xref: /freebsd/sys/contrib/zstd/zlibWrapper/gzguts.h (revision 780fb4a2)
1 /* gzguts.h contains minimal changes required to be compiled with zlibWrapper:
2  * - #include "zlib.h" was changed to #include "zstd_zlibwrapper.h"
3  * - gz_statep was converted to union to work with -Wstrict-aliasing=1      */
4 
5 /* gzguts.h -- zlib internal header definitions for gz* operations
6  * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
7  * For conditions of distribution and use, see http://www.zlib.net/zlib_license.html
8  */
9 
10 #ifdef _LARGEFILE64_SOURCE
11 #  ifndef _LARGEFILE_SOURCE
12 #    define _LARGEFILE_SOURCE 1
13 #  endif
14 #  ifdef _FILE_OFFSET_BITS
15 #    undef _FILE_OFFSET_BITS
16 #  endif
17 #endif
18 
19 #ifdef HAVE_HIDDEN
20 #  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
21 #else
22 #  define ZLIB_INTERNAL
23 #endif
24 
25 #include <stdio.h>
26 #include "zstd_zlibwrapper.h"
27 #include "gzcompatibility.h"
28 #ifdef STDC
29 #  include <string.h>
30 #  include <stdlib.h>
31 #  include <limits.h>
32 #endif
33 
34 #ifndef _POSIX_SOURCE
35 #  define _POSIX_SOURCE
36 #endif
37 #include <fcntl.h>
38 
39 #ifdef _WIN32
40 #  include <stddef.h>
41 #endif
42 
43 #if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
44 #  include <io.h>
45 #endif
46 
47 #if defined(_WIN32) || defined(__CYGWIN__)
48 #  define WIDECHAR
49 #endif
50 
51 #ifdef WINAPI_FAMILY
52 #  define open _open
53 #  define read _read
54 #  define write _write
55 #  define close _close
56 #endif
57 
58 #ifdef NO_DEFLATE       /* for compatibility with old definition */
59 #  define NO_GZCOMPRESS
60 #endif
61 
62 #if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
63 #  ifndef HAVE_VSNPRINTF
64 #    define HAVE_VSNPRINTF
65 #  endif
66 #endif
67 
68 #if defined(__CYGWIN__)
69 #  ifndef HAVE_VSNPRINTF
70 #    define HAVE_VSNPRINTF
71 #  endif
72 #endif
73 
74 #if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
75 #  ifndef HAVE_VSNPRINTF
76 #    define HAVE_VSNPRINTF
77 #  endif
78 #endif
79 
80 #ifndef HAVE_VSNPRINTF
81 #  ifdef MSDOS
82 /* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
83    but for now we just assume it doesn't. */
84 #    define NO_vsnprintf
85 #  endif
86 #  ifdef __TURBOC__
87 #    define NO_vsnprintf
88 #  endif
89 #  ifdef WIN32
90 /* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
91 #    if !defined(vsnprintf) && !defined(NO_vsnprintf)
92 #      if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
93 #         define vsnprintf _vsnprintf
94 #      endif
95 #    endif
96 #  endif
97 #  ifdef __SASC
98 #    define NO_vsnprintf
99 #  endif
100 #  ifdef VMS
101 #    define NO_vsnprintf
102 #  endif
103 #  ifdef __OS400__
104 #    define NO_vsnprintf
105 #  endif
106 #  ifdef __MVS__
107 #    define NO_vsnprintf
108 #  endif
109 #endif
110 
111 /* unlike snprintf (which is required in C99), _snprintf does not guarantee
112    null termination of the result -- however this is only used in gzlib.c where
113    the result is assured to fit in the space provided */
114 #if defined(_MSC_VER) && _MSC_VER < 1900
115 #  define snprintf _snprintf
116 #endif
117 
118 #ifndef local
119 #  define local static
120 #endif
121 /* since "static" is used to mean two completely different things in C, we
122    define "local" for the non-static meaning of "static", for readability
123    (compile with -Dlocal if your debugger can't find static symbols) */
124 
125 /* gz* functions always use library allocation functions */
126 #ifndef STDC
127   extern voidp  malloc OF((uInt size));
128   extern void   free   OF((voidpf ptr));
129 #endif
130 
131 /* get errno and strerror definition */
132 #if defined UNDER_CE
133 #  include <windows.h>
134 #  define zstrerror() gz_strwinerror((DWORD)GetLastError())
135 #else
136 #  ifndef NO_STRERROR
137 #    include <errno.h>
138 #    define zstrerror() strerror(errno)
139 #  else
140 #    define zstrerror() "stdio error (consult errno)"
