cache

package
Version: v3.15.4 Latest Latest
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Published: May 30, 2020 License: MIT Imports: 32 Imported by: 0

Documentation

Overview

Package cache implements the types.Cache interface for storing and retrieving key/value pairs from a range of storage strategies.

Index

Constants

View Source
const (
	TypeDynamoDB   = "dynamodb"
	TypeFile       = "file"
	TypeMemcached  = "memcached"
	TypeMemory     = "memory"
	TypeMultilevel = "multilevel"
	TypeRedis      = "redis"
	TypeS3         = "s3"
)

String constants representing each cache type.

Variables

View Source
var Constructors = map[string]TypeSpec{}

Constructors is a map of all cache types with their specs.

Functions

func Descriptions

func Descriptions() string

Descriptions returns a formatted string of descriptions for each type.

func DocumentPlugin

func DocumentPlugin(
	typeString, description string,
	configSanitiser PluginConfigSanitiser,
)

DocumentPlugin adds a description and an optional configuration sanitiser function to the definition of a registered plugin. This improves the documentation generated by PluginDescriptions.

func New

func New(
	conf Config,
	mgr types.Manager,
	log log.Modular,
	stats metrics.Type,
) (types.Cache, error)

New creates a cache type based on an cache configuration.

func NewDynamoDB

func NewDynamoDB(conf Config, mgr types.Manager, log log.Modular, stats metrics.Type) (types.Cache, error)

NewDynamoDB creates a new DynamoDB cache type.

func NewFile

func NewFile(conf Config, mgr types.Manager, log log.Modular, stats metrics.Type) (types.Cache, error)

NewFile creates a new File cache type.

func NewMemcached

func NewMemcached(
	conf Config, mgr types.Manager, log log.Modular, stats metrics.Type,
) (types.Cache, error)

NewMemcached returns a Memcached processor.

func NewMemory

func NewMemory(conf Config, mgr types.Manager, log log.Modular, stats metrics.Type) (types.Cache, error)

NewMemory creates a new Memory cache type.

func NewMultilevel

func NewMultilevel(conf Config, mgr types.Manager, log log.Modular, stats metrics.Type) (types.Cache, error)

NewMultilevel creates a new Multilevel cache type.

func NewRedis

func NewRedis(
	conf Config, mgr types.Manager, log log.Modular, stats metrics.Type,
) (types.Cache, error)

NewRedis returns a Redis processor.

func NewS3

func NewS3(conf Config, mgr types.Manager, log log.Modular, stats metrics.Type) (types.Cache, error)

NewS3 creates a new S3 cache type.

func PluginCount

func PluginCount() int

PluginCount returns the number of registered plugins. This does NOT count the standard set of components.

func PluginDescriptions

func PluginDescriptions() string

PluginDescriptions generates and returns a markdown formatted document listing each registered plugin and an example configuration for it.

func RegisterPlugin

func RegisterPlugin(
	typeString string,
	configConstructor PluginConfigConstructor,
	constructor PluginConstructor,
)

RegisterPlugin registers a plugin by a unique name so that it can be constructed similar to regular caches. If configuration is not needed for this plugin then configConstructor can be nil. A constructor for the plugin itself must be provided.

func SanitiseConfig

func SanitiseConfig(conf Config) (interface{}, error)

SanitiseConfig creates a sanitised version of a config.

Types

type Config

type Config struct {
	Type       string           `json:"type" yaml:"type"`
	DynamoDB   DynamoDBConfig   `json:"dynamodb" yaml:"dynamodb"`
	File       FileConfig       `json:"file" yaml:"file"`
	Memcached  MemcachedConfig  `json:"memcached" yaml:"memcached"`
	Memory     MemoryConfig     `json:"memory" yaml:"memory"`
	Multilevel MultilevelConfig `json:"multilevel" yaml:"multilevel"`
	Plugin     interface{}      `json:"plugin,omitempty" yaml:"plugin,omitempty"`
	Redis      RedisConfig      `json:"redis" yaml:"redis"`
	S3         S3Config         `json:"s3" yaml:"s3"`
}

Config is the all encompassing configuration struct for all cache types.

func NewConfig

func NewConfig() Config

NewConfig returns a configuration struct fully populated with default values.

