diff options
Diffstat (limited to 'src/libstore/derived-path.hh')
| -rw-r--r-- | src/libstore/derived-path.hh | 202 |
1 files changed, 190 insertions, 12 deletions
diff --git a/src/libstore/derived-path.hh b/src/libstore/derived-path.hh index 7a4261ce0..ec30dac61 100644 --- a/src/libstore/derived-path.hh +++ b/src/libstore/derived-path.hh @@ -24,15 +24,135 @@ class Store; 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); + nlohmann::json toJSON(const Store & store) const; GENERATE_CMP(DerivedPathOpaque, me->path); }; +struct SingleDerivedPath; + +/** + * A single derived path that is built from a derivation + * + * Built derived paths are pair of a derivation and an output name. They are + * evaluated by building the derivation, and then taking the resulting output + * path of the given output name. + */ +struct SingleDerivedPathBuilt { + ref<SingleDerivedPath> drvPath; + std::string output; + + /** + * Get the store path this is ultimately derived from (by realising + * and projecting outputs). + * + * Note that this is *not* a property of the store object being + * referred to, but just of this path --- how we happened to be + * referring to that store object. In other words, this means this + * function breaks "referential transparency". It should therefore + * be used only with great care. + */ + const StorePath & getBaseStorePath() const; + + /** + * Uses `^` as the separator + */ + std::string to_string(const Store & store) const; + /** + * Uses `!` as the separator + */ + std::string to_string_legacy(const Store & store) const; + /** + * The caller splits on the separator, so it works for both variants. + * + * @param xpSettings Stop-gap to avoid globals during unit tests. + */ + static SingleDerivedPathBuilt parse( + const Store & store, ref<SingleDerivedPath> drvPath, + std::string_view outputs, + const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings); + nlohmann::json toJSON(Store & store) const; + + DECLARE_CMP(SingleDerivedPathBuilt); +}; + +using _SingleDerivedPathRaw = std::variant< + DerivedPathOpaque, + SingleDerivedPathBuilt +>; + /** - * A derived path that is built from a derivation + * A "derived path" is a very simple sort of expression (not a Nix + * language expression! But an expression in a the general sense) 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 SingleDerivedPath : _SingleDerivedPathRaw { + using Raw = _SingleDerivedPathRaw; + using Raw::Raw; + + using Opaque = DerivedPathOpaque; + using Built = SingleDerivedPathBuilt; + + inline const Raw & raw() const { + return static_cast<const Raw &>(*this); + } + + /** + * Get the store path this is ultimately derived from (by realising + * and projecting outputs). + * + * Note that this is *not* a property of the store object being + * referred to, but just of this path --- how we happened to be + * referring to that store object. In other words, this means this + * function breaks "referential transparency". It should therefore + * be used only with great care. + */ + const StorePath & getBaseStorePath() const; + + /** + * Uses `^` as the separator + */ + std::string to_string(const Store & store) const; + /** + * Uses `!` as the separator + */ + std::string to_string_legacy(const Store & store) const; + /** + * Uses `^` as the separator + * + * @param xpSettings Stop-gap to avoid globals during unit tests. + */ + static SingleDerivedPath parse( + const Store & store, + std::string_view, + const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings); + /** + * Uses `!` as the separator + * + * @param xpSettings Stop-gap to avoid globals during unit tests. + */ + static SingleDerivedPath parseLegacy( + const Store & store, + std::string_view, + const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings); + nlohmann::json toJSON(Store & store) const; +}; + +static inline ref<SingleDerivedPath> makeConstantStorePathRef(StorePath drvPath) +{ + return make_ref<SingleDerivedPath>(SingleDerivedPath::Opaque { drvPath }); +} + +/** + * A set of derived paths that are 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 @@ -44,10 +164,22 @@ struct DerivedPathOpaque { * output name. */ struct DerivedPathBuilt { - StorePath drvPath; + ref<SingleDerivedPath> drvPath; OutputsSpec outputs; /** + * Get the store path this is ultimately derived from (by realising + * and projecting outputs). + * + * Note that this is *not* a property of the store object being + * referred to, but just of this path --- how we happened to be + * referring to that store object. In other words, this means this + * function breaks "referential transparency". It should therefore + * be used only with great care. + */ + const StorePath & getBaseStorePath() const; + + /** * Uses `^` as the separator */ std::string to_string(const Store & store) const; @@ -57,11 +189,16 @@ struct DerivedPathBuilt { std::string to_string_legacy(const Store & store) const; /** * The caller splits on the separator, so it works for both variants. + * + * @param xpSettings Stop-gap to avoid globals during unit tests. */ - static DerivedPathBuilt parse(const Store & store, std::string_view drvPath, std::string_view outputs); - nlohmann::json toJSON(ref<Store> store) const; + static DerivedPathBuilt parse( + const Store & store, ref<SingleDerivedPath>, + std::string_view, + const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings); + nlohmann::json toJSON(Store & store) const; - GENERATE_CMP(DerivedPathBuilt, me->drvPath, me->outputs); + DECLARE_CMP(DerivedPathBuilt); }; using _DerivedPathRaw = std::variant< @@ -71,13 +208,13 @@ using _DerivedPathRaw = std::variant< /** * A "derived path" is a very simple sort of expression that evaluates - * to (concrete) store path. It is either: + * to one or more (concrete) store paths. It is either: * - * - opaque, in which case it is just a concrete store path with + * - opaque, in which case it is just a single concrete store path with * possibly no known derivation * - * - built, in which case it is a pair of a derivation path and an - * output name. + * - built, in which case it is a pair of a derivation path and some + * output names. */ struct DerivedPath : _DerivedPathRaw { using Raw = _DerivedPathRaw; @@ -91,6 +228,18 @@ struct DerivedPath : _DerivedPathRaw { } /** + * Get the store path this is ultimately derived from (by realising + * and projecting outputs). + * + * Note that this is *not* a property of the store object being + * referred to, but just of this path --- how we happened to be + * referring to that store object. In other words, this means this + * function breaks "referential transparency". It should therefore + * be used only with great care. + */ + const StorePath & getBaseStorePath() const; + + /** * Uses `^` as the separator */ std::string to_string(const Store & store) const; @@ -100,14 +249,43 @@ struct DerivedPath : _DerivedPathRaw { std::string to_string_legacy(const Store & store) const; /** * Uses `^` as the separator + * + * @param xpSettings Stop-gap to avoid globals during unit tests. */ - static DerivedPath parse(const Store & store, std::string_view); + static DerivedPath parse( + const Store & store, + std::string_view, + const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings); /** * Uses `!` as the separator + * + * @param xpSettings Stop-gap to avoid globals during unit tests. */ - static DerivedPath parseLegacy(const Store & store, std::string_view); + static DerivedPath parseLegacy( + const Store & store, + std::string_view, + const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings); + + /** + * Convert a `SingleDerivedPath` to a `DerivedPath`. + */ + static DerivedPath fromSingle(const SingleDerivedPath &); + + nlohmann::json toJSON(Store & store) const; }; typedef std::vector<DerivedPath> DerivedPaths; +/** + * Used by various parser functions to require experimental features as + * needed. + * + * Somewhat unfortunate this cannot just be an implementation detail for + * this module. + * + * @param xpSettings Stop-gap to avoid globals during unit tests. + */ +void drvRequireExperiment( + const SingleDerivedPath & drv, + const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings); } |