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chromium / external / github.com / git / git / refs/tags/v2.7.3 / . / csum-file.c
blob: a172199e44bf370cd66ee7073f5a2228fd9679ef [file] [log] [blame]
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]1/*
2 * csum-file.c
3 *
4 * Copyright (C) 2005 Linus Torvalds
5 *
6 * Simple file write infrastructure for writing SHA1-summed
7 * files. Useful when you write a file that you want to be
8 * able to verify hasn't been messed with afterwards.
9 */
10#include "cache.h"
Nicolas Pitre2a128d62007-10-30 21:06:21[diff] [blame]11#include "progress.h"
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]12#include "csum-file.h"
13
Jeff Kinge74435a2013-10-24 17:59:49[diff] [blame]14static void flush(struct sha1file *f, const void *buf, unsigned int count)
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]15{
Junio C Hamanoe337a042011-02-03 01:29:01[diff] [blame]16 if (0 <= f->check_fd && count) {
17 unsigned char check_buffer[8192];
18 ssize_t ret = read_in_full(f->check_fd, check_buffer, count);
19
20 if (ret < 0)
21 die_errno("%s: sha1 file read error", f->name);
22 if (ret < count)
23 die("%s: sha1 file truncated", f->name);
24 if (memcmp(buf, check_buffer, count))
25 die("sha1 file '%s' validation error", f->name);
26 }
27
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]28 for (;;) {
Junio C Hamano1c15afb2005-12-20 00:18:28[diff] [blame]29 int ret = xwrite(f->fd, buf, count);
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]30 if (ret > 0) {
Nicolas Pitre218558a2007-11-05 03:15:41[diff] [blame]31 f->total += ret;
32 display_throughput(f->tp, f->total);
Florian Forster1d7f1712006-06-18 15:18:09[diff] [blame]33 buf = (char *) buf + ret;
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]34 count -= ret;
35 if (count)
36 continue;
David Rientjes78b713a2006-08-14 20:32:01[diff] [blame]37 return;
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]38 }
39 if (!ret)
Linus Torvaldse1808842005-06-27 05:01:46[diff] [blame]40 die("sha1 file '%s' write error. Out of diskspace", f->name);
Thomas Rastd824cbb2009-06-27 15:58:46[diff] [blame]41 die_errno("sha1 file '%s' write error", f->name);
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]42 }
43}
44
Nicolas Pitre838cd342008-10-10 02:08:51[diff] [blame]45void sha1flush(struct sha1file *f)
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]46{
47 unsigned offset = f->offset;
Linus Torvalds4c81b032008-05-30 15:42:16[diff] [blame]48
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]49 if (offset) {
Nicolas Pitre9126f002008-10-01 18:05:20[diff] [blame]50 git_SHA1_Update(&f->ctx, f->buffer, offset);
Shawn O. Pearcee782e122008-10-10 15:39:20[diff] [blame]51 flush(f, f->buffer, offset);
Dana L. Howf0215362007-05-13 18:28:19[diff] [blame]52 f->offset = 0;
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]53 }
Nicolas Pitre838cd342008-10-10 02:08:51[diff] [blame]54}
55
56int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
57{
58 int fd;
59
60 sha1flush(f);
Nicolas Pitre9126f002008-10-01 18:05:20[diff] [blame]61 git_SHA1_Final(f->buffer, &f->ctx);
Nicolas Pitreac0463e2008-08-29 20:08:00[diff] [blame]62 if (result)
63 hashcpy(result, f->buffer);
Linus Torvalds4c81b032008-05-30 15:42:16[diff] [blame]64 if (flags & (CSUM_CLOSE | CSUM_FSYNC)) {
Nicolas Pitre7ba502c2007-10-17 01:55:48[diff] [blame]65 /* write checksum and close fd */
Shawn O. Pearcee782e122008-10-10 15:39:20[diff] [blame]66 flush(f, f->buffer, 20);
Linus Torvalds4c81b032008-05-30 15:42:16[diff] [blame]67 if (flags & CSUM_FSYNC)
68 fsync_or_die(f->fd, f->name);
Nicolas Pitre7ba502c2007-10-17 01:55:48[diff] [blame]69 if (close(f->fd))
Thomas Rastd824cbb2009-06-27 15:58:46[diff] [blame]70 die_errno("%s: sha1 file error on close", f->name);
Nicolas Pitre7ba502c2007-10-17 01:55:48[diff] [blame]71 fd = 0;
72 } else
73 fd = f->fd;
Junio C Hamanoe337a042011-02-03 01:29:01[diff] [blame]74 if (0 <= f->check_fd) {
75 char discard;
76 int cnt = read_in_full(f->check_fd, &discard, 1);
77 if (cnt < 0)
78 die_errno("%s: error when reading the tail of sha1 file",
79 f->name);
80 if (cnt)
81 die("%s: sha1 file has trailing garbage", f->name);
82 if (close(f->check_fd))
83 die_errno("%s: sha1 file error on close", f->name);
84 }
Sergey Vlasov7bf058f2005-08-08 18:46:13[diff] [blame]85 free(f);
