lix/src/libstore/realisation.cc
2022-01-19 14:37:54 +01:00

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#include "realisation.hh"
#include "store-api.hh"
#include "closure.hh"
#include <nlohmann/json.hpp>
namespace nix {
MakeError(InvalidDerivationOutputId, Error);
DrvOutput DrvOutput::parse(const std::string &strRep) {
size_t n = strRep.find("!");
if (n == strRep.npos)
throw InvalidDerivationOutputId("Invalid derivation output id %s", strRep);
return DrvOutput{
.drvHash = Hash::parseAnyPrefixed(strRep.substr(0, n)),
.outputName = strRep.substr(n+1),
};
}
std::string DrvOutput::to_string() const {
return strHash() + "!" + outputName;
}
std::set<Realisation> Realisation::closure(Store & store, const std::set<Realisation> & startOutputs)
{
std::set<Realisation> res;
Realisation::closure(store, startOutputs, res);
return res;
}
void Realisation::closure(Store & store, const std::set<Realisation> & startOutputs, std::set<Realisation> & res)
{
auto getDeps = [&](const Realisation& current) -> std::set<Realisation> {
std::set<Realisation> res;
for (auto& [currentDep, _] : current.dependentRealisations) {
if (auto currentRealisation = store.queryRealisation(currentDep))
res.insert(*currentRealisation);
else
throw Error(
"Unrealised derivation '%s'", currentDep.to_string());
}
return res;
};
computeClosure<Realisation>(
startOutputs, res,
[&](const Realisation& current,
std::function<void(std::promise<std::set<Realisation>>&)>
processEdges) {
std::promise<std::set<Realisation>> promise;
try {
auto res = getDeps(current);
promise.set_value(res);
} catch (...) {
promise.set_exception(std::current_exception());
}
return processEdges(promise);
});
}
nlohmann::json Realisation::toJSON() const {
auto jsonDependentRealisations = nlohmann::json::object();
for (auto & [depId, depOutPath] : dependentRealisations)
jsonDependentRealisations.emplace(depId.to_string(), depOutPath.to_string());
return nlohmann::json{
{"id", id.to_string()},
{"outPath", outPath.to_string()},
{"signatures", signatures},
{"dependentRealisations", jsonDependentRealisations},
};
}
Realisation Realisation::fromJSON(
const nlohmann::json& json,
const std::string& whence) {
auto getOptionalField = [&](std::string fieldName) -> std::optional<std::string> {
auto fieldIterator = json.find(fieldName);
if (fieldIterator == json.end())
return std::nullopt;
return {*fieldIterator};
};
auto getField = [&](std::string fieldName) -> std::string {
if (auto field = getOptionalField(fieldName))
return *field;
else
throw Error(
"Drv output info file '%1%' is corrupt, missing field %2%",
whence, fieldName);
};
StringSet signatures;
if (auto signaturesIterator = json.find("signatures"); signaturesIterator != json.end())
signatures.insert(signaturesIterator->begin(), signaturesIterator->end());
std::map <DrvOutput, StorePath> dependentRealisations;
if (auto jsonDependencies = json.find("dependentRealisations"); jsonDependencies != json.end())
for (auto & [jsonDepId, jsonDepOutPath] : jsonDependencies->get<std::map<std::string, std::string>>())
dependentRealisations.insert({DrvOutput::parse(jsonDepId), StorePath(jsonDepOutPath)});
return Realisation{
.id = DrvOutput::parse(getField("id")),
.outPath = StorePath(getField("outPath")),
.signatures = signatures,
.dependentRealisations = dependentRealisations,
};
}
std::string Realisation::fingerprint() const
{
auto serialized = toJSON();
serialized.erase("signatures");
return serialized.dump();
}
void Realisation::sign(const SecretKey & secretKey)
{
signatures.insert(secretKey.signDetached(fingerprint()));
}
bool Realisation::checkSignature(const PublicKeys & publicKeys, const std::string & sig) const
{
return verifyDetached(fingerprint(), sig, publicKeys);
}
size_t Realisation::checkSignatures(const PublicKeys & publicKeys) const
{
// FIXME: Maybe we should return `maxSigs` if the realisation corresponds to
// an input-addressed one because in that case the drv is enough to check
// it but we can't know that here.
size_t good = 0;
for (auto & sig : signatures)
if (checkSignature(publicKeys, sig))
good++;
return good;
}
StorePath RealisedPath::path() const {
return std::visit([](auto && arg) { return arg.getPath(); }, raw);
}
bool Realisation::isCompatibleWith(const Realisation & other) const
{
assert (id == other.id);
if (outPath == other.outPath) {
if (dependentRealisations.empty() != other.dependentRealisations.empty()) {
warn(
"Encountered a realisation for '%s' with an empty set of "
"dependencies. This is likely an artifact from an older Nix. "
"Ill try to fix the realisation if I can",
id.to_string());
return true;
} else if (dependentRealisations == other.dependentRealisations) {
return true;
}
}
return false;
}
void RealisedPath::closure(
Store& store,
const RealisedPath::Set& startPaths,
RealisedPath::Set& ret)
{
// FIXME: This only builds the store-path closure, not the real realisation
// closure
StorePathSet initialStorePaths, pathsClosure;
for (auto& path : startPaths)
initialStorePaths.insert(path.path());
store.computeFSClosure(initialStorePaths, pathsClosure);
ret.insert(startPaths.begin(), startPaths.end());
ret.insert(pathsClosure.begin(), pathsClosure.end());
}
void RealisedPath::closure(Store& store, RealisedPath::Set & ret) const
{
RealisedPath::closure(store, {*this}, ret);
}
RealisedPath::Set RealisedPath::closure(Store& store) const
{
RealisedPath::Set ret;
closure(store, ret);
return ret;
}
} // namespace nix