tvl-depot/src/libstore/local-binary-cache-store.cc

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#include "binary-cache-store.hh"
#include "globals.hh"
namespace nix {
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class LocalBinaryCacheStore : public BinaryCacheStore
{
private:
Path binaryCacheDir;
public:
LocalBinaryCacheStore(std::shared_ptr<Store> localStore,
const StoreParams & params, const Path & binaryCacheDir)
: BinaryCacheStore(localStore, params)
, binaryCacheDir(binaryCacheDir)
{
}
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void init() override;
std::string getUri() override
{
return "file://" + binaryCacheDir;
}
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protected:
bool fileExists(const std::string & path) override;
void upsertFile(const std::string & path, const std::string & data) override;
std::shared_ptr<std::string> getFile(const std::string & path) override;
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};
void LocalBinaryCacheStore::init()
{
createDirs(binaryCacheDir + "/nar");
BinaryCacheStore::init();
}
static void atomicWrite(const Path & path, const std::string & s)
{
Path tmp = path + ".tmp." + std::to_string(getpid());
AutoDelete del(tmp, false);
writeFile(tmp, s);
if (rename(tmp.c_str(), path.c_str()))
throw SysError(format("renaming %1% to %2%") % tmp % path);
del.cancel();
}
bool LocalBinaryCacheStore::fileExists(const std::string & path)
{
return pathExists(binaryCacheDir + "/" + path);
}
void LocalBinaryCacheStore::upsertFile(const std::string & path, const std::string & data)
{
atomicWrite(binaryCacheDir + "/" + path, data);
}
std::shared_ptr<std::string> LocalBinaryCacheStore::getFile(const std::string & path)
{
try {
return std::make_shared<std::string>(readFile(binaryCacheDir + "/" + path));
} catch (SysError & e) {
if (e.errNo == ENOENT) return 0;
throw;
}
}
static RegisterStoreImplementation regStore([](
const std::string & uri, const StoreParams & params)
-> std::shared_ptr<Store>
{
if (std::string(uri, 0, 7) != "file://") return 0;
auto store = std::make_shared<LocalBinaryCacheStore>(
std::shared_ptr<Store>(0), params, std::string(uri, 7));
store->init();
return store;
});
}