github.com/cockroachdb/cockroach@v20.2.0-alpha.1+incompatible/pkg/testutils/gossiputil/store_gossiper.go (about)

     1  // Copyright 2015 The Cockroach Authors.
     2  //
     3  // Use of this software is governed by the Business Source License
     4  // included in the file licenses/BSL.txt.
     5  //
     6  // As of the Change Date specified in that file, in accordance with
     7  // the Business Source License, use of this software will be governed
     8  // by the Apache License, Version 2.0, included in the file
     9  // licenses/APL.txt.
    10  
    11  package gossiputil
    12  
    13  import (
    14  	"sync"
    15  	"testing"
    16  
    17  	"github.com/cockroachdb/cockroach/pkg/gossip"
    18  	"github.com/cockroachdb/cockroach/pkg/roachpb"
    19  	"github.com/cockroachdb/cockroach/pkg/util/syncutil"
    20  )
    21  
    22  // StoreGossiper allows tests to push storeDescriptors into gossip and
    23  // synchronize on their callbacks. There can only be one storeGossiper used per
    24  // gossip instance.
    25  type StoreGossiper struct {
    26  	g           *gossip.Gossip
    27  	mu          syncutil.Mutex
    28  	cond        *sync.Cond
    29  	storeKeyMap map[string]struct{}
    30  }
    31  
    32  // NewStoreGossiper creates a store gossiper for use by tests. It adds the
    33  // callback to gossip.
    34  func NewStoreGossiper(g *gossip.Gossip) *StoreGossiper {
    35  	sg := &StoreGossiper{
    36  		g:           g,
    37  		storeKeyMap: make(map[string]struct{}),
    38  	}
    39  	sg.cond = sync.NewCond(&sg.mu)
    40  	// Redundant callbacks are required by StoreGossiper. See GossipWithFunction
    41  	// which waits for all of the callbacks to be invoked.
    42  	g.RegisterCallback(gossip.MakePrefixPattern(gossip.KeyStorePrefix), func(key string, _ roachpb.Value) {
    43  		sg.mu.Lock()
    44  		defer sg.mu.Unlock()
    45  		delete(sg.storeKeyMap, key)
    46  		sg.cond.Broadcast()
    47  	}, gossip.Redundant)
    48  	return sg
    49  }
    50  
    51  // GossipStores queues up a list of stores to gossip and blocks until each one
    52  // is gossiped before returning.
    53  func (sg *StoreGossiper) GossipStores(storeDescs []*roachpb.StoreDescriptor, t *testing.T) {
    54  	storeIDs := make([]roachpb.StoreID, len(storeDescs))
    55  	for i, store := range storeDescs {
    56  		storeIDs[i] = store.StoreID
    57  	}
    58  	sg.GossipWithFunction(storeIDs, func() {
    59  		for i, storeDesc := range storeDescs {
    60  			if err := sg.g.AddInfoProto(gossip.MakeStoreKey(storeIDs[i]), storeDesc, 0); err != nil {
    61  				t.Fatal(err)
    62  			}
    63  		}
    64  	})
    65  }
    66  
    67  // GossipWithFunction calls gossipFn and blocks until gossip callbacks have
    68  // fired on each of the stores specified by storeIDs.
    69  func (sg *StoreGossiper) GossipWithFunction(storeIDs []roachpb.StoreID, gossipFn func()) {
    70  	sg.mu.Lock()
    71  	defer sg.mu.Unlock()
    72  	sg.storeKeyMap = make(map[string]struct{})
    73  	for _, storeID := range storeIDs {
    74  		storeKey := gossip.MakeStoreKey(storeID)
    75  		sg.storeKeyMap[storeKey] = struct{}{}
    76  	}
    77  
    78  	gossipFn()
    79  
    80  	// Wait for gossip callbacks to be invoked on all the stores.
    81  	for len(sg.storeKeyMap) > 0 {
    82  		sg.cond.Wait()
    83  	}
    84  }