Commit | Line | Data |
---|---|---|
313546eb | 1 | /* Interface to zlib. |
ba318903 | 2 | Copyright (C) 2013-2014 Free Software Foundation, Inc. |
313546eb LMI |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
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. | |
10 | ||
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. | |
15 | ||
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/>. */ | |
18 | ||
19 | #include <config.h> | |
20 | ||
21 | #ifdef HAVE_ZLIB | |
22 | ||
23 | #include <zlib.h> | |
24 | ||
25 | #include "lisp.h" | |
26 | #include "character.h" | |
27 | #include "buffer.h" | |
28 | ||
53b64418 PE |
29 | #include <verify.h> |
30 | ||
594a4307 EZ |
31 | static Lisp_Object Qzlib_dll; |
32 | ||
33 | #ifdef WINDOWSNT | |
34 | #include <windows.h> | |
35 | #include "w32.h" | |
36 | ||
37 | /* Macro for defining functions that will be loaded from the zlib DLL. */ | |
38 | #define DEF_ZLIB_FN(rettype,func,args) static rettype (FAR CDECL *fn_##func)args | |
39 | ||
40 | /* Macro for loading zlib functions from the library. */ | |
41 | #define LOAD_ZLIB_FN(lib,func) { \ | |
42 | fn_##func = (void *) GetProcAddress (lib, #func); \ | |
aa942e2b | 43 | if (!fn_##func) return false; \ |
594a4307 EZ |
44 | } |
45 | ||
46 | DEF_ZLIB_FN (int, inflateInit2_, | |
47 | (z_streamp strm, int windowBits, const char *version, int stream_size)); | |
48 | ||
49 | DEF_ZLIB_FN (int, inflate, | |
50 | (z_streamp strm, int flush)); | |
51 | ||
52 | DEF_ZLIB_FN (int, inflateEnd, | |
53 | (z_streamp strm)); | |
54 | ||
aa942e2b EZ |
55 | static bool zlib_initialized; |
56 | ||
594a4307 EZ |
57 | static bool |
58 | init_zlib_functions (void) | |
59 | { | |
60 | HMODULE library = w32_delayed_load (Qzlib_dll); | |
61 | ||
62 | if (!library) | |
63 | { | |
64 | message1 ("zlib library not found"); | |
aa942e2b | 65 | return false; |
594a4307 EZ |
66 | } |
67 | ||
68 | LOAD_ZLIB_FN (library, inflateInit2_); | |
69 | LOAD_ZLIB_FN (library, inflate); | |
70 | LOAD_ZLIB_FN (library, inflateEnd); | |
aa942e2b | 71 | return true; |
594a4307 EZ |
72 | } |
73 | ||
1d238bc7 PE |
74 | #define fn_inflateInit2(strm, windowBits) \ |
75 | fn_inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) | |
76 | ||
594a4307 EZ |
77 | #else /* !WINDOWSNT */ |
78 | ||
1d238bc7 | 79 | #define fn_inflateInit2 inflateInit2 |
594a4307 EZ |
80 | #define fn_inflate inflate |
81 | #define fn_inflateEnd inflateEnd | |
82 | ||
83 | #endif /* WINDOWSNT */ | |
84 | ||
313546eb | 85 | \f |
d0e615c3 PE |
86 | struct decompress_unwind_data |
87 | { | |
de396731 | 88 | ptrdiff_t old_point, start, nbytes; |
313546eb LMI |
89 | z_stream *stream; |
90 | }; | |
91 | ||
92 | static void | |
d0e615c3 PE |
93 | unwind_decompress (void *ddata) |
94 | { | |
313546eb | 95 | struct decompress_unwind_data *data = ddata; |
594a4307 | 96 | fn_inflateEnd (data->stream); |
d0e615c3 | 97 | |
71530c97 | 98 | /* Delete any uncompressed data already inserted on error. */ |
d0e615c3 | 99 | if (data->start) |
de396731 | 100 | del_range (data->start, data->start + data->nbytes); |
71530c97 LMI |
101 | |
102 | /* Put point where it was, or if the buffer has shrunk because the | |
103 | compressed data is bigger than the uncompressed, at | |
104 | point-max. */ | |
105 | SET_PT (min (data->old_point, ZV)); | |
313546eb LMI |
106 | } |
107 | ||
594a4307 EZ |
108 | DEFUN ("zlib-available-p", Fzlib_available_p, Szlib_available_p, 0, 0, 0, |
109 | doc: /* Return t if zlib decompression is available in this instance of Emacs. */) | |
110 | (void) | |
111 | { | |
112 | #ifdef WINDOWSNT | |
113 | Lisp_Object found = Fassq (Qzlib_dll, Vlibrary_cache); | |
114 | if (CONSP (found)) | |
115 | return XCDR (found); | |
116 | else | |
117 | { | |
118 | Lisp_Object status; | |
d2c28fab EZ |
119 | zlib_initialized = init_zlib_functions (); |
120 | status = zlib_initialized ? Qt : Qnil; | |
594a4307 EZ |
121 | Vlibrary_cache = Fcons (Fcons (Qzlib_dll, status), Vlibrary_cache); |
122 | return status; | |
123 | } | |
124 | #else | |
125 | return Qt; | |
126 | #endif | |
127 | } | |
128 | ||
7699d09e LMI |
129 | DEFUN ("zlib-decompress-region", Fzlib_decompress_region, |
130 | Szlib_decompress_region, | |
313546eb | 131 | 2, 2, 0, |
