lix/src/libstore/remote-store.hh
Eelco Dolstra bbe97dff8b Make the Store API more type-safe
Most functions now take a StorePath argument rather than a Path (which
is just an alias for std::string). The StorePath constructor ensures
that the path is syntactically correct (i.e. it looks like
<store-dir>/<base32-hash>-<name>). Similarly, functions like
buildPaths() now take a StorePathWithOutputs, rather than abusing Path
by adding a '!<outputs>' suffix.

Note that the StorePath type is implemented in Rust. This involves
some hackery to allow Rust values to be used directly in C++, via a
helper type whose destructor calls the Rust type's drop()
function. The main issue is the dynamic nature of C++ move semantics:
after we have moved a Rust value, we should not call the drop function
on the original value. So when we move a value, we set the original
value to bitwise zero, and the destructor only calls drop() if the
value is not bitwise zero. This should be sufficient for most types.

Also lots of minor cleanups to the C++ API to make it more modern
(e.g. using std::optional and std::string_view in some places).
2019-12-10 22:06:05 +01:00

161 lines
4.4 KiB
C++

#pragma once
#include <limits>
#include <string>
#include "store-api.hh"
namespace nix {
class Pipe;
class Pid;
struct FdSink;
struct FdSource;
template<typename T> class Pool;
struct ConnectionHandle;
/* FIXME: RemoteStore is a misnomer - should be something like
DaemonStore. */
class RemoteStore : public virtual Store
{
public:
const Setting<int> maxConnections{(Store*) this, 1,
"max-connections", "maximum number of concurrent connections to the Nix daemon"};
const Setting<unsigned int> maxConnectionAge{(Store*) this, std::numeric_limits<unsigned int>::max(),
"max-connection-age", "number of seconds to reuse a connection"};
virtual bool sameMachine() = 0;
RemoteStore(const Params & params);
/* Implementations of abstract store API methods. */
bool isValidPathUncached(const StorePath & path) override;
StorePathSet queryValidPaths(const StorePathSet & paths,
SubstituteFlag maybeSubstitute = NoSubstitute) override;
StorePathSet queryAllValidPaths() override;
void queryPathInfoUncached(const StorePath & path,
Callback<std::shared_ptr<const ValidPathInfo>> callback) noexcept override;
void queryReferrers(const StorePath & path, StorePathSet & referrers) override;
StorePathSet queryValidDerivers(const StorePath & path) override;
StorePathSet queryDerivationOutputs(const StorePath & path) override;
StringSet queryDerivationOutputNames(const StorePath & path) override;
std::optional<StorePath> queryPathFromHashPart(const std::string & hashPart) override;
StorePathSet querySubstitutablePaths(const StorePathSet & paths) override;
void querySubstitutablePathInfos(const StorePathSet & paths,
SubstitutablePathInfos & infos) override;
void addToStore(const ValidPathInfo & info, Source & nar,
RepairFlag repair, CheckSigsFlag checkSigs,
std::shared_ptr<FSAccessor> accessor) override;
StorePath addToStore(const string & name, const Path & srcPath,
bool recursive = true, HashType hashAlgo = htSHA256,
PathFilter & filter = defaultPathFilter, RepairFlag repair = NoRepair) override;
StorePath addTextToStore(const string & name, const string & s,
const StorePathSet & references, RepairFlag repair) override;
void buildPaths(const std::vector<StorePathWithOutputs> & paths, BuildMode buildMode) override;
BuildResult buildDerivation(const StorePath & drvPath, const BasicDerivation & drv,
BuildMode buildMode) override;
void ensurePath(const StorePath & path) override;
void addTempRoot(const StorePath & path) override;
void addIndirectRoot(const Path & path) override;
void syncWithGC() override;
Roots findRoots(bool censor) override;
void collectGarbage(const GCOptions & options, GCResults & results) override;
void optimiseStore() override;
bool verifyStore(bool checkContents, RepairFlag repair) override;
void addSignatures(const StorePath & storePath, const StringSet & sigs) override;
void queryMissing(const std::vector<StorePathWithOutputs> & targets,
StorePathSet & willBuild, StorePathSet & willSubstitute, StorePathSet & unknown,
unsigned long long & downloadSize, unsigned long long & narSize) override;
void connect() override;
unsigned int getProtocol() override;
void flushBadConnections();
protected:
struct Connection
{
AutoCloseFD fd;
FdSink to;
FdSource from;
unsigned int daemonVersion;
std::chrono::time_point<std::chrono::steady_clock> startTime;
virtual ~Connection();
std::exception_ptr processStderr(Sink * sink = 0, Source * source = 0);
};
ref<Connection> openConnectionWrapper();
virtual ref<Connection> openConnection() = 0;
void initConnection(Connection & conn);
ref<Pool<Connection>> connections;
virtual void setOptions(Connection & conn);
ConnectionHandle getConnection();
friend struct ConnectionHandle;
private:
std::atomic_bool failed{false};
};
class UDSRemoteStore : public LocalFSStore, public RemoteStore
{
public:
UDSRemoteStore(const Params & params);
UDSRemoteStore(std::string path, const Params & params);
std::string getUri() override;
bool sameMachine() override
{ return true; }
private:
ref<RemoteStore::Connection> openConnection() override;
std::optional<std::string> path;
};
}