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#pragma once
///@file
#include "lix/libstore/path.hh"
#include "lix/libutil/config.hh"
#include "lix/libutil/result.hh"
#include "lix/libutil/types.hh"
#include "lix/libutil/hash.hh"
#include "lix/libstore/content-address.hh"
#include "lix/libutil/repair-flag.hh"
#include "lix/libutil/sync.hh"
#include "lix/libutil/comparator.hh"
#include "lix/libutil/variant-wrapper.hh"
#include "outputs-spec.hh"
#include <kj/async.h>
#include <map>
#include <variant>
namespace nix {
class Store;
/* Abstract syntax of derivations. */
/**
* A single output of a BasicDerivation (and Derivation).
*/
struct DerivationOutput
{
/**
* The traditional non-fixed-output derivation type.
*/
struct InputAddressed
{
StorePath path;
GENERATE_CMP(InputAddressed, me->path);
};
/**
* Fixed-output derivations, whose output paths are content
* addressed according to that fixed output.
*/
struct CAFixed
{
/**
* Method and hash used for expected hash computation.
*
* References are not allowed by fiat.
*/
ContentAddress ca;
/**
* Return the \ref StorePath "store path" corresponding to this output
*
* @param drvName The name of the derivation this is an output of, without the `.drv`.
* @param outputName The name of this output.
*/
StorePath path(const Store & store, std::string_view drvName, OutputNameView outputName) const;
GENERATE_CMP(CAFixed, me->ca);
};
typedef std::variant<
InputAddressed,
CAFixed
> Raw;
Raw raw;
GENERATE_CMP(DerivationOutput, me->raw);
MAKE_WRAPPER_CONSTRUCTOR(DerivationOutput);
/**
* Force choosing a variant
*/
DerivationOutput() = delete;
/**
* \note when you use this function you should make sure that you're
* passing the right derivation name. When in doubt, you should use
* the safer interface provided by
* BasicDerivation::outputsAndPaths
*/
StorePath path(const Store & store, std::string_view drvName, OutputNameView outputName) const;
JSON toJSON(
const Store & store,
std::string_view drvName,
OutputNameView outputName) const;
/**
* @param xpSettings Stop-gap to avoid globals during unit tests.
*/
static DerivationOutput fromJSON(
const Store & store,
std::string_view drvName,
OutputNameView outputName,
const JSON & json,
const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
};
typedef std::map<std::string, DerivationOutput> DerivationOutputs;
/**
* These are analogues to the previous DerivationOutputs data type,
* but they also contains, for each output, the store
* path in which it would be written. To calculate values of these
* types, see the corresponding functions in BasicDerivation.
*/
typedef std::map<std::string, std::pair<DerivationOutput, StorePath>>
DerivationOutputsAndPaths;
/**
* For inputs that are sub-derivations, we specify exactly which
* output IDs we are interested in.
*/
typedef std::map<StorePath, StringSet> DerivationInputs;
struct DerivationType {
/**
* Input-addressed derivation types
*/
struct InputAddressed {
GENERATE_CMP(InputAddressed);
};
/**
* Content-addressed derivation types
*/
struct ContentAddressed {
GENERATE_CMP(ContentAddressed);
};
typedef std::variant<
InputAddressed,
ContentAddressed
> Raw;
Raw raw;
GENERATE_CMP(DerivationType, me->raw);
MAKE_WRAPPER_CONSTRUCTOR(DerivationType);
/**
* Force choosing a variant
*/
DerivationType() = delete;
/**
* Do the outputs of the derivation have paths calculated from their
* content, or from the derivation itself?
*/
bool isCA() const;
/**
* Is the content of the outputs fixed <em>a priori</em> via a hash?
* Never true for non-CA derivations.
*/
bool isFixed() const;
/**
* Whether the derivation is fully sandboxed. If false, the sandbox
* is opened up, e.g. the derivation has access to the network. Note
* that whether or not we actually sandbox the derivation is
* controlled separately. Always true for non-CA derivations.
*/
bool isSandboxed() const;
};
struct BasicDerivation
{
/**
* keyed on symbolic IDs
*/
DerivationOutputs outputs;
/**
* inputs that are sources
*/
StorePathSet inputSrcs;
std::string platform;
Path builder;
Strings args;
StringPairs env;
std::string name;
BasicDerivation() = default;
virtual ~BasicDerivation() { };
bool isBuiltin() const;
/**
* Return true iff this is a fixed-output derivation.
*/
DerivationType type() const;
/**
* Return the output names of a derivation.
*/
StringSet outputNames() const;
/**
* Calculates the maps that contains all the DerivationOutputs, but
* augmented with knowledge of the Store paths they would be written
* into.
