Start preparing for 1.8.4.2
[alt-git.git] / zlib.c
blob61e6df0fdce6dfaf38da7af996d7fe801db8f00c
1 /*
2 * zlib wrappers to make sure we don't silently miss errors
3 * at init time.
4 */
5 #include "cache.h"
7 static const char *zerr_to_string(int status)
9 switch (status) {
10 case Z_MEM_ERROR:
11 return "out of memory";
12 case Z_VERSION_ERROR:
13 return "wrong version";
14 case Z_NEED_DICT:
15 return "needs dictionary";
16 case Z_DATA_ERROR:
17 return "data stream error";
18 case Z_STREAM_ERROR:
19 return "stream consistency error";
20 default:
21 return "unknown error";
26 * avail_in and avail_out in zlib are counted in uInt, which typically
27 * limits the size of the buffer we can use to 4GB when interacting
28 * with zlib in a single call to inflate/deflate.
30 /* #define ZLIB_BUF_MAX ((uInt)-1) */
31 #define ZLIB_BUF_MAX ((uInt) 1024 * 1024 * 1024) /* 1GB */
32 static inline uInt zlib_buf_cap(unsigned long len)
34 return (ZLIB_BUF_MAX < len) ? ZLIB_BUF_MAX : len;
37 static void zlib_pre_call(git_zstream *s)
39 s->z.next_in = s->next_in;
40 s->z.next_out = s->next_out;
41 s->z.total_in = s->total_in;
42 s->z.total_out = s->total_out;
43 s->z.avail_in = zlib_buf_cap(s->avail_in);
44 s->z.avail_out = zlib_buf_cap(s->avail_out);
47 static void zlib_post_call(git_zstream *s)
49 unsigned long bytes_consumed;
50 unsigned long bytes_produced;
52 bytes_consumed = s->z.next_in - s->next_in;
53 bytes_produced = s->z.next_out - s->next_out;
54 if (s->z.total_out != s->total_out + bytes_produced)
55 die("BUG: total_out mismatch");
56 if (s->z.total_in != s->total_in + bytes_consumed)
57 die("BUG: total_in mismatch");
59 s->total_out = s->z.total_out;
60 s->total_in = s->z.total_in;
61 s->next_in = s->z.next_in;
62 s->next_out = s->z.next_out;
63 s->avail_in -= bytes_consumed;
64 s->avail_out -= bytes_produced;
67 void git_inflate_init(git_zstream *strm)
69 int status;
71 zlib_pre_call(strm);
72 status = inflateInit(&strm->z);
73 zlib_post_call(strm);
74 if (status == Z_OK)
75 return;
76 die("inflateInit: %s (%s)", zerr_to_string(status),
77 strm->z.msg ? strm->z.msg : "no message");
80 void git_inflate_init_gzip_only(git_zstream *strm)
83 * Use default 15 bits, +16 is to accept only gzip and to
84 * yield Z_DATA_ERROR when fed zlib format.
86 const int windowBits = 15 + 16;
87 int status;
89 zlib_pre_call(strm);
90 status = inflateInit2(&strm->z, windowBits);
91 zlib_post_call(strm);
92 if (status == Z_OK)
93 return;
94 die("inflateInit2: %s (%s)", zerr_to_string(status),
95 strm->z.msg ? strm->z.msg : "no message");
98 void git_inflate_end(git_zstream *strm)
100 int status;
102 zlib_pre_call(strm);
103 status = inflateEnd(&strm->z);
104 zlib_post_call(strm);
105 if (status == Z_OK)
106 return;
107 error("inflateEnd: %s (%s)", zerr_to_string(status),
108 strm->z.msg ? strm->z.msg : "no message");
111 int git_inflate(git_zstream *strm, int flush)
113 int status;
115 for (;;) {
116 zlib_pre_call(strm);
117 /* Never say Z_FINISH unless we are feeding everything */
118 status = inflate(&strm->z,
119 (strm->z.avail_in != strm->avail_in)
120 ? 0 : flush);
121 if (status == Z_MEM_ERROR)
122 die("inflate: out of memory");
123 zlib_post_call(strm);
126 * Let zlib work another round, while we can still
127 * make progress.
