This changes the RPC server to ignore methods using *context.Context as parameter
and *error as return value type. Methods with such types would crash the server when
called.
This changes the error code returned by the RPC server in certain situations:
- handler panic: code -32603
- result marshaling error: code -32603
- attempt to subscribe via HTTP: code -32001
In all of the above cases, the server previously returned the default error
code -32000.
Co-authored-by: Nicholas Zhao <nicholas.zhao@gmail.com>
Co-authored-by: Felix Lange <fjl@twurst.com>
* rpc: remove 'exported or builtin' restriction for parameters
There is no technial reason for this restriction because package reflect
can create values of any type. Requiring parameters and return values to
be exported causes a lot of noise in package exports.
* rpc: fix staticcheck warnings
New APIs added:
client.RegisterName(namespace, service) // makes service available to server
client.Notify(ctx, method, args...) // sends a notification
ClientFromContext(ctx) // to get a client in handler method
This is essentially a rewrite of the server-side code. JSON-RPC
processing code is now the same on both server and client side. Many
minor issues were fixed in the process and there is a new test suite for
JSON-RPC spec compliance (and non-compliance in some cases).
List of behavior changes:
- Method handlers are now called with a per-request context instead of a
per-connection context. The context is canceled right after the method
returns.
- Subscription error channels are always closed when the connection
ends. There is no need to also wait on the Notifier's Closed channel
to detect whether the subscription has ended.
- Client now omits "params" instead of sending "params": null when there
are no arguments to a call. The previous behavior was not compliant
with the spec. The server still accepts "params": null.
- Floating point numbers are allowed as "id". The spec doesn't allow
them, but we handle request "id" as json.RawMessage and guarantee that
the same number will be sent back.
- Logging is improved significantly. There is now a message at DEBUG
level for each RPC call served.
