database

Documentation

Overview

Copyright © 2018 Zhao Ming <mint.zhao.chiu@gmail.com>.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Index

• Variables
• type Batch
• type Database
• type Iterator
• type KeyValePair

Variables

var (
	// ErrKeyNotFound returned if no key stored in database
	ErrKeyNotFound = errors.New("key not found")
)

Types

type Batch

type Batch interface {
	// Set set key/value pair
	Set(bucket, key string, value []byte) error

	// Delete delete key/value from database
	Delete(bucket, key string) error

	// Commit commit all operations to database
	Commit() error

	// Release release the resources hold by Batch
	Release() error
}

Batch collect operations together send to database atomically.

type Database

type Database interface {
	// Open open database handler
	Open() error

	// Get get key/value pair from database
	Get(bucket, key string) ([]byte, error)

	// Set set key/value pair
	Set(bucket, key string, value []byte) error

	// Delete delete key/value from database
	Delete(bucket, key string) error

	// NewBatch returns a Batch interface to handle multi key/value pairs writes.
	NewBatch() (Batch, error)

	// NewIterator iterate over a key prefix
	NewIterator(bucket, prefix string) (Iterator, error)

	// Close close database
	Close() error
}

Database contains all the funcs to handle database

type Iterator

type Iterator interface {
	// HasNext return true if iterator isn't over, otherwise false
	HasNext() bool

	// Value return matched key/value pair
	Value() (*KeyValePair, error)

	// Next move pointer to next matched value
	Next() error

	// Close close iterator
	Close() error
}

Iterator seek key by prefix

type KeyValePair

type KeyValePair struct {
	Bucket, Key string
	Value       []byte
}

KeyValuePair