1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
|
#include "values.hh"
#include "globals.hh"
#include "db.hh"
static void copyFile(string src, string dst)
{
int res = system(("cat " + src + " > " + dst).c_str()); /* !!! escape */
if (WEXITSTATUS(res) != 0)
throw Error("cannot copy " + src + " to " + dst);
}
static string absValuePath(string s)
{
return nixValues + "/" + s;
}
Hash addValue(string path)
{
Hash hash = hashPath(path);
string name;
if (queryDB(nixDB, dbRefs, hash, name)) {
debug((string) hash + " already known");
return hash;
}
string baseName = baseNameOf(path);
string targetName = (string) hash + "-" + baseName;
copyFile(path, absValuePath(targetName));
setDB(nixDB, dbRefs, hash, targetName);
return hash;
}
#if 0
/* Download object referenced by the given URL into the sources
directory. Return the file name it was downloaded to. */
string fetchURL(string url)
{
string filename = baseNameOf(url);
string fullname = nixSourcesDir + "/" + filename;
struct stat st;
if (stat(fullname.c_str(), &st)) {
cerr << "fetching " << url << endl;
/* !!! quoting */
string shellCmd =
"cd " + nixSourcesDir + " && wget --quiet -N \"" + url + "\"";
int res = system(shellCmd.c_str());
if (WEXITSTATUS(res) != 0)
throw Error("cannot fetch " + url);
}
return fullname;
}
#endif
string queryValuePath(Hash hash)
{
bool checkedNet = false;
while (1) {
string name, url;
if (queryDB(nixDB, dbRefs, hash, name)) {
string fn = absValuePath(name);
/* Verify that the file hasn't changed. !!! race !!! slow */
if (hashPath(fn) != hash)
throw Error("file " + fn + " is stale");
return fn;
}
throw Error("a file with hash " + (string) hash + " is requested, "
"but it is not known to exist locally or on the network");
#if 0
if (checkedNet)
throw Error("consistency problem: file fetched from " + url +
" should have hash " + (string) hash + ", but it doesn't");
if (!queryDB(nixDB, dbNetSources, hash, url))
throw Error("a file with hash " + (string) hash + " is requested, "
"but it is not known to exist locally or on the network");
checkedNet = true;
fn = fetchURL(url);
setDB(nixDB, dbRefs, hash, fn);
#endif
}
}
|
