From 0948b8e94dfbf87ed2a695c6c7d8dac250e2c293 Mon Sep 17 00:00:00 2001 From: John Ericson Date: Fri, 1 Oct 2021 18:05:53 +0000 Subject: [PATCH] Reduce variants for derivation hash modulo This changes was taken from dynamic derivation (#4628). It` somewhat undoes the refactors I first did for floating CA derivations, as the benefit of hindsight + requirements of dynamic derivations made me reconsider some things. They aren't to consequential, but I figured they might be good to land first, before the more profound changes @thufschmitt has in the works. --- src/libexpr/primops.cc | 45 ++++++++------- src/libstore/derivations.cc | 111 ++++++++++++++++++++++-------------- src/libstore/derivations.hh | 40 +++++++++++-- src/libstore/local-store.cc | 4 +- src/nix/develop.cc | 3 +- 5 files changed, 131 insertions(+), 72 deletions(-) diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 3124025aa..0980e75f4 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -1207,32 +1207,37 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * // hash per output. auto hashModulo = hashDerivationModulo(*state.store, Derivation(drv), true); std::visit(overloaded { - [&](Hash & h) { - for (auto & i : outputs) { - auto outPath = state.store->makeOutputPath(i, h, drvName); - drv.env[i] = state.store->printStorePath(outPath); - drv.outputs.insert_or_assign(i, - DerivationOutput { - .output = DerivationOutputInputAddressed { - .path = std::move(outPath), - }, - }); + [&](const DrvHash & drvHash) { + auto & h = drvHash.hash; + switch (drvHash.kind) { + case DrvHash::Kind::Deferred: + for (auto & i : outputs) { + drv.outputs.insert_or_assign(i, + DerivationOutput { + .output = DerivationOutputDeferred{}, + }); + } + break; + case DrvHash::Kind::Regular: + for (auto & i : outputs) { + auto outPath = state.store->makeOutputPath(i, h, drvName); + drv.env[i] = state.store->printStorePath(outPath); + drv.outputs.insert_or_assign(i, + DerivationOutput { + .output = DerivationOutputInputAddressed { + .path = std::move(outPath), + }, + }); + } + break; } }, - [&](CaOutputHashes &) { + [&](const CaOutputHashes &) { // Shouldn't happen as the toplevel derivation is not CA. assert(false); }, - [&](DeferredHash &) { - for (auto & i : outputs) { - drv.outputs.insert_or_assign(i, - DerivationOutput { - .output = DerivationOutputDeferred{}, - }); - } - }, }, - hashModulo); + hashModulo.raw()); } diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc index a49be0057..1fe45bd87 100644 --- a/src/libstore/derivations.cc +++ b/src/libstore/derivations.cc @@ -510,7 +510,7 @@ static const DrvHashModulo pathDerivationModulo(Store & store, const StorePath & */ DrvHashModulo hashDerivationModulo(Store & store, const Derivation & drv, bool maskOutputs) { - bool isDeferred = false; + auto kind = DrvHash::Kind::Regular; /* Return a fixed hash for fixed-output derivations. */ switch (drv.type()) { case DerivationType::CAFixed: { @@ -526,7 +526,7 @@ DrvHashModulo hashDerivationModulo(Store & store, const Derivation & drv, bool m return outputHashes; } case DerivationType::CAFloating: - isDeferred = true; + kind = DrvHash::Kind::Deferred; break; case DerivationType::InputAddressed: break; @@ -537,21 +537,20 @@ DrvHashModulo hashDerivationModulo(Store & store, const Derivation & drv, bool m /* For other derivations, replace the inputs paths with recursive calls to this function. */ std::map inputs2; - for (auto & i : drv.inputDrvs) { - const auto & res = pathDerivationModulo(store, i.first); + for (auto & [drvPath, inputOutputs0] : drv.inputDrvs) { + // Avoid lambda capture restriction with standard / Clang + auto & inputOutputs = inputOutputs0; + const auto & res = pathDerivationModulo(store, drvPath); std::visit(overloaded { // Regular non-CA derivation, replace derivation - [&](const Hash & drvHash) { - inputs2.insert_or_assign(drvHash.to_string(Base16, false), i.second); - }, - [&](const DeferredHash & deferredHash) { - isDeferred = true; - inputs2.insert_or_assign(deferredHash.hash.to_string(Base16, false), i.second); + [&](const DrvHash & drvHash) { + kind |= drvHash.kind; + inputs2.insert_or_assign(drvHash.hash.to_string(Base16, false), inputOutputs); }, // CA derivation's output hashes [&](const CaOutputHashes & outputHashes) { std::set justOut = { "out" }; - for (auto & output : i.second) { + for (auto & output : inputOutputs) { /* Put each one in with a single "out" output.. */ const auto h = outputHashes.at(output); inputs2.insert_or_assign( @@ -559,15 +558,24 @@ DrvHashModulo hashDerivationModulo(Store & store, const Derivation & drv, bool m justOut); } }, - }, res); + }, res.raw()); } auto hash = hashString(htSHA256, drv.unparse(store, maskOutputs, &inputs2)); - if (isDeferred) - return DeferredHash { hash }; - else - return hash; + return DrvHash { .hash = hash, .kind = kind }; +} + + +void operator |= (DrvHash::Kind & self, const DrvHash::Kind & other) noexcept +{ + switch (other) { + case DrvHash::Kind::Regular: + break; + case DrvHash::Kind::Deferred: + self = other; + break; + } } @@ -575,20 +583,15 @@ std::map staticOutputHashes(Store & store, const Derivation & { std::map res; std::visit(overloaded { - [&](const Hash & drvHash) { + [&](const DrvHash & drvHash) { for (auto & outputName : drv.outputNames()) { - res.insert({outputName, drvHash}); - } - }, - [&](const DeferredHash & deferredHash) { - for (auto & outputName : drv.outputNames()) { - res.insert({outputName, deferredHash.hash}); + res.insert({outputName, drvHash.hash}); } }, [&](const CaOutputHashes & outputHashes) { res = outputHashes; }, - }, hashDerivationModulo(store, drv, true)); + }, hashDerivationModulo(store, drv, true).raw()); return res; } @@ -738,7 +741,7 @@ static void rewriteDerivation(Store & store, BasicDerivation & drv, const String auto hashModulo = hashDerivationModulo(store, Derivation(drv), true); for (auto & [outputName, output] : drv.outputs) { if (std::holds_alternative(output.output)) { - Hash h = std::get(hashModulo); + auto & h = hashModulo.requireNoFixedNonDeferred(); auto outPath = store.makeOutputPath(outputName, h, drv.name); drv.env[outputName] = store.printStorePath(outPath); output = DerivationOutput { @@ -751,31 +754,51 @@ static void rewriteDerivation(Store & store, BasicDerivation & drv, const String } +const Hash & DrvHashModulo::requireNoFixedNonDeferred() const { + auto * drvHashOpt = std::get_if(&raw()); + assert(drvHashOpt); + assert(drvHashOpt->kind == DrvHash::Kind::Regular); + return drvHashOpt->hash; +} + +static bool tryResolveInput( + Store & store, StorePathSet & inputSrcs, StringMap & inputRewrites, + const StorePath & inputDrv, const StringSet & inputOutputs) +{ + auto inputDrvOutputs = store.queryPartialDerivationOutputMap(inputDrv); + + auto getOutput = [&](const std::string & outputName) { + auto & actualPathOpt = inputDrvOutputs.at(outputName); + if (!actualPathOpt) + warn("output %s of input %s missing, aborting the resolving", + outputName, + store.printStorePath(inputDrv) + ); + return actualPathOpt; + }; + + for (auto & outputName : inputOutputs) { + auto actualPathOpt = getOutput(outputName); + if (!actualPathOpt) return false; + auto actualPath = *actualPathOpt; + inputRewrites.emplace( + downstreamPlaceholder(store, inputDrv, outputName), + store.printStorePath(actualPath)); + inputSrcs.insert(std::move(actualPath)); + } + + return true; +} + std::optional Derivation::tryResolve(Store & store) { BasicDerivation resolved { *this }; // Input paths that