cache

Documentation

Overview

Abstract implementation of various distributed caches. We can save an object to cache and retrieve it object by its key, using various implementations.

Index

• func NewDefaultCacheFactory() *build.Factory
• type CacheEntry
  • func NewCacheEntry(key string, value interface{}, timeout int64) *CacheEntry
  • func (c *CacheEntry) Expiration() time.Time
  • func (c *CacheEntry) IsExpired() bool
  • func (c *CacheEntry) Key() string
  • func (c *CacheEntry) SetValue(value interface{}, timeout int64)
  • func (c *CacheEntry) Value() interface{}
• type ICache
• type MemoryCache
  • func NewMemoryCache() *MemoryCache
  • func NewMemoryCacheFromConfig(cfg *config.ConfigParams) *MemoryCache
  • func (c *MemoryCache) Cleanup()
  • func (c *MemoryCache) Clear(correlationId string) error
  • func (c *MemoryCache) Configure(cfg *config.ConfigParams)
  • func (c *MemoryCache) Remove(correlationId string, key string) error
  • func (c *MemoryCache) Retrieve(correlationId string, key string) (interface{}, error)
  • func (c *MemoryCache) RetrieveAs(correlationId string, key string, result interface{}) (interface{}, error)
  • func (c *MemoryCache) Store(correlationId string, key string, value interface{}, timeout int64) (interface{}, error)
• type NullCache
  • func NewNullCache() *NullCache
  • func (c *NullCache) Remove(correlationId string, key string) error
  • func (c *NullCache) Retrieve(correlationId string, key string) (interface{}, error)
  • func (c *NullCache) RetrieveAs(correlationId string, key string, result interface{}) (interface{}, error)
  • func (c *NullCache) Store(correlationId string, key string, value interface{}, timeout int64) (interface{}, error)

Functions

func NewDefaultCacheFactory

func NewDefaultCacheFactory() *build.Factory

Create a new instance of the factory. Returns *build.Factory

Types

type CacheEntry

type CacheEntry struct {
	// contains filtered or unexported fields
}

Data object to store cached values with their keys used by MemoryCache

func NewCacheEntry

func NewCacheEntry(key string, value interface{}, timeout int64) *CacheEntry

Creates a new instance of the cache entry and assigns its values. Parameters:

• key string a unique key to locate the value.
• value interface{] a value to be stored.
• timeout int64 expiration timeout in milliseconds.

Returns *CacheEntry

func (*CacheEntry) Expiration

func (c *CacheEntry) Expiration() time.Time

Gets the expiration timeout. Returns time.Time the expiration timeout in milliseconds.

func (*CacheEntry) IsExpired

func (c *CacheEntry) IsExpired() bool

Checks if this value already expired. Returns bool true if the value already expires and false otherwise.

func (*CacheEntry) Key

func (c *CacheEntry) Key() string

Gets the key to locate the cached value. Returns string the value key.

func (*CacheEntry) SetValue

func (c *CacheEntry) SetValue(value interface{}, timeout int64)

Sets a new value and extends its expiration. Parameters:

• value interface{} a new cached value.
• timeout int64 a expiration timeout in milliseconds.

func (*CacheEntry) Value

func (c *CacheEntry) Value() interface{}

Gets the cached value. Returns interface{} the value object.

type ICache

type ICache interface {
	// Retrieves cached value from the cache using its key. If value is missing in the cache or expired it returns nil.
	Retrieve(correlationId string, key string) (interface{}, error)
	// Retrieves cached value from the cache using its key into reference object. If value is missing in the cache or expired it returns false.
	RetrieveAs(correlationId string, key string, result interface{}) (interface{}, error)
	// Stores value in the cache with expiration time.
	Store(correlationId string, key string, value interface{}, timeout int64) (interface{}, error)
	// Removes a value from the cache by its key.
	Remove(correlationId string, key string) error
}

Interface for caches that are used to cache values to improve performance.

type MemoryCache

type MemoryCache struct {
	// contains filtered or unexported fields
}

Cache that stores values in the process memory.

Remember: This implementation is not suitable for synchronization of distributed processes.

