Make RemoteStore::ConnectionHandle part of class and expose

Will need to do subclass-specific implementations in the next commit.
This isn't because there will be multiple variations of the daemon
protocol (whew!) but because different clients pick and choose different
parts to use.
This commit is contained in:
John Ericson 2023-04-17 12:14:15 -04:00
parent 0a30b07277
commit 13269ba93b
3 changed files with 47 additions and 40 deletions

View file

@ -1,5 +1,6 @@
#include "remote-store.hh"
#include "worker-protocol.hh"
#include "pool.hh"
namespace nix {
@ -94,4 +95,34 @@ struct RemoteStore::Connection
std::exception_ptr processStderr(Sink * sink = 0, Source * source = 0, bool flush = true);
};
/**
* A wrapper around Pool<RemoteStore::Connection>::Handle that marks
* the connection as bad (causing it to be closed) if a non-daemon
* exception is thrown before the handle is closed. Such an exception
* causes a deviation from the expected protocol and therefore a
* desynchronization between the client and daemon.
*/
struct RemoteStore::ConnectionHandle
{
Pool<RemoteStore::Connection>::Handle handle;
bool daemonException = false;
ConnectionHandle(Pool<RemoteStore::Connection>::Handle && handle)
: handle(std::move(handle))
{ }
ConnectionHandle(ConnectionHandle && h)
: handle(std::move(h.handle))
{ }
~ConnectionHandle();
RemoteStore::Connection & operator * () { return *handle; }
RemoteStore::Connection * operator -> () { return &*handle; }
void processStderr(Sink * sink = 0, Source * source = 0, bool flush = true);
void withFramedSink(std::function<void(Sink & sink)> fun);
};
}

View file

@ -159,49 +159,25 @@ void RemoteStore::setOptions(Connection & conn)
}
/* A wrapper around Pool<RemoteStore::Connection>::Handle that marks
the connection as bad (causing it to be closed) if a non-daemon
exception is thrown before the handle is closed. Such an exception
causes a deviation from the expected protocol and therefore a
desynchronization between the client and daemon. */
struct ConnectionHandle
RemoteStore::ConnectionHandle::~ConnectionHandle()
{
Pool<RemoteStore::Connection>::Handle handle;
bool daemonException = false;
ConnectionHandle(Pool<RemoteStore::Connection>::Handle && handle)
: handle(std::move(handle))
{ }
ConnectionHandle(ConnectionHandle && h)
: handle(std::move(h.handle))
{ }
~ConnectionHandle()
{
if (!daemonException && std::uncaught_exceptions()) {
handle.markBad();
debug("closing daemon connection because of an exception");
}
}
}
RemoteStore::Connection * operator -> () { return &*handle; }
RemoteStore::Connection & operator * () { return *handle; }
void processStderr(Sink * sink = 0, Source * source = 0, bool flush = true)
{
void RemoteStore::ConnectionHandle::processStderr(Sink * sink, Source * source, bool flush)
{
auto ex = handle->processStderr(sink, source, flush);
if (ex) {
daemonException = true;
std::rethrow_exception(ex);
}
}
void withFramedSink(std::function<void(Sink & sink)> fun);
};
}
ConnectionHandle RemoteStore::getConnection()
RemoteStore::ConnectionHandle RemoteStore::getConnection()
{
return ConnectionHandle(connections->get());
}
@ -1099,7 +1075,7 @@ std::exception_ptr RemoteStore::Connection::processStderr(Sink * sink, Source *
return nullptr;
}
void ConnectionHandle::withFramedSink(std::function<void(Sink & sink)> fun)
void RemoteStore::ConnectionHandle::withFramedSink(std::function<void(Sink & sink)> fun)
{
(*this)->to.flush();

View file

@ -17,7 +17,6 @@ class Pid;
struct FdSink;
struct FdSource;
template<typename T> class Pool;
struct ConnectionHandle;
struct RemoteStoreConfig : virtual StoreConfig
{
@ -182,6 +181,8 @@ protected:
void setOptions() override;
struct ConnectionHandle;
ConnectionHandle getConnection();
friend struct ConnectionHandle;
@ -199,5 +200,4 @@ private:
std::shared_ptr<Store> evalStore);
};
}