lix/src/libcmd/command.hh
regnat 9355ecd543 Add a new Cmd type working on RealisedPaths
Where a `RealisedPath` is a store path with its history, meaning either
an opaque path for stuff that has been directly added to the store, or a
`Realisation` for stuff that has been built by a derivation

This is a low-level refactoring that doesn't bring anything by itself
(except a few dozen extra lines of code :/ ), but raising the
abstraction level a bit is important on a number of levels:

- Commands like `nix build` have to query for the realisations after the
  build is finished which is fragile (see
  27905f12e4a7207450abe37c9ed78e31603b67e1 for example). Having them
  oprate directly at the realisation level would avoid that
- Others like `nix copy` currently operate directly on (built) store
  paths, but need a bit more information as they will need to register
  the realisations on the remote side
2021-01-28 09:38:44 +01:00

292 lines
7.2 KiB
C++

#pragma once
#include "installables.hh"
#include "args.hh"
#include "common-eval-args.hh"
#include "path.hh"
#include "flake/lockfile.hh"
#include "store-api.hh"
#include <optional>
namespace nix {
extern std::string programPath;
extern char * * savedArgv;
class EvalState;
struct Pos;
class Store;
static constexpr Command::Category catSecondary = 100;
static constexpr Command::Category catUtility = 101;
static constexpr Command::Category catNixInstallation = 102;
static constexpr auto installablesCategory = "Options that change the interpretation of installables";
struct NixMultiCommand : virtual MultiCommand, virtual Command
{
nlohmann::json toJSON() override;
};
/* A command that requires a Nix store. */
struct StoreCommand : virtual Command
{
StoreCommand();
void run() override;
ref<Store> getStore();
virtual ref<Store> createStore();
virtual void run(ref<Store>) = 0;
private:
std::shared_ptr<Store> _store;
};
struct EvalCommand : virtual StoreCommand, MixEvalArgs
{
ref<EvalState> getEvalState();
std::shared_ptr<EvalState> evalState;
};
struct MixFlakeOptions : virtual Args, EvalCommand
{
flake::LockFlags lockFlags;
MixFlakeOptions();
virtual std::optional<FlakeRef> getFlakeRefForCompletion()
{ return {}; }
};
/* How to handle derivations in commands that operate on store paths. */
enum class OperateOn {
/* Operate on the output path. */
Output,
/* Operate on the .drv path. */
Derivation
};
struct SourceExprCommand : virtual Args, MixFlakeOptions
{
std::optional<Path> file;
std::optional<std::string> expr;
// FIXME: move this; not all commands (e.g. 'nix run') use it.
OperateOn operateOn = OperateOn::Output;
SourceExprCommand();
std::vector<std::shared_ptr<Installable>> parseInstallables(
ref<Store> store, std::vector<std::string> ss);
std::shared_ptr<Installable> parseInstallable(
ref<Store> store, const std::string & installable);
virtual Strings getDefaultFlakeAttrPaths();
virtual Strings getDefaultFlakeAttrPathPrefixes();
void completeInstallable(std::string_view prefix);
};
enum class Realise {
/* Build the derivation. Postcondition: the
derivation outputs exist. */
Outputs,
/* Don't build the derivation. Postcondition: the store derivation
exists. */
Derivation,
/* Evaluate in dry-run mode. Postcondition: nothing. */
Nothing
};
/* A command that operates on a list of "installables", which can be
store paths, attribute paths, Nix expressions, etc. */
struct InstallablesCommand : virtual Args, SourceExprCommand
{
std::vector<std::shared_ptr<Installable>> installables;
InstallablesCommand();
void prepare() override;
virtual bool useDefaultInstallables() { return true; }
std::optional<FlakeRef> getFlakeRefForCompletion() override;
private:
std::vector<std::string> _installables;
};
/* A command that operates on exactly one "installable" */
struct InstallableCommand : virtual Args, SourceExprCommand
{
std::shared_ptr<Installable> installable;
InstallableCommand();
void prepare() override;
