Commit | Line | Data |
---|---|---|
313546eb LMI |
1 | /* Interface to zlib. |
2 | Copyright (C) 2013 Free Software Foundation, Inc. | |
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 | ||
594a4307 EZ |
29 | static Lisp_Object Qzlib_dll; |
30 | ||
31 | #ifdef WINDOWSNT | |
32 | #include <windows.h> | |
33 | #include "w32.h" | |
34 | ||
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 | |
37 | ||
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 0; \ | |
42 | } | |
43 | ||
44 | DEF_ZLIB_FN (int, inflateInit2_, | |
45 | (z_streamp strm, int windowBits, const char *version, int stream_size)); | |
46 | ||
47 | DEF_ZLIB_FN (int, inflate, | |
48 | (z_streamp strm, int flush)); | |
49 | ||
50 | DEF_ZLIB_FN (int, inflateEnd, | |
51 | (z_streamp strm)); | |
52 | ||
53 | static bool | |
54 | init_zlib_functions (void) | |
55 | { | |
56 | HMODULE library = w32_delayed_load (Qzlib_dll); | |
57 | ||
58 | if (!library) | |
59 | { | |
60 | message1 ("zlib library not found"); | |
61 | return 0; | |
62 | } | |
63 | ||
64 | LOAD_ZLIB_FN (library, inflateInit2_); | |
65 | LOAD_ZLIB_FN (library, inflate); | |
66 | LOAD_ZLIB_FN (library, inflateEnd); | |
67 | return 1; | |
68 | } | |
69 | ||
70 | #else /* !WINDOWSNT */ | |
71 | ||
72 | #define fn_inflateInit2_ inflateInit2_ | |
73 | #define fn_inflate inflate | |
74 | #define fn_inflateEnd inflateEnd | |
75 | ||
76 | #endif /* WINDOWSNT */ | |
77 | ||
78 | #define fn_inflateInit2(strm, windowBits) \ | |
79 | fn_inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) | |
80 | ||
313546eb | 81 | \f |
d0e615c3 PE |
82 | struct decompress_unwind_data |
83 | { | |
313546eb LMI |
84 | ptrdiff_t old_point, start; |
85 | z_stream *stream; | |
86 | }; | |
87 | ||
88 | static void | |
d0e615c3 PE |
89 | unwind_decompress (void *ddata) |
90 | { | |
313546eb | 91 | struct decompress_unwind_data *data = ddata; |
594a4307 | 92 | fn_inflateEnd (data->stream); |
d0e615c3 PE |
93 | |
94 | /* Delete any uncompressed data already inserted and restore point. */ | |
95 | if (data->start) | |
96 | { | |
97 | del_range (data->start, PT); | |
98 | SET_PT (data->old_point); | |
99 | } | |
313546eb LMI |
100 | } |
101 | ||
594a4307 EZ |
102 | DEFUN ("zlib-available-p", Fzlib_available_p, Szlib_available_p, 0, 0, 0, |
103 | doc: /* Return t if zlib decompression is available in this instance of Emacs. */) | |
104 | (void) | |
105 | { | |
106 | #ifdef WINDOWSNT | |
107 | Lisp_Object found = Fassq (Qzlib_dll, Vlibrary_cache); | |
108 | if (CONSP (found)) | |
109 | return XCDR (found); | |
110 | else | |
111 | { | |
112 | Lisp_Object status; | |
113 | status = init_zlib_functions () ? Qt : Qnil; | |
114 | Vlibrary_cache = Fcons (Fcons (Qzlib_dll, status), Vlibrary_cache); | |
115 | return status; | |
116 | } | |
117 | #else | |
118 | return Qt; | |
119 | #endif | |
120 | } | |
121 | ||
313546eb LMI |
122 | DEFUN ("decompress-gzipped-region", Fdecompress_gzipped_region, |
123 | Sdecompress_gzipped_region, | |
124 | 2, 2, 0, | |
125 | doc: /* Decompress a gzip-compressed region. | |
d0e615c3 PE |
126 | Replace the text in the region by the decompressed data. |
127 | On failure, return nil and leave the data in place. | |
128 | This function can be called only in unibyte buffers. */) | |
313546eb LMI |
129 | (Lisp_Object start, Lisp_Object end) |
130 | { | |
d0e615c3 | 131 | ptrdiff_t istart, iend, pos_byte; |
313546eb | 132 | z_stream stream; |
