Documentation

Overview

Package store is an interface for distributed data storage. The design document is located at https://github.com/micro/development/blob/master/design/store.md

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

This section is empty.

Types

type DeleteOption

type DeleteOption func(d *DeleteOptions)

DeleteOption sets values in DeleteOptions

func DeleteFrom

func DeleteFrom(database, table string) DeleteOption

DeleteFrom the database and table

type DeleteOptions

type DeleteOptions struct {
	Database, Table string
}

DeleteOptions configures an individual Delete operation

type ListOption

type ListOption func(l *ListOptions)

ListOption sets values in ListOptions

func ListFrom

func ListFrom(database, table string) ListOption

ListFrom the database and table

func ListLimit

func ListLimit(l uint) ListOption

ListLimit limits the number of returned keys to l

func ListOffset

func ListOffset(o uint) ListOption

ListOffset starts returning responses from o. Use in conjunction with Limit for pagination.

func ListPrefix

func ListPrefix(p string) ListOption

ListPrefix returns all keys that are prefixed with key

func ListSuffix

func ListSuffix(s string) ListOption

ListSuffix returns all keys that end with key

type ListOptions

type ListOptions struct {
	// List from the following
	Database, Table string
	// Prefix returns all keys that are prefixed with key
	Prefix string
	// Suffix returns all keys that end with key
	Suffix string
	// Limit limits the number of returned keys
	Limit uint
	// Offset when combined with Limit supports pagination
	Offset uint
}

ListOptions configures an individual List operation

type Option

type Option func(o *Options)

Option sets values in Options

func Database

func Database(db string) Option

Database allows multiple isolated stores to be kept in one backend, if supported.

func Nodes

func Nodes(a ...string) Option

Nodes contains the addresses or other connection information of the backing storage. For example, an etcd implementation would contain the nodes of the cluster. A SQL implementation could contain one or more connection strings.

func Table

func Table(t string) Option

Table is analagous to a table in database backends or a key prefix in KV backends

func WithClient

func WithClient(c client.Client) Option

WithClient sets the stores client to use for RPC

func WithContext

func WithContext(c context.Context) Option

WithContext sets the stores context, for any extra configuration

type Options

type Options struct {
	// Nodes contains the addresses or other connection information of the backing storage.
	// For example, an etcd implementation would contain the nodes of the cluster.
	// A SQL implementation could contain one or more connection strings.
	Nodes []string
	// Database allows multiple isolated stores to be kept in one backend, if supported.
	Database string
	// Table is analagous to a table in database backends or a key prefix in KV backends
	Table string
	// Context should contain all implementation specific options, using context.WithValue.
	Context context.Context
	// Client to use for RPC
	Client client.Client
}

Options contains configuration for the Store

type ReadOption

type ReadOption func(r *ReadOptions)

ReadOption sets values in ReadOptions

func ReadFrom

func ReadFrom(database, table string) ReadOption

ReadFrom the database and table

func ReadLimit

func ReadLimit(l uint) ReadOption

ReadLimit limits the number of responses to l

func ReadOffset

func ReadOffset(o uint) ReadOption

ReadOffset starts returning responses from o. Use in conjunction with Limit for pagination

func ReadPrefix

func ReadPrefix() ReadOption

ReadPrefix returns all records that are prefixed with key

func ReadSuffix

func ReadSuffix() ReadOption

ReadSuffix returns all records that have the suffix key

type ReadOptions

type ReadOptions struct {
	Database, Table string
	// Prefix returns all records that are prefixed with key
	Prefix bool
	// Suffix returns all records that have the suffix key
	Suffix bool
	// Limit limits the number of returned records
	Limit uint
	// Offset when combined with Limit supports pagination
	Offset uint
}

ReadOptions configures an individual Read operation

type Record

type Record struct {
	// The key to store the record
	Key string `json:"key"`
	// The value within the record
	Value []byte `json:"value"`
	// Any associated metadata for indexing
	Metadata map[string]interface{} `json:"metadata"`
	// Time to expire a record: TODO: change to timestamp
	Expiry time.Duration `json:"expiry,omitempty"`
}

Record is an item stored or retrieved from a Store

type Store

type Store interface {
	// Init initialises the store. It must perform any required setup on the backing storage implementation and check that it is ready for use, returning any errors.
	Init(...Option) error
	// Options allows you to view the current options.
	Options() Options
	// Read takes a single key name and optional ReadOptions. It returns matching []*Record or an error.
	Read(key string, opts ...ReadOption) ([]*Record, error)
	// Write() writes a record to the store, and returns an error if the record was not written.
	Write(r *Record, opts ...WriteOption) error
	// Delete removes the record with the corresponding key from the store.
	Delete(key string, opts ...DeleteOption) error
	// List returns any keys that match, or an empty list with no error if none matched.
	List(opts ...ListOption) ([]string, error)
	// Close the store
	Close() error
	// String returns the name of the implementation.
	String() string
}

Store is a data storage interface

var (
	// ErrNotFound is returned when a key doesn't exist
	ErrNotFound = errors.New("not found")
	// DefaultStore is the memory store.
	DefaultStore Store = new(noopStore)
)

type WriteOption

type WriteOption func(w *WriteOptions)

WriteOption sets values in WriteOptions

func WriteExpiry

func WriteExpiry(t time.Time) WriteOption

WriteExpiry is the time the record expires

func WriteTTL

func WriteTTL(d time.Duration) WriteOption

WriteTTL is the time the record expires

func WriteTo

func WriteTo(database, table string) WriteOption

WriteTo the database and table

type WriteOptions

type WriteOptions struct {
	Database, Table string
	// Expiry is the time the record expires
	Expiry time.Time
	// TTL is the time until the record expires
	TTL time.Duration
}

WriteOptions configures an individual Write operation If Expiry and TTL are set TTL takes precedence

Directories

Path Synopsis
cache Package cache implements a faulting style read cache on top of multiple micro stores
cockroach Package cockroach implements the cockroach store
file Package local is a file system backed store
memory Package memory is a in-memory store store
service Package service implements the store service interface
service/proto