nixos/nix
1
1
Fork 0
mirror of https://github.com/NixOS/nix.git synced 2025-11-27 04:30:59 +01:00
Code Activity

std::visit by reference

Browse source 
I had started the trend of doing `std::visit` by value (because a type
error once mislead me into thinking that was the only form that
existed). While the optomizer in principle should be able to deal with
extra coppying or extra indirection once the lambdas inlined, sticking
with by reference is the conventional default. I hope this might even
improve performance.
This commit is contained in:
John Ericson 2021-09-30 21:31:21 +00:00
parent 6a8d6246f6
commit 242f9bf3dc
19 changed files with 88 additions and 88 deletions
Download patch file Download diff file Expand all files Collapse all files

6
src/libstore/build/entry-points.cc
View file

@ -11,12 +11,12 @@ void Store::buildPaths(const std::vector<DerivedPath> & reqs, BuildMode buildMod
Worker worker(*this, evalStore ? *evalStore : *this);
Goals goals;
for (auto & br : reqs) {
for (const auto & br : reqs) {
std::visit(overloaded {
[&](DerivedPath::Built bfd) {
[&](const DerivedPath::Built & bfd) {
goals.insert(worker.makeDerivationGoal(bfd.drvPath, bfd.outputs, buildMode));
},
[&](DerivedPath::Opaque bo) {
[&](const DerivedPath::Opaque & bo) {
goals.insert(worker.makePathSubstitutionGoal(bo.path, buildMode == bmRepair ? Repair : NoRepair));
},
}, br.raw());

18
src/libstore/build/local-derivation-goal.cc
View file

@ -1094,10 +1094,10 @@ void LocalDerivationGoal::writeStructuredAttrs()
static StorePath pathPartOfReq(const DerivedPath & req)
{
return std::visit(overloaded {
[&](DerivedPath::Opaque bo) {
[&](const DerivedPath::Opaque & bo) {
return bo.path;
},
[&](DerivedPath::Built bfd) {
[&](const DerivedPath::Built & bfd) {
return bfd.drvPath;
},
}, req.raw());
@ -2155,8 +2155,8 @@ void LocalDerivationGoal::registerOutputs()
/* Since we'll use the already installed versions of these, we
can treat them as leaves and ignore any references they
have. */
[&](AlreadyRegistered _) { return StringSet {}; },
[&](PerhapsNeedToRegister refs) {
[&](const AlreadyRegistered &) { return StringSet {}; },
[&](const PerhapsNeedToRegister & refs) {
StringSet referencedOutputs;
/* FIXME build inverted map up front so no quadratic waste here */
for (auto & r : refs.refs)
@ -2192,11 +2192,11 @@ void LocalDerivationGoal::registerOutputs()
};
std::optional<StorePathSet> referencesOpt = std::visit(overloaded {
[&](AlreadyRegistered skippedFinalPath) -> std::optional<StorePathSet> {
[&](const AlreadyRegistered & skippedFinalPath) -> std::optional<StorePathSet> {
finish(skippedFinalPath.path);
return std::nullopt;
},
[&](PerhapsNeedToRegister r) -> std::optional<StorePathSet> {
[&](const PerhapsNeedToRegister & r) -> std::optional<StorePathSet> {
return r.refs;
},
}, outputReferencesIfUnregistered.at(outputName));
@ -2312,7 +2312,7 @@ void LocalDerivationGoal::registerOutputs()
};
ValidPathInfo newInfo = std::visit(overloaded {
[&](DerivationOutputInputAddressed output) {
[&](const DerivationOutputInputAddressed & output) {
/* input-addressed case */
auto requiredFinalPath = output.path;
/* Preemptively add rewrite rule for final hash, as that is
@ -2331,14 +2331,14 @@ void LocalDerivationGoal::registerOutputs()
newInfo0.references.insert(newInfo0.path);
return newInfo0;
},
[&](DerivationOutputCAFixed dof) {
[&](const DerivationOutputCAFixed & dof) {
auto newInfo0 = newInfoFromCA(DerivationOutputCAFloating {
.method = dof.hash.method,
.hashType = dof.hash.hash.type,
});
/* Check wanted hash */
Hash & wanted = dof.hash.hash;
const Hash & wanted = dof.hash.hash;
assert(newInfo0.ca);
auto got = getContentAddressHash(*newInfo0.ca);
if (wanted != got) {