func (*Config) UnmarshalYAML

func (c *Config) UnmarshalYAML(value *yaml.Node) error

UnmarshalYAML ensures that when parsing configs that are in a map or slice the default values are still applied.

type DynamoDB

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

DynamoDB is a DynamoDB based cache implementation.

func (*DynamoDB) Add

func (d *DynamoDB) Add(key string, value []byte) error

Add attempts to set the value of a key only if the key does not already exist and returns an error if the key already exists.

func (*DynamoDB) CloseAsync

func (d *DynamoDB) CloseAsync()

CloseAsync shuts down the cache.

func (*DynamoDB) Delete

func (d *DynamoDB) Delete(key string) error

Delete attempts to remove a key.

func (*DynamoDB) Get

func (d *DynamoDB) Get(key string) ([]byte, error)

Get attempts to locate and return a cached value by its key, returns an error if the key does not exist.

func (*DynamoDB) Set

func (d *DynamoDB) Set(key string, value []byte) error

Set attempts to set the value of a key.

func (*DynamoDB) SetMulti

func (d *DynamoDB) SetMulti(items map[string][]byte) error

SetMulti attempts to set the value of multiple keys, if any keys fail to be set an error is returned.

func (*DynamoDB) WaitForClose

func (d *DynamoDB) WaitForClose(timeout time.Duration) error

WaitForClose blocks until the cache has closed down.

type DynamoDBConfig

type DynamoDBConfig struct {
	ConsistentRead bool   `json:"consistent_read" yaml:"consistent_read"`
	DataKey        string `json:"data_key" yaml:"data_key"`
	HashKey        string `json:"hash_key" yaml:"hash_key"`
	Table          string `json:"table" yaml:"table"`
	TTL            string `json:"ttl" yaml:"ttl"`
	TTLKey         string `json:"ttl_key" yaml:"ttl_key"`
	retries.Config `json:",inline" yaml:",inline"`
	// contains filtered or unexported fields
}

DynamoDBConfig contains config fields for the DynamoDB cache type.

func NewDynamoDBConfig

func NewDynamoDBConfig() DynamoDBConfig

NewDynamoDBConfig creates a MemoryConfig populated with default values.

type File

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

File is a file system based cache implementation.

func (*File) Add

func (f *File) Add(key string, value []byte) error

Add attempts to set the value of a key only if the key does not already exist and returns an error if the key already exists.

func (*File) CloseAsync

func (f *File) CloseAsync()

CloseAsync shuts down the cache.

func (*File) Delete

func (f *File) Delete(key string) error

Delete attempts to remove a key.

func (*File) Get

func (f *File) Get(key string) ([]byte, error)

Get attempts to locate and return a cached value by its key, returns an error if the key does not exist.

func (*File) Set

func (f *File) Set(key string, value []byte) error

Set attempts to set the value of a key.

func (*File) SetMulti

func (f *File) SetMulti(items map[string][]byte) error

SetMulti attempts to set the value of multiple keys, returns an error if any keys fail.

func (*File) WaitForClose

func (f *File) WaitForClose(timeout time.Duration) error

WaitForClose blocks until the cache has closed down.

type FileConfig

type FileConfig struct {
	Directory string `json:"directory" yaml:"directory"`
}

FileConfig contains config fields for the File cache type.

func NewFileConfig

func NewFileConfig() FileConfig

NewFileConfig creates a FileConfig populated with default values.

type Memcached

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

Memcached is a cache that connects to memcached servers.

func (*Memcached) Add

func (m *Memcached) Add(key string, value []byte) error

Add attempts to set the value of a key only if the key does not already exist and returns an error if the key already exists or if the operation fails.

func (*Memcached) CloseAsync

func (m *Memcached) CloseAsync()

CloseAsync shuts down the cache.

func (*Memcached) Delete

func (m *Memcached) Delete(key string) error

Delete attempts to remove a key.

func (*Memcached) Get

func (m *Memcached) Get(key string) ([]byte, error)

Get attempts to locate and return a cached value by its key, returns an error if the key does not exist or if the operation failed.

func (*Memcached) Set

func (m *Memcached) Set(key string, value []byte) error

Set attempts to set the value of a key.

