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Commit | Line | Data |
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c38138cd LT |
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" | |
11 | #include "csum-file.h" | |
12 | ||
78b713a1 | 13 | static void sha1flush(struct sha1file *f, unsigned int count) |
c38138cd LT |
14 | { |
15 | void *buf = f->buffer; | |
16 | ||
17 | for (;;) { | |
1c15afb9 | 18 | int ret = xwrite(f->fd, buf, count); |
c38138cd | 19 | if (ret > 0) { |
1d7f171c | 20 | buf = (char *) buf + ret; |
c38138cd LT |
21 | count -= ret; |
22 | if (count) | |
23 | continue; | |
78b713a1 | 24 | return; |
c38138cd LT |
25 | } |
26 | if (!ret) | |
e1808845 | 27 | die("sha1 file '%s' write error. Out of diskspace", f->name); |
e1808845 | 28 | die("sha1 file '%s' write error (%s)", f->name, strerror(errno)); |
c38138cd LT |
29 | } |
30 | } | |
31 | ||
f0215369 | 32 | int sha1close(struct sha1file *f, unsigned char *result, int final) |
c38138cd LT |
33 | { |
34 | unsigned offset = f->offset; | |
35 | if (offset) { | |
36 | SHA1_Update(&f->ctx, f->buffer, offset); | |
37 | sha1flush(f, offset); | |
f0215369 | 38 | f->offset = 0; |
c38138cd | 39 | } |
f0215369 DH |
40 | if (!final) |
41 | return 0; /* only want to flush (no checksum write, no close) */ | |
c38138cd | 42 | SHA1_Final(f->buffer, &f->ctx); |
e1808845 | 43 | if (result) |
e702496e | 44 | hashcpy(result, f->buffer); |
f0215369 | 45 | sha1flush(f, 20); |
e1808845 LT |
46 | if (close(f->fd)) |
47 | die("%s: sha1 file error on close (%s)", f->name, strerror(errno)); | |
7bf058f0 | 48 | free(f); |
c38138cd LT |
49 | return 0; |
50 | } | |
51 | ||
52 | int sha1write(struct sha1file *f, void *buf, unsigned int count) | |
53 | { | |
78d1e84f NP |
54 | if (f->do_crc) |
55 | f->crc32 = crc32(f->crc32, buf, count); | |
c38138cd LT |
56 | while (count) { |
57 | unsigned offset = f->offset; | |
58 | unsigned left = sizeof(f->buffer) - offset; | |
59 | unsigned nr = count > left ? left : count; | |
60 | ||
61 | memcpy(f->buffer + offset, buf, nr); | |
62 | count -= nr; | |
63 | offset += nr; | |
1d7f171c | 64 | buf = (char *) buf + nr; |
c38138cd LT |
65 | left -= nr; |
66 | if (!left) { | |
67 | SHA1_Update(&f->ctx, f->buffer, offset); | |
68 | sha1flush(f, offset); | |
69 | offset = 0; | |
70 | } | |
71 | f->offset = offset; | |
72 | } | |
73 | return 0; | |
74 | } | |
75 | ||
4397f014 LT |
76 | struct sha1file *sha1fd(int fd, const char *name) |
77 | { | |
78 | struct sha1file *f; | |
79 | unsigned len; | |
80 | ||
81 | f = xmalloc(sizeof(*f)); | |
82 | ||
83 | len = strlen(name); | |
84 | if (len >= PATH_MAX) | |
85 | die("you wascally wabbit, you"); | |
86 | f->namelen = len; | |
87 | memcpy(f->name, name, len+1); | |
88 | ||
89 | f->fd = fd; | |
90 | f->error = 0; | |
91 | f->offset = 0; | |
78d1e84f | 92 | f->do_crc = 0; |
4397f014 LT |
93 | SHA1_Init(&f->ctx); |
94 | return f; | |
95 | } | |
96 | ||
78d1e84f NP |
97 | void crc32_begin(struct sha1file *f) |
98 | { | |
99 | f->crc32 = crc32(0, Z_NULL, 0); | |
100 | f->do_crc = 1; | |
101 | } | |
c38138cd | 102 | |
78d1e84f NP |
103 | uint32_t crc32_end(struct sha1file *f) |
104 | { | |
105 | f->do_crc = 0; | |
106 | return f->crc32; | |
107 | } |