std::optional<FlakeRef> getFlakeRefForCompletion() override
{
return parseFlakeRef(_installable, absPath("."));
}
private:
std::string _installable{"."};
};
/* A command that operates on zero or more store paths. */
struct RealisedPathsCommand : public InstallablesCommand
{
private:
bool recursive = false;
bool all = false;
protected:
Realise realiseMode = Realise::Derivation;
public:
RealisedPathsCommand(bool recursive = false);
using StoreCommand::run;
virtual void run(ref<Store> store, std::vector<RealisedPath> paths) = 0;
void run(ref<Store> store) override;
bool useDefaultInstallables() override { return !all; }
};
struct StorePathsCommand : public RealisedPathsCommand
{
StorePathsCommand(bool recursive = false);
using RealisedPathsCommand::run;
virtual void run(ref<Store> store, std::vector<StorePath> storePaths) = 0;
void run(ref<Store> store, std::vector<RealisedPath> paths) override;
};
/* A command that operates on exactly one store path. */
struct StorePathCommand : public InstallablesCommand
{
using StoreCommand::run;
virtual void run(ref<Store> store, const StorePath & storePath) = 0;
void run(ref<Store> store) override;
};
/* A helper class for registering commands globally. */
struct RegisterCommand
{
typedef std::map<std::vector<std::string>, std::function<ref<Command>()>> Commands;
static Commands * commands;
RegisterCommand(std::vector<std::string> && name,
std::function<ref<Command>()> command)
{
if (!commands) commands = new Commands;
commands->emplace(name, command);
}
static nix::Commands getCommandsFor(const std::vector<std::string> & prefix);
};
template<class T>
static RegisterCommand registerCommand(const std::string & name)
{
return RegisterCommand({name}, [](){ return make_ref<T>(); });
}
template<class T>
static RegisterCommand registerCommand2(std::vector<std::string> && name)
{
return RegisterCommand(std::move(name), [](){ return make_ref<T>(); });
}
Buildables build(ref<Store> store, Realise mode,
std::vector<std::shared_ptr<Installable>> installables, BuildMode bMode = bmNormal);
std::set<StorePath> toStorePaths(ref<Store> store,
Realise mode, OperateOn operateOn,
std::vector<std::shared_ptr<Installable>> installables);
StorePath toStorePath(ref<Store> store,
Realise mode, OperateOn operateOn,
std::shared_ptr<Installable> installable);
std::set<StorePath> toDerivations(ref<Store> store,
std::vector<std::shared_ptr<Installable>> installables,
bool useDeriver = false);
std::set<RealisedPath> toRealisedPaths(
ref<Store> store,
Realise mode,
OperateOn operateOn,
std::vector<std::shared_ptr<Installable>> installables);
/* Helper function to generate args that invoke $EDITOR on
filename:lineno. */
Strings editorFor(const Pos & pos);
struct MixProfile : virtual StoreCommand
{
std::optional<Path> profile;
MixProfile();
/* If 'profile' is set, make it point at 'storePath'. */
void updateProfile(const StorePath & storePath);
/* If 'profile' is set, make it point at the store path produced
by 'buildables'. */
void updateProfile(const Buildables & buildables);
};
struct MixDefaultProfile : MixProfile
{
MixDefaultProfile();
};
struct MixEnvironment : virtual Args {
StringSet keep, unset;
Strings stringsEnv;
std::vector<char*> vectorEnv;
bool ignoreEnvironment;
MixEnvironment();
/* Modify global environ based on ignoreEnvironment, keep, and unset. It's expected that exec will be called before this class goes out of scope, otherwise environ will become invalid. */
void setEnviron();
};
void completeFlakeRef(ref<Store> store, std::string_view prefix);
void completeFlakeRefWithFragment(
ref<EvalState> evalState,
flake::LockFlags lockFlags,
Strings attrPathPrefixes,
const Strings & defaultFlakeAttrPaths,
std::string_view prefix);
std::string showVersions(const std::set<std::string> & versions);
void printClosureDiff(
ref<Store> store,
const StorePath & beforePath,
const StorePath & afterPath,
std::string_view indent);
}