Nix/src/libfetchers/fetchers.hh
2021-04-09 13:51:57 +02:00

156 lines
4.2 KiB
C++

#pragma once
#include "types.hh"
#include "hash.hh"
#include "path.hh"
#include "attrs.hh"
#include "url.hh"
#include <memory>
namespace nix { class Store; }
namespace nix::fetchers {
struct Tree
{
Path actualPath;
StorePath storePath;
Tree(Path && actualPath, StorePath && storePath) : actualPath(actualPath), storePath(std::move(storePath)) {}
};
struct InputScheme;
/* The Input object is generated by a specific fetcher, based on the
* user-supplied input attribute in the flake.nix file, and contains
* the information that the specific fetcher needs to perform the
* actual fetch. The Input object is most commonly created via the
* "fromURL()" or "fromAttrs()" static functions which are provided
* the url or attrset specified in the flake file.
*/
struct Input
{
friend struct InputScheme;
std::shared_ptr<InputScheme> scheme; // note: can be null
Attrs attrs;
bool immutable = false;
bool direct = true;
public:
static Input fromURL(const std::string & url);
static Input fromURL(const ParsedURL & url);
static Input fromAttrs(Attrs && attrs);
ParsedURL toURL() const;
std::string toURLString(const std::map<std::string, std::string> & extraQuery = {}) const;
std::string to_string() const;
Attrs toAttrs() const;
/* Check whether this is a "direct" input, that is, not
one that goes through a registry. */
bool isDirect() const { return direct; }
/* Check whether this is an "immutable" input, that is,
one that contains a commit hash or content hash. */
bool isImmutable() const { return immutable; }
bool hasAllInfo() const;
bool operator ==(const Input & other) const;
bool contains(const Input & other) const;
std::pair<Tree, Input> fetch(ref<Store> store) const;
Input applyOverrides(
std::optional<std::string> ref,
std::optional<Hash> rev) const;
void clone(const Path & destDir) const;
std::optional<Path> getSourcePath() const;
void markChangedFile(
std::string_view file,
std::optional<std::string> commitMsg) const;
StorePath computeStorePath(Store & store) const;
// Convenience functions for common attributes.
std::string getType() const;
std::optional<Hash> getNarHash() const;
std::optional<std::string> getRef() const;
std::optional<Hash> getRev() const;
std::optional<uint64_t> getRevCount() const;
std::optional<time_t> getLastModified() const;
};
/* The InputScheme represents a type of fetcher. Each fetcher
* registers with nix at startup time. When processing an input for a
* flake, each scheme is given an opportunity to "recognize" that
* input from the url or attributes in the flake file's specification
* and return an Input object to represent the input if it is
* recognized. The Input object contains the information the fetcher
* needs to actually perform the "fetch()" when called.
*/
struct InputScheme
{
virtual ~InputScheme()
{ }
virtual std::optional<Input> inputFromURL(const ParsedURL & url) = 0;
virtual std::optional<Input> inputFromAttrs(const Attrs & attrs) = 0;
virtual ParsedURL toURL(const Input & input);
virtual bool hasAllInfo(const Input & input) = 0;
virtual Input applyOverrides(
const Input & input,
std::optional<std::string> ref,
std::optional<Hash> rev);
virtual void clone(const Input & input, const Path & destDir);
virtual std::optional<Path> getSourcePath(const Input & input);
virtual void markChangedFile(const Input & input, std::string_view file, std::optional<std::string> commitMsg);
virtual std::pair<Tree, Input> fetch(ref<Store> store, const Input & input) = 0;
};
void registerInputScheme(std::shared_ptr<InputScheme> && fetcher);
struct DownloadFileResult
{
StorePath storePath;
std::string etag;
std::string effectiveUrl;
};
DownloadFileResult downloadFile(
ref<Store> store,
const std::string & url,
const std::string & name,
bool immutable,
const Headers & headers = {});
std::pair<Tree, time_t> downloadTarball(
ref<Store> store,
const std::string & url,
const std::string & name,
bool immutable,
const Headers & headers = {});
}