aboutsummaryrefslogtreecommitdiff
path: root/src/libstore/derived-path.hh
blob: 5a38203aed363184b762ee6108ad14027b3762f7 (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
#pragma once

#include "util.hh"
#include "path.hh"
#include "realisation.hh"

#include <optional>
#include <variant>

#include <nlohmann/json_fwd.hpp>

namespace nix {

class Store;

/**
 * An opaque derived path.
 *
 * Opaque derived paths are just store paths, and fully evaluated. They
 * cannot be simplified further. Since they are opaque, they cannot be
 * built, but they can fetched.
 */
struct DerivedPathOpaque {
    StorePath path;

    nlohmann::json toJSON(ref<Store> store) const;
    std::string to_string(const Store & store) const;
    static DerivedPathOpaque parse(const Store & store, std::string_view);
};

/**
 * A derived path that is built from a derivation
 *
 * Built derived paths are pair of a derivation and some output names.
 * They are evaluated by building the derivation, and then replacing the
 * output names with the resulting outputs.
 *
 * Note that does mean a derived store paths evaluates to multiple
 * opaque paths, which is sort of icky as expressions are supposed to
 * evaluate to single values. Perhaps this should have just a single
 * output name.
 */
struct DerivedPathBuilt {
    StorePath drvPath;
    std::set<std::string> outputs;

    std::string to_string(const Store & store) const;
    static DerivedPathBuilt parse(const Store & store, std::string_view);
    nlohmann::json toJSON(ref<Store> store) const;
};

using _DerivedPathRaw = std::variant<
    DerivedPathOpaque,
    DerivedPathBuilt
>;

/**
 * A "derived path" is a very simple sort of expression that evaluates
 * to (concrete) store path. It is either:
 *
 * - opaque, in which case it is just a concrete store path with
 *   possibly no known derivation
 *
 * - built, in which case it is a pair of a derivation path and an
 *   output name.
 */
struct DerivedPath : _DerivedPathRaw {
    using Raw = _DerivedPathRaw;
    using Raw::Raw;

    using Opaque = DerivedPathOpaque;
    using Built = DerivedPathBuilt;

    inline const Raw & raw() const {
        return static_cast<const Raw &>(*this);
    }

    std::string to_string(const Store & store) const;
    static DerivedPath parse(const Store & store, std::string_view);
};

/**
 * A built derived path with hints in the form of optional concrete output paths.
 *
 * See 'BuiltPath' for more an explanation.
 */
struct BuiltPathBuilt {
    StorePath drvPath;
    std::map<std::string, StorePath> outputs;

    nlohmann::json toJSON(ref<Store> store) const;
    static BuiltPathBuilt parse(const Store & store, std::string_view);
};

using _BuiltPathRaw = std::variant<
    DerivedPath::Opaque,
    BuiltPathBuilt
>;

/**
 * A built path. Similar to a `DerivedPath`, but enriched with the corresponding
 * output path(s).
 */
struct BuiltPath : _BuiltPathRaw {
    using Raw = _BuiltPathRaw;
    using Raw::Raw;

    using Opaque = DerivedPathOpaque;
    using Built = BuiltPathBuilt;

    inline const Raw & raw() const {
        return static_cast<const Raw &>(*this);
    }

    StorePathSet outPaths() const;
    RealisedPath::Set toRealisedPaths(Store & store) const;

};

typedef std::vector<DerivedPath> DerivedPaths;
typedef std::vector<BuiltPath> BuiltPaths;

nlohmann::json derivedPathsWithHintsToJSON(const BuiltPaths & buildables, ref<Store> store);
nlohmann::json derivedPathsToJSON(const DerivedPaths & , ref<Store> store);

}