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Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrEmptyKey = errors.New("key cannot be empty")
ErrEmptyKey is returned when key is empty.
var ErrIndexOutOfRange = errors.New("iterator index out of range")
ErrIndexOutOfRange is returned when the iterator index is not in a valid range.
var ErrKeyNotFound = errors.New("key not found")
ErrKeyNotFound is returned when there is no value associated with a key.
Functions ¶
This section is empty.
Types ¶
type Codec ¶ added in v1.0.0
type Codec interface {
// Encode the object into a slice of bytes.
Encode(obj interface{}) ([]byte, error)
// Decode the bytes to its original data object and assign it to the given
// variable. Value underlying `value` must be a pointer to the correct type
// for object.
Decode(data []byte, value interface{}) error
}
Codec can do encoding/decoding between arbitrary data object and bytes.
type DB ¶
type DB interface {
// Close the DB and free all of its resources. The DB must not be used after
// being closed.
Close() error
// Insert writes the key-value into the DB.
Insert(key string, value interface{}) error
// Get the value associated with the given key and write it to the value
// interface. The value interface must be a pointer. If the key cannot be
// found, then ErrKeyNotFound is returned.
Get(key string, value interface{}) error
// Delete the value with the given key from the DB.
Delete(key string) error
// Size returns the number of key/value pairs in the DB where the key begins
// with the given prefix.
Size(prefix string) (int, error)
// Iterator over the key/value pairs in the DB where the key begins with the
// given prefix.
Iterator(prefix string) Iterator
}
DB is a key-value database which requires the key to be a string and the value can be encoded/decoded by the codec. It allows user to maintain multiple tables with the same underlying database driver.
type Iterator ¶
type Iterator interface {
// Next will progress the iterator to the next element. If there are more
// elements in the iterator, then it will return true, otherwise it will
// return false.
Next() bool
// Key of the current key-value tuple. Calling Key() without calling Next()
// or when no next item in the iter may result in `ErrIndexOutOfRange`
Key() (string, error)
// Value of the current key-value tuple. Calling Value() without calling
// Next() or when no next item in the iter will result in
// `ErrIndexOutOfRange`
Value(value interface{}) error
}
Iterator is used to iterate through the data in the store.
type Table ¶ added in v1.0.0
type Table interface {
// Insert writes the key-value into the Table.
Insert(key string, value interface{}) error
// Get the value associated with the given key and write it to the value
// interface. The value interface must be a pointer. If the key cannot be
// found, then ErrKeyNotFound is returned.
Get(key string, value interface{}) error
// Delete the value with the given key from the Table.
Delete(key string) error
// Size returns the number of key/value pairs in the Table.
Size() (int, error)
// Iterator over the key/value pairs in the Table.
Iterator() Iterator
}
A Table is an abstraction over the DB that partitions key/value pairs. The Table name must be unique compared to other Table names. The key/value pairs are encoded and decoded using the Codec of the underlying DB.
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