go.temporal.io/server@v1.23.0/common/client_cache.go (about)

     1  // The MIT License
     2  //
     3  // Copyright (c) 2020 Temporal Technologies Inc.  All rights reserved.
     4  //
     5  // Copyright (c) 2020 Uber Technologies, Inc.
     6  //
     7  // Permission is hereby granted, free of charge, to any person obtaining a copy
     8  // of this software and associated documentation files (the "Software"), to deal
     9  // in the Software without restriction, including without limitation the rights
    10  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    11  // copies of the Software, and to permit persons to whom the Software is
    12  // furnished to do so, subject to the following conditions:
    13  //
    14  // The above copyright notice and this permission notice shall be included in
    15  // all copies or substantial portions of the Software.
    16  //
    17  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    18  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    19  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    20  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    21  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    22  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    23  // THE SOFTWARE.
    24  
    25  package common
    26  
    27  import (
    28  	"sync"
    29  )
    30  
    31  type (
    32  	// ClientCache store initialized clients
    33  	ClientCache interface {
    34  		GetClientForKey(key string) (interface{}, error)
    35  		GetClientForClientKey(clientKey string) (interface{}, error)
    36  		GetAllClients() ([]interface{}, error)
    37  	}
    38  
    39  	keyResolver interface {
    40  		Lookup(key string) (string, error)
    41  		GetAllAddresses() ([]string, error)
    42  	}
    43  
    44  	clientProvider func(string) (interface{}, error)
    45  
    46  	clientCacheImpl struct {
    47  		keyResolver    keyResolver
    48  		clientProvider clientProvider
    49  
    50  		cacheLock sync.RWMutex
    51  		clients   map[string]interface{}
    52  	}
    53  )
    54  
    55  // NewClientCache creates a new client cache based on membership
    56  func NewClientCache(
    57  	keyResolver keyResolver,
    58  	clientProvider clientProvider,
    59  ) ClientCache {
    60  
    61  	return &clientCacheImpl{
    62  		keyResolver:    keyResolver,
    63  		clientProvider: clientProvider,
    64  
    65  		clients: make(map[string]interface{}),
    66  	}
    67  }
    68  
    69  func (c *clientCacheImpl) GetClientForKey(key string) (interface{}, error) {
    70  	clientKey, err := c.keyResolver.Lookup(key)
    71  	if err != nil {
    72  		return nil, err
    73  	}
    74  
    75  	return c.GetClientForClientKey(clientKey)
    76  }
    77  
    78  func (c *clientCacheImpl) GetClientForClientKey(clientKey string) (interface{}, error) {
    79  	c.cacheLock.RLock()
    80  	client, ok := c.clients[clientKey]
    81  	c.cacheLock.RUnlock()
    82  	if ok {
    83  		return client, nil
    84  	}
    85  
    86  	c.cacheLock.Lock()
    87  	defer c.cacheLock.Unlock()
    88  
    89  	client, ok = c.clients[clientKey]
    90  	if ok {
    91  		return client, nil
    92  	}
    93  
    94  	client, err := c.clientProvider(clientKey)
    95  	if err != nil {
    96  		return nil, err
    97  	}
    98  	c.clients[clientKey] = client
    99  	return client, nil
   100  }
   101  
   102  func (c *clientCacheImpl) GetAllClients() ([]interface{}, error) {
   103  	var result []interface{}
   104  	allAddresses, err := c.keyResolver.GetAllAddresses()
   105  	if err != nil {
   106  		return nil, err
   107  	}
   108  	for _, addr := range allAddresses {
   109  		client, err := c.GetClientForClientKey(addr)
   110  		if err != nil {
   111  			return nil, err
   112  		}
   113  		result = append(result, client)
   114  	}
   115  
   116  	return result, nil
   117  }