen;                /* length of current code */
    int nextlen = tree[0].dl.len; /* length of next code */
    int count = 0;             /* repeat count of the current code */
    int max_count = 7;         /* max repeat count */
    int min_count = 4;         /* min repeat count */

    /* tree[max_code+1].dl.len = -1; */  /* guard already set */
    if (nextlen == 0) max_count = 138, min_count = 3;

    for (n = 0; n <= max_code; n++) {
        curlen = nextlen; nextlen = tree[n+1].dl.len;
        if (++count < max_count && curlen == nextlen) {
            continue;
        } else if (count < min_count) {
            do { send_code(state, curlen, state.ts.bl_tree); } while (--count != 0);

        } else if (curlen != 0) {
            if (curlen != prevlen) {
                send_code(state, curlen, state.ts.bl_tree); count--;
            }
            Assert(state,count >= 3 && count <= 6, " 3_6?");
            send_code(state,REP_3_6, state.ts.bl_tree); send_bits(state,count-3, 2);

        } else if (count <= 10) {
            send_code(state,REPZ_3_10, state.ts.bl_tree); send_bits(state,count-3, 3);

        } else {
            send_code(state,REPZ_11_138, state.ts.bl_tree); send_bits(state,count-11, 7);
        }
        count = 0; prevlen = curlen;
        if (nextlen == 0) {
            max_count = 138, min_count = 3;
        } else if (curlen == nextlen) {
            max_count = 6, min_count = 3;
        } else {
            max_count = 7, min_count = 4;
        }
    }
}

/* ===========================================================================
 * Construct the Huffman tree for the bit lengths and return the index in
 * bl_order of the last bit length code to send.
 */
int build_bl_tree(TState &state)
{
    int max_blindex;  /* index of last bit length code of non zero freq */

    /* Determine the bit length frequencies for literal and distance trees */
    scan_tree(state,(ct_data *)state.ts.dyn_ltree, state.ts.l_desc.max_code);
    scan_tree(state,(ct_data *)state.ts.dyn_dtree, state.ts.d_desc.max_code);

    /* Build the bit length tree: */
    build_tree(state,(tree_desc *)(&state.ts.bl_desc));
    /* opt_len now includes the length of the tree representations, except
     * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
     */

    /* Determine the number of bit length codes to send. The pkzip format
     * requires that at least 4 bit length codes be sent. (appnote.txt says
     * 3 but the actual value used is 4.)
     */
    for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
        if (state.ts.bl_tree[bl_order[max_blindex]].dl.len != 0) break;
    }
    /* Update opt_len to include the bit length tree and counts */
    state.ts.opt_len += 3*(max_blindex+1) + 5+5+4;
    Trace("\ndyn trees: dyn %ld, stat %ld", state.ts.opt_len, state.ts.static_len);

    return max_blindex;
}

/* ===========================================================================
 * Send the header for a block using dynamic Huffman trees: the counts, the
 * lengths of the bit length codes, the literal tree and the distance tree.
 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
 */
void send_all_trees(TState &state,int lcodes, int dcodes, int blcodes)
{
    int rank;                    /* index in bl_order */

    Assert(state,lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
    Assert(state,lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
            "too many codes");
    Trace("\nbl counts: ");
    send_bits(state,lcodes-257, 5);
    /* not +255 as stated in appnote.txt 1.93a or -256 in 2.04c */
    send_bits(state,dcodes-1,   5);
    send_bits(state,blcodes-4,  4); /* not -3 as stated in appnote.txt */
    for (rank = 0; rank < blcodes; rank++) {
        Trace("\nbl code %2d ", bl_order[rank]);
        send_bits(state,state.ts.bl_tree[bl_order[rank]].dl.len, 3);
    }    
    Trace("\nbl tree: sent %ld", state.bs.bits_sent);

    send_tree(state,(ct_data *)state.ts.dyn_ltree, lcodes-1); /* send the literal tree */
    Trace("\nlit tree: sent %ld", state.bs.bits_sent);

    send_tree(state,(ct_data *)state.ts.dyn_dtree, dcodes-1); /* send the distance tree */
    Trace("\ndist tree: sent %ld", state.bs.bits_sent);
}

/* ===========================================================================
 * Determine the best encoding for the current block: dynamic trees, static
 * trees or store, and output the encoded block to the zip file. This function
 * returns the total compressed length (in bytes) for the file so far.
 */
ulg flush_block(TState &state,char *buf, ulg stored_len, int eof)
{
    ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
    int max_blindex;  /* index of last bit length code of non zero freq */

    state.ts.flag_buf[state.ts.last_flags] = state.ts.flags; /* Save the flags for the last 8 items */

     /* Check if the file is ascii or binary */
    if (*state.ts.file_type == (ush)UNKNOWN) set_file_type(state);

    /* Construct the literal and distance trees */
    build_tree(state,(tree_desc *)(&state.ts.l_desc));
    Trace("\nlit data: dyn %ld, stat %ld", state.ts.opt_len, state.ts.static_len);

    build_tree(state,(tree_desc *)(&state.ts.d_desc));
    Trace("\ndist data: dyn %ld, stat %ld", state.ts.opt_len, state.ts.static_len);
    /* At this point, opt_len and static_len are the total bit lengths of
     * the compressed block data, excluding the tree representations.
     */

    /* Build the bit length tree for the above two trees, and get the index
     * in bl_order of the last bit length code to send.
     */
    max_blindex = build_bl_tree(state);

    /* Determine the best encoding. Compute first the block length in bytes */
    opt_lenb = (state.ts.opt_len+3+7)>>3;
    static_lenb = (state.ts.static_len+3+7)>>3;
    state.ts.input_len += stored_len; /* for debugging only */

    Trace("\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
            opt_lenb, state.ts.opt_len, static_lenb, state.ts.static_len, stored_len,
            state.ts.last_lit, state.ts.last_dist);

    if (static_lenb <= opt_lenb) opt_lenb = static_lenb;

    // Originally, zip allowed the file to be transformed from a compressed
    // into a stored file in the case where compression failed, there
    // was only one block, and it was allowed to change. I've removed this
    // possibility since the code's cleaner if no changes are allowed.
    //if (stored_len <= opt_lenb && eof && state.ts.cmpr_bytelen == 0L
    //   && state.ts.cmpr_len_bits == 0L && state.seekable)
    //{   // && state.ts.file_method != NULL
    //    // Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there:
    //    Assert(state,buf!=NULL,"block vanished");
    //    copy_block(state,buf, (unsigned)stored_len, 0); // without header
    //    state.ts.cmpr_bytelen = stored_len;
    //    Assert(state,false,"unimplemented *state.ts.file_method = STORE;");
    //    //*state.ts.file_method = STORE;
    //}
    //else
    if (stored_len+4 <= opt_lenb && buf != (char*)NULL) {
                       /* 4: two words for the lengths */
        /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
         * Otherwise we can't have processed more than WSIZE input bytes since
         * the last block flush, because compression would have been
         * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
         * transform a block into a stored block.
         */
        send_bits(state,(STORED_BLOCK<<1)+eof, 3);  /* send block type */
        state.ts.cmpr_bytelen += ((state.ts.cmpr_len_bits + 3 + 7) >> 3) + stored_len + 4;
        state.ts.cmpr_len_bits = 0L;

        copy_block(state,buf, (unsigned)stored_len, 1); /* with header */
    }
    else if (static_lenb == opt_lenb) {
        send_bits(state,(STATIC_TREES<<1)+eof, 3);
        compress_block(state,(ct_data *)state.ts.static_ltree, (ct_data *)state.ts.static_dtree);
        state.ts.cmpr_len_bits += 3 + state.ts.static_len;
        state.ts.cmpr_bytelen += state.ts.cmpr_len_bits >> 3;
        state.ts.cmpr_len_bits &= 7L;
    }
    else {
        send_bits(state,(DYN_TREES<<1)+eof, 3);
        send_all_trees(state,state.ts.l_desc.max_code+1, state.ts.d_desc.max_code+1, max_blindex+1);
        compress_block(state,(ct_data *)state.ts.dyn_ltree, (ct_data *)state.ts.dyn_dtree);
        state.ts.cmpr_len_bits += 3 + state.ts.opt_len;
        state.ts.cmpr_bytelen += state.ts.cmpr_len_bits >> 3;
        state.ts.cmpr_len_bits &= 7L;
    }
    Assert(state,((state.ts.cmpr_bytelen << 3) + state.ts.cmpr_len_bits) == state.bs.bits_sent, "bad compressed size");
    init_block(state);

    if (eof) {
        // Assert(state,input_len == isize, "bad input size");
        bi_windup(state);
        state.ts.cmpr_len_bits += 7;  /* align on byte boundary */
    }
    Trace("\n");

    return state.ts.cmpr_bytelen + (state.ts.cmpr_len_bits >> 3);
}

/* ===========================================================================
 * Save the match info and tally the frequency counts. Return true if
 * the current block must be flushed.
 */
int ct_tally (TState &state,int dist, int lc)
{
    state.ts.l_buf[state.ts.last_lit++] = (uch)lc;
    if (dist == 0) {
        /* lc is the unmatched char */
        state.ts.dyn_ltree[lc].fc.freq++;
    } else {
        /* Here, lc is the match length - MIN_MATCH */
        dist--;             /* dist = match distance - 1 */
        Assert(state,(ush)dist < (ush)MAX_DIST &&
               (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
               (ush)d_code(dist) < (ush)D_CODES,  "ct_tally: bad match");

        state.ts.dyn_ltree[state.ts.length_code[lc]+LITERALS+1].fc.freq++;
        state.ts.dyn_dtree[d_code(dist)].fc.freq++;

        state.ts.d_buf[state.ts.last_dist++] = (ush)dist;
        state.ts.flags |= state.ts.flag_bit;
    }
    state.ts.flag_bit <<= 1;

