all messages for Emacs-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
blob eebaa2eb30da98c24c57717f2f22c4d0683e9659 6121 bytes (raw)
name: src/decompress.c 	 # note: path name is non-authoritative(*)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
 
/* Interface to zlib.
   Copyright (C) 2013-2018 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

#ifdef HAVE_ZLIB

#include <zlib.h>

#include "lisp.h"
#include "buffer.h"
#include "composite.h"

#include <verify.h>

#ifdef WINDOWSNT
# include <windows.h>
# include "w32.h"

DEF_DLL_FN (int, inflateInit2_,
	    (z_streamp strm, int windowBits, const char *version,
	     int stream_size));
DEF_DLL_FN (int, inflate, (z_streamp strm, int flush));
DEF_DLL_FN (int, inflateEnd, (z_streamp strm));

static bool zlib_initialized;

static bool
init_zlib_functions (void)
{
  HMODULE library = w32_delayed_load (Qzlib);

  if (!library)
    return false;

  LOAD_DLL_FN (library, inflateInit2_);
  LOAD_DLL_FN (library, inflate);
  LOAD_DLL_FN (library, inflateEnd);
  return true;
}

# undef inflate
# undef inflateEnd
# undef inflateInit2_

# define inflate fn_inflate
# define inflateEnd fn_inflateEnd
# define inflateInit2_ fn_inflateInit2_

#endif	/* WINDOWSNT */

\f
struct decompress_unwind_data
{
  ptrdiff_t old_point, start, nbytes;
  z_stream *stream;
};

static void
unwind_decompress (void *ddata)
{
  struct decompress_unwind_data *data = ddata;
  inflateEnd (data->stream);

  /* Delete any uncompressed data already inserted on error.  */
  if (data->start)
    del_range (data->start, data->start + data->nbytes);

  /* Put point where it was, or if the buffer has shrunk because the
     compressed data is bigger than the uncompressed, at
     point-max.  */
  SET_PT (min (data->old_point, ZV));
}

DEFUN ("zlib-available-p", Fzlib_available_p, Szlib_available_p, 0, 0, 0,
       doc: /* Return t if zlib decompression is available in this instance of Emacs.  */)
     (void)
{
#ifdef WINDOWSNT
  Lisp_Object found = Fassq (Qzlib, Vlibrary_cache);
  if (CONSP (found))
    return XCDR (found);
  else
    {
      Lisp_Object status;
      zlib_initialized = init_zlib_functions ();
      status = zlib_initialized ? Qt : Qnil;
      Vlibrary_cache = Fcons (Fcons (Qzlib, status), Vlibrary_cache);
      return status;
    }
#else
  return Qt;
#endif
}

DEFUN ("zlib-decompress-region", Fzlib_decompress_region,
       Szlib_decompress_region,
       2, 2, 0,
       doc: /* Decompress a gzip- or zlib-compressed region.
Replace the text in the region by the decompressed data.
On failure, return nil and leave the data in place.
This function can be called only in unibyte buffers.  */)
  (Lisp_Object start, Lisp_Object end)
{
  ptrdiff_t istart, iend, pos_byte;
  z_stream stream;
  int inflate_status;
  struct decompress_unwind_data unwind_data;
  ptrdiff_t count = SPECPDL_INDEX ();

  validate_region (&start, &end);

  if (! NILP (BVAR (current_buffer, enable_multibyte_characters)))
    error ("This function can be called only in unibyte buffers");

#ifdef WINDOWSNT
  if (!zlib_initialized)
    zlib_initialized = init_zlib_functions ();
  if (!zlib_initialized)
    {
      message1 ("zlib library not found");
      return Qnil;
    }
#endif

  /* This is a unibyte buffer, so character positions and bytes are
     the same.  */
  istart = XINT (start);
  iend = XINT (end);

  /* Do the following before manipulating the gap. */
  modify_text (istart, iend);

  move_gap_both (iend, iend);

  stream.zalloc = Z_NULL;
  stream.zfree = Z_NULL;
  stream.opaque = Z_NULL;
  stream.avail_in = 0;
  stream.next_in = Z_NULL;

  /* The magic number 32 apparently means "autodetect both the gzip and
     zlib formats" according to zlib.h.  */
  if (inflateInit2 (&stream, MAX_WBITS + 32) != Z_OK)
    return Qnil;

  unwind_data.start = iend;
  unwind_data.stream = &stream;
  unwind_data.old_point = PT;
  unwind_data.nbytes = 0;
  record_unwind_protect_ptr (unwind_decompress, &unwind_data);

  /* Insert the decompressed data at the end of the compressed data.  */
  SET_PT (iend);

  pos_byte = istart;

  /* Keep calling 'inflate' until it reports an error or end-of-input.  */
  do
    {
      /* Maximum number of bytes that one 'inflate' call should read and write.
	 Do not make avail_out too large, as that might unduly delay C-g.
	 zlib requires that avail_in and avail_out not exceed UINT_MAX.  */
      ptrdiff_t avail_in = min (iend - pos_byte, UINT_MAX);
      int avail_out = 16 * 1024;
      int decompressed;

      if (GAP_SIZE < avail_out)
	make_gap (avail_out - GAP_SIZE);
      stream.next_in = BYTE_POS_ADDR (pos_byte);
      stream.avail_in = avail_in;
      stream.next_out = GPT_ADDR;
      stream.avail_out = avail_out;
      inflate_status = inflate (&stream, Z_NO_FLUSH);
      pos_byte += avail_in - stream.avail_in;
      decompressed = avail_out - stream.avail_out;
      insert_from_gap (decompressed, decompressed, 0);
      unwind_data.nbytes += decompressed;
      maybe_quit ();
    }
  while (inflate_status == Z_OK);

  if (inflate_status != Z_STREAM_END)
    return unbind_to (count, Qnil);

  unwind_data.start = 0;

  /* Delete the compressed data.  */
  del_range_2 (istart, istart, /* byte and char offsets are the same. */
               iend, iend, 0);

  signal_after_change (istart, iend - istart, unwind_data.nbytes);
  update_compositions (istart, istart, CHECK_HEAD);

  return unbind_to (count, Qt);
}

\f
/***********************************************************************
			    Initialization
 ***********************************************************************/
void
syms_of_decompress (void)
{
  defsubr (&Szlib_decompress_region);
  defsubr (&Szlib_available_p);
}

#endif /* HAVE_ZLIB */

debug log:

solving eebaa2eb30 ...
found eebaa2eb30 in https://yhetil.org/emacs/20180108192415.GA5531@ACM/
found 41de6da1dd in https://git.savannah.gnu.org/cgit/emacs.git
preparing index
index prepared:
100644 41de6da1dd2a0090e8e798a994d6f84466be021b	src/decompress.c

applying [1/1] https://yhetil.org/emacs/20180108192415.GA5531@ACM/
diff --git a/src/decompress.c b/src/decompress.c
index 41de6da1dd..eebaa2eb30 100644

Checking patch src/decompress.c...
Applied patch src/decompress.c cleanly.

index at:
100644 eebaa2eb30da98c24c57717f2f22c4d0683e9659	src/decompress.c

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this external index

	https://git.savannah.gnu.org/cgit/emacs.git
	https://git.savannah.gnu.org/cgit/emacs/org-mode.git

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.