diff-index: fix compilation warnings.
[git/git-svn.git] / csum-file.c
blob5f9249aeedfa7d4156cf412da6a7e7d77f33ff86
1 /*
2 * csum-file.c
4 * Copyright (C) 2005 Linus Torvalds
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"
13 static int sha1flush(struct sha1file *f, unsigned int count)
15 void *buf = f->buffer;
17 for (;;) {
18 int ret = xwrite(f->fd, buf, count);
19 if (ret > 0) {
20 buf += ret;
21 count -= ret;
22 if (count)
23 continue;
24 return 0;
26 if (!ret)
27 die("sha1 file '%s' write error. Out of diskspace", f->name);
28 die("sha1 file '%s' write error (%s)", f->name, strerror(errno));
32 int sha1close(struct sha1file *f, unsigned char *result, int update)
34 unsigned offset = f->offset;
35 if (offset) {
36 SHA1_Update(&f->ctx, f->buffer, offset);
37 sha1flush(f, offset);
39 SHA1_Final(f->buffer, &f->ctx);
40 if (result)
41 memcpy(result, f->buffer, 20);
42 if (update)
43 sha1flush(f, 20);
44 if (close(f->fd))
45 die("%s: sha1 file error on close (%s)", f->name, strerror(errno));
46 free(f);
47 return 0;
50 int sha1write(struct sha1file *f, void *buf, unsigned int count)
52 while (count) {
53 unsigned offset = f->offset;
54 unsigned left = sizeof(f->buffer) - offset;
55 unsigned nr = count > left ? left : count;
57 memcpy(f->buffer + offset, buf, nr);
58 count -= nr;
59 offset += nr;
60 buf += nr;
61 left -= nr;
62 if (!left) {
63 SHA1_Update(&f->ctx, f->buffer, offset);
64 sha1flush(f, offset);
65 offset = 0;
67 f->offset = offset;
69 return 0;
72 struct sha1file *sha1create(const char *fmt, ...)
74 struct sha1file *f;
75 unsigned len;
76 va_list arg;
77 int fd;
79 f = xmalloc(sizeof(*f));
81 va_start(arg, fmt);
82 len = vsnprintf(f->name, sizeof(f->name), fmt, arg);
83 va_end(arg);
84 if (len >= PATH_MAX)
85 die("you wascally wabbit, you");
86 f->namelen = len;
88 fd = open(f->name, O_CREAT | O_EXCL | O_WRONLY, 0666);
89 if (fd < 0)
90 die("unable to open %s (%s)", f->name, strerror(errno));
91 f->fd = fd;
92 f->error = 0;
93 f->offset = 0;
94 SHA1_Init(&f->ctx);
95 return f;
98 struct sha1file *sha1fd(int fd, const char *name)
100 struct sha1file *f;
101 unsigned len;
103 f = xmalloc(sizeof(*f));
105 len = strlen(name);
106 if (len >= PATH_MAX)
107 die("you wascally wabbit, you");
108 f->namelen = len;
109 memcpy(f->name, name, len+1);
111 f->fd = fd;
112 f->error = 0;
113 f->offset = 0;
114 SHA1_Init(&f->ctx);
115 return f;
118 int sha1write_compressed(struct sha1file *f, void *in, unsigned int size)
120 z_stream stream;
121 unsigned long maxsize;
122 void *out;
124 memset(&stream, 0, sizeof(stream));
125 deflateInit(&stream, Z_DEFAULT_COMPRESSION);
126 maxsize = deflateBound(&stream, size);
127 out = xmalloc(maxsize);
129 /* Compress it */
130 stream.next_in = in;
131 stream.avail_in = size;
133 stream.next_out = out;
134 stream.avail_out = maxsize;
136 while (deflate(&stream, Z_FINISH) == Z_OK)
137 /* nothing */;
138 deflateEnd(&stream);
140 size = stream.total_out;
141 sha1write(f, out, size);
142 free(out);
143 return size;