Create IPC Client

Question

I just recently updated my local repo of go-ethereum to commit 8ec6ccc54d1da7bbaa87bd0b489b1778ea729c90

I previously used the IPC Client like this in my code:

var client rpc.Client
if len(pathToIPCEndpoint) == 0 {
    glog.Errorf("No path to ipc endpoint specified, using default path: %s\n", node.DefaultIPCEndpoint())
    client, err = rpc.NewIPCClient(node.DefaultIPCEndpoint())
    if err != nil {
        glog.Fatalln(err)
    }
} else {
    client, err = rpc.NewIPCClient(pathToIPCEndpoint)
    if err != nil {
        glog.Fatalln(err)
    }
}

backend = backends.NewRPCBackend(client)

It seems like one should use rpc.DialIPC() since NewIPCCLient does not exists anymore. However I can't quite figure out how to migrate this code and couldn't find any documentation on the API changes.

Thanks in advance

Answer 1

The changes were introduced in this commit ("rpc: add new client, use it everywhere"). Have a look at the split-diff view to understand how internal calls to the APIs have changed.

You'll need to include a connection context from the Go-lang context package, and pass that in to DialIPC() as a parameter.

Instead of a JSON-encoded structure, the new API returns a pointer to a Client structure (from newClient())...:

c := &Client{
    writeConn:   conn,
    isHTTP:      isHTTP,
    connectFunc: connectFunc,
    close:       make(chan struct{}),
    didQuit:     make(chan struct{}),
    reconnected: make(chan net.Conn),
    readErr:     make(chan error),
    readResp:    make(chan []*jsonrpcMessage),
    requestOp:   make(chan *requestOp),
    sendDone:    make(chan error, 1),
    respWait:    make(map[string]*requestOp),
    subs:        make(map[string]*ClientSubscription),

...which you can continue to pass to NewRPCBackend(), which has been updated to take a pointer argument.