lix/src/libstore/derivations.hh
John Ericson 230c9b4329 Change types to prepare the way for CA derivations
We've added the variant to `DerivationOutput` to support them, but made
`DerivationOutput::path` partial to avoid actually implementing them.

With this chage, we can all collaborate on "just" removing
`DerivationOutput::path` calls to implement CA derivations.
2020-07-12 23:53:33 +00:00

135 lines
3.7 KiB
C++

#pragma once
#include "path.hh"
#include "types.hh"
#include "hash.hh"
#include "content-address.hh"
#include <map>
namespace nix {
/* Abstract syntax of derivations. */
struct DerivationOutputInputAddressed
{
/* Will need to become `std::optional<StorePath>` once input-addressed
derivations are allowed to depend on cont-addressed derivations */
StorePath path;
};
struct DerivationOutputFixed
{
FixedOutputHash hash; /* hash used for expected hash computation */
};
struct DerivationOutputFloating
{
/* information used for expected hash computation */
FileIngestionMethod method;
HashType hashType;
};
struct DerivationOutput
{
std::variant<
DerivationOutputInputAddressed,
DerivationOutputFixed,
DerivationOutputFloating
> output;
std::optional<HashType> hashAlgoOpt(const Store & store) const;
std::optional<StorePath> pathOpt(const Store & store, std::string_view drvName) const;
/* DEPRECATED: Remove after CA drvs are fully implemented */
StorePath path(const Store & store, std::string_view drvName) const {
auto p = pathOpt(store, drvName);
if (!p) throw Error("floating content-addressed derivations are not yet implemented");
return *p;
}
};
typedef std::map<string, DerivationOutput> DerivationOutputs;
/* For inputs that are sub-derivations, we specify exactly which
output IDs we are interested in. */
typedef std::map<StorePath, StringSet> DerivationInputs;
typedef std::map<string, string> StringPairs;
struct BasicDerivation
{
DerivationOutputs outputs; /* keyed on symbolic IDs */
StorePathSet inputSrcs; /* inputs that are sources */
string platform;
Path builder;
Strings args;
StringPairs env;
std::string name;
BasicDerivation() { }
virtual ~BasicDerivation() { };
/* Return the path corresponding to the output identifier `id' in
the given derivation. */
const StorePath findOutput(const Store & store, const std::string & id) const;
bool isBuiltin() const;
/* Return true iff this is a fixed-output derivation. */
bool isFixedOutput() const;
/* Return the output paths of a derivation. */
StorePathSet outputPaths(const Store & store) const;
/* Return the output names of a derivation. */
StringSet outputNames() const;
static std::string_view nameFromPath(const StorePath & storePath);
};
struct Derivation : BasicDerivation
{
DerivationInputs inputDrvs; /* inputs that are sub-derivations */
/* Print a derivation. */
std::string unparse(const Store & store, bool maskOutputs,
std::map<std::string, StringSet> * actualInputs = nullptr) const;
Derivation() { }
};
class Store;
enum RepairFlag : bool { NoRepair = false, Repair = true };
/* Write a derivation to the Nix store, and return its path. */
StorePath writeDerivation(ref<Store> store,
const Derivation & drv, std::string_view name, RepairFlag repair = NoRepair);
/* Read a derivation from a file. */
Derivation readDerivation(const Store & store, const Path & drvPath, std::string_view name);
// FIXME: remove
bool isDerivation(const string & fileName);
Hash hashDerivationModulo(Store & store, const Derivation & drv, bool maskOutputs);
/* Memoisation of hashDerivationModulo(). */
typedef std::map<StorePath, Hash> DrvHashes;
extern DrvHashes drvHashes; // FIXME: global, not thread-safe
bool wantOutput(const string & output, const std::set<string> & wanted);
struct Source;
struct Sink;
Source & readDerivation(Source & in, const Store & store, BasicDerivation & drv, std::string_view name);
void writeDerivation(Sink & out, const Store & store, const BasicDerivation & drv);
std::string hashPlaceholder(const std::string & outputName);
}