*/
DerivationOutputsAndPaths outputsAndPaths(const Store & store) const;
static std::string_view nameFromPath(const StorePath & storePath);
GENERATE_CMP(BasicDerivation,
me->outputs,
me->inputSrcs,
me->platform,
me->builder,
me->args,
me->env,
me->name);
};
struct Derivation : BasicDerivation
{
/**
* inputs that are sub-derivations
*/
std::map<StorePath, std::set<OutputName>> inputDrvs;
/**
* Print a derivation.
*/
std::string unparse(const Store & store, bool maskOutputs,
std::map<std::string, StringSet> * actualInputs = nullptr) const;
/**
* Check that the derivation is valid and does not present any
* illegal states.
*
* This is mainly a matter of checking the outputs, where our C++
* representation supports all sorts of combinations we do not yet
* allow.
*/
kj::Promise<Result<void>> checkInvariants(Store & store, const StorePath & drvPath) const;
Derivation() = default;
Derivation(const BasicDerivation & bd) : BasicDerivation(bd) { }
Derivation(BasicDerivation && bd) : BasicDerivation(std::move(bd)) { }
JSON toJSON(const Store & store) const;
static Derivation fromJSON(
const Store & store,
const JSON & json,
const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
GENERATE_CMP(Derivation,
static_cast<const BasicDerivation &>(*me),
me->inputDrvs);
};
class Store;
/**
* Write a derivation to the Nix store, and return its path.
*/
kj::Promise<Result<StorePath>> writeDerivation(Store & store,
const Derivation & drv,
RepairFlag repair = NoRepair,
bool readOnly = false);
/**
* Read a derivation from a file.
*/
Derivation parseDerivation(
const Store & store,
std::string && s,
std::string_view name,
const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
/**
* \todo Remove.
*
* Use Path::isDerivation instead.
*/
bool isDerivation(std::string_view fileName);
/**
* Calculate the name that will be used for the store path for this
* output.
*
* This is usually <drv-name>-<output-name>, but is just <drv-name> when
* the output name is "out".
*/
std::string outputPathName(std::string_view drvName, OutputNameView outputName);
/**
* The hashes modulo of a derivation.
*
* Each output is given a hash, although in practice only the content-addressed
* derivations (i.e. fixed-output) will have a different hash for each
* output.
*/
struct DrvHash {
/**
* Map from output names to hashes
*/
std::map<std::string, Hash> hashes;
};
/**
* Returns hashes with the details of fixed-output subderivations
* expunged.
*
* A fixed-output derivation is a derivation whose outputs have a
* specified content hash and hash algorithm. (Currently they must have
* exactly one output (`out`), which is specified using the `outputHash`
* and `outputHashAlgo` attributes, but the algorithm doesn't assume
* this.) We don't want changes to such derivations to propagate upwards
* through the dependency graph, changing output paths everywhere.
*
* For instance, if we change the url in a call to the `fetchurl`
* function, we do not want to rebuild everything depending on it---after
* all, (the hash of) the file being downloaded is unchanged. So the
* *output paths* should not change. On the other hand, the *derivation
* paths* should change to reflect the new dependency graph.
*
* For fixed-output derivations, this returns a map from the name of
* each output to its hash, unique up to the output's contents.
*
* For regular derivations, it returns a single hash of the derivation
* ATerm, after subderivations have been likewise expunged from that
* derivation.
*/
kj::Promise<Result<DrvHash>>
hashDerivationModulo(Store & store, const Derivation & drv, bool maskOutputs);
/**
* Return a map associating each output to a hash that uniquely identifies its
* derivation (modulo the self-references).
*
* \todo What is the Hash in this map?
*/
kj::Promise<Result<std::map<std::string, Hash>>>
staticOutputHashes(Store & store, const Derivation & drv);
/**
* Memoisation of hashDerivationModulo().
*/
typedef std::map<StorePath, DrvHash> DrvHashes;
// FIXME: global, though at least thread-safe.
extern Sync<DrvHashes> drvHashes;
struct Source;
struct Sink;
Source & readDerivation(Source & in, const Store & store, BasicDerivation & drv, std::string_view name);
WireFormatGenerator serializeDerivation(const Store & store, const BasicDerivation & drv);
void writeDerivation(Sink & out, const Store & store, const BasicDerivation & drv);
/**
* This creates an opaque and almost certainly unique string
* deterministically from the output name.
*
* It is used as a placeholder to allow derivations to refer to their
* own outputs without needing to use the hash of a derivation in
* itself, making the hash near-impossible to calculate.
*/
std::string hashPlaceholder(const OutputNameView outputName);
}
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