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
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
#include "remote-fs-accessor.hh"
#include "nar-accessor.hh"
#include "json.hh"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
namespace nix {
RemoteFSAccessor::RemoteFSAccessor(ref<Store> store, const Path & cacheDir)
: store(store)
, cacheDir(cacheDir)
{
if (cacheDir != "")
createDirs(cacheDir);
}
Path RemoteFSAccessor::makeCacheFile(std::string_view hashPart, const std::string & ext)
{
assert(cacheDir != "");
return fmt("%s/%s.%s", cacheDir, hashPart, ext);
}
ref<FSAccessor> RemoteFSAccessor::addToCache(std::string_view hashPart, std::string && nar)
{
if (cacheDir != "") {
try {
/* FIXME: do this asynchronously. */
writeFile(makeCacheFile(hashPart, "nar"), nar);
} catch (...) {
ignoreException();
}
}
auto narAccessor = makeNarAccessor(std::move(nar));
nars.emplace(hashPart, narAccessor);
if (cacheDir != "") {
try {
std::ostringstream str;
JSONPlaceholder jsonRoot(str);
listNar(jsonRoot, narAccessor, "", true);
writeFile(makeCacheFile(hashPart, "ls"), str.str());
} catch (...) {
ignoreException();
}
}
return narAccessor;
}
std::pair<ref<FSAccessor>, Path> RemoteFSAccessor::fetch(const Path & path_, bool requireValidPath)
{
auto path = canonPath(path_);
auto [storePath, restPath] = store->toStorePath(path);
if (requireValidPath && !store->isValidPath(storePath))
throw InvalidPath("path '%1%' is not a valid store path", store->printStorePath(storePath));
auto i = nars.find(std::string(storePath.hashPart()));
if (i != nars.end()) return {i->second, restPath};
std::string listing;
Path cacheFile;
if (cacheDir != "" && pathExists(cacheFile = makeCacheFile(storePath.hashPart(), "nar"))) {
try {
listing = nix::readFile(makeCacheFile(storePath.hashPart(), "ls"));
auto narAccessor = makeLazyNarAccessor(listing,
[cacheFile](uint64_t offset, uint64_t length) {
AutoCloseFD fd = open(cacheFile.c_str(), O_RDONLY | O_CLOEXEC);
if (!fd)
throw SysError("opening NAR cache file '%s'", cacheFile);
if (lseek(fd.get(), offset, SEEK_SET) != (off_t) offset)
throw SysError("seeking in '%s'", cacheFile);
std::string buf(length, 0);
readFull(fd.get(), buf.data(), length);
return buf;
});
nars.emplace(storePath.hashPart(), narAccessor);
return {narAccessor, restPath};
} catch (SysError &) { }
try {
auto narAccessor = makeNarAccessor(nix::readFile(cacheFile));
nars.emplace(storePath.hashPart(), narAccessor);
return {narAccessor, restPath};
} catch (SysError &) { }
}
StringSink sink;
store->narFromPath(storePath, sink);
return {addToCache(storePath.hashPart(), std::move(sink.s)), restPath};
}
FSAccessor::Stat RemoteFSAccessor::stat(const Path & path)
{
auto res = fetch(path);
return res.first->stat(res.second);
}
StringSet RemoteFSAccessor::readDirectory(const Path & path)
{
auto res = fetch(path);
return res.first->readDirectory(res.second);
}
std::string RemoteFSAccessor::readFile(const Path & path, bool requireValidPath)
{
auto res = fetch(path, requireValidPath);
return res.first->readFile(res.second);
}
std::string RemoteFSAccessor::readLink(const Path & path)
{
auto res = fetch(path);
return res.first->readLink(res.second);
}
}
|