sorted

Documentation

Overview

Package sorted provides a KeyValue interface and constructor registry.

Index

• Variables
• func RegisterKeyValue(typ string, fn func(jsonconfig.Obj) (KeyValue, error))
• type BatchMutation
  • func NewBatchMutation() BatchMutation
• type Iterator
• type KeyValue
  • func NewKeyValue(cfg jsonconfig.Obj) (KeyValue, error)
  • func NewMemoryKeyValue() KeyValue
• type Mutation
• type Wiper

Variables

var ErrNotFound = errors.New("index: key not found")

Functions

func RegisterKeyValue

func RegisterKeyValue(typ string, fn func(jsonconfig.Obj) (KeyValue, error))

Types

type BatchMutation

type BatchMutation interface {
	Set(key, value string)
	Delete(key string)
}

func NewBatchMutation

func NewBatchMutation() BatchMutation

type Iterator

type Iterator interface {
	// Next moves the iterator to the next key/value pair.
	// It returns false when the iterator is exhausted.
	Next() bool

	// Key returns the key of the current key/value pair.
	// Only valid after a call to Next returns true.
	Key() string

	// KeyBytes returns the key as bytes. The returned bytes
	// should not be written and are invalid after the next call
	// to Next or Close.
	// TODO(bradfitz): rename this and change it to return a
	// mem.RO instead?
	KeyBytes() []byte

	// Value returns the value of the current key/value pair.
	// Only valid after a call to Next returns true.
	Value() string

	// ValueBytes returns the value as bytes. The returned bytes
	// should not be written and are invalid after the next call
	// to Next or Close.
	// TODO(bradfitz): rename this and change it to return a
	// mem.RO instead?
	ValueBytes() []byte

	// Close closes the iterator and returns any accumulated error. Exhausting
	// all the key/value pairs in a table is not considered to be an error.
	// It is valid to call Close multiple times. Other methods should not be
	// called after the iterator has been closed.
	Close() error
}

Iterator iterates over an index KeyValue's key/value pairs in key order.

An iterator must be closed after use, but it is not necessary to read an iterator until exhaustion.

An iterator is not necessarily goroutine-safe, but it is safe to use multiple iterators concurrently, with each in a dedicated goroutine.

type KeyValue

type KeyValue interface {
	// Get gets the value for the given key. It returns ErrNotFound if the DB
	// does not contain the key.
	Get(key string) (string, error)

	Set(key, value string) error

	// Delete deletes keys. Deleting a non-existent key does not return an error.
	Delete(key string) error

	BeginBatch() BatchMutation
	CommitBatch(b BatchMutation) error

	// Find returns an iterator positioned before the first key/value pair
	// whose key is 'greater than or equal to' the given key. There may be no
	// such pair, in which case the iterator will return false on Next.
	//
	// The optional end value specifies the exclusive upper
	// bound. If the empty string, the iterator returns keys
	// where "key >= start".
	// If non-empty, the iterator returns keys where
	// "key >= start && key < endHint".
	//
	// Any error encountered will be implicitly returned via the iterator. An
	// error-iterator will yield no key/value pairs and closing that iterator
	// will return that error.
	Find(start, end string) Iterator

	// Close is a polite way for the server to shut down the storage.
	// Implementations should never lose data after a Set, Delete,
	// or CommmitBatch, though.
	Close() error
}

KeyValue is a sorted, enumerable key-value interface supporting batch mutations.

func NewKeyValue

func NewKeyValue(cfg jsonconfig.Obj) (KeyValue, error)

func NewMemoryKeyValue

func NewMemoryKeyValue() KeyValue

NewMemoryKeyValue returns a KeyValue implementation that's backed only by memory. It's mostly useful for tests and development.

type Mutation

type Mutation interface {
	Key() string
	Value() string
	IsDelete() bool
}

type Wiper

type Wiper interface {
	KeyValue

	// Wipe removes all key/value pairs.
	Wipe() error
}

Wiper is an optional interface that may be implemented by storage implementations.