Merge branch 'jc/help' into maint
[git/jnareb-git.git] / zlib.c
blob2b2c0c780e3fca6217c688298053a01aad724505
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 void git_deflate_init_gzip(git_zstream *strm, int level)
174 * Use default 15 bits, +16 is to generate gzip header/trailer
175 * instead of the zlib wrapper.
177 const int windowBits = 15 + 16;
178 int status;
180 zlib_pre_call(strm);
181 status = deflateInit2(&strm->z, level,
182 Z_DEFLATED, windowBits,
183 8, Z_DEFAULT_STRATEGY);
184 zlib_post_call(strm);
185 if (status == Z_OK)
186 return;
187 die("deflateInit2: %s (%s)", zerr_to_string(status),
188 strm->z.msg ? strm->z.msg : "no message");
191 int git_deflate_abort(git_zstream *strm)
193 int status;
195 zlib_pre_call(strm);
196 status = deflateEnd(&strm->z);
197 zlib_post_call(strm);
198 return status;
201 void git_deflate_end(git_zstream *strm)
203 int status = git_deflate_abort(strm);
205 if (status == Z_OK)
206 return;
207 error("deflateEnd: %s (%s)", zerr_to_string(status),
208 strm->z.msg ? strm->z.msg : "no message");
211 int git_deflate_end_gently(git_zstream *strm)
213 int status;
215 zlib_pre_call(strm);
216 status = deflateEnd(&strm->z);
217 zlib_post_call(strm);
218 return status;
221 int git_deflate(git_zstream *strm, int flush)
223 int status;
225 for (;;) {
226 zlib_pre_call(strm);
228 /* Never say Z_FINISH unless we are feeding everything */
229 status = deflate(&strm->z,
230 (strm->z.avail_in != strm->avail_in)
231 ? 0 : flush);
232 if (status == Z_MEM_ERROR)
233 die("deflate: out of memory");
234 zlib_post_call(strm);
237 * Let zlib work another round, while we can still
238 * make progress.
240 if ((strm->avail_out && !strm->z.avail_out) &&
241 (status == Z_OK || status == Z_BUF_ERROR))
242 continue;
243 break;
246 switch (status) {
247 /* Z_BUF_ERROR: normal, needs more space in the output buffer */
248 case Z_BUF_ERROR:
249 case Z_OK:
250 case Z_STREAM_END:
251 return status;
252 default:
253 break;
255 error("deflate: %s (%s)", zerr_to_string(status),
256 strm->z.msg ? strm->z.msg : "no message");
257 return status;