aboutsummaryrefslogtreecommitdiff
path: root/src/libexpr/primops/fetchgit.cc
blob: dc526485fa31356c3a21a507ef858e1f729ce111 (plain)
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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
#include "fetchgit.hh"
#include "primops.hh"
#include "eval-inline.hh"
#include "download.hh"
#include "store-api.hh"
#include "pathlocks.hh"

#include <sys/time.h>

#include <regex>

#include <nlohmann/json.hpp>

using namespace std::string_literals;

namespace nix {

GitInfo exportGit(ref<Store> store, const std::string & uri,
    std::experimental::optional<std::string> ref, const std::string & rev,
    const std::string & name)
{
    if (!ref && rev == "" && hasPrefix(uri, "/") && pathExists(uri + "/.git")) {

        bool clean = true;

        try {
            runProgram("git", true, { "-C", uri, "diff-index", "--quiet", "HEAD", "--" });
        } catch (ExecError e) {
            if (!WIFEXITED(e.status) || WEXITSTATUS(e.status) != 1) throw;
            clean = false;
        }

        if (!clean) {

            /* This is an unclean working tree. So copy all tracked
               files. */

            GitInfo gitInfo;
            gitInfo.rev = "0000000000000000000000000000000000000000";
            gitInfo.shortRev = std::string(gitInfo.rev, 0, 7);

            auto files = tokenizeString<std::set<std::string>>(
                runProgram("git", true, { "-C", uri, "ls-files", "-z" }), "\0"s);

            PathFilter filter = [&](const Path & p) -> bool {
                assert(hasPrefix(p, uri));
                auto st = lstat(p);
                if (S_ISDIR(st.st_mode)) return true;
                std::string file(p, uri.size() + 1);
                return files.count(file);
            };

            gitInfo.storePath = store->addToStore("source", uri, true, htSHA256, filter);

            return gitInfo;
        }
    }

    if (!ref) ref = "master";

    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.
    GitInfo gitInfo;
    gitInfo.rev = rev != "" ? rev : chomp(readFile(localRefFile));
    gitInfo.shortRev = std::string(gitInfo.rev, 0, 7);

    printTalkative("using revision %s of repo '%s'", uri, gitInfo.rev);

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

    try {
        // FIXME: doesn't handle empty lines
        auto json = nlohmann::json::parse(readFile(storeLink));

        assert(json["name"] == name && json["rev"] == gitInfo.rev);

        gitInfo.storePath = json["storePath"];

        if (store->isValidPath(gitInfo.storePath)) {
            gitInfo.revCount = json["revCount"];
            return gitInfo;
        }

    } catch (SysError & e) {
        if (e.errNo != ENOENT) throw;
    }

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

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

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

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

    gitInfo.revCount = std::stoull(runProgram("git", true, { "-C", cacheDir, "rev-list", "--count", gitInfo.rev }));

    nlohmann::json json;
    json["storePath"] = gitInfo.storePath;
    json["uri"] = uri;
    json["name"] = name;
    json["rev"] = gitInfo.rev;
    json["revCount"] = gitInfo.revCount;

    writeFile(storeLink, json.dump());

    return gitInfo;
}

static void prim_fetchGit(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
    std::string url;
    std::experimental::optional<std::string> ref;
    std::string rev;
    std::string name = "source";
    PathSet context;

    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")
                url = state.coerceToString(*attr.pos, *attr.value, context, false, false);
            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.coerceToString(pos, *args[0], context, false, false);

    if (!isUri(url)) url = absPath(url);

    // FIXME: git externals probably can be used to bypass the URI
    // whitelist. Ah well.
    state.checkURI(url);

    auto gitInfo = exportGit(state.store, url, ref, rev, name);

    state.mkAttrs(v, 8);
    mkString(*state.allocAttr(v, state.sOutPath), gitInfo.storePath, PathSet({gitInfo.storePath}));
    mkString(*state.allocAttr(v, state.symbols.create("rev")), gitInfo.rev);
    mkString(*state.allocAttr(v, state.symbols.create("shortRev")), gitInfo.shortRev);
    mkInt(*state.allocAttr(v, state.symbols.create("revCount")), gitInfo.revCount);
    v.attrs->sort();
}

static RegisterPrimOp r("fetchGit", 1, prim_fetchGit);

}