    /* Output the flags if they fill a byte: */
    if ((state.ts.last_lit & 7) == 0) {
        state.ts.flag_buf[state.ts.last_flags++] = state.ts.flags;
        state.ts.flags = 0, state.ts.flag_bit = 1;
    }
    /* Try to guess if it is profitable to stop the current block here */
    if (state.level > 2 && (state.ts.last_lit & 0xfff) == 0) {
        /* Compute an upper bound for the compressed length */
        ulg out_length = (ulg)state.ts.last_lit*8L;
        ulg in_length = (ulg)state.ds.strstart-state.ds.block_start;
        int dcode;
        for (dcode = 0; dcode < D_CODES; dcode++) {
            out_length += (ulg)state.ts.dyn_dtree[dcode].fc.freq*(5L+extra_dbits[dcode]);
        }
        out_length >>= 3;
        Trace("\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
               state.ts.last_lit, state.ts.last_dist, in_length, out_length,
               100L - out_length*100L/in_length);
        if (state.ts.last_dist < state.ts.last_lit/2 && out_length < in_length/2) return 1;
    }
    return (state.ts.last_lit == LIT_BUFSIZE-1 || state.ts.last_dist == DIST_BUFSIZE);
    /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
     * on 16 bit machines and because stored blocks are restricted to
     * 64K-1 bytes.
     */
}

/* ===========================================================================
 * Send the block data compressed using the given Huffman trees
 */
void compress_block(TState &state,ct_data *ltree, ct_data *dtree)
{
    unsigned dist;      /* distance of matched string */
    int lc;             /* match length or unmatched char (if dist == 0) */
    unsigned lx = 0;    /* running index in l_buf */
    unsigned dx = 0;    /* running index in d_buf */
    unsigned fx = 0;    /* running index in flag_buf */
    uch flag = 0;       /* current flags */
    unsigned code;      /* the code to send */
    int extra;          /* number of extra bits to send */

    if (state.ts.last_lit != 0) do {
        if ((lx & 7) == 0) flag = state.ts.flag_buf[fx++];
        lc = state.ts.l_buf[lx++];
        if ((flag & 1) == 0) {
            send_code(state,lc, ltree); /* send a literal byte */
        } else {
            /* Here, lc is the match length - MIN_MATCH */
            code = state.ts.length_code[lc];
            send_code(state,code+LITERALS+1, ltree); /* send the length code */
            extra = extra_lbits[code];
            if (extra != 0) {
                lc -= state.ts.base_length[code];
                send_bits(state,lc, extra);        /* send the extra length bits */
            }
            dist = state.ts.d_buf[dx++];
            /* Here, dist is the match distance - 1 */
            code = d_code(dist);
            Assert(state,code < D_CODES, "bad d_code");

            send_code(state,code, dtree);       /* send the distance code */
            extra = extra_dbits[code];
            if (extra != 0) {
                dist -= state.ts.base_dist[code];
                send_bits(state,dist, extra);   /* send the extra distance bits */
            }
        } /* literal or match pair ? */
        flag >>= 1;
    } while (lx < state.ts.last_lit);

    send_code(state,END_BLOCK, ltree);
}

/* ===========================================================================
 * Set the file type to ASCII or BINARY, using a crude approximation:
 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
 * IN assertion: the fields freq of dyn_ltree are set and the total of all
 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
 */
void set_file_type(TState &state)
{
    int n = 0;
    unsigned ascii_freq = 0;
    unsigned bin_freq = 0;
    while (n < 7)        bin_freq += state.ts.dyn_ltree[n++].fc.freq;
    while (n < 128)    ascii_freq += state.ts.dyn_ltree[n++].fc.freq;
    while (n < LITERALS) bin_freq += state.ts.dyn_ltree[n++].fc.freq;
    *state.ts.file_type = (ush)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
}


/* ===========================================================================
 * Initialize the bit string routines.
 */
void bi_init (TState &state,char *tgt_buf, unsigned tgt_size, int flsh_allowed)
{
    state.bs.out_buf = tgt_buf;
    state.bs.out_size = tgt_size;
    state.bs.out_offset = 0;
    state.bs.flush_flg = flsh_allowed;

    state.bs.bi_buf = 0;
    state.bs.bi_valid = 0;
    state.bs.bits_sent = 0L;
}

/* ===========================================================================
 * Send a value on a given number of bits.
 * IN assertion: length <= 16 and value fits in length bits.
 */
void send_bits(TState &state,int value, int length)
{
    Assert(state,length > 0 && length <= 15, "invalid length");
    state.bs.bits_sent += (ulg)length;
    /* If not enough room in bi_buf, use (bi_valid) bits from bi_buf and
     * (Buf_size - bi_valid) bits from value to flush the filled bi_buf,
     * then fill in the rest of (value), leaving (length - (Buf_size-bi_valid))
     * unused bits in bi_buf.
     */
    state.bs.bi_buf |= (value << state.bs.bi_valid);
    state.bs.bi_valid += length;
    if (state.bs.bi_valid > (int)Buf_size) {
        PUTSHORT(state,state.bs.bi_buf);
        state.bs.bi_valid -= Buf_size;
        state.bs.bi_buf = (unsigned)value >> (length - state.bs.bi_valid);
    }
}

/* ===========================================================================
 * Reverse the first len bits of a code, using straightforward code (a faster
 * method would use a table)
 * IN assertion: 1 <= len <= 15
 */
unsigned bi_reverse(unsigned code, int len)
{
    register unsigned res = 0;
    do {
        res |= code & 1;
        code >>= 1, res <<= 1;
    } while (--len > 0);
    return res >> 1;
}

/* ===========================================================================
 * Write out any remaining bits in an incomplete byte.
 */
void bi_windup(TState &state)
{
    if (state.bs.bi_valid > 8) {
        PUTSHORT(state,state.bs.bi_buf);
    } else if (state.bs.bi_valid > 0) {
        PUTBYTE(state,state.bs.bi_buf);
    }
    if (state.bs.flush_flg) {
        state.flush_outbuf(state.param,state.bs.out_buf, &state.bs.out_offset);
    }
    state.bs.bi_buf = 0;
    state.bs.bi_valid = 0;
    state.bs.bits_sent = (state.bs.bits_sent+7) & ~7;
}

/* ===========================================================================
 * Copy a stored block to the zip file, storing first the length and its
 * one's complement if requested.
 */
void copy_block(TState &state, char *block, unsigned len, int header)
{
    bi_windup(state);              /* align on byte boundary */

    if (header) {
        PUTSHORT(state,(ush)len);
        PUTSHORT(state,(ush)~len);
        state.bs.bits_sent += 2*16;
    }
    if (state.bs.flush_flg) {
        state.flush_outbuf(state.param,state.bs.out_buf, &state.bs.out_offset);
        state.bs.out_offset = len;
        state.flush_outbuf(state.param,block, &state.bs.out_offset);
    } else if (state.bs.out_offset + len > state.bs.out_size) {
        Assert(state,false,"output buffer too small for in-memory compression");
    } else {
        memcpy(state.bs.out_buf + state.bs.out_offset, block, len);
        state.bs.out_offset += len;
    }
    state.bs.bits_sent += (ulg)len<<3;
}








/* ===========================================================================
 *  Prototypes for functions.
 */

void fill_window  (TState &state);
ulg deflate_fast  (TState &state);

int  longest_match (TState &state,IPos cur_match);


/* ===========================================================================
 * Update a hash value with the given input byte
 * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
 *    input characters, so that a running hash key can be computed from the
 *    previous key instead of complete recalculation each time.
 */
#define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)

/* ===========================================================================
 * Insert string s in the dictionary and set match_head to the previous head
 * of the hash chain (the most recent string with same hash key). Return
 * the previous length of the hash chain.
 * IN  assertion: all calls to to INSERT_STRING are made with consecutive
 *    input characters and the first MIN_MATCH bytes of s are valid
 *    (except for the last MIN_MATCH-1 bytes of the input file).
 */
#define INSERT_STRING(s, match_head) \
   (UPDATE_HASH(state.ds.ins_h, state.ds.window[(s) + (MIN_MATCH-1)]), \
    state.ds.prev[(s) & WMASK] = match_head = state.ds.head[state.ds.ins_h], \
    state.ds.head[state.ds.ins_h] = (s))

