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Commit | Line | Data |
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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) | |
27 | die("sha1 file '%s' write error. Out of diskspace", f->name); | |
28 | if (errno == EAGAIN || errno == EINTR) | |
29 | continue; | |
30 | die("sha1 file '%s' write error (%s)", f->name, strerror(errno)); | |
31 | } | |
32 | } | |
33 | ||
34 | int sha1close(struct sha1file *f, unsigned char *result, int update) | |
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); | |
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)); | |
48 | return 0; | |
49 | } | |
50 | ||
51 | int sha1write(struct sha1file *f, void *buf, unsigned int count) | |
52 | { | |
53 | while (count) { | |
54 | unsigned offset = f->offset; | |
55 | unsigned left = sizeof(f->buffer) - offset; | |
56 | unsigned nr = count > left ? left : count; | |
57 | ||
58 | memcpy(f->buffer + offset, buf, nr); | |
59 | count -= nr; | |
60 | offset += nr; | |
61 | buf += nr; | |
62 | left -= nr; | |
63 | if (!left) { | |
64 | SHA1_Update(&f->ctx, f->buffer, offset); | |
65 | sha1flush(f, offset); | |
66 | offset = 0; | |
67 | } | |
68 | f->offset = offset; | |
69 | } | |
70 | return 0; | |
71 | } | |
72 | ||
73 | struct sha1file *sha1create(const char *fmt, ...) | |
74 | { | |
75 | struct sha1file *f; | |
76 | unsigned len; | |
77 | va_list arg; | |
78 | int fd; | |
79 | ||
80 | f = xmalloc(sizeof(*f)); | |
81 | ||
82 | va_start(arg, fmt); | |
83 | len = vsnprintf(f->name, sizeof(f->name), fmt, arg); | |
84 | va_end(arg); | |
85 | if (len >= PATH_MAX) | |
86 | die("you wascally wabbit, you"); | |
87 | f->namelen = len; | |
88 | ||
89 | fd = open(f->name, O_CREAT | O_EXCL | O_WRONLY, 0666); | |
90 | if (fd < 0) | |
91 | die("unable to open %s (%s)", f->name, strerror(errno)); | |
92 | f->fd = fd; | |
93 | f->error = 0; | |
94 | f->offset = 0; | |
95 | SHA1_Init(&f->ctx); | |
96 | return f; | |
97 | } | |
98 | ||
99 | struct sha1file *sha1fd(int fd, const char *name) | |
100 | { | |
101 | struct sha1file *f; | |
102 | unsigned len; | |
103 | ||
104 | f = xmalloc(sizeof(*f)); | |
105 | ||
106 | len = strlen(name); | |
107 | if (len >= PATH_MAX) | |
108 | die("you wascally wabbit, you"); | |
109 | f->namelen = len; | |
110 | memcpy(f->name, name, len+1); | |
111 | ||
112 | f->fd = fd; | |
113 | f->error = 0; | |
114 | f->offset = 0; | |
115 | SHA1_Init(&f->ctx); | |
116 | return f; | |
117 | } | |
118 | ||
119 | int sha1write_compressed(struct sha1file *f, void *in, unsigned int size) | |
120 | { | |
121 | z_stream stream; | |
122 | unsigned long maxsize; | |
123 | void *out; | |
124 | ||
125 | memset(&stream, 0, sizeof(stream)); | |
126 | deflateInit(&stream, Z_DEFAULT_COMPRESSION); | |
127 | maxsize = deflateBound(&stream, size); | |
128 | out = xmalloc(maxsize); | |
129 | ||
130 | /* Compress it */ | |
131 | stream.next_in = in; | |
132 | stream.avail_in = size; | |
133 | ||
134 | stream.next_out = out; | |
135 | stream.avail_out = maxsize; | |
136 | ||
137 | while (deflate(&stream, Z_FINISH) == Z_OK) | |
138 | /* nothing */; | |
139 | deflateEnd(&stream); | |
140 | ||
141 | size = stream.total_out; | |
142 | sha1write(f, out, size); | |
143 | free(out); | |
144 | return size; | |
145 | } | |
146 | ||
147 |