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Simer Plaha
Simer Plaha

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Intro to SwayDB

SwayDB is an embeddable persistent and in-memory key-value store/database.

Here I will try to demonstrate on how to create a Map in Scala and play with some basic APIs to do simple CRUD operations.

Creating a Map

You can ignore Nothing and Bag.Less for now which will explained in future posts.

import swaydb._ //swaydb's APIs
import swaydb.serializers.Default._ //default serialisers

val map = memory.Map[Int, String, Nothing, Bag.Less]().get //create a memory map

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Similarly a persistent Map can be created by replacing memory.Map with persistent.Map and providing a folder name.

val map = persistent.Map[Int, String, Nothing, Bag.Less](dir = "target/myMap").get
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Basic Put & Get

map.put(key = 1, value = "one")
map.get(key = 1) //returns Some("one")

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Expiring & Updating data

//put and expire after 1 hour
map.put(key = 2, value = "two", expireAfter = 1.hour) 
//updates value but leave the expiration unchanged.
map.update(key = 2, value = "two updated")
//returns expiration deadline.
map.expiration(key = 2) 
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Remove/Deleting data

Batch removes both keys.

map.remove(keys = Seq(1, 2))
//return true - Map is now empty.
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Run on Scastie.


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Git Concepts I Wish I Knew Years Ago

The most used technology by developers is not Javascript.

It's not Python or HTML.

It hardly even gets mentioned in interviews or listed as a pre-requisite for jobs.

I'm talking about Git and version control of course.

One does not simply learn git