/* ===========================================================================
 * Initialize the "longest match" routines for a new file
 *
 * IN assertion: window_size is > 0 if the input file is already read or
 *    mmap'ed in the window[] array, 0 otherwise. In the first case,
 *    window_size is sufficient to contain the whole input file plus
 *    MIN_LOOKAHEAD bytes (to avoid referencing memory beyond the end
 *    of window[] when looking for matches towards the end).
 */
void lm_init (TState &state, int pack_level, ush *flags)
{
    register unsigned j;

    Assert(state,pack_level>=1 && pack_level<=8,"bad pack level");

    /* Do not slide the window if the whole input is already in memory
     * (window_size > 0)
     */
    state.ds.sliding = 0;
    if (state.ds.window_size == 0L) {
        state.ds.sliding = 1;
        state.ds.window_size = (ulg)2L*WSIZE;
    }

    /* Initialize the hash table (avoiding 64K overflow for 16 bit systems).
     * prev[] will be initialized on the fly.
     */
    state.ds.head[HASH_SIZE-1] = NIL;
    memset((char*)state.ds.head, NIL, (unsigned)(HASH_SIZE-1)*sizeof(*state.ds.head));

    /* Set the default configuration parameters:
     */
    state.ds.max_lazy_match   = configuration_table[pack_level].max_lazy;
    state.ds.good_match       = configuration_table[pack_level].good_length;
    state.ds.nice_match       = configuration_table[pack_level].nice_length;
    state.ds.max_chain_length = configuration_table[pack_level].max_chain;
    if (pack_level <= 2) {
       *flags |= FAST;
    } else if (pack_level >= 8) {
       *flags |= SLOW;
    }
    /* ??? reduce max_chain_length for binary files */

    state.ds.strstart = 0;
    state.ds.block_start = 0L;

    j = WSIZE;
    j <<= 1; // Can read 64K in one step
    state.ds.lookahead = state.readfunc(state, (char*)state.ds.window, j);

    if (state.ds.lookahead == 0 || state.ds.lookahead == (unsigned)EOF) {
       state.ds.eofile = 1, state.ds.lookahead = 0;
       return;
    }
    state.ds.eofile = 0;
    /* Make sure that we always have enough lookahead. This is important
     * if input comes from a device such as a tty.
     */
    if (state.ds.lookahead < MIN_LOOKAHEAD) fill_window(state);

    state.ds.ins_h = 0;
    for (j=0; j<MIN_MATCH-1; j++) UPDATE_HASH(state.ds.ins_h, state.ds.window[j]);
    /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
     * not important since only literal bytes will be emitted.
     */
}


/* ===========================================================================
 * Set match_start to the longest match starting at the given string and
 * return its length. Matches shorter or equal to prev_length are discarded,
 * in which case the result is equal to prev_length and match_start is
 * garbage.
 * IN assertions: cur_match is the head of the hash chain for the current
 *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
 */
// For 80x86 and 680x0 and ARM, an optimized version is in match.asm or
// match.S. The code is functionally equivalent, so you can use the C version
// if desired. Which I do so desire!
int longest_match(TState &state,IPos cur_match)
{
    unsigned chain_length = state.ds.max_chain_length;   /* max hash chain length */
    register uch far *scan = state.ds.window + state.ds.strstart; /* current string */
    register uch far *match;                    /* matched string */
    register int len;                           /* length of current match */
    int best_len = state.ds.prev_length;                 /* best match length so far */
    IPos limit = state.ds.strstart > (IPos)MAX_DIST ? state.ds.strstart - (IPos)MAX_DIST : NIL;
    /* Stop when cur_match becomes <= limit. To simplify the code,
     * we prevent matches with the string of window index 0.
     */

  // The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
  // It is easy to get rid of this optimization if necessary.
    Assert(state,HASH_BITS>=8 && MAX_MATCH==258,"Code too clever");



    register uch far *strend = state.ds.window + state.ds.strstart + MAX_MATCH;
    register uch scan_end1  = scan[best_len-1];
    register uch scan_end   = scan[best_len];

    /* Do not waste too much time if we already have a good match: */
    if (state.ds.prev_length >= state.ds.good_match) {
        chain_length >>= 2;
    }

    Assert(state,state.ds.strstart <= state.ds.window_size-MIN_LOOKAHEAD, "insufficient lookahead");

    do {
        Assert(state,cur_match < state.ds.strstart, "no future");
        match = state.ds.window + cur_match;

        /* Skip to next match if the match length cannot increase
         * or if the match length is less than 2:
         */
        if (match[best_len]   != scan_end  ||
            match[best_len-1] != scan_end1 ||
            *match            != *scan     ||
            *++match          != scan[1])      continue;

        /* The check at best_len-1 can be removed because it will be made
         * again later. (This heuristic is not always a win.)
         * It is not necessary to compare scan[2] and match[2] since they
         * are always equal when the other bytes match, given that
         * the hash keys are equal and that HASH_BITS >= 8.
         */
        scan += 2, match++;

        /* We check for insufficient lookahead only every 8th comparison;
         * the 256th check will be made at strstart+258.
         */
        do {
        } while (*++scan == *++match && *++scan == *++match &&
                 *++scan == *++match && *++scan == *++match &&
                 *++scan == *++match && *++scan == *++match &&
                 *++scan == *++match && *++scan == *++match &&
                 scan < strend);

        Assert(state,scan <= state.ds.window+(unsigned)(state.ds.window_size-1), "wild scan");
                          
        len = MAX_MATCH - (int)(strend - scan);
        scan = strend - MAX_MATCH;


        if (len > best_len) {
            state.ds.match_start = cur_match;
            best_len = len;
            if (len >= state.ds.nice_match) break;
            scan_end1  = scan[best_len-1];
            scan_end   = scan[best_len];
        }
    } while ((cur_match = state.ds.prev[cur_match & WMASK]) > limit
             && --chain_length != 0);

    return best_len;
}



#define check_match(state,start, match, length)
// or alternatively...
//void check_match(TState &state,IPos start, IPos match, int length)
//{ // check that the match is indeed a match
//    if (memcmp((char*)state.ds.window + match,
//                (char*)state.ds.window + start, length) != EQUAL) {
//        fprintf(stderr,
//            " start %d, match %d, length %d\n",
//            start, match, length);
//        error("invalid match");
//    }
//    if (state.verbose > 1) {
//        fprintf(stderr,"\\[%d,%d]", start-match, length);
//        do { fprintf(stdout,"%c",state.ds.window[start++]); } while (--length != 0);
//    }
//}

/* ===========================================================================
 * Fill the window when the lookahead becomes insufficient.
 * Updates strstart and lookahead, and sets eofile if end of input file.
 *
 * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
 *    At least one byte has been read, or eofile is set; file reads are
 *    performed for at least two bytes (required for the translate_eol option).
 */
void fill_window(TState &state)
{
    register unsigned n, m;
    unsigned more;    /* Amount of free space at the end of the window. */

    do {
        more = (unsigned)(state.ds.window_size - (ulg)state.ds.lookahead - (ulg)state.ds.strstart);

        /* If the window is almost full and there is insufficient lookahead,
         * move the upper half to the lower one to make room in the upper half.
         */
        if (more == (unsigned)EOF) {
            /* Very unlikely, but possible on 16 bit machine if strstart == 0
             * and lookahead == 1 (input done one byte at time)
             */
            more--;

        /* For MMAP or BIG_MEM, the whole input file is already in memory so
         * we must not perform sliding. We must however call (*read_buf)() in
         * order to compute the crc, update lookahead and possibly set eofile.
         */
        } else if (state.ds.strstart >= WSIZE+MAX_DIST && state.ds.sliding) {

            /* By the IN assertion, the window is not empty so we can't confuse
             * more == 0 with more == 64K on a 16 bit machine.
             */
            memcpy((char*)state.ds.window, (char*)state.ds.window+WSIZE, (unsigned)WSIZE);
            state.ds.match_start -= WSIZE;
            state.ds.strstart    -= WSIZE; /* we now have strstart >= MAX_DIST: */

            state.ds.block_start -= (long) WSIZE;

            for (n = 0; n < HASH_SIZE; n++) {
                m = state.ds.head[n];
                state.ds.head[n] = (Pos)(m >= WSIZE ? m-WSIZE : NIL);
            }
            for (n = 0; n < WSIZE; n++) {
                m = state.ds.prev[n];
                state.ds.prev[n] = (Pos)(m >= WSIZE ? m-WSIZE : NIL);
                /* If n is not on any hash chain, prev[n] is garbage but
                 * its value will never be used.
                 */
            }
            more += WSIZE;
        }
        if (state.ds.eofile) return;

