about summary refs log tree commit diff
path: root/src/libstore/http-binary-cache-store.cc
blob: 3d17a89660e19df5dd95bc7657b7a198adbb023a (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
#include "binary-cache-store.hh"
#include "download.hh"
#include "globals.hh"
#include "nar-info-disk-cache.hh"

namespace nix {

MakeError(UploadToHTTP, Error);

class HttpBinaryCacheStore : public BinaryCacheStore
{
private:

    Path cacheUri;

    struct State
    {
        bool enabled = true;
        std::chrono::steady_clock::time_point disabledUntil;
    };

    Sync<State> _state;

public:

    HttpBinaryCacheStore(
        const Params & params, const Path & _cacheUri)
        : BinaryCacheStore(params)
        , cacheUri(_cacheUri)
    {
        if (cacheUri.back() == '/')
            cacheUri.pop_back();

        diskCache = getNarInfoDiskCache();
    }

    std::string getUri() override
    {
        return cacheUri;
    }

    void init() override
    {
        // FIXME: do this lazily?
        if (!diskCache->cacheExists(cacheUri, wantMassQuery_, priority)) {
            try {
                BinaryCacheStore::init();
            } catch (UploadToHTTP &) {
                throw Error("'%s' does not appear to be a binary cache", cacheUri);
            }
            diskCache->createCache(cacheUri, storeDir, wantMassQuery_, priority);
        }
    }

protected:

    void maybeDisable()
    {
        auto state(_state.lock());
        if (state->enabled && settings.tryFallback) {
            int t = 60;
            printError("disabling binary cache '%s' for %s seconds", getUri(), t);
            state->enabled = false;
            state->disabledUntil = std::chrono::steady_clock::now() + std::chrono::seconds(t);
        }
    }

    void checkEnabled()
    {
        auto state(_state.lock());
        if (state->enabled) return;
        if (std::chrono::steady_clock::now() > state->disabledUntil) {
            state->enabled = true;
            debug("re-enabling binary cache '%s'", getUri());
            return;
        }
        throw SubstituterDisabled("substituter '%s' is disabled", getUri());
    }

    bool fileExists(const std::string & path) override
    {
        checkEnabled();

        try {
            DownloadRequest request(cacheUri + "/" + path);
            request.head = true;
            getDownloader()->download(request);
            return true;
        } catch (DownloadError & e) {
            /* S3 buckets return 403 if a file doesn't exist and the
               bucket is unlistable, so treat 403 as 404. */
            if (e.error == Downloader::NotFound || e.error == Downloader::Forbidden)
                return false;
            maybeDisable();
            throw;
        }
    }

    void upsertFile(const std::string & path,
        const std::string & data,
        const std::string & mimeType) override
    {
        auto req = DownloadRequest(cacheUri + "/" + path);
        req.data = std::make_shared<string>(data); // FIXME: inefficient
        req.mimeType = mimeType;
        try {
            getDownloader()->download(req);
        } catch (DownloadError & e) {
            throw UploadToHTTP("while uploading to HTTP binary cache at '%s': %s", cacheUri, e.msg());
        }
    }

    DownloadRequest makeRequest(const std::string & path)
    {
        DownloadRequest request(cacheUri + "/" + path);
        request.tries = 8;
        return request;
    }

    void getFile(const std::string & path, Sink & sink) override
    {
        checkEnabled();
        auto request(makeRequest(path));
        try {
            getDownloader()->download(std::move(request), sink);
        } catch (DownloadError & e) {
            if (e.error == Downloader::NotFound || e.error == Downloader::Forbidden)
                throw NoSuchBinaryCacheFile("file '%s' does not exist in binary cache '%s'", path, getUri());
            maybeDisable();
            throw;
        }
    }

    void getFile(const std::string & path,
        Callback<std::shared_ptr<std::string>> callback) override
    {
        checkEnabled();

        auto request(makeRequest(path));

        getDownloader()->enqueueDownload(request,
            {[callback, this](std::future<DownloadResult> result) {
                try {
                    callback(result.get().data);
                } catch (DownloadError & e) {
                    if (e.error == Downloader::NotFound || e.error == Downloader::Forbidden)
                        return callback(std::shared_ptr<std::string>());
                    maybeDisable();
                    callback.rethrow();
                } catch (...) {
                    callback.rethrow();
                }
            }});
    }

};

static RegisterStoreImplementation regStore([](
    const std::string & uri, const Store::Params & params)
    -> std::shared_ptr<Store>
{
    if (std::string(uri, 0, 7) != "http://" &&
        std::string(uri, 0, 8) != "https://" &&
        (getEnv("_NIX_FORCE_HTTP_BINARY_CACHE_STORE") != "1" || std::string(uri, 0, 7) != "file://")
        ) return 0;
    auto store = std::make_shared<HttpBinaryCacheStore>(params, uri);
    store->init();
    return store;
});

}