NimbusDB

NimbusDB is a key value store. The aim of this project is to understand the core behaviour of Redis and its design. It provides various set of commands similar to Redis along with various data structures and more.

Core Features

• Key-Value Store Supports commands like SET, GET, DEL, INCR, INCRBY etc.
• Data type support String, Numbers, Set, List.
• Pub/Sub support For Publishers and Subscribers channels.
• Disk Persistence Supports Append Only Logs (AOF) for data recovery mechanism.

Installation and How to use this

• Fork the repo and clone it.
• Open 2 terminals.
• Run command go run main.go in one terminal and Run command telnet localhost 6379 in other one.
• Important Note: NimbusDB runs on port 6379.

Commands

SET

Set the key in the store. Syntax: SET key value

nimbusdb > SET name john
OK

GET

Get the key from the store. Syntax: GET key

nimbusdb > SET name john
OK
nimbusdb > GET name
john

DELETE

Delete key from the store. Syntax: DEL key

nimbusdb > SET name john
OK
nimbusdb > GET name
john
nimbusdb > DEL name
john Deleted

Note

It works with smallcase set, get, del commands also.

Data Types

NimbusDB support few important datatypes.

Strings

Nimbus supports the string data type, and you can use the SET and GET commands mentioned above to work with strings.

Numbers

Nimbus supports the number data type and also offers a separate set of commands designed to work with it. Below is a detailed explanation of these commands.

INCR

Increase the value by 1. Syntax: INCR key

nimbusdb > SET count 1
OK
nimbusdb > INCR count
2

INCRBY

Increase the value by some x value. Syntax: INCRBY key x

nimbusdb > SET count 1
OK
nimbusdb > INCR count
2
nimbusdb > INCRBY count 5
7

DECR

Decrease the value by 1. Syntax: DECR key

nimbusdb > GET count
7
nimbusdb > DECR count
6

DECRBY

Decrease the value by some x value. Syntax: DECRBY key value

nimbusdb > GET count
7
nimbusdb > DECRBY count 4
3

Lists

List also offers it separate set of commands designed to work with it. Below are the detaled explanation of commands.

LPUSH

Push the element to the left side of the list. Syntax: LPUSH key value

nimbusdb > LPUSH cities delhi
1
nimbusdb > LPUSH cities jaipur
2

RPUSH

Push the element to the right side of the list. Syntax: RPUSH key value

nimbusdb > RPUSH cities lucknow
3
nimbusdb > RPUSH cities bhopal
4

LLEN

Returns the length of the list. Syntax: LLEN key

nimbusdb > LLEN cities
4

LPOP

Removes the leftmost element from the list. Syntax: LPOP key

nimbusdb > LPOP cities
jaipur

RPOP

Removes the rightmost element from the list. Syntax: RPOP key

nimbusdb > RPOP cities
bhopal

LINDEX

Returns the element from the list at that index. Syntax: LINDEX key value

nimbusdb > LINDEX cities 0
delhi
nimbusdb > LINDEX cities 1
lucknow

Sets

Set also offers it separate set of commands designed to work with it. Below are the detailed explanation of commands.

SADD

Returns the 1 when insert successfull else 0. Syntax: SADD key value

nimbusdb > SADD cities lucknow
1
nimbusdb > SADD cities jaipur
1
nimbusdb > SADD cities lucknow
0

SMEMBERS

Returns the list of all elements present in the set. Synatx: SMEMBERS key

nimbusdb > SMEMBERS cities
[lucknow  jaipur]

SISMEMBER

Returns 1 if the element exists in the set else 0. Syntax: SISMEMBER key value

nimbusdb > SADD cities delhi
1
nimbusdb > SMEMBERS cities
[lucknow  jaipur  delhi]
nimbusdb > SISMEMBER cities delhi
1

SREM

Returns 1 if the element removed successfully else 0 if the element doesn't exists Syntax: SREM key value

nimbusdb > SREM cities jaipur
1
nimbusdb > SMEMBERS cities
[lucknow  delhi]
nimbusdb > SISMEMBER cities jaipur
0
nimbusdb > SREM cities jaipur
0

Pub/Sub support for Channels

NimbubsDB also supports dealing with channels. It provides SUBSCRIBE and PUBLISH command to handle them.

SUBSCRIBE

Subscribes to the channel. Syntax: SUBSCRIBE channel_name

PUBLISH

Publishes to the channel. Syntax: PUBLISH channel_name message

Below example is the simulation of SUBSCRIBE AND PUBLISH command.

nimbusdb > SUBSCRIBE chat-1
SUBSCRIBED
nimbusdb > PUBLISH chat-1 hello
+hello
nimbusdb > PUBLISHED
nimbusdb > +hey, how are you

nimbusdb > SUBSCRIBE chat-1
SUBSCRIBED
nimbusdb > +hello
nimbusdb > PUBLISH chat-1 hey, how are you
+hey, how are you
nimbusdb > PUBLISHED

Pub/Sub support

NimbusDB provides Pub/Sub support to deal with channels. For more info, checkout the command section here.

Disk Persistence

NimbusDB uses Append-Only Logs for disk persistence and data recovery. Each time a command is executed, NimbusDB records it in a file to ensure data is saved. When the database restarts, it loads the entire log file at once, allowing it to resume from the point it was last at without any data loss.