        /* If there was no sliding:
         *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
         *    more == window_size - lookahead - strstart
         * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
         * => more >= window_size - 2*WSIZE + 2
         * In the MMAP or BIG_MEM case (not yet supported in gzip),
         *   window_size == input_size + MIN_LOOKAHEAD  &&
         *   strstart + lookahead <= input_size => more >= MIN_LOOKAHEAD.
         * Otherwise, window_size == 2*WSIZE so more >= 2.
         * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
         */
        Assert(state,more >= 2, "more < 2");

        n = state.readfunc(state, (char*)state.ds.window+state.ds.strstart+state.ds.lookahead, more);

        if (n == 0 || n == (unsigned)EOF) {
            state.ds.eofile = 1;
        } else {
            state.ds.lookahead += n;
        }
    } while (state.ds.lookahead < MIN_LOOKAHEAD && !state.ds.eofile);
}

/* ===========================================================================
 * Flush the current block, with given end-of-file flag.
 * IN assertion: strstart is set to the end of the current match.
 */
#define FLUSH_BLOCK(state,eof) \
   flush_block(state,state.ds.block_start >= 0L ? (char*)&state.ds.window[(unsigned)state.ds.block_start] : \
                (char*)NULL, (long)state.ds.strstart - state.ds.block_start, (eof))

/* ===========================================================================
 * Processes a new input file and return its compressed length. This
 * function does not perform lazy evaluation of matches and inserts
 * new strings in the dictionary only for unmatched strings or for short
 * matches. It is used only for the fast compression options.
 */
ulg deflate_fast(TState &state)
{
    IPos hash_head = NIL;       /* head of the hash chain */
    int flush;                  /* set if current block must be flushed */
    unsigned match_length = 0;  /* length of best match */

    state.ds.prev_length = MIN_MATCH-1;
    while (state.ds.lookahead != 0) {
        /* Insert the string window[strstart .. strstart+2] in the
         * dictionary, and set hash_head to the head of the hash chain:
         */
        if (state.ds.lookahead >= MIN_MATCH)
        INSERT_STRING(state.ds.strstart, hash_head);

        /* Find the longest match, discarding those <= prev_length.
         * At this point we have always match_length < MIN_MATCH
         */
        if (hash_head != NIL && state.ds.strstart - hash_head <= MAX_DIST) {
            /* To simplify the code, we prevent matches with the string
             * of window index 0 (in particular we have to avoid a match
             * of the string with itself at the start of the input file).
             */
            /* Do not look for matches beyond the end of the input.
             * This is necessary to make deflate deterministic.
             */
            if ((unsigned)state.ds.nice_match > state.ds.lookahead) state.ds.nice_match = (int)state.ds.lookahead;
            match_length = longest_match (state,hash_head);
            /* longest_match() sets match_start */
            if (match_length > state.ds.lookahead) match_length = state.ds.lookahead;
        }
        if (match_length >= MIN_MATCH) {
            check_match(state,state.ds.strstart, state.ds.match_start, match_length);

            flush = ct_tally(state,state.ds.strstart-state.ds.match_start, match_length - MIN_MATCH);

            state.ds.lookahead -= match_length;

            /* Insert new strings in the hash table only if the match length
             * is not too large. This saves time but degrades compression.
             */
            if (match_length <= state.ds.max_insert_length
                && state.ds.lookahead >= MIN_MATCH) {
                match_length--; /* string at strstart already in hash table */
                do {
                    state.ds.strstart++;
                    INSERT_STRING(state.ds.strstart, hash_head);
                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
                     * always MIN_MATCH bytes ahead.
                     */
                } while (--match_length != 0);
                state.ds.strstart++;
            } else {
                state.ds.strstart += match_length;
                match_length = 0;
                state.ds.ins_h = state.ds.window[state.ds.strstart];
                UPDATE_HASH(state.ds.ins_h, state.ds.window[state.ds.strstart+1]);
                Assert(state,MIN_MATCH==3,"Call UPDATE_HASH() MIN_MATCH-3 more times");
            }
        } else {
            /* No match, output a literal byte */
            flush = ct_tally (state,0, state.ds.window[state.ds.strstart]);
            state.ds.lookahead--;
            state.ds.strstart++;
        }
        if (flush) FLUSH_BLOCK(state,0), state.ds.block_start = state.ds.strstart;

        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes
         * for the next match, plus MIN_MATCH bytes to insert the
         * string following the next match.
         */
        if (state.ds.lookahead < MIN_LOOKAHEAD) fill_window(state);
    }
    return FLUSH_BLOCK(state,1); /* eof */
}

/* ===========================================================================
 * Same as above, but achieves better compression. We use a lazy
 * evaluation for matches: a match is finally adopted only if there is
 * no better match at the next window position.
 */
ulg deflate(TState &state)
{
    IPos hash_head = NIL;       /* head of hash chain */
    IPos prev_match;            /* previous match */
    int flush;                  /* set if current block must be flushed */
    int match_available = 0;    /* set if previous match exists */
    register unsigned match_length = MIN_MATCH-1; /* length of best match */

    if (state.level <= 3) return deflate_fast(state); /* optimized for speed */

    /* Process the input block. */
    while (state.ds.lookahead != 0) {
        /* Insert the string window[strstart .. strstart+2] in the
         * dictionary, and set hash_head to the head of the hash chain:
         */
        if (state.ds.lookahead >= MIN_MATCH)
        INSERT_STRING(state.ds.strstart, hash_head);

        /* Find the longest match, discarding those <= prev_length.
         */
        state.ds.prev_length = match_length, prev_match = state.ds.match_start;
        match_length = MIN_MATCH-1;

        if (hash_head != NIL && state.ds.prev_length < state.ds.max_lazy_match &&
            state.ds.strstart - hash_head <= MAX_DIST) {
            /* To simplify the code, we prevent matches with the string
             * of window index 0 (in particular we have to avoid a match
             * of the string with itself at the start of the input file).
             */
            /* Do not look for matches beyond the end of the input.
             * This is necessary to make deflate deterministic.
             */
            if ((unsigned)state.ds.nice_match > state.ds.lookahead) state.ds.nice_match = (int)state.ds.lookahead;
            match_length = longest_match (state,hash_head);
            /* longest_match() sets match_start */
            if (match_length > state.ds.lookahead) match_length = state.ds.lookahead;

            /* Ignore a length 3 match if it is too distant: */
            if (match_length == MIN_MATCH && state.ds.strstart-state.ds.match_start > TOO_FAR){
                /* If prev_match is also MIN_MATCH, match_start is garbage
                 * but we will ignore the current match anyway.
                 */
                match_length = MIN_MATCH-1;
            }
        }
        /* If there was a match at the previous step and the current
         * match is not better, output the previous match:
         */
        if (state.ds.prev_length >= MIN_MATCH && match_length <= state.ds.prev_length) {
            unsigned max_insert = state.ds.strstart + state.ds.lookahead - MIN_MATCH;
            check_match(state,state.ds.strstart-1, prev_match, state.ds.prev_length);
            flush = ct_tally(state,state.ds.strstart-1-prev_match, state.ds.prev_length - MIN_MATCH);

            /* Insert in hash table all strings up to the end of the match.
             * strstart-1 and strstart are already inserted.
             */
            state.ds.lookahead -= state.ds.prev_length-1;
            state.ds.prev_length -= 2;
            do {
                if (++state.ds.strstart <= max_insert) {
                    INSERT_STRING(state.ds.strstart, hash_head);
                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
                     * always MIN_MATCH bytes ahead.
                     */
                }
            } while (--state.ds.prev_length != 0);
            state.ds.strstart++;
            match_available = 0;
            match_length = MIN_MATCH-1;

            if (flush) FLUSH_BLOCK(state,0), state.ds.block_start = state.ds.strstart;

        } else if (match_available) {
            /* If there was no match at the previous position, output a
             * single literal. If there was a match but the current match
             * is longer, truncate the previous match to a single literal.
             */
            if (ct_tally (state,0, state.ds.window[state.ds.strstart-1])) {
                FLUSH_BLOCK(state,0), state.ds.block_start = state.ds.strstart;
            }
            state.ds.strstart++;
            state.ds.lookahead--;
        } else {
            /* There is no previous match to compare with, wait for
             * the next step to decide.
             */
            match_available = 1;
            state.ds.strstart++;
            state.ds.lookahead--;
        }
//        Assert(state,strstart <= isize && lookahead <= isize, "a bit too far");

