lix/src/libexpr/flake/flakeref.hh

76 lines
2.3 KiB
C++

#pragma once
#include "types.hh"
#include "hash.hh"
#include "fetchers.hh"
#include <variant>
namespace nix {
class Store;
typedef std::string FlakeId;
/* A flake reference specifies how to fetch a flake or raw source
* (e.g. from a Git repository). It is created from a URL-like syntax
* (e.g. 'github:NixOS/patchelf'), an attrset representation (e.g. '{
* type="github"; owner = "NixOS"; repo = "patchelf"; }'), or a local
* path.
*
* Each flake will have a number of FlakeRef objects: one for each
* input to the flake.
*
* The normal method of constructing a FlakeRef is by starting with an
* input description (usually the attrs or a url from the flake file),
* locating a fetcher for that input, and then capturing the Input
* object that fetcher generates (usually via
* FlakeRef::fromAttrs(attrs) or parseFlakeRef(url) calls).
*
* The actual fetch not have been performed yet (i.e. a FlakeRef may
* be lazy), but the fetcher can be invoked at any time via the
* FlakeRef to ensure the store is populated with this input.
*/
struct FlakeRef
{
/* fetcher-specific representation of the input, sufficient to
perform the fetch operation. */
fetchers::Input input;
/* sub-path within the fetched input that represents this input */
Path subdir;
bool operator==(const FlakeRef & other) const;
FlakeRef(fetchers::Input && input, const Path & subdir)
: input(std::move(input)), subdir(subdir)
{ }
// FIXME: change to operator <<.
std::string to_string() const;
fetchers::Attrs toAttrs() const;
FlakeRef resolve(ref<Store> store) const;
static FlakeRef fromAttrs(const fetchers::Attrs & attrs);
std::pair<fetchers::Tree, FlakeRef> fetchTree(ref<Store> store) const;
};
std::ostream & operator << (std::ostream & str, const FlakeRef & flakeRef);
FlakeRef parseFlakeRef(
const std::string & url, const std::optional<Path> & baseDir = {}, bool allowMissing = false);
std::optional<FlakeRef> maybeParseFlake(
const std::string & url, const std::optional<Path> & baseDir = {});
std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
const std::string & url, const std::optional<Path> & baseDir = {}, bool allowMissing = false);
std::optional<std::pair<FlakeRef, std::string>> maybeParseFlakeRefWithFragment(
const std::string & url, const std::optional<Path> & baseDir = {});
}