func (*Memcached) SetMulti

func (m *Memcached) SetMulti(items map[string][]byte) error

SetMulti attempts to set the value of multiple keys, returns an error if any keys fail.

func (*Memcached) WaitForClose

func (m *Memcached) WaitForClose(timeout time.Duration) error

WaitForClose blocks until the cache has closed down.

type MemcachedConfig

type MemcachedConfig struct {
	Addresses   []string `json:"addresses" yaml:"addresses"`
	Prefix      string   `json:"prefix" yaml:"prefix"`
	TTL         int32    `json:"ttl" yaml:"ttl"`
	Retries     int      `json:"retries" yaml:"retries"`
	RetryPeriod string   `json:"retry_period" yaml:"retry_period"`
}

MemcachedConfig is a config struct for a memcached connection.

func NewMemcachedConfig

func NewMemcachedConfig() MemcachedConfig

NewMemcachedConfig returns a MemcachedConfig with default values.

type Memory

type Memory struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

Memory is a memory based cache implementation.

func (*Memory) Add

func (m *Memory) Add(key string, value []byte) error

Add attempts to set the value of a key only if the key does not already exist and returns an error if the key already exists.

func (*Memory) CloseAsync

func (m *Memory) CloseAsync()

CloseAsync shuts down the cache.

func (*Memory) Delete

func (m *Memory) Delete(key string) error

Delete attempts to remove a key.

func (*Memory) Get

func (m *Memory) Get(key string) ([]byte, error)

Get attempts to locate and return a cached value by its key, returns an error if the key does not exist.

func (*Memory) Set

func (m *Memory) Set(key string, value []byte) error

Set attempts to set the value of a key.

func (*Memory) SetMulti

func (m *Memory) SetMulti(items map[string][]byte) error

SetMulti attempts to set the value of multiple keys, returns an error if any keys fail.

func (*Memory) WaitForClose

func (m *Memory) WaitForClose(timeout time.Duration) error

WaitForClose blocks until the cache has closed down.

type MemoryConfig

type MemoryConfig struct {
	TTL                int               `json:"ttl" yaml:"ttl"`
	CompactionInterval string            `json:"compaction_interval" yaml:"compaction_interval"`
	InitValues         map[string]string `json:"init_values" yaml:"init_values"`
}

MemoryConfig contains config fields for the Memory cache type.

func NewMemoryConfig

func NewMemoryConfig() MemoryConfig

NewMemoryConfig creates a MemoryConfig populated with default values.

type Multilevel

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

Multilevel is a file system based cache implementation.

func (*Multilevel) Add

func (l *Multilevel) Add(key string, value []byte) error

Add attempts to set the value of a key only if the key does not already exist and returns an error if the key already exists.

func (*Multilevel) CloseAsync

func (l *Multilevel) CloseAsync()

CloseAsync shuts down the cache.

func (*Multilevel) Delete

func (l *Multilevel) Delete(key string) error

Delete attempts to remove a key.

func (*Multilevel) Get

func (l *Multilevel) Get(key string) ([]byte, error)

Get attempts to locate and return a cached value by its key, returns an error if the key does not exist.

func (*Multilevel) Set

func (l *Multilevel) Set(key string, value []byte) error

Set attempts to set the value of a key.

func (*Multilevel) SetMulti

func (l *Multilevel) SetMulti(items map[string][]byte) error

SetMulti attempts to set the value of multiple keys, returns an error if any keys fail.

func (*Multilevel) WaitForClose

func (l *Multilevel) WaitForClose(timeout time.Duration) error

WaitForClose blocks until the cache has closed down.

type MultilevelConfig

type MultilevelConfig []string

MultilevelConfig contains config fields for the Multilevel cache type.

func NewMultilevelConfig

func NewMultilevelConfig() MultilevelConfig

NewMultilevelConfig creates a MultilevelConfig populated with default values.

type PluginConfigConstructor

type PluginConfigConstructor func() interface{}

PluginConfigConstructor is a func that returns a pointer to a new and fully populated configuration struct for a plugin type.

type PluginConfigSanitiser

type PluginConfigSanitiser func(conf interface{}) interface{}

PluginConfigSanitiser is a function that takes a configuration object for a plugin and returns a sanitised (minimal) version of it for printing in examples and plugin documentation.