        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes
         * for the next match, plus MIN_MATCH bytes to insert the
         * string following the next match.
         */
        if (state.ds.lookahead < MIN_LOOKAHEAD) fill_window(state);
    }
    if (match_available) ct_tally (state,0, state.ds.window[state.ds.strstart-1]);

    return FLUSH_BLOCK(state,1); /* eof */
}












int putlocal(struct zlist far *z, WRITEFUNC wfunc,void *param)
{ // Write a local header described by *z to file *f.  Return a ZE_ error code.
  PUTLG(LOCSIG, f);
  PUTSH(z->ver, f);
  PUTSH(z->lflg, f);
  PUTSH(z->how, f);
  PUTLG(z->tim, f);
  PUTLG(z->crc, f);
  PUTLG(z->siz, f);
  PUTLG(z->len, f);
  PUTSH(z->nam, f);
  PUTSH(z->ext, f);
  size_t res = (size_t)wfunc(param, z->iname, (unsigned int)z->nam);
  if (res!=z->nam) return ZE_TEMP;
  if (z->ext)
  { res = (size_t)wfunc(param, z->extra, (unsigned int)z->ext);
    if (res!=z->ext) return ZE_TEMP;
  }
  return ZE_OK;
}

int putextended(struct zlist far *z, WRITEFUNC wfunc, void *param)
{ // Write an extended local header described by *z to file *f. Returns a ZE_ code
  PUTLG(EXTLOCSIG, f);
  PUTLG(z->crc, f);
  PUTLG(z->siz, f);
  PUTLG(z->len, f);
  return ZE_OK;
}

int putcentral(struct zlist far *z, WRITEFUNC wfunc, void *param)
{ // Write a central header entry of *z to file *f. Returns a ZE_ code.
  PUTLG(CENSIG, f);
  PUTSH(z->vem, f);
  PUTSH(z->ver, f);
  PUTSH(z->flg, f);
  PUTSH(z->how, f);
  PUTLG(z->tim, f);
  PUTLG(z->crc, f);
  PUTLG(z->siz, f);
  PUTLG(z->len, f);
  PUTSH(z->nam, f);
  PUTSH(z->cext, f);
  PUTSH(z->com, f);
  PUTSH(z->dsk, f);
  PUTSH(z->att, f);
  PUTLG(z->atx, f);
  PUTLG(z->off, f);
  if ((size_t)wfunc(param, z->iname, (unsigned int)z->nam) != z->nam ||
      (z->cext && (size_t)wfunc(param, z->cextra, (unsigned int)z->cext) != z->cext) ||
      (z->com && (size_t)wfunc(param, z->comment, (unsigned int)z->com) != z->com))
    return ZE_TEMP;
  return ZE_OK;
}


int putend(int n, ulg s, ulg c, extent m, char *z, WRITEFUNC wfunc, void *param)
{ // write the end of the central-directory-data to file *f.
  PUTLG(ENDSIG, f);
  PUTSH(0, f);
  PUTSH(0, f);
  PUTSH(n, f);
  PUTSH(n, f);
  PUTLG(s, f);
  PUTLG(c, f);
  PUTSH(m, f);
  // Write the comment, if any
  if (m && wfunc(param, z, (unsigned int)m) != m) return ZE_TEMP;
  return ZE_OK;
}






const ulg crc_table[256] = {
  0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
  0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
  0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
  0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
  0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
  0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
  0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
  0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
  0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
  0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
  0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
  0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
  0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
  0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
  0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
  0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
  0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
  0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
  0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
  0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
  0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
  0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
  0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
  0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
  0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
  0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
  0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
  0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
  0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
  0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
  0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
  0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
  0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
  0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
  0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
  0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
  0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
  0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
  0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
  0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
  0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
  0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
  0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
  0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
  0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
  0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
  0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
  0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
  0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
  0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
  0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
  0x2d02ef8dL
};

#define CRC32(c, b) (crc_table[((int)(c) ^ (b)) & 0xff] ^ ((c) >> 8))
#define DO1(buf)  crc = CRC32(crc, *buf++)
#define DO2(buf)  DO1(buf); DO1(buf)
#define DO4(buf)  DO2(buf); DO2(buf)
#define DO8(buf)  DO4(buf); DO4(buf)

ulg crc32(ulg crc, const uch *buf, extent len)
{ if (buf==NULL) return 0L;
  crc = crc ^ 0xffffffffL;
  while (len >= 8) {DO8(buf); len -= 8;}
  if (len) do {DO1(buf);} while (--len);
  return crc ^ 0xffffffffL;  // (instead of ~c for 64-bit machines)
}








bool HasZipSuffix(const char *fn)
{ const char *ext = fn+strlen(fn);
  while (ext>fn && *ext!='.') ext--;
  if (ext==fn && *ext!='.') return false;
  if (stricmp(ext,".Z")==0) return true;
  if (stricmp(ext,".zip")==0) return true;
  if (stricmp(ext,".zoo")==0) return true;
  if (stricmp(ext,".arc")==0) return true;
  if (stricmp(ext,".lzh")==0) return true;
  if (stricmp(ext,".arj")==0) return true;
  if (stricmp(ext,".gz")==0) return true;
  if (stricmp(ext,".tgz")==0) return true;
  return false;
}


time_t filetime2timet(const FILETIME ft)
{ SYSTEMTIME st; FileTimeToSystemTime(&ft,&st);
  if (st.wYear<1970) {st.wYear=1970; st.wMonth=1; st.wDay=1;}
  if (st.wYear>=2038) {st.wYear=2037; st.wMonth=12; st.wDay=31;}
  struct tm tm;
  tm.tm_sec = st.wSecond;
  tm.tm_min = st.wMinute;
  tm.tm_hour = st.wHour;
  tm.tm_mday = st.wDay;
  tm.tm_mon = st.wMonth-1;
  tm.tm_year = st.wYear-1900;
  tm.tm_isdst = 0;
  time_t t = mktime(&tm);
  return t;
}


ZRESULT GetFileInfo(HANDLE hf, ulg *attr, long *size, iztimes *times, ulg *timestamp)
{ 
	DWORD type=GetFileType(hf);
  if (type!=FILE_TYPE_DISK) 
	  return ZR_NOTINITED;
  // The handle must be a handle to a file
  // The date and time is returned in a long with the date most significant to allow
  // unsigned integer comparison of absolute times. The attributes have two
  // high bytes unix attr, and two low bytes a mapping of that to DOS attr.
  //struct stat s; int res=stat(fn,&s); if (res!=0) return false;
  // translate windows file attributes into zip ones.
  BY_HANDLE_FILE_INFORMATION bhi; 
  BOOL res=GetFileInformationByHandle(hf,&bhi);
  if (!res) 
	  return ZR_NOFILE;
  DWORD fa=bhi.dwFileAttributes; 
  ulg a=0;
  // Zip uses the lower word for its interpretation of windows stuff
  if (fa&FILE_ATTRIBUTE_READONLY) a|=0x01;
  if (fa&FILE_ATTRIBUTE_HIDDEN)   a|=0x02;
  if (fa&FILE_ATTRIBUTE_SYSTEM)   a|=0x04;
  if (fa&FILE_ATTRIBUTE_DIRECTORY)a|=0x10;
  if (fa&FILE_ATTRIBUTE_ARCHIVE)  a|=0x20;
  // It uses the upper word for standard unix attr, which we must manually construct
  if (fa&FILE_ATTRIBUTE_DIRECTORY)a|=0x40000000;  // directory
  else a|=0x80000000;  // normal file
  a|=0x01000000;      // readable
  if (fa&FILE_ATTRIBUTE_READONLY) {}
  else a|=0x00800000; // writeable
  // now just a small heuristic to check if it's an executable:
  DWORD red, hsize=GetFileSize(hf,NULL); if (hsize>40)
  { SetFilePointer(hf,0,NULL,FILE_BEGIN); unsigned short magic; ReadFile(hf,&magic,sizeof(magic),&red,NULL);
    SetFilePointer(hf,36,NULL,FILE_BEGIN); unsigned long hpos;  ReadFile(hf,&hpos,sizeof(hpos),&red,NULL);
    if (magic==0x54AD && hsize>hpos+4+20+28)
    { SetFilePointer(hf,hpos,NULL,FILE_BEGIN); unsigned long signature; ReadFile(hf,&signature,sizeof(signature),&red,NULL);
      if (signature==IMAGE_DOS_SIGNATURE || signature==IMAGE_OS2_SIGNATURE
         || signature==IMAGE_OS2_SIGNATURE_LE || signature==IMAGE_NT_SIGNATURE)
      { a |= 0x00400000; // executable
      }
    }
  }
  //
  if (attr!=NULL) *attr = a;
  if (size!=NULL) *size = hsize;
  if (times!=NULL)
  { // time_t is 32bit number of seconds elapsed since 0:0:0GMT, Jan1, 1970.
    // but FILETIME is 64bit number of 100-nanosecs since Jan1, 1601
    times->atime = filetime2timet(bhi.ftLastAccessTime);
    times->mtime = filetime2timet(bhi.ftLastWriteTime);
    times->ctime = filetime2timet(bhi.ftCreationTime);
  }
  if (timestamp!=NULL)
  { WORD dosdate,dostime;
    FileTimeToDosDateTime(&bhi.ftLastWriteTime,&dosdate,&dostime);
    *timestamp = (WORD)dostime | (((DWORD)dosdate)<<16);
  }
  return ZR_OK;
}





///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////

class TZip
{ public:
  TZip() : hfout(0),hmapout(0),zfis(0),obuf(0),hfin(0),writ(0),oerr(false),hasputcen(false),ooffset(0) {}
  ~TZip() {}

