103 lines
2.6 KiB
Go
103 lines
2.6 KiB
Go
package rpc
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import (
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"reflect"
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"git.loafle.net/commons_go/rpc/protocol"
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)
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/**
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Network connection
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Handshake(1..n)
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Send request
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HTTP
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*/
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// NewRPCRegistry returns a new RPC registry.
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func NewRegistry() Registry {
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return &rpcRegistry{
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services: new(serviceMap),
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}
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}
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type Registry interface {
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RegisterService(receiver interface{}, name string) error
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HasMethod(method string) bool
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Invoke(codec protocol.RegistryCodec) (result interface{}, err error)
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}
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// RPCRegistry serves registered RPC services using registered codecs.
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type rpcRegistry struct {
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services *serviceMap
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}
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// RegisterService adds a new service to the server.
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//
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// The name parameter is optional: if empty it will be inferred from
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// the receiver type name.
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//
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// Methods from the receiver will be extracted if these rules are satisfied:
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//
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// - The receiver is exported (begins with an upper case letter) or local
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// (defined in the package registering the service).
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// - The method name is exported.
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// - The method has two arguments: *args, *reply.
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// - All two arguments are pointers.
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// - The first and second arguments are exported or local.
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// - The method has return type error.
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//
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// All other methods are ignored.
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func (rr *rpcRegistry) RegisterService(receiver interface{}, name string) error {
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return rr.services.register(receiver, name)
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}
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// HasMethod returns true if the given method is registered.
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//
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// The method uses a dotted notation as in "Service.Method".
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func (rr *rpcRegistry) HasMethod(method string) bool {
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if _, _, err := rr.services.get(method); err == nil {
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return true
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}
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return false
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}
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// Invoke execute a method.
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//
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// Codecs are defined to process a given serialization scheme, e.g., JSON or
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// XML. A codec is chosen based on the "Content-Type" header from the request,
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// excluding the charset definition.
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func (rr *rpcRegistry) Invoke(codec protocol.RegistryCodec) (result interface{}, err error) {
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serviceSpec, methodSpec, errGet := rr.services.get(codec.Method())
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if errGet != nil {
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return nil, errGet
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}
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// Decode the args.
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args := reflect.New(methodSpec.argsType)
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if errRead := codec.ReadParams(args.Interface()); errRead != nil {
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return nil, errRead
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}
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// Call the service method.
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reply := reflect.New(methodSpec.replyType)
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errValue := methodSpec.method.Func.Call([]reflect.Value{
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serviceSpec.rcvr,
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args,
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reply,
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})
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// Cast the result to error if needed.
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var errResult error
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errInter := errValue[0].Interface()
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if errInter != nil {
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errResult = errInter.(error)
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}
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if errResult != nil {
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return nil, errResult
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}
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return reply.Interface(), nil
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}
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