lix/src/libstore/local-binary-cache-store.cc
2018-05-30 13:34:37 +02:00

105 lines
2.6 KiB
C++

#include "binary-cache-store.hh"
#include "globals.hh"
#include "nar-info-disk-cache.hh"
namespace nix {
class LocalBinaryCacheStore : public BinaryCacheStore
{
private:
Path binaryCacheDir;
public:
LocalBinaryCacheStore(
const Params & params, const Path & binaryCacheDir)
: BinaryCacheStore(params)
, binaryCacheDir(binaryCacheDir)
{
}
void init() override;
std::string getUri() override
{
return "file://" + binaryCacheDir;
}
protected:
bool fileExists(const std::string & path) override;
void upsertFile(const std::string & path,
const std::string & data,
const std::string & mimeType) override;
void getFile(const std::string & path,
Callback<std::shared_ptr<std::string>> callback) override
{
try {
// FIXME: O(n) space
callback(std::make_shared<std::string>(readFile(binaryCacheDir + "/" + path)));
} catch (SysError & e) {
if (e.errNo == ENOENT) callback(nullptr); else callback.rethrow();
} catch (...) { callback.rethrow(); }
}
PathSet queryAllValidPaths() override
{
PathSet paths;
for (auto & entry : readDirectory(binaryCacheDir)) {
if (entry.name.size() != 40 ||
!hasSuffix(entry.name, ".narinfo"))
continue;
paths.insert(storeDir + "/" + entry.name.substr(0, entry.name.size() - 8));
}
return paths;
}
};
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,
const std::string & mimeType)
{
atomicWrite(binaryCacheDir + "/" + path, data);
}
static RegisterStoreImplementation regStore([](
const std::string & uri, const Store::Params & params)
-> std::shared_ptr<Store>
{
if (getEnv("_NIX_FORCE_HTTP_BINARY_CACHE_STORE") == "1" ||
std::string(uri, 0, 7) != "file://")
return 0;
auto store = std::make_shared<LocalBinaryCacheStore>(params, std::string(uri, 7));
store->init();
return store;
});
}