  // These variables say about the file we're writing into
  // We can write to pipe, file-by-handle, file-by-name, memory-to-memmapfile
  HANDLE hfout;             // if valid, we'll write here (for files or pipes)
  HANDLE hmapout;           // otherwise, we'll write here (for memmap)
  unsigned ooffset;         // for hfout, this is where the pointer was initially
  ZRESULT oerr;             // did a write operation give rise to an error?
  unsigned writ;            // how far have we written. This is maintained by Add, not write(), to avoid confusion over seeks
  bool ocanseek;            // can we seek?
  char *obuf;               // this is where we've locked mmap to view.
  unsigned int opos;        // current pos in the mmap
  unsigned int mapsize;     // the size of the map we created
  bool hasputcen;           // have we yet placed the central directory?
  //
  TZipFileInfo *zfis;       // each file gets added onto this list, for writing the table at the end

  ZRESULT Create(void *z,unsigned int len,DWORD flags);
  static unsigned sflush(void *param,const char *buf, unsigned *size);
  static unsigned swrite(void *param,const char *buf, unsigned size);
  unsigned int write(const char *buf,unsigned int size);
  bool oseek(unsigned int pos);
  ZRESULT GetMemory(void **pbuf, unsigned long *plen);
  ZRESULT Close();

  // some variables to do with the file currently being read:
  // I haven't done it object-orientedly here, just put them all
  // together, since OO didn't seem to make the design any clearer.
  ulg attr; iztimes times; ulg timestamp;  // all open_* methods set these
  bool iseekable; long isize,ired;         // size is not set until close() on pips
  ulg crc;                                 // crc is not set until close(). iwrit is cumulative
  HANDLE hfin; bool selfclosehf;           // for input files and pipes
  const char *bufin; unsigned int lenin,posin; // for memory
  // and a variable for what we've done with the input: (i.e. compressed it!)
  ulg csize;                               // compressed size, set by the compression routines
  // and this is used by some of the compression routines
  char buf[16384];


  ZRESULT open_file(const TCHAR *fn);
  ZRESULT open_handle(HANDLE hf,unsigned int len);
  ZRESULT open_mem(void *src,unsigned int len);
  ZRESULT open_dir();
  static unsigned sread(TState &s,char *buf,unsigned size);
  unsigned read(char *buf, unsigned size);
  ZRESULT iclose();

  ZRESULT ideflate(TZipFileInfo *zfi);
  ZRESULT istore();

  ZRESULT Add(const char *odstzn, void *src,unsigned int len, DWORD flags);
  ZRESULT AddCentral();

};

ZRESULT TZip::Create(void *z,unsigned int len,DWORD flags)
{ 
	if (hfout!=0 || hmapout!=0 || obuf!=0 || writ!=0 || oerr!=ZR_OK || hasputcen) 
		return ZR_NOTINITED;
	//
	if (flags==ZIP_HANDLE)
	{ 
		HANDLE hf = (HANDLE)z;
		BOOL res = DuplicateHandle(GetCurrentProcess(),hf,GetCurrentProcess(),&hfout,0,FALSE,DUPLICATE_SAME_ACCESS);
		if (!res) 
			return ZR_NODUPH;
		// now we have our own hfout, which we must close. And the caller will close hf
		DWORD type = GetFileType(hfout);
		ocanseek = (type==FILE_TYPE_DISK);
		if (type==FILE_TYPE_DISK) 
			ooffset=SetFilePointer(hfout,0,NULL,FILE_CURRENT);
		else 
			ooffset=0;
		return ZR_OK;
	}
	else if (flags==ZIP_FILENAME)
	{ 
#ifdef _UNICODE
		const TCHAR *fn = (const TCHAR*)z;
		hfout = CreateFileW(fn,GENERIC_WRITE,0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
#else
		const char *fn = (const char*)z;
		hfout = CreateFileA(fn,GENERIC_WRITE,0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
#endif

		if (hfout==INVALID_HANDLE_VALUE) 
		{
			hfout=0;
			return ZR_NOFILE;
		}
		ocanseek=true;
		ooffset=0;
		return ZR_OK;
	}
	else if (flags==ZIP_MEMORY)
	{ 
		unsigned int size = len;
		if (size==0) 
			return ZR_MEMSIZE;
		if (z!=0) 
			obuf=(char*)z;
		else
		{ 
			hmapout = CreateFileMapping(INVALID_HANDLE_VALUE,NULL,PAGE_READWRITE,0,size,NULL);
			if (hmapout==NULL) 
				return ZR_NOALLOC;
			obuf = (char*)MapViewOfFile(hmapout,FILE_MAP_ALL_ACCESS,0,0,size);
			if (obuf==0) 
			{
				CloseHandle(hmapout); 
				hmapout=0; 
				return ZR_NOALLOC;
			}
		}
		ocanseek=true;
		opos=0; 
		mapsize=size;
		return ZR_OK;
	}
	else 
		return ZR_ARGS;
}


unsigned TZip::sflush(void *param,const char *buf, unsigned *size)
{ // static
  if (*size==0) return 0;
  TZip *zip = (TZip*)param;
  unsigned int writ = zip->write(buf,*size);
  if (writ!=0) *size=0;
  return writ;
}
unsigned TZip::swrite(void *param,const char *buf, unsigned size)
{ // static
  if (size==0) return 0;
  TZip *zip=(TZip*)param; return zip->write(buf,size);
}
unsigned int TZip::write(const char *buf,unsigned int size)
{ if (obuf!=0)
  { if (opos+size>=mapsize) {oerr=ZR_MEMSIZE; return 0;}
    memcpy(obuf+opos, buf, size);
    opos+=size;
    return size;
  }
  else if (hfout!=0)
  { DWORD writ; WriteFile(hfout,buf,size,&writ,NULL);
    return writ;
  }
  oerr=ZR_NOTINITED; return 0;
}

bool TZip::oseek(unsigned int pos)
{ if (!ocanseek) {oerr=ZR_SEEK; return false;}
  if (obuf!=0)
  { if (pos>=mapsize) {oerr=ZR_MEMSIZE; return false;}
    opos=pos;
    return true;
  }
  else if (hfout!=0)
  { SetFilePointer(hfout,pos+ooffset,NULL,FILE_BEGIN);
    return true;
  }
  oerr=ZR_NOTINITED; return 0;
}

ZRESULT TZip::GetMemory(void **pbuf, unsigned long *plen)
{ // When the user calls GetMemory, they're presumably at the end
  // of all their adding. In any case, we have to add the central
  // directory now, otherwise the memory we tell them won't be complete.
  if (!hasputcen) AddCentral(); hasputcen=true;
  if (pbuf!=NULL) *pbuf=(void*)obuf;
  if (plen!=NULL) *plen=writ;
  if (obuf==NULL) return ZR_NOTMMAP;
  return ZR_OK;
}

ZRESULT TZip::Close()
{ // if the directory hadn't already been added through a call to GetMemory,
  // then we do it now
  ZRESULT res=ZR_OK; if (!hasputcen) res=AddCentral(); hasputcen=true;
  if (obuf!=0 && hmapout!=0) UnmapViewOfFile(obuf); obuf=0;
  if (hmapout!=0) CloseHandle(hmapout); hmapout=0;
  if (hfout!=0) CloseHandle(hfout); hfout=0;
  return res;
}




ZRESULT TZip::open_file(const TCHAR *fn)
{ hfin=0; bufin=0; selfclosehf=false; crc=CRCVAL_INITIAL; isize=0; csize=0; ired=0;
  if (fn==0) return ZR_ARGS;
  HANDLE hf = CreateFile(fn,GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,0,NULL);
  if (hf==INVALID_HANDLE_VALUE) return ZR_NOFILE;
  ZRESULT res = open_handle(hf,0);
  if (res!=ZR_OK) {CloseHandle(hf); return res;}
  selfclosehf=true;
  return ZR_OK;
}
ZRESULT TZip::open_handle(HANDLE hf,unsigned int len)
{ hfin=0; bufin=0; selfclosehf=false; crc=CRCVAL_INITIAL; isize=0; csize=0; ired=0;
  if (hf==0 || hf==INVALID_HANDLE_VALUE) return ZR_ARGS;
  DWORD type = GetFileType(hf);
  if (type==FILE_TYPE_DISK)
  { ZRESULT res = GetFileInfo(hf,&attr,&isize,&times,&timestamp);
    if (res!=ZR_OK) return res;
    SetFilePointer(hf,0,NULL,FILE_BEGIN); // because GetFileInfo will have screwed it up
    iseekable=true; hfin=hf;
    return ZR_OK;
  }
  else
  { attr= 0x80000000;      // just a normal file
    isize = -1;            // can't know size until at the end
    if (len!=0) isize=len; // unless we were told explicitly!
    iseekable=false;
    SYSTEMTIME st; GetLocalTime(&st);
    FILETIME ft;   SystemTimeToFileTime(&st,&ft);
    WORD dosdate,dostime; FileTimeToDosDateTime(&ft,&dosdate,&dostime);
    times.atime = filetime2timet(ft);
    times.mtime = times.atime;
    times.ctime = times.atime;
    timestamp = (WORD)dostime | (((DWORD)dosdate)<<16);
    hfin=hf;
    return ZR_OK;
  }
}
ZRESULT TZip::open_mem(void *src,unsigned int len)
{ hfin=0; bufin=(const char*)src; selfclosehf=false; crc=CRCVAL_INITIAL; ired=0; csize=0; ired=0;
  lenin=len; posin=0;
  if (src==0 || len==0) return ZR_ARGS;
  attr= 0x80000000; // just a normal file
  isize = len;
  iseekable=true;
  SYSTEMTIME st; GetLocalTime(&st);
  FILETIME ft;   SystemTimeToFileTime(&st,&ft);
  WORD dosdate,dostime; FileTimeToDosDateTime(&ft,&dosdate,&dostime);
  times.atime = filetime2timet(ft);
  times.mtime = times.atime;
  times.ctime = times.atime;
  timestamp = (WORD)dostime | (((DWORD)dosdate)<<16);
  return ZR_OK;
}
ZRESULT TZip::open_dir()
{ hfin=0; bufin=0; selfclosehf=false; crc=CRCVAL_INITIAL; isize=0; csize=0; ired=0;
  attr= 0x41C00010; // a readable writable directory, and again directory
  isize = 0;
  iseekable=false;
  SYSTEMTIME st; GetLocalTime(&st);
  FILETIME ft;   SystemTimeToFileTime(&st,&ft);
  WORD dosdate,dostime; FileTimeToDosDateTime(&ft,&dosdate,&dostime);
  times.atime = filetime2timet(ft);
  times.mtime = times.atime;
  times.ctime = times.atime;
  timestamp = (WORD)dostime | (((DWORD)dosdate)<<16);
  return ZR_OK;
}