Nicolas Pitre7ba502c2007-10-17 01:55:48[diff] [blame]86 return fd;
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]87}
88
Junio C Hamanof06a5e62014-01-10 18:33:09[diff] [blame]89void sha1write(struct sha1file *f, const void *buf, unsigned int count)
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]90{
91 while (count) {
92 unsigned offset = f->offset;
93 unsigned left = sizeof(f->buffer) - offset;
94 unsigned nr = count > left ? left : count;
Jeff Kinge74435a2013-10-24 17:59:49[diff] [blame]95 const void *data;
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]96
Nicolas Pitrea8032d12008-09-02 14:22:20[diff] [blame]97 if (f->do_crc)
98 f->crc32 = crc32(f->crc32, buf, nr);
99
100 if (nr == sizeof(f->buffer)) {
101 /* process full buffer directly without copy */
102 data = buf;
103 } else {
104 memcpy(f->buffer + offset, buf, nr);
105 data = f->buffer;
106 }
107
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]108 count -= nr;
109 offset += nr;
Florian Forster1d7f1712006-06-18 15:18:09[diff] [blame]110 buf = (char *) buf + nr;
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]111 left -= nr;
112 if (!left) {
Nicolas Pitre9126f002008-10-01 18:05:20[diff] [blame]113 git_SHA1_Update(&f->ctx, data, offset);
Shawn O. Pearcee782e122008-10-10 15:39:20[diff] [blame]114 flush(f, data, offset);
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]115 offset = 0;
116 }
117 f->offset = offset;
118 }
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]119}
120
Linus Torvalds4397f012005-06-28 18:10:06[diff] [blame]121struct sha1file *sha1fd(int fd, const char *name)
122{
Nicolas Pitre2a128d62007-10-30 21:06:21[diff] [blame]123 return sha1fd_throughput(fd, name, NULL);
124}
125
Junio C Hamanoe337a042011-02-03 01:29:01[diff] [blame]126struct sha1file *sha1fd_check(const char *name)
127{
128 int sink, check;
129 struct sha1file *f;
130
131 sink = open("/dev/null", O_WRONLY);
132 if (sink < 0)
Jeff King599d2232015-03-18 06:30:12[diff] [blame]133 die_errno("unable to open /dev/null");
Junio C Hamanoe337a042011-02-03 01:29:01[diff] [blame]134 check = open(name, O_RDONLY);
Jeff King599d2232015-03-18 06:30:12[diff] [blame]135 if (check < 0)
136 die_errno("unable to open '%s'", name);
Junio C Hamanoe337a042011-02-03 01:29:01[diff] [blame]137 f = sha1fd(sink, name);
138 f->check_fd = check;
139 return f;
140}
141
Nicolas Pitre2a128d62007-10-30 21:06:21[diff] [blame]142struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp)
143{
Nicolas Pitreec640ed2007-11-05 03:54:50[diff] [blame]144 struct sha1file *f = xmalloc(sizeof(*f));
Linus Torvalds4397f012005-06-28 18:10:06[diff] [blame]145 f->fd = fd;
Junio C Hamanoe337a042011-02-03 01:29:01[diff] [blame]146 f->check_fd = -1;
Linus Torvalds4397f012005-06-28 18:10:06[diff] [blame]147 f->offset = 0;
Nicolas Pitre218558a2007-11-05 03:15:41[diff] [blame]148 f->total = 0;
Nicolas Pitre2a128d62007-10-30 21:06:21[diff] [blame]149 f->tp = tp;
Nicolas Pitreec640ed2007-11-05 03:54:50[diff] [blame]150 f->name = name;
Nicolas Pitre78d1e842007-04-09 05:06:31[diff] [blame]151 f->do_crc = 0;
Nicolas Pitre9126f002008-10-01 18:05:20[diff] [blame]152 git_SHA1_Init(&f->ctx);
Linus Torvalds4397f012005-06-28 18:10:06[diff] [blame]153 return f;
154}
155
Junio C Hamano6c526142011-11-18 00:26:54[diff] [blame]156void sha1file_checkpoint(struct sha1file *f, struct sha1file_checkpoint *checkpoint)
157{
158 sha1flush(f);
159 checkpoint->offset = f->total;
160 checkpoint->ctx = f->ctx;
161}
162
163int sha1file_truncate(struct sha1file *f, struct sha1file_checkpoint *checkpoint)
164{
165 off_t offset = checkpoint->offset;
166
167 if (ftruncate(f->fd, offset) ||
168 lseek(f->fd, offset, SEEK_SET) != offset)
169 return -1;
170 f->total = offset;
171 f->ctx = checkpoint->ctx;
172 f->offset = 0; /* sha1flush() was called in checkpoint */
173 return 0;
174}
175
Nicolas Pitre78d1e842007-04-09 05:06:31[diff] [blame]176void crc32_begin(struct sha1file *f)
177{
Stephen Boyd1e4cd682011-04-03 07:06:54[diff] [blame]178 f->crc32 = crc32(0, NULL, 0);
Nicolas Pitre78d1e842007-04-09 05:06:31[diff] [blame]179 f->do_crc = 1;
180}
Linus Torvaldsc38138c2005-06-27 03:27:56[diff] [blame]181
Nicolas Pitre78d1e842007-04-09 05:06:31[diff] [blame]182uint32_t crc32_end(struct sha1file *f)
183{
184 f->do_crc = 0;
185 return f->crc32;
186}