agones.dev/agones@v1.53.0/pkg/gameserversets/gameserver_state_cache.go (about)

     1  // Copyright 2018 Google LLC All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package gameserversets
    16  
    17  import (
    18  	"sync"
    19  
    20  	agonesv1 "agones.dev/agones/pkg/apis/agones/v1"
    21  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    22  )
    23  
    24  // gameServerSetCacheEntry manages a list of items created and deleted locally for a single game server set.
    25  type gameServerSetCacheEntry struct {
    26  	pendingCreation map[string]*agonesv1.GameServer
    27  	pendingDeletion map[string]*agonesv1.GameServer
    28  	mu              sync.Mutex
    29  }
    30  
    31  func (e *gameServerSetCacheEntry) created(gs *agonesv1.GameServer) {
    32  	e.mu.Lock()
    33  	defer e.mu.Unlock()
    34  	if e.pendingCreation == nil {
    35  		e.pendingCreation = map[string]*agonesv1.GameServer{}
    36  	}
    37  	e.pendingCreation[gs.Name] = gs.DeepCopy()
    38  }
    39  
    40  func (e *gameServerSetCacheEntry) deleted(gs *agonesv1.GameServer) {
    41  	e.mu.Lock()
    42  	defer e.mu.Unlock()
    43  
    44  	if e.pendingDeletion == nil {
    45  		e.pendingDeletion = map[string]*agonesv1.GameServer{}
    46  	}
    47  
    48  	// Was pending creation, but deleted already.
    49  	delete(e.pendingCreation, gs.Name)
    50  
    51  	gsClone := gs.DeepCopy()
    52  	t := metav1.Now()
    53  	gsClone.ObjectMeta.DeletionTimestamp = &t
    54  	e.pendingDeletion[gs.Name] = gsClone
    55  }
    56  
    57  // reconcileWithUpdatedServerList returns a list of game servers for a game server set taking into account
    58  // the complete list of game servers passed as parameter and a list of pending creations and deletions.
    59  func (e *gameServerSetCacheEntry) reconcileWithUpdatedServerList(list []*agonesv1.GameServer) []*agonesv1.GameServer {
    60  	e.mu.Lock()
    61  	defer e.mu.Unlock()
    62  
    63  	var result []*agonesv1.GameServer
    64  
    65  	found := map[string]bool{}
    66  
    67  	for _, gs := range list {
    68  		if d := e.pendingDeletion[gs.Name]; d != nil {
    69  			if !gs.ObjectMeta.DeletionTimestamp.IsZero() {
    70  				// has deletion timestamp - return theirs
    71  				result = append(result, d)
    72  				delete(e.pendingDeletion, gs.Name)
    73  			} else {
    74  				result = append(result, d)
    75  			}
    76  		} else {
    77  			// object not deleted locally, trust the list.
    78  			result = append(result, gs)
    79  		}
    80  
    81  		if e.pendingCreation[gs.Name] != nil {
    82  			// object was pending creation and now showed up in list results, remove local overlay.
    83  			delete(e.pendingCreation, gs.Name)
    84  		}
    85  
    86  		found[gs.Name] = true
    87  	}
    88  
    89  	// now delete from 'pendingDeletion' all the items that were not found in the result.
    90  	for gsName := range e.pendingDeletion {
    91  		if !found[gsName] {
    92  			// ("GSSC: %v is now fully deleted", gsName)
    93  			delete(e.pendingDeletion, gsName)
    94  		}
    95  	}
    96  
    97  	// add all game servers that are pending creation which were not in the list
    98  	for _, gs := range e.pendingCreation {
    99  		result = append(result, gs)
   100  	}
   101  
   102  	return result
   103  }
   104  
   105  // gameServerStateCache manages per-GSS cache of items created and deleted by this controller process
   106  // to compensate for latency due to eventual consistency between client actions and K8s API server.
   107  type gameServerStateCache struct {
   108  	cache sync.Map
   109  }
   110  
   111  func (c *gameServerStateCache) forGameServerSet(gsSet *agonesv1.GameServerSet) *gameServerSetCacheEntry {
   112  	v, _ := c.cache.LoadOrStore(gsSet.ObjectMeta.Namespace+"/"+gsSet.ObjectMeta.Name, &gameServerSetCacheEntry{})
   113  	return v.(*gameServerSetCacheEntry)
   114  }
   115  
   116  func (c *gameServerStateCache) deleteGameServerSet(gsSet *agonesv1.GameServerSet) {
   117  	c.cache.Delete(gsSet.ObjectMeta.Namespace + "/" + gsSet.ObjectMeta.Name)
   118  }