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Diffstat (limited to 'src/libexpr/flake/flakeref.cc')
| -rw-r--r-- | src/libexpr/flake/flakeref.cc | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/src/libexpr/flake/flakeref.cc b/src/libexpr/flake/flakeref.cc new file mode 100644 index 000000000..701546671 --- /dev/null +++ b/src/libexpr/flake/flakeref.cc @@ -0,0 +1,199 @@ +#include "flakeref.hh" +#include "store-api.hh" +#include "url.hh" +#include "fetchers.hh" +#include "registry.hh" + +namespace nix { + +#if 0 +// 'dir' path elements cannot start with a '.'. We also reject +// potentially dangerous characters like ';'. +const static std::string subDirElemRegex = "(?:[a-zA-Z0-9_-]+[a-zA-Z0-9._-]*)"; +const static std::string subDirRegex = subDirElemRegex + "(?:/" + subDirElemRegex + ")*"; +#endif + +std::string FlakeRef::to_string() const +{ + auto url = input.toURL(); + if (subdir != "") + url.query.insert_or_assign("dir", subdir); + return url.to_string(); +} + +fetchers::Attrs FlakeRef::toAttrs() const +{ + auto attrs = input.toAttrs(); + if (subdir != "") + attrs.emplace("dir", subdir); + return attrs; +} + +std::ostream & operator << (std::ostream & str, const FlakeRef & flakeRef) +{ + str << flakeRef.to_string(); + return str; +} + +bool FlakeRef::operator ==(const FlakeRef & other) const +{ + return input == other.input && subdir == other.subdir; +} + +FlakeRef FlakeRef::resolve(ref<Store> store) const +{ + auto [input2, extraAttrs] = lookupInRegistries(store, input); + return FlakeRef(std::move(input2), fetchers::maybeGetStrAttr(extraAttrs, "dir").value_or(subdir)); +} + +FlakeRef parseFlakeRef( + const std::string & url, const std::optional<Path> & baseDir, bool allowMissing) +{ + auto [flakeRef, fragment] = parseFlakeRefWithFragment(url, baseDir, allowMissing); + if (fragment != "") + throw Error("unexpected fragment '%s' in flake reference '%s'", fragment, url); + return flakeRef; +} + +std::optional<FlakeRef> maybeParseFlakeRef( + const std::string & url, const std::optional<Path> & baseDir) +{ + try { + return parseFlakeRef(url, baseDir); + } catch (Error &) { + return {}; + } +} + +std::pair<FlakeRef, std::string> parseFlakeRefWithFragment( + const std::string & url, const std::optional<Path> & baseDir, bool allowMissing) +{ + using namespace fetchers; + + static std::string fnRegex = "[0-9a-zA-Z-._~!$&'\"()*+,;=]+"; + + static std::regex pathUrlRegex( + "(/?" + fnRegex + "(?:/" + fnRegex + ")*/?)" + + "(?:\\?(" + queryRegex + "))?" + + "(?:#(" + queryRegex + "))?", + std::regex::ECMAScript); + + static std::regex flakeRegex( + "((" + flakeIdRegexS + ")(?:/(?:" + refAndOrRevRegex + "))?)" + + "(?:#(" + queryRegex + "))?", + std::regex::ECMAScript); + + std::smatch match; + + /* Check if 'url' is a flake ID. This is an abbreviated syntax for + 'flake:<flake-id>?ref=<ref>&rev=<rev>'. */ + + if (std::regex_match(url, match, flakeRegex)) { + auto parsedURL = ParsedURL{ + .url = url, + .base = "flake:" + std::string(match[1]), + .scheme = "flake", + .authority = "", + .path = match[1], + }; + + return std::make_pair( + FlakeRef(Input::fromURL(parsedURL), ""), + percentDecode(std::string(match[6]))); + } + + /* Check if 'url' is a path (either absolute or relative to + 'baseDir'). If so, search upward to the root of the repo + (i.e. the directory containing .git). */ + + else if (std::regex_match(url, match, pathUrlRegex)) { + std::string path = match[1]; + if (!baseDir && !hasPrefix(path, "/")) + throw BadURL("flake reference '%s' is not an absolute path", url); + path = absPath(path, baseDir, true); + + if (!S_ISDIR(lstat(path).st_mode)) + throw BadURL("path '%s' is not a flake (because it's not a directory)", path); + + if (!allowMissing && !pathExists(path + "/flake.nix")) + throw BadURL("path '%s' is not a flake (because it doesn't contain a 'flake.nix' file)", path); + + auto fragment = percentDecode(std::string(match[3])); + + auto flakeRoot = path; + std::string subdir; + + while (flakeRoot != "/") { + if (pathExists(flakeRoot + "/.git")) { + auto base = std::string("git+file://") + flakeRoot; + + auto parsedURL = ParsedURL{ + .url = base, // FIXME + .base = base, + .scheme = "git+file", + .authority = "", + .path = flakeRoot, + .query = decodeQuery(match[2]), + }; + + if (subdir != "") { + if (parsedURL.query.count("dir")) + throw Error("flake URL '%s' has an inconsistent 'dir' parameter", url); + parsedURL.query.insert_or_assign("dir", subdir); + } + + if (pathExists(flakeRoot + "/.git/shallow")) + parsedURL.query.insert_or_assign("shallow", "1"); + + return std::make_pair( + FlakeRef(Input::fromURL(parsedURL), get(parsedURL.query, "dir").value_or("")), + fragment); + } + + subdir = std::string(baseNameOf(flakeRoot)) + (subdir.empty() ? "" : "/" + subdir); + flakeRoot = dirOf(flakeRoot); + } + + fetchers::Attrs attrs; + attrs.insert_or_assign("type", "path"); + attrs.insert_or_assign("path", path); + + return std::make_pair(FlakeRef(Input::fromAttrs(std::move(attrs)), ""), fragment); + } + + else { + auto parsedURL = parseURL(url); + std::string fragment; + std::swap(fragment, parsedURL.fragment); + return std::make_pair( + FlakeRef(Input::fromURL(parsedURL), get(parsedURL.query, "dir").value_or("")), + fragment); + } +} + +std::optional<std::pair<FlakeRef, std::string>> maybeParseFlakeRefWithFragment( + const std::string & url, const std::optional<Path> & baseDir) +{ + try { + return parseFlakeRefWithFragment(url, baseDir); + } catch (Error & e) { + return {}; + } +} + +FlakeRef FlakeRef::fromAttrs(const fetchers::Attrs & attrs) +{ + auto attrs2(attrs); + attrs2.erase("dir"); + return FlakeRef( + fetchers::Input::fromAttrs(std::move(attrs2)), + fetchers::maybeGetStrAttr(attrs, "dir").value_or("")); +} + +std::pair<fetchers::Tree, FlakeRef> FlakeRef::fetchTree(ref<Store> store) const +{ + auto [tree, lockedInput] = input.fetch(store); + return {std::move(tree), FlakeRef(std::move(lockedInput), subdir)}; +} + +} |