2 Copyright (C) 2013 Free Software Foundation, Inc.
4 This file is part of GNU Emacs.
6 GNU Emacs is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
26 #include "character.h"
29 static Lisp_Object Qzlib_dll
;
35 /* Macro for defining functions that will be loaded from the zlib DLL. */
36 #define DEF_ZLIB_FN(rettype,func,args) static rettype (FAR CDECL *fn_##func)args
38 /* Macro for loading zlib functions from the library. */
39 #define LOAD_ZLIB_FN(lib,func) { \
40 fn_##func = (void *) GetProcAddress (lib, #func); \
41 if (!fn_##func) return false; \
44 DEF_ZLIB_FN (int, inflateInit2_
,
45 (z_streamp strm
, int windowBits
, const char *version
, int stream_size
));
47 DEF_ZLIB_FN (int, inflate
,
48 (z_streamp strm
, int flush
));
50 DEF_ZLIB_FN (int, inflateEnd
,
53 static bool zlib_initialized
;
56 init_zlib_functions (void)
58 HMODULE library
= w32_delayed_load (Qzlib_dll
);
62 message1 ("zlib library not found");
66 LOAD_ZLIB_FN (library
, inflateInit2_
);
67 LOAD_ZLIB_FN (library
, inflate
);
68 LOAD_ZLIB_FN (library
, inflateEnd
);
72 #define fn_inflateInit2(strm, windowBits) \
73 fn_inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
75 #else /* !WINDOWSNT */
77 #define fn_inflateInit2 inflateInit2
78 #define fn_inflate inflate
79 #define fn_inflateEnd inflateEnd
81 #endif /* WINDOWSNT */
84 struct decompress_unwind_data
86 ptrdiff_t old_point
, start
;
91 unwind_decompress (void *ddata
)
93 struct decompress_unwind_data
*data
= ddata
;
94 fn_inflateEnd (data
->stream
);
96 /* Delete any uncompressed data already inserted and restore point. */
99 del_range (data
->start
, PT
);
100 SET_PT (data
->old_point
);
104 DEFUN ("zlib-available-p", Fzlib_available_p
, Szlib_available_p
, 0, 0, 0,
105 doc
: /* Return t if zlib decompression is available in this instance of Emacs. */)
109 Lisp_Object found
= Fassq (Qzlib_dll
, Vlibrary_cache
);
115 status
= init_zlib_functions () ? Qt
: Qnil
;
116 Vlibrary_cache
= Fcons (Fcons (Qzlib_dll
, status
), Vlibrary_cache
);
124 DEFUN ("zlib-decompress-region", Fzlib_decompress_region
,
125 Szlib_decompress_region
,
127 doc
: /* Decompress a gzip- or zlib-compressed region.
128 Replace the text in the region by the decompressed data.
129 On failure, return nil and leave the data in place.
130 This function can be called only in unibyte buffers. */)
131 (Lisp_Object start
, Lisp_Object end
)
133 ptrdiff_t istart
, iend
, pos_byte
;
136 struct decompress_unwind_data unwind_data
;
137 ptrdiff_t count
= SPECPDL_INDEX ();
139 validate_region (&start
, &end
);
141 if (! NILP (BVAR (current_buffer
, enable_multibyte_characters
)))
142 error ("This function can be called only in unibyte buffers");
145 if (!zlib_initialized
)
146 zlib_initialized
= init_zlib_functions ();
149 /* This is a unibyte buffer, so character positions and bytes are
151 istart
= XINT (start
);
153 move_gap_both (iend
, iend
);
155 stream
.zalloc
= Z_NULL
;
156 stream
.zfree
= Z_NULL
;
157 stream
.opaque
= Z_NULL
;
159 stream
.next_in
= Z_NULL
;
161 /* The magic number 32 apparently means "autodect both the gzip and
162 zlib formats" according to zlib.h. */
163 if (fn_inflateInit2 (&stream
, MAX_WBITS
+ 32) != Z_OK
)
166 unwind_data
.start
= iend
;
167 unwind_data
.stream
= &stream
;
168 unwind_data
.old_point
= PT
;
170 record_unwind_protect_ptr (unwind_decompress
, &unwind_data
);
172 /* Insert the decompressed data at the end of the compressed data. */
177 /* Keep calling 'inflate' until it reports an error or end-of-input. */
180 /* Maximum number of bytes that one 'inflate' call should read and write.
181 zlib requires that these values not exceed UINT_MAX.
182 Do not make avail_out too large, as that might unduly delay C-g. */
183 ptrdiff_t avail_in
= min (iend
- pos_byte
, UINT_MAX
);
184 ptrdiff_t avail_out
= min (1 << 14, UINT_MAX
);
186 ptrdiff_t decompressed
;
188 if (GAP_SIZE
< avail_out
)
189 make_gap (avail_out
- GAP_SIZE
);
190 stream
.next_in
= BYTE_POS_ADDR (pos_byte
);
191 stream
.avail_in
= avail_in
;
192 stream
.next_out
= GPT_ADDR
;
193 stream
.avail_out
= avail_out
;
194 inflate_status
= fn_inflate (&stream
, Z_NO_FLUSH
);
195 pos_byte
+= avail_in
- stream
.avail_in
;
196 decompressed
= avail_out
- stream
.avail_out
;
197 insert_from_gap (decompressed
, decompressed
, 0);
200 while (inflate_status
== Z_OK
);
202 if (inflate_status
!= Z_STREAM_END
)
203 return unbind_to (count
, Qnil
);
205 unwind_data
.start
= 0;
207 /* Delete the compressed data. */
208 del_range (istart
, iend
);
210 return unbind_to (count
, Qt
);
214 /***********************************************************************
216 ***********************************************************************/
218 syms_of_decompress (void)
220 DEFSYM (Qzlib_dll
, "zlib");
221 defsubr (&Szlib_decompress_region
);
222 defsubr (&Szlib_available_p
);
225 #endif /* HAVE_ZLIB */