NewClient

The NewClient(tlsConfig *tls.Config, logger *zerolog.Logger) (*Client, error) method is used to create a new fRPC client.

It takes two arguments:

  • tlsConfig: a *tls.Config that will be used to configure TLS for the underlying connection. This can be left as nil if no TLS is required.
  • logger: a *zerolog.Logger that will be used to log all events. This can be left as nil if no logging is required.

It returns an fRPC *Client on success and an error otherwise.

Connect

The Connect(addr string) error method is used to initiate a connection to an fRPC server. If a *tls.Config was provided when the client was created (using NewClient) it will be used to configure TLS for the connection.

An error will be returned if the connection fails.

The Connect function should only be called once. If FromConn was already called on this client, Connect will return an error.

FromConn

The FromConn(conn net.Conn) error method is used to create a new fRPC client from an existing net.Conn. This is useful if you want to reuse an existing connection, or if you have a custom transport that you want to use. If a *tls.Config was provided when the client was created (using NewClient), it will be ignored.

An error will be returned if the connection fails.

The FromConn function should only be called once. If Connect was already called on this client, FromConn will return an error.”

Closed

The Closed() bool method is used to check if the client is closed. This method will return true if the client is closed or has not yet been initialized, and false otherwise.

Error

The Error() error method is used to check if the client has encountered an error. This method will return an error if the client has encountered an error, or nil otherwise.

This method is meant to be used to check if the client encountered an error that caused it to close.

Close

The Close() error method is used to close the client. It will return an error if the client encounters an error while closing (or if it is already closed), and will cancel any pending RPCs.

WritePacket

The WritePacket(p *packet.Packet) error method is used to write a raw frisbee packet to the underlying connection. Normal fRPC operations should not use this method, however it is available when extending fRPC with custom protocols or messaging patterns directly for use with the underlying Frisbee library.

Flush

The Flush() error method is used to flush the underlying connection. Normal fRPC operations should not use this method, however it is available when extending fRPC with custom protocols or messaging patterns directly for use with the underlying Frisbee library.

CloseChannel

The CloseChannel() <- chan struct{} method is used to signal to a listener that the Client has been closed. The returned channel will be closed when the client is closed, and the Error() method can be used to check if the connection was closed due to an error.

Raw

The Raw() (net.Conn, error) method is used to get the underlying net.Conn from the fRPC Client. This is useful if you want to extend fRPC with custom protocols or messaging patterns directly for use with the underlying Frisbee library.

Logger

The Logger() *zerolog.Logger method is used to get the logger that was provided when the client was created. This is useful if you want to extend fRPC with custom protocols or messaging patterns directly for use with the underlying Frisbee library.

Generated Methods

When generating the fRPC Client, each service in the .proto file also results in a generated service Client. Then, for each RPC in the service, a method is generated on the appropriate the service client. For example, if the .proto file contains the following service definition:

service MyService {
  rpc MyMethod(MyRequest) returns (MyResponse) {}
}

Then the generated service Client method is:

func (c *MyService) MyMethod(ctx context.Context, req *MyRequest) (res *MyResponse, err error) {
  ...
}

And it’s meant to be invoked using:

res, err := c.MyService.MyMethod(ctx, req)

Unlike gRPC, where each service requires creating a new RPC Client, fRPC creates a single client for all your services.