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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 | ||
13 | static int sha1flush(struct sha1file *f, unsigned int count) | |
14 | { | |
15 | void *buf = f->buffer; | |
16 | ||
17 | for (;;) { | |
18 | int ret = write(f->fd, buf, count); | |
19 | if (ret > 0) { | |
20 | buf += ret; | |
21 | count -= ret; | |
22 | if (count) | |
23 | continue; | |
24 | return 0; | |
25 | } | |
26 | if (!ret) | |
e1808845 | 27 | die("sha1 file '%s' write error. Out of diskspace", f->name); |
c38138cd LT |
28 | if (errno == EAGAIN || errno == EINTR) |
29 | continue; | |
e1808845 | 30 | die("sha1 file '%s' write error (%s)", f->name, strerror(errno)); |
c38138cd LT |
31 | } |
32 | } | |
33 | ||
e1808845 | 34 | int sha1close(struct sha1file *f, unsigned char *result, int update) |
c38138cd LT |
35 | { |
36 | unsigned offset = f->offset; | |
37 | if (offset) { | |
38 | SHA1_Update(&f->ctx, f->buffer, offset); | |
39 | sha1flush(f, offset); | |
40 | } | |
41 | SHA1_Final(f->buffer, &f->ctx); | |
e1808845 LT |
42 | if (result) |
43 | memcpy(result, f->buffer, 20); | |
44 | if (update) | |
45 | sha1flush(f, 20); | |
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 | { | |
54 | while (count) { | |
55 | unsigned offset = f->offset; | |
56 | unsigned left = sizeof(f->buffer) - offset; | |
57 | unsigned nr = count > left ? left : count; | |
58 | ||
59 | memcpy(f->buffer + offset, buf, nr); | |
60 | count -= nr; | |
61 | offset += nr; | |
2700628e | 62 | buf += nr; |
c38138cd LT |
63 | left -= nr; |
64 | if (!left) { | |
65 | SHA1_Update(&f->ctx, f->buffer, offset); | |
66 | sha1flush(f, offset); | |
67 | offset = 0; | |
68 | } | |
69 | f->offset = offset; | |
70 | } | |
71 | return 0; | |
72 | } | |
73 | ||
74 | struct sha1file *sha1create(const char *fmt, ...) | |
75 | { | |
c38138cd LT |
76 | struct sha1file *f; |
77 | unsigned len; | |
78 | va_list arg; | |
79 | int fd; | |
80 | ||
e1808845 LT |
81 | f = xmalloc(sizeof(*f)); |
82 | ||
c38138cd | 83 | va_start(arg, fmt); |
e1808845 | 84 | len = vsnprintf(f->name, sizeof(f->name), fmt, arg); |
c38138cd | 85 | va_end(arg); |
c38138cd LT |
86 | if (len >= PATH_MAX) |
87 | die("you wascally wabbit, you"); | |
e1808845 LT |
88 | f->namelen = len; |
89 | ||
f312de01 | 90 | fd = open(f->name, O_CREAT | O_EXCL | O_WRONLY, 0666); |
c38138cd | 91 | if (fd < 0) |
e1808845 | 92 | die("unable to open %s (%s)", f->name, strerror(errno)); |
c38138cd LT |
93 | f->fd = fd; |
94 | f->error = 0; | |
95 | f->offset = 0; | |
96 | SHA1_Init(&f->ctx); | |
97 | return f; | |
98 | } | |
99 | ||
4397f014 LT |
100 | struct sha1file *sha1fd(int fd, const char *name) |
101 | { | |
102 | struct sha1file *f; | |
103 | unsigned len; | |
104 | ||
105 | f = xmalloc(sizeof(*f)); | |
106 | ||
107 | len = strlen(name); | |
108 | if (len >= PATH_MAX) | |
109 | die("you wascally wabbit, you"); | |
110 | f->namelen = len; | |
111 | memcpy(f->name, name, len+1); | |
112 | ||
113 | f->fd = fd; | |
114 | f->error = 0; | |
115 | f->offset = 0; | |
116 | SHA1_Init(&f->ctx); | |
117 | return f; | |
118 | } | |
119 | ||
c38138cd LT |
120 | int sha1write_compressed(struct sha1file *f, void *in, unsigned int size) |
121 | { | |
122 | z_stream stream; | |
123 | unsigned long maxsize; | |
124 | void *out; | |
125 | ||
126 | memset(&stream, 0, sizeof(stream)); | |
127 | deflateInit(&stream, Z_DEFAULT_COMPRESSION); | |
128 | maxsize = deflateBound(&stream, size); | |
129 | out = xmalloc(maxsize); | |
130 | ||
131 | /* Compress it */ | |
132 | stream.next_in = in; | |
133 | stream.avail_in = size; | |
134 | ||
135 | stream.next_out = out; | |
136 | stream.avail_out = maxsize; | |
137 | ||
138 | while (deflate(&stream, Z_FINISH) == Z_OK) | |
139 | /* nothing */; | |
140 | deflateEnd(&stream); | |
141 | ||
142 | size = stream.total_out; | |
143 | sha1write(f, out, size); | |
144 | free(out); | |
145 | return size; | |
146 | } | |
147 | ||
148 |