unsigned TZip::sread(TState &s,char *buf,unsigned size)
{ // static
  TZip *zip = (TZip*)s.param;
  return zip->read(buf,size);
}

unsigned TZip::read(char *buf, unsigned size)
{ if (bufin!=0)
  { if (posin>=lenin) return 0; // end of input
    ulg red = lenin-posin;
    if (red>size) red=size;
    memcpy(buf, bufin+posin, red);
    posin += red;
    ired += red;
    crc = crc32(crc, (uch*)buf, red);
    return red;
  }
  else if (hfin!=0)
  { DWORD red;
    BOOL ok = ReadFile(hfin,buf,size,&red,NULL);
    if (!ok) return 0;
    ired += red;
    crc = crc32(crc, (uch*)buf, red);
    return red;
  }
  else {oerr=ZR_NOTINITED; return 0;}
}

ZRESULT TZip::iclose()
{ if (selfclosehf && hfin!=0) CloseHandle(hfin); hfin=0;
  bool mismatch = (isize!=-1 && isize!=ired);
  isize=ired; // and crc has been being updated anyway
  if (mismatch) return ZR_MISSIZE;
  else return ZR_OK;
}



ZRESULT TZip::ideflate(TZipFileInfo *zfi)
{ TState state;
  state.readfunc=sread; state.flush_outbuf=sflush;
  state.param=this; state.level=8; state.seekable=iseekable; state.err=NULL;
  // the following line will make ct_init realise it has to perform the init
  state.ts.static_dtree[0].dl.len = 0;
  // It would be nicer if I could figure out precisely which data had to
  // be initted each time, and which didn't, but that's kind of difficult.
  // Maybe for the next version...
  //
  bi_init(state,buf, sizeof(buf), TRUE); // it used to be just 1024-size, not 16384 as here
  ct_init(state,&zfi->att);
  lm_init(state,state.level, &zfi->flg);
  ulg sz = deflate(state);
  csize=sz;
  if (state.err!=NULL) return ZR_FLATE;
  else return ZR_OK;
}

ZRESULT TZip::istore()
{ ulg size=0;
  for (;;)
  { unsigned int cin=read(buf,16384); if (cin<=0 || cin==(unsigned int)EOF) break;
    unsigned int cout = write(buf,cin); if (cout!=cin) return ZR_MISSIZE;
    size += cin;
  }
  csize=size;
  return ZR_OK;
}




ZRESULT TZip::Add(const char *odstzn, void *src,unsigned int len, DWORD flags)
{ 
	if (oerr) 
		return ZR_FAILED;
	if (hasputcen) 
		return ZR_ENDED;

	// zip has its own notion of what its names should look like: i.e. dir/file.stuff
	char dstzn[MAX_PATH]; 
	strcpy(dstzn, odstzn);
	if (*dstzn == 0) 
		return ZR_ARGS;
	char *d=dstzn; 
	while (*d != 0) 
	{
		if (*d == '\\') 
			*d = '/'; d++;
	}
	bool isdir = (flags==ZIP_FOLDER);
	bool needs_trailing_slash = (isdir && dstzn[strlen(dstzn)-1]!='/');
	int method=DEFLATE; 
	if (isdir || HasZipSuffix(dstzn)) 
		method=STORE;

	// now open whatever was our input source:
	ZRESULT openres;
	if (flags==ZIP_FILENAME) 
		openres=open_file((const TCHAR*)src);
	else if (flags==ZIP_HANDLE) 
		openres=open_handle((HANDLE)src,len);
	else if (flags==ZIP_MEMORY) 
		openres=open_mem(src,len);
	else if (flags==ZIP_FOLDER) 
		openres=open_dir();
	else return ZR_ARGS;
	if (openres!=ZR_OK) 
		return openres;

	// A zip "entry" consists of a local header (which includes the file name),
	// then the compressed data, and possibly an extended local header.

	// Initialize the local header
	TZipFileInfo zfi; zfi.nxt=NULL;
	strcpy(zfi.name,"");
	strcpy(zfi.iname,dstzn); 
	zfi.nam=strlen(zfi.iname);
	if (needs_trailing_slash) 
	{
		strcat(zfi.iname,"/"); 
		zfi.nam++;
	}
	strcpy(zfi.zname,"");
	zfi.extra=NULL; zfi.ext=0;   // extra header to go after this compressed data, and its length
	zfi.cextra=NULL; zfi.cext=0; // extra header to go in the central end-of-zip directory, and its length
	zfi.comment=NULL; zfi.com=0; // comment, and its length
	zfi.mark = 1;
	zfi.dosflag = 0;
	zfi.att = (ush)BINARY;
	zfi.vem = (ush)0xB17; // 0xB00 is win32 os-code. 0x17 is 23 in decimal: zip 2.3
	zfi.ver = (ush)20;    // Needs PKUNZIP 2.0 to unzip it
	zfi.tim = timestamp;
	// Even though we write the header now, it will have to be rewritten, since we don't know compressed size or crc.
	zfi.crc = 0;            // to be updated later
	zfi.flg = 8;            // 8 means 'there is an extra header'. Assume for the moment that we need it.
	zfi.lflg = zfi.flg;     // to be updated later
	zfi.how = (ush)method;  // to be updated later
	zfi.siz = (ulg)(method==STORE && isize>=0 ? isize : 0); // to be updated later
	zfi.len = (ulg)(isize);  // to be updated later
	zfi.dsk = 0;
	zfi.atx = attr;
	zfi.off = writ+ooffset;         // offset within file of the start of this local record
	// stuff the 'times' structure into zfi.extra
	char xloc[EB_L_UT_SIZE]; 
	zfi.extra=xloc;  
	zfi.ext=EB_L_UT_SIZE;
	char xcen[EB_C_UT_SIZE]; 
	zfi.cextra=xcen; 
	zfi.cext=EB_C_UT_SIZE;
	xloc[0]  = 'U';
	xloc[1]  = 'T';
	xloc[2]  = EB_UT_LEN(3);       // length of data part of e.f.
	xloc[3]  = 0;
	xloc[4]  = EB_UT_FL_MTIME | EB_UT_FL_ATIME | EB_UT_FL_CTIME;
	xloc[5]  = (char)(times.mtime);
	xloc[6]  = (char)(times.mtime >> 8);
	xloc[7]  = (char)(times.mtime >> 16);
	xloc[8]  = (char)(times.mtime >> 24);
	xloc[9]  = (char)(times.atime);
	xloc[10] = (char)(times.atime >> 8);
	xloc[11] = (char)(times.atime >> 16);
	xloc[12] = (char)(times.atime >> 24);
	xloc[13] = (char)(times.ctime);
	xloc[14] = (char)(times.ctime >> 8);
	xloc[15] = (char)(times.ctime >> 16);
	xloc[16] = (char)(times.ctime >> 24);
	memcpy(zfi.cextra,zfi.extra,EB_C_UT_SIZE);
	zfi.cextra[EB_LEN] = EB_UT_LEN(1);


	// (1) Start by writing the local header:
	int r = putlocal(&zfi,swrite,this);
	if (r!=ZE_OK) 
	{
		iclose(); 
		return ZR_WRITE;
	}
	writ += 4 + LOCHEAD + (unsigned int)zfi.nam + (unsigned int)zfi.ext;
	if (oerr!=ZR_OK) 
	{
		iclose(); 
		return oerr;
	}