d0e615c3 | 133 | int inflate_status; |
313546eb LMI |
134 | struct decompress_unwind_data unwind_data; |
135 | ptrdiff_t count = SPECPDL_INDEX (); | |
136 | ||
137 | validate_region (&start, &end); | |
313546eb LMI |
138 | |
139 | if (! NILP (BVAR (current_buffer, enable_multibyte_characters))) | |
d0e615c3 | 140 | error ("This function can be called only in unibyte buffers"); |
313546eb LMI |
141 | |
142 | /* This is a unibyte buffer, so character positions and bytes are | |
d0e615c3 | 143 | the same. */ |
313546eb LMI |
144 | istart = XINT (start); |
145 | iend = XINT (end); | |
99a32242 | 146 | move_gap_both (iend, iend); |
313546eb LMI |
147 | |
148 | stream.zalloc = Z_NULL; | |
149 | stream.zfree = Z_NULL; | |
150 | stream.opaque = Z_NULL; | |
151 | stream.avail_in = 0; | |
152 | stream.next_in = Z_NULL; | |
153 | ||
d0e615c3 | 154 | /* This magic number apparently means "this is gzip". */ |
594a4307 | 155 | if (fn_inflateInit2 (&stream, 16 + MAX_WBITS) != Z_OK) |
313546eb LMI |
156 | return Qnil; |
157 | ||
313546eb LMI |
158 | unwind_data.start = iend; |
159 | unwind_data.stream = &stream; | |
d0e615c3 PE |
160 | unwind_data.old_point = PT; |
161 | ||
313546eb LMI |
162 | record_unwind_protect_ptr (unwind_decompress, &unwind_data); |
163 | ||
d0e615c3 PE |
164 | /* Insert the decompressed data at the end of the compressed data. */ |
165 | SET_PT (iend); | |
313546eb | 166 | |
d0e615c3 PE |
167 | pos_byte = istart; |
168 | ||
169 | /* Keep calling 'inflate' until it reports an error or end-of-input. */ | |
170 | do | |
171 | { | |
172 | /* Maximum number of bytes that one 'inflate' call should read and write. | |
173 | zlib requires that these values not exceed UINT_MAX. | |
174 | Do not make avail_out too large, as that might unduly delay C-g. */ | |
175 | ptrdiff_t avail_in = min (iend - pos_byte, UINT_MAX); | |
176 | ptrdiff_t avail_out = min (1 << 14, UINT_MAX); | |
177 | ||
178 | ptrdiff_t decompressed; | |
179 | ||
180 | if (GAP_SIZE < avail_out) | |
181 | make_gap (avail_out - GAP_SIZE); | |
182 | stream.next_in = BYTE_POS_ADDR (pos_byte); | |
183 | stream.avail_in = avail_in; | |
184 | stream.next_out = GPT_ADDR; | |
185 | stream.avail_out = avail_out; | |
594a4307 | 186 | inflate_status = fn_inflate (&stream, Z_NO_FLUSH); |
d0e615c3 PE |
187 | pos_byte += avail_in - stream.avail_in; |
188 | decompressed = avail_out - stream.avail_out; | |
189 | insert_from_gap (decompressed, decompressed, 0); | |
190 | QUIT; | |
191 | } | |
192 | while (inflate_status == Z_OK); | |
313546eb | 193 | |
d0e615c3 PE |
194 | if (inflate_status != Z_STREAM_END) |
195 | return unbind_to (count, Qnil); | |
313546eb LMI |
196 | |
197 | unwind_data.start = 0; | |
313546eb | 198 | |
d0e615c3 | 199 | /* Delete the compressed data. */ |
313546eb LMI |
200 | del_range (istart, iend); |
201 | ||
d0e615c3 | 202 | return unbind_to (count, Qt); |
313546eb LMI |
203 | } |
204 | ||
205 | \f | |
206 | /*********************************************************************** | |
207 | Initialization | |
208 | ***********************************************************************/ | |
209 | void | |
210 | syms_of_decompress (void) | |
211 | { | |
594a4307 | 212 | DEFSYM (Qzlib_dll, "zlib"); |
313546eb | 213 | defsubr (&Sdecompress_gzipped_region); |
594a4307 | 214 | defsubr (&Szlib_available_p); |
313546eb LMI |
215 | } |
216 | ||
217 | #endif /* HAVE_ZLIB */ |