This function is useful for when a plugins configuration struct is very large and complex, but can sometimes be expressed in a more concise way without losing the original intent.

type PluginConstructor

type PluginConstructor func(
	config interface{},
	manager types.Manager,
	logger log.Modular,
	metrics metrics.Type,
) (types.Cache, error)

PluginConstructor is a func that constructs a Benthos cache plugin. These are plugins that are specific to certain use cases, experimental, private or otherwise unfit for widespread general use. Any number of plugins can be specified when using Benthos as a framework.

The configuration object will be the result of the PluginConfigConstructor after overlaying the user configuration.

type Redis

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

Redis is a cache that connects to redis servers.

func (*Redis) Add

func (r *Redis) Add(key string, value []byte) error

Add attempts to set the value of a key only if the key does not already exist and returns an error if the key already exists or if the operation fails.

func (*Redis) CloseAsync

func (r *Redis) CloseAsync()

CloseAsync shuts down the cache.

func (*Redis) Delete

func (r *Redis) Delete(key string) error

Delete attempts to remove a key.

func (*Redis) Get

func (r *Redis) Get(key string) ([]byte, error)

Get attempts to locate and return a cached value by its key, returns an error if the key does not exist or if the operation failed.

func (*Redis) Set

func (r *Redis) Set(key string, value []byte) error

Set attempts to set the value of a key.

func (*Redis) SetMulti

func (r *Redis) SetMulti(items map[string][]byte) error

SetMulti attempts to set the value of multiple keys, returns an error if any keys fail.

func (*Redis) WaitForClose

func (r *Redis) WaitForClose(timeout time.Duration) error

WaitForClose blocks until the cache has closed down.

type RedisConfig

type RedisConfig struct {
	URL         string `json:"url" yaml:"url"`
	Prefix      string `json:"prefix" yaml:"prefix"`
	Expiration  string `json:"expiration" yaml:"expiration"`
	Retries     int    `json:"retries" yaml:"retries"`
	RetryPeriod string `json:"retry_period" yaml:"retry_period"`
}

RedisConfig is a config struct for a redis connection.

func NewRedisConfig

func NewRedisConfig() RedisConfig

NewRedisConfig returns a RedisConfig with default values.

type S3

type S3 struct {
	// contains filtered or unexported fields
}

S3 is a file system based cache implementation.

func (*S3) Add

func (s *S3) Add(key string, value []byte) error

Add attempts to set the value of a key only if the key does not already exist and returns an error if the key already exists.

func (*S3) CloseAsync

func (s *S3) CloseAsync()

CloseAsync shuts down the cache.

func (*S3) Delete

func (s *S3) Delete(key string) error

Delete attempts to remove a key.

func (*S3) Get

func (s *S3) Get(key string) ([]byte, error)

Get attempts to locate and return a cached value by its key, returns an error if the key does not exist.

func (*S3) Set

func (s *S3) Set(key string, value []byte) error

Set attempts to set the value of a key.

func (*S3) SetMulti

func (s *S3) SetMulti(items map[string][]byte) error

SetMulti attempts to set the value of multiple keys, returns an error if any keys fail.

func (*S3) WaitForClose

func (s *S3) WaitForClose(timeout time.Duration) error

WaitForClose blocks until the cache has closed down.

type S3Config

type S3Config struct {
	sess.Config        `json:",inline" yaml:",inline"`
	Bucket             string `json:"bucket" yaml:"bucket"`
	ForcePathStyleURLs bool   `json:"force_path_style_urls" yaml:"force_path_style_urls"`
	ContentType        string `json:"content_type" yaml:"content_type"`
	Timeout            string `json:"timeout" yaml:"timeout"`
	Retries            int    `json:"retries" yaml:"retries"`
}

S3Config contains config fields for the S3 cache type.

func NewS3Config

func NewS3Config() S3Config

NewS3Config creates a S3Config populated with default values.

type TypeSpec

type TypeSpec struct {
	Summary     string
	Description string
	Footnotes   string
	FieldSpecs  docs.FieldSpecs
	// contains filtered or unexported fields
}

TypeSpec is a constructor and a usage description for each cache type.

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