	//(2) Write deflated/stored file to zip file
	ZRESULT writeres=ZR_OK;
	if (!isdir && method==DEFLATE) 
		writeres=ideflate(&zfi);
	else if (!isdir && method==STORE) 
		writeres=istore();
	else if (isdir) 
		csize=0;
	iclose();
	writ += csize;
	if (oerr!=ZR_OK) 
		return oerr;
	if (writeres!=ZR_OK) 
		return ZR_WRITE;

	// (3) Either rewrite the local header with correct information...
	bool first_header_has_size_right = (zfi.siz==csize);
	zfi.crc = crc;
	zfi.siz = csize;
	zfi.len = isize;
	if (ocanseek)
	{ 
		zfi.how = (ush)method;
		if ((zfi.flg & 1) == 0) 
			zfi.flg &= ~8; // clear the extended local header flag
		zfi.lflg = zfi.flg;
		// rewrite the local header:
		if (!oseek(zfi.off-ooffset)) 
			return ZR_SEEK;
		if ((r = putlocal(&zfi, swrite,this)) != ZE_OK) 
			return ZR_WRITE;
		if (!oseek(writ)) 
			return ZR_SEEK;
	}
	else
	{ 
		// (4) ... or put an updated header at the end
		if (zfi.how != (ush) method) 
			return ZR_NOCHANGE;
		if (method==STORE && !first_header_has_size_right) 
			return ZR_NOCHANGE;
		if ((r = putextended(&zfi, swrite,this)) != ZE_OK) 
			return ZR_WRITE;
		writ += 16L;
		zfi.flg = zfi.lflg; // if flg modified by inflate, for the central index
	}
	if (oerr!=ZR_OK) 
		return oerr;

	// Keep a copy of the zipfileinfo, for our end-of-zip directory
	char *cextra = new char[zfi.cext]; 
	memcpy(cextra,zfi.cextra,zfi.cext); zfi.cextra=cextra;
	TZipFileInfo *pzfi = new TZipFileInfo; 
	memcpy(pzfi,&zfi,sizeof(zfi));
	if (zfis==NULL) 
		zfis=pzfi;
	else 
	{
		TZipFileInfo *z=zfis; 
		while (z->nxt!=NULL) 
			z=z->nxt; 
		z->nxt=pzfi;
	}
	return ZR_OK;
}

ZRESULT TZip::AddCentral()
{ // write central directory
  int numentries = 0;
  ulg pos_at_start_of_central = writ;
  //ulg tot_unc_size=0, tot_compressed_size=0;
  bool okay=true;
  for (TZipFileInfo *zfi=zfis; zfi!=NULL; )
  { if (okay)
    { int res = putcentral(zfi, swrite,this);
      if (res!=ZE_OK) okay=false;
    }
    writ += 4 + CENHEAD + (unsigned int)zfi->nam + (unsigned int)zfi->cext + (unsigned int)zfi->com;
    //tot_unc_size += zfi->len;
    //tot_compressed_size += zfi->siz;
    numentries++;
    //
    TZipFileInfo *zfinext = zfi->nxt;
    if (zfi->cextra!=0) delete[] zfi->cextra;
    delete zfi;
    zfi = zfinext;
  }
  ulg center_size = writ - pos_at_start_of_central;
  if (okay)
  { int res = putend(numentries, center_size, pos_at_start_of_central+ooffset, 0, NULL, swrite,this);
    if (res!=ZE_OK) okay=false;
    writ += 4 + ENDHEAD + 0;
  }
  if (!okay) return ZR_WRITE;
  return ZR_OK;
}





ZRESULT lasterrorZ=ZR_OK;

unsigned int FormatZipMessageZ(ZRESULT code, char *buf,unsigned int len)
{ if (code==ZR_RECENT) code=lasterrorZ;
  const char *msg="unknown zip result code";
  switch (code)
  { case ZR_OK: msg="Success"; break;
    case ZR_NODUPH: msg="Culdn't duplicate handle"; break;
    case ZR_NOFILE: msg="Couldn't create/open file"; break;
    case ZR_NOALLOC: msg="Failed to allocate memory"; break;
    case ZR_WRITE: msg="Error writing to file"; break;
    case ZR_NOTFOUND: msg="File not found in the zipfile"; break;
    case ZR_MORE: msg="Still more data to unzip"; break;
    case ZR_CORRUPT: msg="Zipfile is corrupt or not a zipfile"; break;
    case ZR_READ: msg="Error reading file"; break;
    case ZR_ARGS: msg="Caller: faulty arguments"; break;
    case ZR_PARTIALUNZ: msg="Caller: the file had already been partially unzipped"; break;
    case ZR_NOTMMAP: msg="Caller: can only get memory of a memory zipfile"; break;
    case ZR_MEMSIZE: msg="Caller: not enough space allocated for memory zipfile"; break;
    case ZR_FAILED: msg="Caller: there was a previous error"; break;
    case ZR_ENDED: msg="Caller: additions to the zip have already been ended"; break;
    case ZR_ZMODE: msg="Caller: mixing creation and opening of zip"; break;
    case ZR_NOTINITED: msg="Zip-bug: internal initialisation not completed"; break;
    case ZR_SEEK: msg="Zip-bug: trying to seek the unseekable"; break;
    case ZR_MISSIZE: msg="Zip-bug: the anticipated size turned out wrong"; break;
    case ZR_NOCHANGE: msg="Zip-bug: tried to change mind, but not allowed"; break;
    case ZR_FLATE: msg="Zip-bug: an internal error during flation"; break;
  }
  unsigned int mlen=(unsigned int)strlen(msg);
  if (buf==0 || len==0) return mlen;
  unsigned int n=mlen; if (n+1>len) n=len-1;
  strncpy(buf,msg,n); buf[n]=0;
  return mlen;
}



typedef struct
{ DWORD flag;
  TZip *zip;
} TZipHandleData;


HZIP CreateZipZ(void *z,unsigned int len,DWORD flags)
{ 
	tzset();
	TZip *zip = new TZip();
	lasterrorZ = zip->Create(z,len,flags);
	if (lasterrorZ != ZR_OK) 
	{
		delete zip; 
		return 0;
	}
	TZipHandleData *han = new TZipHandleData;
	han->flag = 2; 
	han->zip = zip; 
	return (HZIP)han;
}

ZRESULT ZipAdd(HZIP hz, const TCHAR *dstzn, void *src, unsigned int len, DWORD flags)
{ 
	if (hz == 0) 
	{
		lasterrorZ = ZR_ARGS;
		return ZR_ARGS;
	}
	TZipHandleData *han = (TZipHandleData*)hz;
	if (han->flag != 2) 
	{
		lasterrorZ = ZR_ZMODE;
		return ZR_ZMODE;
	}
	TZip *zip = han->zip;


	if (flags == ZIP_FILENAME)
	{
		char szDest[MAX_PATH*2];
		memset(szDest, 0, sizeof(szDest));

#ifdef _UNICODE
		// need to convert Unicode dest to ANSI
		int nActualChars = WideCharToMultiByte(CP_ACP,	// code page
								0,						// performance and mapping flags
								(LPCWSTR) dstzn,		// wide-character string
								-1,						// number of chars in string
								szDest,					// buffer for new string
								MAX_PATH*2-2,			// size of buffer
								NULL,					// default for unmappable chars
								NULL);					// set when default char used
		if (nActualChars == 0)
			return ZR_ARGS; 
#else
		strcpy(szDest, dstzn);
#endif

		lasterrorZ = zip->Add(szDest, src, len, flags);
	}
	else
	{
		lasterrorZ = zip->Add((char *)dstzn, src, len, flags);
	}

	return lasterrorZ;
}

ZRESULT ZipGetMemory(HZIP hz, void **buf, unsigned long *len)
{ if (hz==0) {if (buf!=0) *buf=0; if (len!=0) *len=0; lasterrorZ=ZR_ARGS;return ZR_ARGS;}
  TZipHandleData *han = (TZipHandleData*)hz;
  if (han->flag!=2) {lasterrorZ=ZR_ZMODE;return ZR_ZMODE;}
  TZip *zip = han->zip;
  lasterrorZ = zip->GetMemory(buf,len);
  return lasterrorZ;
}

ZRESULT CloseZipZ(HZIP hz)
{ if (hz==0) {lasterrorZ=ZR_ARGS;return ZR_ARGS;}
  TZipHandleData *han = (TZipHandleData*)hz;
  if (han->flag!=2) {lasterrorZ=ZR_ZMODE;return ZR_ZMODE;}
  TZip *zip = han->zip;
  lasterrorZ = zip->Close();
  delete zip;
  delete han;
  return lasterrorZ;
}

bool IsZipHandleZ(HZIP hz)
{ if (hz==0) return true;
  TZipHandleData *han = (TZipHandleData*)hz;
  return (han->flag==2);
}

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License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer (Senior) Hans Dietrich Software
United States United States
I attended St. Michael's College of the University of Toronto, with the intention of becoming a priest. A friend in the University's Computer Science Department got me interested in programming, and I have been hooked ever since.

Recently, I have moved to Los Angeles where I am doing consulting and development work.

For consulting and custom software development, please see www.hdsoft.org.






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