client.go

Documentation: google.golang.org/grpc/xds/internal/testutils/fakeclient

     1  /*
     2   *
     3   * Copyright 2019 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  // Package fakeclient provides a fake implementation of an xDS client.
    20  package fakeclient
    21  
    22  import (
    23  	"context"
    24  
    25  	"google.golang.org/grpc/internal/testutils"
    26  	"google.golang.org/grpc/internal/xds/bootstrap"
    27  	"google.golang.org/grpc/xds/internal/xdsclient"
    28  	"google.golang.org/grpc/xds/internal/xdsclient/load"
    29  )
    30  
    31  // Client is a fake implementation of an xds client. It exposes a bunch of
    32  // channels to signal the occurrence of various events.
    33  type Client struct {
    34  	// Embed XDSClient so this fake client implements the interface, but it's
    35  	// never set (it's always nil). This may cause nil panic since not all the
    36  	// methods are implemented.
    37  	xdsclient.XDSClient
    38  
    39  	name         string
    40  	loadReportCh *testutils.Channel
    41  	lrsCancelCh  *testutils.Channel
    42  	loadStore    *load.Store
    43  	bootstrapCfg *bootstrap.Config
    44  }
    45  
    46  // ReportLoadArgs wraps the arguments passed to ReportLoad.
    47  type ReportLoadArgs struct {
    48  	// Server is the name of the server to which the load is reported.
    49  	Server *bootstrap.ServerConfig
    50  }
    51  
    52  // ReportLoad starts reporting load about clusterName to server.
    53  func (xdsC *Client) ReportLoad(server *bootstrap.ServerConfig) (loadStore *load.Store, cancel func()) {
    54  	xdsC.loadReportCh.Send(ReportLoadArgs{Server: server})
    55  	return xdsC.loadStore, func() {
    56  		xdsC.lrsCancelCh.Send(nil)
    57  	}
    58  }
    59  
    60  // WaitForCancelReportLoad waits for a load report to be cancelled and returns
    61  // context.DeadlineExceeded otherwise.
    62  func (xdsC *Client) WaitForCancelReportLoad(ctx context.Context) error {
    63  	_, err := xdsC.lrsCancelCh.Receive(ctx)
    64  	return err
    65  }
    66  
    67  // LoadStore returns the underlying load data store.
    68  func (xdsC *Client) LoadStore() *load.Store {
    69  	return xdsC.loadStore
    70  }
    71  
    72  // WaitForReportLoad waits for ReportLoad to be invoked on this client and
    73  // returns the arguments passed to it.
    74  func (xdsC *Client) WaitForReportLoad(ctx context.Context) (ReportLoadArgs, error) {
    75  	val, err := xdsC.loadReportCh.Receive(ctx)
    76  	if err != nil {
    77  		return ReportLoadArgs{}, err
    78  	}
    79  	return val.(ReportLoadArgs), nil
    80  }
    81  
    82  // BootstrapConfig returns the bootstrap config.
    83  func (xdsC *Client) BootstrapConfig() *bootstrap.Config {
    84  	return xdsC.bootstrapCfg
    85  }
    86  
    87  // SetBootstrapConfig updates the bootstrap config.
    88  func (xdsC *Client) SetBootstrapConfig(cfg *bootstrap.Config) {
    89  	xdsC.bootstrapCfg = cfg
    90  }
    91  
    92  // Name returns the name of the xds client.
    93  func (xdsC *Client) Name() string {
    94  	return xdsC.name
    95  }
    96  
    97  // NewClient returns a new fake xds client.
    98  func NewClient() *Client {
    99  	return NewClientWithName("")
   100  }
   101  
   102  // NewClientWithName returns a new fake xds client with the provided name. This
   103  // is used in cases where multiple clients are created in the tests and we need
   104  // to make sure the client is created for the expected balancer name.
   105  func NewClientWithName(name string) *Client {
   106  	return &Client{
   107  		name:         name,
   108  		loadReportCh: testutils.NewChannel(),
   109  		lrsCancelCh:  testutils.NewChannel(),
   110  		loadStore:    load.NewStore(),
   111  		bootstrapCfg: &bootstrap.Config{ClientDefaultListenerResourceNameTemplate: "%s"},
   112  	}
   113  }
   114
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