diff options
Diffstat (limited to 'src/libfetchers/registry.cc')
| -rw-r--r-- | src/libfetchers/registry.cc | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/src/libfetchers/registry.cc b/src/libfetchers/registry.cc new file mode 100644 index 000000000..d4134ce29 --- /dev/null +++ b/src/libfetchers/registry.cc @@ -0,0 +1,212 @@ +#include "registry.hh" +#include "fetchers.hh" +#include "util.hh" +#include "globals.hh" +#include "store-api.hh" + +#include <nlohmann/json.hpp> + +namespace nix::fetchers { + +std::shared_ptr<Registry> Registry::read( + const Path & path, RegistryType type) +{ + auto registry = std::make_shared<Registry>(type); + + if (!pathExists(path)) + return std::make_shared<Registry>(type); + + try { + + auto json = nlohmann::json::parse(readFile(path)); + + auto version = json.value("version", 0); + + if (version == 2) { + for (auto & i : json["flakes"]) { + auto toAttrs = jsonToAttrs(i["to"]); + Attrs extraAttrs; + auto j = toAttrs.find("dir"); + if (j != toAttrs.end()) { + extraAttrs.insert(*j); + toAttrs.erase(j); + } + auto exact = i.find("exact"); + registry->entries.push_back( + Entry { + .from = Input::fromAttrs(jsonToAttrs(i["from"])), + .to = Input::fromAttrs(std::move(toAttrs)), + .extraAttrs = extraAttrs, + .exact = exact != i.end() && exact.value() + }); + } + } + + else + throw Error("flake registry '%s' has unsupported version %d", path, version); + + } catch (nlohmann::json::exception & e) { + warn("cannot parse flake registry '%s': %s", path, e.what()); + } catch (Error & e) { + warn("cannot read flake registry '%s': %s", path, e.what()); + } + + return registry; +} + +void Registry::write(const Path & path) +{ + nlohmann::json arr; + for (auto & entry : entries) { + nlohmann::json obj; + obj["from"] = attrsToJson(entry.from.toAttrs()); + obj["to"] = attrsToJson(entry.to.toAttrs()); + if (!entry.extraAttrs.empty()) + obj["to"].update(attrsToJson(entry.extraAttrs)); + if (entry.exact) + obj["exact"] = true; + arr.emplace_back(std::move(obj)); + } + + nlohmann::json json; + json["version"] = 2; + json["flakes"] = std::move(arr); + + createDirs(dirOf(path)); + writeFile(path, json.dump(2)); +} + +void Registry::add( + const Input & from, + const Input & to, + const Attrs & extraAttrs) +{ + entries.emplace_back( + Entry { + .from = from, + .to = to, + .extraAttrs = extraAttrs + }); +} + +void Registry::remove(const Input & input) +{ + // FIXME: use C++20 std::erase. + for (auto i = entries.begin(); i != entries.end(); ) + if (i->from == input) + i = entries.erase(i); + else + ++i; +} + +static Path getSystemRegistryPath() +{ + return settings.nixConfDir + "/registry.json"; +} + +static std::shared_ptr<Registry> getSystemRegistry() +{ + static auto systemRegistry = + Registry::read(getSystemRegistryPath(), Registry::System); + return systemRegistry; +} + +Path getUserRegistryPath() +{ + return getHome() + "/.config/nix/registry.json"; +} + +std::shared_ptr<Registry> getUserRegistry() +{ + static auto userRegistry = + Registry::read(getUserRegistryPath(), Registry::User); + return userRegistry; +} + +static std::shared_ptr<Registry> flagRegistry = + std::make_shared<Registry>(Registry::Flag); + +std::shared_ptr<Registry> getFlagRegistry() +{ + return flagRegistry; +} + +void overrideRegistry( + const Input & from, + const Input & to, + const Attrs & extraAttrs) +{ + flagRegistry->add(from, to, extraAttrs); +} + +static std::shared_ptr<Registry> getGlobalRegistry(ref<Store> store) +{ + static auto reg = [&]() { + auto path = settings.flakeRegistry.get(); + + if (!hasPrefix(path, "/")) { + auto storePath = downloadFile(store, path, "flake-registry.json", false).storePath; + if (auto store2 = store.dynamic_pointer_cast<LocalFSStore>()) + store2->addPermRoot(storePath, getCacheDir() + "/nix/flake-registry.json", true); + path = store->toRealPath(storePath); + } + + return Registry::read(path, Registry::Global); + }(); + + return reg; +} + +Registries getRegistries(ref<Store> store) +{ + Registries registries; + registries.push_back(getFlagRegistry()); + registries.push_back(getUserRegistry()); + registries.push_back(getSystemRegistry()); + registries.push_back(getGlobalRegistry(store)); + return registries; +} + +std::pair<Input, Attrs> lookupInRegistries( + ref<Store> store, + const Input & _input) +{ + Attrs extraAttrs; + int n = 0; + Input input(_input); + + restart: + + n++; + if (n > 100) throw Error("cycle detected in flake registry for '%s'", input.to_string()); + + for (auto & registry : getRegistries(store)) { + // FIXME: O(n) + for (auto & entry : registry->entries) { + if (entry.exact) { + if (entry.from == input) { + input = entry.to; + extraAttrs = entry.extraAttrs; + goto restart; + } + } else { + if (entry.from.contains(input)) { + input = entry.to.applyOverrides( + !entry.from.getRef() && input.getRef() ? input.getRef() : std::optional<std::string>(), + !entry.from.getRev() && input.getRev() ? input.getRev() : std::optional<Hash>()); + extraAttrs = entry.extraAttrs; + goto restart; + } + } + } + } + + if (!input.isDirect()) + throw Error("cannot find flake '%s' in the flake registries", input.to_string()); + + debug("looked up '%s' -> '%s'", _input.to_string(), input.to_string()); + + return {input, extraAttrs}; +} + +} |