141 #  endif
142 #endif
143 
144 /* provide prototypes for these when building zlib without LFS */
145 #if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
146     ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
147     ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
148     ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
149     ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
150 #endif
151 
152 /* default memLevel */
153 #if MAX_MEM_LEVEL >= 8
154 #  define DEF_MEM_LEVEL 8
155 #else
156 #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
157 #endif
158 
159 /* default i/o buffer size -- double this for output when reading (this and
160    twice this must be able to fit in an unsigned type) */
161 #define GZBUFSIZE 8192
162 
163 /* gzip modes, also provide a little integrity check on the passed structure */
164 #define GZ_NONE 0
165 #define GZ_READ 7247
166 #define GZ_WRITE 31153
167 #define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
168 
169 /* values for gz_state how */
170 #define LOOK 0      /* look for a gzip header */
171 #define COPY 1      /* copy input directly */
172 #define GZIP 2      /* decompress a gzip stream */
173 
174 /* internal gzip file state data structure */
175 typedef struct {
176         /* exposed contents for gzgetc() macro */
177     struct gzFile_s x;      /* "x" for exposed */
178                             /* x.have: number of bytes available at x.next */
179                             /* x.next: next output data to deliver or write */
180                             /* x.pos: current position in uncompressed data */
181         /* used for both reading and writing */
182     int mode;               /* see gzip modes above */
183     int fd;                 /* file descriptor */
184     char *path;             /* path or fd for error messages */
185     unsigned size;          /* buffer size, zero if not allocated yet */
186     unsigned want;          /* requested buffer size, default is GZBUFSIZE */
187     unsigned char *in;      /* input buffer (double-sized when writing) */
188     unsigned char *out;     /* output buffer (double-sized when reading) */
189     int direct;             /* 0 if processing gzip, 1 if transparent */
190         /* just for reading */
191     int how;                /* 0: get header, 1: copy, 2: decompress */
192     z_off64_t start;        /* where the gzip data started, for rewinding */
193     int eof;                /* true if end of input file reached */
194     int past;               /* true if read requested past end */
195         /* just for writing */
196     int level;              /* compression level */
197     int strategy;           /* compression strategy */
198         /* seek request */
199     z_off64_t skip;         /* amount to skip (already rewound if backwards) */
200     int seek;               /* true if seek request pending */
201         /* error information */
202     int err;                /* error code */
203     char *msg;              /* error message */
204         /* zlib inflate or deflate stream */
205     z_stream strm;          /* stream structure in-place (not a pointer) */
206 } gz_state;
207 
208 typedef union {
209     gz_state FAR *state;
210     gzFile file;
211 } gz_statep;
212 
213 /* shared functions */
214 void ZLIB_INTERNAL gz_error OF((gz_statep, int, const char *));
215 #if defined UNDER_CE
216 char ZLIB_INTERNAL *gz_strwinerror OF((DWORD error));
217 #endif
218 
219 /* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
220    value -- needed when comparing unsigned to z_off64_t, which is signed
221    (possible z_off64_t types off_t, off64_t, and long are all signed) */
222 #ifdef INT_MAX
223 #  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > INT_MAX)
224 #else
225 unsigned ZLIB_INTERNAL gz_intmax OF((void));
226 #  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
227 #endif
228