Configuration parameters

options:
  timeout: default caching timeout in milliseconds (default: 1 minute)
  max_size: maximum number of values stored in this cache (default: 1000)

see ICache

Example

cache := NewMemoryCache();
res, err := cache.Store("123", "key1", "ABC", 10000);

func NewMemoryCache

func NewMemoryCache() *MemoryCache

Creates a new instance of the cache. Returns *MemoryCache

func NewMemoryCacheFromConfig

func NewMemoryCacheFromConfig(cfg *config.ConfigParams) *MemoryCache

Creates a new instance of the cache. Parameters

• cfg *config.ConfigParams configuration parameters to be set.

Returns *MemoryCache

func (*MemoryCache) Cleanup

func (c *MemoryCache) Cleanup()

Cleanup memory cache

func (*MemoryCache) Clear

func (c *MemoryCache) Clear(correlationId string) error

Clear a value from the cache. Parameters:

• correlationId string transaction id to trace execution through call chain.

func (*MemoryCache) Configure

func (c *MemoryCache) Configure(cfg *config.ConfigParams)

Configures component by passing configuration parameters. Parameters:

• config *config.ConfigParams configuration parameters to be set.

func (*MemoryCache) Remove

func (c *MemoryCache) Remove(correlationId string, key string) error

Removes a value from the cache by its key. Parameters:

• correlationId string transaction id to trace execution through call chain.
• key string a unique value key.

Returns error

func (*MemoryCache) Retrieve

func (c *MemoryCache) Retrieve(correlationId string, key string) (interface{}, error)

Retrieves cached value from the cache using its key. If value is missing in the cache or expired it returns null. Parameters:

• correlationId string transaction id to trace execution through call chain.
• key string a unique value key.

Returns interface{}, error

func (*MemoryCache) RetrieveAs

func (c *MemoryCache) RetrieveAs(correlationId string, key string, result interface{}) (interface{}, error)

Retrive cached value from the cache using its key and restore into reference object. If value is missing in the cache or expired it returns false. Parameters:

• correlationId string transaction id to trace execution through call chain.
• key string a unique value key.
• result pointer to object for restore

Returns bool, error

func (*MemoryCache) Store

func (c *MemoryCache) Store(correlationId string, key string, value interface{}, timeout int64) (interface{}, error)

Stores value in the cache with expiration time, if success return stored value. Parameters:

• correlationId string transaction id to trace execution through call chain.
• key string a unique value key.
• value interface{} a value to store.
• timeout int64 expiration timeout in milliseconds.

Returns interface{}, error

type NullCache

type NullCache struct{}

Dummy cache implementation that doesn't do anything.

It can be used in testing or in situations when cache is required but shall be disabled.

func NewNullCache

func NewNullCache() *NullCache

Creates a new instance of the cache. Returns *NullCache

func (*NullCache) Remove

func (c *NullCache) Remove(correlationId string, key string) error

Removes a value from the cache by its key. Parameters:

• correlationId string transaction id to trace execution through call chain.\
• key string a unique value key.

Returns error

func (*NullCache) Retrieve

func (c *NullCache) Retrieve(correlationId string, key string) (interface{}, error)

Retrieves cached value from the cache using its key. If value is missing in the cache or expired it returns null. Parameters:

• correlationId string transaction id to trace execution through call chain.
• key string a unique value key.

Returns interface{}, error

func (*NullCache) RetrieveAs

func (c *NullCache) RetrieveAs(correlationId string, key string, result interface{}) (interface{}, error)

Retrieve cached value from the cache using its key and restore into reference object. If value is missing in the cache or expired it returns false. Parameters:

• correlationId string transaction id to trace execution through call chain.
• key string a unique value key.
• refObj pointer to object for restore

Returns bool, error

func (*NullCache) Store

func (c *NullCache) Store(correlationId string, key string, value interface{}, timeout int64) (interface{}, error)

Stores value in the cache with expiration time, if success return stored value. Parameters:

• correlationId string transaction id to trace execution through call chain.
• key string a unique value key.
• value interface{} a value to store.
• timeout int64 expiration timeout in milliseconds.

Returns interface{}, error