about summary refs log tree commit diff
path: root/src/libexpr/primops/fetchgit.cc
blob: 4c5799bfed56dab8eb8f344d47d3e23f8657735b (plain) (blame)
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
131
132
133
134
135
136
137
#include "primops.hh"
#include "eval-inline.hh"
#include "download.hh"
#include "store-api.hh"
#include "pathlocks.hh"

#include <sys/time.h>

#include <regex>

using namespace std::string_literals;

namespace nix {

Path exportGit(ref<Store> store, const std::string & uri,
    const std::string & ref, const std::string & rev,
    const std::string & name)
{
    if (rev != "") {
        std::regex revRegex("^[0-9a-fA-F]{40}$");
        if (!std::regex_match(rev, revRegex))
            throw Error("invalid Git revision '%s'", rev);
    }

    Path cacheDir = getCacheDir() + "/nix/git";

    if (!pathExists(cacheDir)) {
        createDirs(cacheDir);
        runProgram("git", true, { "init", "--bare", cacheDir });
    }

    std::string localRef = hashString(htSHA256, fmt("%s-%s", uri, ref)).to_string(Base32, false);

    Path localRefFile = cacheDir + "/refs/heads/" + localRef;

    /* If the local ref is older than ‘tarball-ttl’ seconds, do a git
       fetch to update the local ref to the remote ref. */
    time_t now = time(0);
    struct stat st;
    if (stat(localRefFile.c_str(), &st) != 0 ||
        st.st_mtime < now - settings.tarballTtl)
    {
        Activity act(*logger, lvlTalkative, actUnknown, fmt("fetching Git repository '%s'", uri));

        // FIXME: git stderr messes up our progress indicator, so
        // we're using --quiet for now. Should process its stderr.
        runProgram("git", true, { "-C", cacheDir, "fetch", "--quiet", "--force", "--", uri, ref + ":" + localRef });

        struct timeval times[2];
        times[0].tv_sec = now;
        times[0].tv_usec = 0;
        times[1].tv_sec = now;
        times[1].tv_usec = 0;

        utimes(localRefFile.c_str(), times);
    }

    // FIXME: check whether rev is an ancestor of ref.
    std::string commitHash = rev != "" ? rev : chomp(readFile(localRefFile));

    printTalkative("using revision %s of repo '%s'", uri, commitHash);

    std::string storeLinkName = hashString(htSHA512, name + std::string("\0"s) + commitHash).to_string(Base32, false);
    Path storeLink = cacheDir + "/" + storeLinkName + ".link";
    PathLocks storeLinkLock({storeLink}, fmt("waiting for lock on '%1%'...", storeLink));

    if (pathExists(storeLink)) {
        auto storePath = readLink(storeLink);
        store->addTempRoot(storePath);
        if (store->isValidPath(storePath)) {
            return storePath;
        }
    }

    // FIXME: should pipe this, or find some better way to extract a
    // revision.
    auto tar = runProgram("git", true, { "-C", cacheDir, "archive", commitHash });

    Path tmpDir = createTempDir();
    AutoDelete delTmpDir(tmpDir, true);

    runProgram("tar", true, { "x", "-C", tmpDir }, tar);

    auto storePath = store->addToStore(name, tmpDir);

    replaceSymlink(storePath, storeLink);

    return storePath;
}

static void prim_fetchgit(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
    // FIXME: cut&paste from fetch().
    if (state.restricted) throw Error("'fetchgit' is not allowed in restricted mode");

    std::string url;
    std::string ref = "master";
    std::string rev;
    std::string name = "source";

    state.forceValue(*args[0]);

    if (args[0]->type == tAttrs) {

        state.forceAttrs(*args[0], pos);

        for (auto & attr : *args[0]->attrs) {
            string n(attr.name);
            if (n == "url") {
                PathSet context;
                url = state.coerceToString(*attr.pos, *attr.value, context, false, false);
                if (hasPrefix(url, "/")) url = "file://" + url;
            }
            else if (n == "ref")
                ref = state.forceStringNoCtx(*attr.value, *attr.pos);
            else if (n == "rev")
                rev = state.forceStringNoCtx(*attr.value, *attr.pos);
            else if (n == "name")
                name = state.forceStringNoCtx(*attr.value, *attr.pos);
            else
                throw EvalError("unsupported argument '%s' to 'fetchgit', at %s", attr.name, *attr.pos);
        }

        if (url.empty())
            throw EvalError(format("'url' argument required, at %1%") % pos);

    } else
        url = state.forceStringNoCtx(*args[0], pos);

    Path storePath = exportGit(state.store, url, ref, rev, name);

    mkString(v, storePath, PathSet({storePath}));
}

static RegisterPrimOp r("__fetchgit", 1, prim_fetchgit);

}