about summary refs log tree commit diff
path: root/src/libexpr/primops/fetchMercurial.cc
blob: 2a423f61bb896d8e14747a01ccee62234aa0cc79 (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
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
#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 {

struct HgInfo
{
    Path storePath;
    std::string branch;
    std::string rev;
    uint64_t revCount = 0;
};

std::regex commitHashRegex("^[0-9a-fA-F]{40}$");

HgInfo exportMercurial(ref<Store> store, const std::string & uri,
    std::string rev, const std::string & name)
{
    if (rev == "" && hasPrefix(uri, "/") && pathExists(uri + "/.hg")) {

        bool clean = runProgram("hg", true, { "status", "-R", uri, "--modified", "--added", "--removed" }) == "";

        if (!clean) {

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

            printTalkative("copying unclean Mercurial working tree '%s'", uri);

            HgInfo hgInfo;
            hgInfo.rev = "0000000000000000000000000000000000000000";
            hgInfo.branch = chomp(runProgram("hg", true, { "branch", "-R", uri }));

            auto files = tokenizeString<std::set<std::string>>(
                runProgram("hg", true, { "status", "-R", uri, "--clean", "--modified", "--added", "--no-status", "--print0" }), "\0"s);

            PathFilter filter = [&](const Path & p) -> bool {
                assert(hasPrefix(p, uri));
                auto st = lstat(p);
                std::string file(p, uri.size() + 1);
                if (file == ".hg") return false;
                // FIXME: filter out directories with no tracked files.
                if (S_ISDIR(st.st_mode)) return true;
                return files.count(file);
            };

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

            return hgInfo;
        }
    }

    if (rev == "") rev = "default";

    Path cacheDir = fmt("%s/nix/hg/%s", getCacheDir(), hashString(htSHA256, uri).to_string(Base32, false));

    Path stampFile = fmt("%s/.hg/%s.stamp", cacheDir, hashString(htSHA512, rev).to_string(Base32, false));

    /* If we haven't pulled this repo less than ‘tarball-ttl’ seconds,
       do so now. */
    time_t now = time(0);
    struct stat st;
    if (stat(stampFile.c_str(), &st) != 0 ||
        st.st_mtime <= now - settings.tarballTtl)
    {
        /* Except that if this is a commit hash that we already have,
           we don't have to pull again. */
        if (!(std::regex_match(rev, commitHashRegex)
                && pathExists(cacheDir)
                && runProgram(
                    RunOptions("hg", { "log", "-R", cacheDir, "-r", rev, "--template", "1" })
                    .killStderr(true)).second == "1"))
        {
            Activity act(*logger, lvlTalkative, actUnknown, fmt("fetching Mercurial repository '%s'", uri));

            if (pathExists(cacheDir)) {
                runProgram("hg", true, { "pull", "-R", cacheDir, "--", uri });
            } else {
                createDirs(dirOf(cacheDir));
                runProgram("hg", true, { "clone", "--noupdate", "--", uri, cacheDir });
            }
        }

        writeFile(stampFile, "");
    }

    auto tokens = tokenizeString<std::vector<std::string>>(
        runProgram("hg", true, { "log", "-R", cacheDir, "-r", rev, "--template", "{node} {rev} {branch}" }));
    assert(tokens.size() == 3);

    HgInfo hgInfo;
    hgInfo.rev = tokens[0];
    hgInfo.revCount = std::stoull(tokens[1]);
    hgInfo.branch = tokens[2];

    std::string storeLinkName = hashString(htSHA512, name + std::string("\0"s) + hgInfo.rev).to_string(Base32, false);
    Path storeLink = fmt("%s/.hg/%s.link", cacheDir, storeLinkName);

    try {
        auto json = nlohmann::json::parse(readFile(storeLink));

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

        hgInfo.storePath = json["storePath"];

        if (store->isValidPath(hgInfo.storePath)) {
            printTalkative("using cached Mercurial store path '%s'", hgInfo.storePath);
            return hgInfo;
        }

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

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

    runProgram("hg", true, { "archive", "-R", cacheDir, "-r", rev, tmpDir });

    deletePath(tmpDir + "/.hg_archival.txt");

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

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

    writeFile(storeLink, json.dump());

    return hgInfo;
}

static void prim_fetchMercurial(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
    std::string url;
    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 == "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 'fetchMercurial', 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 hgInfo = exportMercurial(state.store, url, rev, name);

    state.mkAttrs(v, 8);
    mkString(*state.allocAttr(v, state.sOutPath), hgInfo.storePath, PathSet({hgInfo.storePath}));
    mkString(*state.allocAttr(v, state.symbols.create("branch")), hgInfo.branch);
    mkString(*state.allocAttr(v, state.symbols.create("rev")), hgInfo.rev);
    mkString(*state.allocAttr(v, state.symbols.create("shortRev")), std::string(hgInfo.rev, 0, 12));
    mkInt(*state.allocAttr(v, state.symbols.create("revCount")), hgInfo.revCount);
    v.attrs->sort();
}

static RegisterPrimOp r("fetchMercurial", 1, prim_fetchMercurial);

}