keyvaluedb

Documentation

Index

• func CheckKey(key []byte) error
• func CheckKeyAndValue(key []byte, val any) error
• func CheckValue(val any) error
• func IsEmpty(db KeyValueDB) (empty bool, err error)
• type DBTransaction
• type DBTx
• type Iterable
• type Iterator
• type KeyValueDB
• type Reader
• type Writer

Functions

func CheckKey

func CheckKey(key []byte) error

func CheckKeyAndValue

func CheckKeyAndValue(key []byte, val any) error

func CheckValue

func CheckValue(val any) error

func IsEmpty

func IsEmpty(db KeyValueDB) (empty bool, err error)

IsEmpty is returns true if the key value DB is empty

Types

type DBTransaction

type DBTransaction interface {
	Writer
	Reader
	// Commit commits all pending changes
	Commit() error
	// Rollback reverts everything and nothing is changed
	Rollback() error
}

DBTransaction key value database transaction

type DBTx

type DBTx interface {
	StartTx() (DBTransaction, error)
}

DBTx interface for database transactions NB! all transactions MUST be completed by either calling Commit() or Rollback() which releases the transaction. Only one read-write transaction is allowed at a time.

type Iterable

type Iterable interface {
	// First creates a binary-alphabetical forward iterator starting with first item.
	// If the DB is empty the returned iterator returned is not valid (it.Valid() == false)
	// NB! when done iterator MUST be released with Close() or next DB operation will result in deadlock
	First() Iterator
	// Last creates a binary-alphabetical iterator starting with last item.
	// If the DB is empty the returned iterator returned is not valid (it.Valid() == false)
	// NB! when done iterator MUST be released with Close() or next DB operation will result in deadlock
	Last() Iterator
	// Find returns forward iterator to the closest binary-alphabetical match.
	// If no match or DB is empty the returned iterator returned is not valid (it.Valid() == false)
	// NB! when done iterator MUST be released with Close() or next DB operation will result in deadlock
	Find(key []byte) Iterator
}

Iterable wraps the NewIterator methods of a backing data store.

type Iterator

type Iterator interface {
	// Next moves the iterator to the next key value pair
	Next()
	// Prev returns previous key/value pair
	Prev()
	// Valid returns state of the iterator, if at the end false is returned
	Valid() bool
	// Key returns the key of the current key/value pair, or nil if not valid.
	Key() []byte
	// Value returns the value of the current key/value pair, or error if not valid.
	Value(value any) error
	// Close releases associated resources. Release should always succeed and can
	// be called multiple times without causing error.
	Close() error
}

type KeyValueDB

type KeyValueDB interface {
	Reader
	Writer
	Iterable
	DBTx
}

KeyValueDB contains all the methods required by the high level database to not only access the key-value data store but also the chain freezer.

type Reader

type Reader interface {
	// Read reads the value for key stored in the DB
	Read(key []byte, value any) (bool, error)
}

Reader interface for DB

type Writer

type Writer interface {
	// Write inserts the given value into the DB.
	Write(key []byte, value any) error
	// Delete removes the key from the key-value data store.
	Delete(key []byte) error
}

Writer interface for DB