we'll want to rewrite in the derivation StringMap inputRewrites; - for (auto & input : inputDrvs) { - auto inputDrvOutputs = store.queryPartialDerivationOutputMap(input.first); - StringSet newOutputNames; - for (auto & outputName : input.second) { - auto actualPathOpt = inputDrvOutputs.at(outputName); - if (!actualPathOpt) { - warn("output %s of input %s missing, aborting the resolving", - outputName, - store.printStorePath(input.first) - ); - return std::nullopt; - } - auto actualPath = *actualPathOpt; - inputRewrites.emplace( - downstreamPlaceholder(store, input.first, outputName), - store.printStorePath(actualPath)); - resolved.inputSrcs.insert(std::move(actualPath)); - } - } + for (auto & [inputDrv, inputOutputs] : inputDrvs) + if (!tryResolveInput(store, resolved.inputSrcs, inputRewrites, inputDrv, inputOutputs)) + return std::nullopt; rewriteDerivation(store, resolved, inputRewrites); diff --git a/src/libstore/derivations.hh b/src/libstore/derivations.hh index 132de82b6..2fb18d7f7 100644 --- a/src/libstore/derivations.hh +++ b/src/libstore/derivations.hh @@ -175,13 +175,43 @@ std::string outputPathName(std::string_view drvName, std::string_view outputName // whose output hashes are always known since they are fixed up-front. typedef std::map CaOutputHashes; -struct DeferredHash { Hash hash; }; +struct DrvHash { + Hash hash; + + enum struct Kind { + // Statically determined derivations. + // This hash will be directly used to compute the output paths + Regular, + // Floating-output derivations (and their dependencies). + Deferred, + }; + + Kind kind; +}; + +void operator |= (DrvHash::Kind & self, const DrvHash::Kind & other) noexcept; typedef std::variant< - Hash, // regular DRV normalized hash - CaOutputHashes, // Fixed-output derivation hashes - DeferredHash // Deferred hashes for floating outputs drvs and their dependencies -> DrvHashModulo; + // Regular normalized derivation hash, and whether it was deferred (because + // an ancestor derivation is a floating content addressed derivation). + DrvHash, + // Fixed-output derivation hashes + CaOutputHashes +> DrvHashModuloRaw; + +struct DrvHashModulo : DrvHashModuloRaw { + using Raw = DrvHashModuloRaw; + using Raw::Raw; + + /* Get hash, throwing if it is per-output CA hashes or a + deferred Drv hash. + */ + const Hash & requireNoFixedNonDeferred() const; + + inline const Raw & raw() const { + return static_cast(*this); + } +}; /* Returns hashes with the details of fixed-output subderivations expunged. diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc index 1ee71b1c0..9230be15a 100644 --- a/src/libstore/local-store.cc +++ b/src/libstore/local-store.cc @@ -701,8 +701,8 @@ void LocalStore::checkDerivationOutputs(const StorePath & drvPath, const Derivat [&](const DerivationOutputInputAddressed & doia) { if (!h) { // somewhat expensive so we do lazily - auto temp = hashDerivationModulo(*this, drv, true); - h = std::get(temp); + auto h0 = hashDerivationModulo(*this, drv, true); + h = h0.requireNoFixedNonDeferred(); } StorePath recomputed = makeOutputPath(i.first, *h, drvName); if (doia.path != recomputed) diff --git a/src/nix/develop.cc b/src/nix/develop.cc index 8af5da9d0..dafcafd79 100644 --- a/src/nix/develop.cc +++ b/src/nix/develop.cc @@ -206,7 +206,8 @@ static StorePath getDerivationEnvironment(ref store, ref evalStore output.second = { .output = DerivationOutputInputAddressed { .path = StorePath::dummy } }; drv.env[output.first] = ""; } - Hash h = std::get<0>(hashDerivationModulo(*evalStore, drv, true)); + auto h0 = hashDerivationModulo(*evalStore, drv, true); + const Hash & h = h0.requireNoFixedNonDeferred(); for (auto & output : drv.outputs) { auto outPath = store->makeOutputPath(output.first, h, drv.name);