memorydb

Documentation

Overview

Package memorydb implements the key-value database layer based on memory maps.

Index

• type Database
  • func New() *Database
  • func NewWithCap(size int) *Database
  • func (db *Database) Close() error
  • func (db *Database) Compact(start []byte, limit []byte) error
  • func (db *Database) Delete(key []byte) error
  • func (db *Database) Get(key []byte) ([]byte, error)
  • func (db *Database) Has(key []byte) (bool, error)
  • func (db *Database) Len() int
  • func (db *Database) NewBatch() fourtwentydb.Batch
  • func (db *Database) NewIterator(prefix []byte, start []byte) fourtwentydb.Iterator
  • func (db *Database) Put(key []byte, value []byte) error
  • func (db *Database) Stat(property string) (string, error)

Types

type Database

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

Database is an ephemeral key-value store. Apart from basic data storage functionality it also supports batch writes and iterating over the keyspace in binary-alphabetical order.

func New

func New() *Database

New returns a wrapped map with all the required database interface methods implemented.

func NewWithCap

func NewWithCap(size int) *Database

NewWithCap returns a wrapped map pre-allocated to the provided capcity with all the required database interface methods implemented.

func (*Database) Close

func (db *Database) Close() error

Close deallocates the internal map and ensures any consecutive data access op failes with an error.

func (*Database) Compact

func (db *Database) Compact(start []byte, limit []byte) error

Compact is not supported on a memory database, but there's no need either as a memory database doesn't waste space anyway.

func (*Database) Delete

func (db *Database) Delete(key []byte) error

Delete removes the key from the key-value store.

func (*Database) Get

func (db *Database) Get(key []byte) ([]byte, error)

Get retrieves the given key if it's present in the key-value store.

func (*Database) Has

func (db *Database) Has(key []byte) (bool, error)

Has retrieves if a key is present in the key-value store.

func (*Database) Len

func (db *Database) Len() int

Len returns the number of entries currently present in the memory database.

Note, this method is only used for testing (i.e. not public in general) and does not have explicit checks for closed-ness to allow simpler testing code.

func (*Database) NewBatch

func (db *Database) NewBatch() fourtwentydb.Batch

NewBatch creates a write-only key-value store that buffers changes to its host database until a final write is called.

func (*Database) NewIterator

func (db *Database) NewIterator(prefix []byte, start []byte) fourtwentydb.Iterator

NewIterator creates a binary-alphabetical iterator over a subset of database content with a particular key prefix, starting at a particular initial key (or after, if it does not exist).

func (*Database) Put

func (db *Database) Put(key []byte, value []byte) error

Put inserts the given value into the key-value store.

func (*Database) Stat

func (db *Database) Stat(property string) (string, error)

Stat returns a particular internal stat of the database.