7699d09e | 132 | doc: /* Decompress a gzip- or zlib-compressed region. |
d0e615c3 PE |
133 | Replace the text in the region by the decompressed data. |
134 | On failure, return nil and leave the data in place. | |
135 | This function can be called only in unibyte buffers. */) | |
313546eb LMI |
136 | (Lisp_Object start, Lisp_Object end) |
137 | { | |
d0e615c3 | 138 | ptrdiff_t istart, iend, pos_byte; |
313546eb | 139 | z_stream stream; |
d0e615c3 | 140 | int inflate_status; |
313546eb LMI |
141 | struct decompress_unwind_data unwind_data; |
142 | ptrdiff_t count = SPECPDL_INDEX (); | |
143 | ||
144 | validate_region (&start, &end); | |
313546eb LMI |
145 | |
146 | if (! NILP (BVAR (current_buffer, enable_multibyte_characters))) | |
d0e615c3 | 147 | error ("This function can be called only in unibyte buffers"); |
313546eb | 148 | |
aa942e2b EZ |
149 | #ifdef WINDOWSNT |
150 | if (!zlib_initialized) | |
151 | zlib_initialized = init_zlib_functions (); | |
866c710e EZ |
152 | if (!zlib_initialized) |
153 | return Qnil; | |
aa942e2b EZ |
154 | #endif |
155 | ||
313546eb | 156 | /* This is a unibyte buffer, so character positions and bytes are |
d0e615c3 | 157 | the same. */ |
313546eb LMI |
158 | istart = XINT (start); |
159 | iend = XINT (end); | |
99a32242 | 160 | move_gap_both (iend, iend); |
313546eb LMI |
161 | |
162 | stream.zalloc = Z_NULL; | |
163 | stream.zfree = Z_NULL; | |
164 | stream.opaque = Z_NULL; | |
165 | stream.avail_in = 0; | |
166 | stream.next_in = Z_NULL; | |
167 | ||
526e5233 | 168 | /* The magic number 32 apparently means "autodetect both the gzip and |
7699d09e LMI |
169 | zlib formats" according to zlib.h. */ |
170 | if (fn_inflateInit2 (&stream, MAX_WBITS + 32) != Z_OK) | |
313546eb LMI |
171 | return Qnil; |
172 | ||
313546eb LMI |
173 | unwind_data.start = iend; |
174 | unwind_data.stream = &stream; | |
d0e615c3 | 175 | unwind_data.old_point = PT; |
de396731 | 176 | unwind_data.nbytes = 0; |
313546eb LMI |
177 | record_unwind_protect_ptr (unwind_decompress, &unwind_data); |
178 | ||
d0e615c3 PE |
179 | /* Insert the decompressed data at the end of the compressed data. */ |
180 | SET_PT (iend); | |
313546eb | 181 | |
d0e615c3 PE |
182 | pos_byte = istart; |
183 | ||
184 | /* Keep calling 'inflate' until it reports an error or end-of-input. */ | |
185 | do | |
186 | { | |
187 | /* Maximum number of bytes that one 'inflate' call should read and write. | |
53b64418 | 188 | Do not make avail_out too large, as that might unduly delay C-g. |
2d065031 | 189 | zlib requires that avail_in and avail_out not exceed UINT_MAX. */ |
d0e615c3 | 190 | ptrdiff_t avail_in = min (iend - pos_byte, UINT_MAX); |
2d065031 PE |
191 | int avail_out = 16 * 1024; |
192 | int decompressed; | |
d0e615c3 PE |
193 | |
194 | if (GAP_SIZE < avail_out) | |
195 | make_gap (avail_out - GAP_SIZE); | |
196 | stream.next_in = BYTE_POS_ADDR (pos_byte); | |
197 | stream.avail_in = avail_in; | |
198 | stream.next_out = GPT_ADDR; | |
199 | stream.avail_out = avail_out; | |
594a4307 | 200 | inflate_status = fn_inflate (&stream, Z_NO_FLUSH); |
d0e615c3 PE |
201 | pos_byte += avail_in - stream.avail_in; |
202 | decompressed = avail_out - stream.avail_out; | |
203 | insert_from_gap (decompressed, decompressed, 0); | |
de396731 | 204 | unwind_data.nbytes += decompressed; |
d0e615c3 PE |
205 | QUIT; |
206 | } | |
207 | while (inflate_status == Z_OK); | |
313546eb | 208 | |
d0e615c3 PE |
209 | if (inflate_status != Z_STREAM_END) |
210 | return unbind_to (count, Qnil); | |
313546eb LMI |
211 | |
212 | unwind_data.start = 0; | |
313546eb | 213 | |
d0e615c3 | 214 | /* Delete the compressed data. */ |
313546eb LMI |
215 | del_range (istart, iend); |
216 | ||
d0e615c3 | 217 | return unbind_to (count, Qt); |
313546eb LMI |
218 | } |
219 | ||
220 | \f | |
221 | /*********************************************************************** | |
222 | Initialization | |
223 | ***********************************************************************/ | |
224 | void | |
225 | syms_of_decompress (void) | |
226 | { | |
594a4307 | 227 | DEFSYM (Qzlib_dll, "zlib"); |
7699d09e | 228 | defsubr (&Szlib_decompress_region); |
594a4307 | 229 | defsubr (&Szlib_available_p); |
313546eb LMI |
230 | } |
231 | ||
232 | #endif /* HAVE_ZLIB */ |