mirror of https://github.com/grpc/grpc-go.git
94 lines
3.2 KiB
Go
94 lines
3.2 KiB
Go
/*
|
|
*
|
|
* Copyright 2014, Google Inc.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are
|
|
* met:
|
|
*
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above
|
|
* copyright notice, this list of conditions and the following disclaimer
|
|
* in the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* * Neither the name of Google Inc. nor the names of its
|
|
* contributors may be used to endorse or promote products derived from
|
|
* this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
*/
|
|
|
|
package grpc
|
|
|
|
import (
|
|
"time"
|
|
|
|
"golang.org/x/net/context"
|
|
"google.golang.org/grpc/transport"
|
|
)
|
|
|
|
// Picker picks a Conn for RPC requests.
|
|
// This is EXPERIMENTAL and please do not implement your own Picker for now.
|
|
type Picker interface {
|
|
// Init does initial processing for the Picker, e.g., initiate some connections.
|
|
Init(cc *ClientConn) error
|
|
// Pick blocks until either a transport.ClientTransport is ready for the upcoming RPC
|
|
// or some error happens.
|
|
Pick(ctx context.Context) (transport.ClientTransport, error)
|
|
// State returns the connectivity state of the underlying connections.
|
|
State() ConnectivityState
|
|
// WaitForStateChange blocks until the state changes to something other than
|
|
// the sourceState or timeout fires on cc. It returns false if timeout fires,
|
|
// and true otherwise.
|
|
WaitForStateChange(timeout time.Duration, sourceState ConnectivityState) bool
|
|
// Close closes all the Conn's owned by this Picker.
|
|
Close() error
|
|
}
|
|
|
|
// unicastPicker is the default Picker which is used when there is no custom Picker
|
|
// specified by users. It always picks the same Conn.
|
|
type unicastPicker struct {
|
|
conn *Conn
|
|
}
|
|
|
|
func (p *unicastPicker) Init(cc *ClientConn) error {
|
|
c, err := NewConn(cc)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
p.conn = c
|
|
return nil
|
|
}
|
|
|
|
func (p *unicastPicker) Pick(ctx context.Context) (transport.ClientTransport, error) {
|
|
return p.conn.Wait(ctx)
|
|
}
|
|
|
|
func (p *unicastPicker) State() ConnectivityState {
|
|
return p.conn.State()
|
|
}
|
|
|
|
func (p *unicastPicker) WaitForStateChange(timeout time.Duration, sourceState ConnectivityState) bool {
|
|
return p.conn.WaitForStateChange(timeout, sourceState)
|
|
}
|
|
|
|
func (p *unicastPicker) Close() error {
|
|
if p.conn != nil {
|
|
return p.conn.Close()
|
|
}
|
|
return nil
|
|
}
|