lmdb-storage

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lmdb-storage is a Go language library used to save key-value data. It is a further packaging of the lmdb database. This library further adds the functions of batch reading and writing and automatic partitioning based on lmdb-go, which is more suitable for dealing with large amounts of data reading and writing.

Installation

Use the go get to install lmdb-storage.

go get github.com/dingyuqi/lmdb-storage

Usage

New lmdb driver

Call NewLmdbDriver() to get a Driver object, providing a total of three parameters:

1. root: the root path to save data
2. mapSize: size of one DB file
3. blockSize: batch size of reading and writing

Tip

If you do not want to set mapSize and blockSize, you can call NewDefaultLmdbDriver(). This function only needs to provide the root path parameter. The default mapSize is 5MB and blockSize is 10000.

package main

import (
	lmdb "github.com/dingyuqi/lmdb-storage"
	"log"
)

// TestDataPath lmdb database root path
// please use your own local path
var TestDataPath = "D:/test_lmdb"

func main() {
	// init a default driver
	defaultDriver, err := lmdb.NewDefaultLmdbDriver(TestDataPath)
	if err != nil {
		log.Fatalln(err)
	}
	// init a user-defined driver
	definedDriver, err := lmdb.NewLmdbDriver(TestDataPath, 5*1024*1024, 10000)
	if err != nil {
		log.Fatalln(err)
	}
}

Read data in batches

Important

If a certain key in the query cannot be searched in the database, it will not appear in the returned result.

package main

import (
	lmdb "github.com/dingyuqi/lmdb-storage"
	"log"
)

// TestDataPath lmdb database root path
// please use your own local path
var TestDataPath = "D:/test_lmdb"

func main() {
	// init a default driver
	driver, err := lmdb.NewDefaultLmdbDriver(TestDataPath)
	if err != nil {
		log.Fatalln(err)
	}
	data := map[string]struct{}{"3": {}, "2": {}, "1": {}, "102": {}}
	result, err := driver.Get(data)
	if err != nil {
		log.Println("get error", err)
		return
	}
	log.Println("result:", result)
}

License

MIT License