129 if ((strm->avail_out && !strm->z.avail_out) &&
130 (status == Z_OK || status == Z_BUF_ERROR))
131 continue;
132 break;
135 switch (status) {
136 /* Z_BUF_ERROR: normal, needs more space in the output buffer */
137 case Z_BUF_ERROR:
138 case Z_OK:
139 case Z_STREAM_END:
140 return status;
141 default:
142 break;
144 error("inflate: %s (%s)", zerr_to_string(status),
145 strm->z.msg ? strm->z.msg : "no message");
146 return status;
149 #if defined(NO_DEFLATE_BOUND) || ZLIB_VERNUM < 0x1200
150 #define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
151 #endif
153 unsigned long git_deflate_bound(git_zstream *strm, unsigned long size)
155 return deflateBound(&strm->z, size);
158 void git_deflate_init(git_zstream *strm, int level)
160 int status;
162 zlib_pre_call(strm);
163 status = deflateInit(&strm->z, level);
164 zlib_post_call(strm);
165 if (status == Z_OK)
166 return;
167 die("deflateInit: %s (%s)", zerr_to_string(status),
168 strm->z.msg ? strm->z.msg : "no message");
171 static void do_git_deflate_init(git_zstream *strm, int level, int windowBits)
173 int status;
175 zlib_pre_call(strm);
176 status = deflateInit2(&strm->z, level,
177 Z_DEFLATED, windowBits,
178 8, Z_DEFAULT_STRATEGY);
179 zlib_post_call(strm);
180 if (status == Z_OK)
181 return;
182 die("deflateInit2: %s (%s)", zerr_to_string(status),
183 strm->z.msg ? strm->z.msg : "no message");
186 void git_deflate_init_gzip(git_zstream *strm, int level)
189 * Use default 15 bits, +16 is to generate gzip header/trailer
190 * instead of the zlib wrapper.
192 do_git_deflate_init(strm, level, 15 + 16);
195 void git_deflate_init_raw(git_zstream *strm, int level)
198 * Use default 15 bits, negate the value to get raw compressed
199 * data without zlib header and trailer.
201 do_git_deflate_init(strm, level, -15);
204 int git_deflate_abort(git_zstream *strm)
206 int status;
208 zlib_pre_call(strm);
209 status = deflateEnd(&strm->z);
210 zlib_post_call(strm);
211 return status;
214 void git_deflate_end(git_zstream *strm)
216 int status = git_deflate_abort(strm);
218 if (status == Z_OK)
219 return;
220 error("deflateEnd: %s (%s)", zerr_to_string(status),
221 strm->z.msg ? strm->z.msg : "no message");
224 int git_deflate_end_gently(git_zstream *strm)
226 int status;
228 zlib_pre_call(strm);
229 status = deflateEnd(&strm->z);
230 zlib_post_call(strm);
231 return status;
234 int git_deflate(git_zstream *strm, int flush)
236 int status;
238 for (;;) {
239 zlib_pre_call(strm);
241 /* Never say Z_FINISH unless we are feeding everything */
242 status = deflate(&strm->z,
243 (strm->z.avail_in != strm->avail_in)
244 ? 0 : flush);
245 if (status == Z_MEM_ERROR)
246 die("deflate: out of memory");
247 zlib_post_call(strm);
250 * Let zlib work another round, while we can still
251 * make progress.
253 if ((strm->avail_out && !strm->z.avail_out) &&
254 (status == Z_OK || status == Z_BUF_ERROR))
255 continue;
256 break;
259 switch (status) {
260 /* Z_BUF_ERROR: normal, needs more space in the output buffer */
261 case Z_BUF_ERROR:
262 case Z_OK:
263 case Z_STREAM_END:
264 return status;
265 default:
266 break;
268 error("deflate: %s (%s)", zerr_to_string(status),
269 strm->z.msg ? strm->z.msg : "no message");
270 return status;