Skip to content

C API: wait on async path writer when parsing store path #325

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
RossComputerGuy wants to merge 2 commits into
base: main
Choose a base branch
from
+37 −14
Open

C API: wait on async path writer when parsing store path #325

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
7bff820
C API: wait on async path writer when parsing store path
RossComputerGuy Jan 23, 2026
1409b8c
Add async path writer option to eval state
RossComputerGuy Feb 3, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 8 additions & 1 deletion src/libexpr-c/nix_api_expr.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -137,6 +137,7 @@ nix_eval_state_builder * nix_eval_state_builder_new(nix_c_context * context, Sto
return unsafe_new_with_self<nix_eval_state_builder>([&](auto * self) {
return nix_eval_state_builder{
.store = nix::ref<nix::Store>(store->ptr),
.asyncPathWriter = nix::ref<nix::AsyncPathWriter>(store->asyncPathWriter),
.settings = nix::EvalSettings{/* &bool */ self->readOnlyMode},
.fetchSettings = nix::fetchers::Settings{},
.readOnlyMode = true,
Expand Down Expand Up @@ -190,7 +191,13 @@ EvalState * nix_eval_state_build(nix_c_context * context, nix_eval_state_builder
return EvalState{
.fetchSettings = std::move(builder->fetchSettings),
.settings = std::move(builder->settings),
.state = nix::EvalState(builder->lookupPath, builder->store, self->fetchSettings, self->settings),
.state = nix::EvalState(
builder->lookupPath,
builder->store,
self->fetchSettings,
self->settings,
nullptr,
builder->asyncPathWriter),
};
});
}
Expand Down
1 change: 1 addition & 0 deletions src/libexpr-c/nix_api_expr_internal.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ extern "C" {
struct nix_eval_state_builder
{
nix::ref<nix::Store> store;
nix::ref<nix::AsyncPathWriter> asyncPathWriter;
nix::EvalSettings settings;
nix::fetchers::Settings fetchSettings;
nix::LookupPath lookupPath;
Expand Down
5 changes: 3 additions & 2 deletions src/libexpr/eval.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -262,7 +262,8 @@ EvalState::EvalState(
ref<Store> store,
const fetchers::Settings & fetchSettings,
const EvalSettings & settings,
std::shared_ptr<Store> buildStore)
std::shared_ptr<Store> buildStore,
std::shared_ptr<AsyncPathWriter> asyncPathWriter)
: fetchSettings{fetchSettings}
, settings{settings}
, symbols(StaticEvalSymbols::staticSymbolTable())
Expand Down Expand Up @@ -325,7 +326,7 @@ EvalState::EvalState(
, debugRepl(nullptr)
, debugStop(false)
, trylevel(0)
, asyncPathWriter(AsyncPathWriter::make(store))
, asyncPathWriter(asyncPathWriter ? asyncPathWriter : AsyncPathWriter::make(store))
, srcToStore(make_ref<decltype(srcToStore)::element_type>())
, importResolutionCache(make_ref<decltype(importResolutionCache)::element_type>())
, fileEvalCache(make_ref<decltype(fileEvalCache)::element_type>())
Expand Down
14 changes: 8 additions & 6 deletions src/libexpr/include/nix/expr/eval.hh
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -516,18 +516,20 @@ private:
public:

/**
* @param lookupPath Only used during construction.
* @param store The store to use for instantiation
* @param fetchSettings Must outlive the lifetime of this EvalState!
* @param settings Must outlive the lifetime of this EvalState!
* @param buildStore The store to use for builds ("import from derivation", C API `nix_string_realise`)
* @param lookupPath Only used during construction.
* @param store The store to use for instantiation
* @param fetchSettings Must outlive the lifetime of this EvalState!
* @param settings Must outlive the lifetime of this EvalState!
* @param buildStore The store to use for builds ("import from derivation", C API `nix_string_realise`)
* @param asyncPathWriter The async path writer to use
*/
EvalState(
const LookupPath & lookupPath,
ref<Store> store,
const fetchers::Settings & fetchSettings,
const EvalSettings & settings,
std::shared_ptr<Store> buildStore = nullptr);
std::shared_ptr<Store> buildStore = nullptr,
std::shared_ptr<AsyncPathWriter> asyncPathWriter = nullptr);
~EvalState();

/**
Expand Down
20 changes: 15 additions & 5 deletions src/libstore-c/nix_api_store.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -44,17 +44,26 @@ Store * nix_store_open(nix_c_context * context, const char * uri, const char ***
try {
std::string uri_str = uri ? uri : "";

if (uri_str.empty())
return new Store{nix::openStore()};
if (uri_str.empty()) {
auto store = nix::openStore();
auto asyncPathWriter = nix::AsyncPathWriter::make(store);
return new Store{asyncPathWriter, store};
}

if (!params)
return new Store{nix::openStore(uri_str)};
if (!params) {
auto store = nix::openStore(uri_str);
auto asyncPathWriter = nix::AsyncPathWriter::make(store);
return new Store{asyncPathWriter, store};
}

nix::Store::Config::Params params_map;
for (size_t i = 0; params[i] != nullptr; i++) {
params_map[params[i][0]] = params[i][1];
}
return new Store{nix::openStore(uri_str, params_map)};

auto store = nix::openStore(uri_str, params_map);
auto asyncPathWriter = nix::AsyncPathWriter::make(store);
return new Store{asyncPathWriter, store};
}
NIXC_CATCH_ERRS_NULL
}
Expand Down Expand Up @@ -127,6 +136,7 @@ StorePath * nix_store_parse_path(nix_c_context * context, Store * store, const c
context->last_err_code = NIX_OK;
try {
nix::StorePath s = store->ptr->parseStorePath(path);
store->asyncPathWriter->waitForPath(s);
return new StorePath{std::move(s)};
}
NIXC_CATCH_ERRS_NULL
Expand Down
2 changes: 2 additions & 0 deletions src/libstore-c/nix_api_store_internal.h
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,12 +1,14 @@
#ifndef NIX_API_STORE_INTERNAL_H
#define NIX_API_STORE_INTERNAL_H
#include "nix/store/async-path-writer.hh"
#include "nix/store/store-api.hh"
#include "nix/store/derivations.hh"

extern "C" {

struct Store
{
nix::ref<nix::AsyncPathWriter> asyncPathWriter;
nix::ref<nix::Store> ptr;
};

Expand Down