Redis-like Server in TypeScript

Overview

This project is a simplified Redis-like server built using TypeScript. It implements core features of Redis, such as key-value storage, transactions, streams, replication, and more. The server is designed to handle commands using the RESP (REdis Serialization Protocol) and provides a robust foundation for understanding the internals of a Redis-like in-memory database.

Features

1. Basic Key-Value Operations

• SET Command: Store a key-value pair in memory.
• GET Command: Retrieve the value associated with a key.
• Key Expiration: Optionally set a TTL (Time-To-Live) for keys.

2. Transactions

• MULTI/EXEC: Group multiple commands into an atomic transaction.
• DISCARD: Cancel a transaction.

3. Stream Operations

• XADD: Add entries to a stream.
• XRANGE: Retrieve entries from a stream within a specified range.

4. List Operations

• LPUSH: Add an element to the head of a list.
• RPUSH: Add an element to the tail of a list.
• LPOP: Remove and return the first element of a list.
• RPOP: Remove and return the last element of a list.
• LLEN: Get the length of a list.
• LRANGE: Get a range of elements from a list.
• LTRIM: Trim a list to a specified range.
• LMOVE: Atomically move elements from one list to another.
• LINDEX: Get an element at a specific index in a list.
• LSET: Set the value of an element in a list at a specific index.
• LREM: Remove elements from a list.
• LINSERT: Insert an element before or after another element in a list.
• LGETALL: Retrieve all elements in a list.

5. Set Operations

• SADD: Add one or more members to a set.
• SREM: Remove one or more members from a set.
• SISMEMBER: Check if a member exists in a set.
• SINTER: Return the intersection of multiple sets.
• SCARD: Return the cardinality (size) of a set.

6. Sorted Set Operations

• ZADD: Add one or more members to a sorted set, or update the score for members that already exist.
• ZREM: Remove one or more members from a sorted set.
• ZSCORE: Get the score associated with the given member in a sorted set.
• ZRANK: Determine the index of a member in a sorted set, with scores ordered from low to high.
• ZRANGE: Return a range of members in a sorted set, by index.

7. Pub/Sub (Publish/Subscribe)

• SUBSCRIBE: Subscribe to a channel to receive messages.
• UNSUBSCRIBE: Unsubscribe from a channel.
• PUBLISH: Publish a message to a channel.

8. Replication

• REPLCONF/PSYNC: Support for master-slave replication.

9. Persistence

• RDB Loading: Load key-value pairs from an RDB file on server startup.

10. Basic Commands

• PING: Test server responsiveness.
• ECHO: Echo back the provided message.
• INFO: Retrieve server information.

11. Advanced Commands

• WAIT: Block until write commands are acknowledged by replicas.

Installation

Prerequisites

• Node.js: Ensure you have Node.js installed (v14.x or higher recommended).
• TypeScript: The project is built using TypeScript, so make sure to have TypeScript installed.

Steps

1. Clone the Repository:

   git clone https://github.com/Vivek-C-Shah/Redis-CLI-TypeScript.git
   cd Redis-CLI-TypeScript

2. Install Dependencies:

   npm install

3. Run the Server:

   npm start

   You can specify a different port if needed.

4. Connect using Redis CLI:

   redis-cli -p 6380

Usage

Basic Key-Value Operations

• SET Command:

  SET mykey "Hello, World!"

• GET Command:

  GET mykey

Transactions

• Start a Transaction:

  MULTI

• Queue Commands:

  SET key1 "Value1"
  SET key2 "Value2"

• Execute the Transaction:

  EXEC

• Discard the Transaction:

  DISCARD

Stream Operations

• Add to Stream:

  XADD mystream * field1 "value1"

• Read from Stream:

  XRANGE mystream 0-0 +

List Operations

• Add Elements to a List:

  LPUSH mylist "first"
  RPUSH mylist "second"

• Remove Elements from a List:

  LPOP mylist
  RPOP mylist

• Get the Length of a List:

  LLEN mylist

• Get a Range of Elements from a List:

  LRANGE mylist 0 -1

• Trim a List to a Specified Range:

  LTRIM mylist 0 1

• Move Elements Between Lists:

  LMOVE list1 list2 LEFT RIGHT

• Get an Element by Index:

  LINDEX mylist 0

• Set the Value of an Element at a Specific Index:

  LSET mylist 0 "new_value"

• Remove Elements from a List:

  LREM mylist 1 "value_to_remove"

• Insert an Element Before or After Another Element:

  LINSERT mylist BEFORE "pivot_value" "new_value"

• Retrieve All Elements in a List:

  LGETALL mylist

Set Operations

• Add Elements to a Set:

  SADD myset "member1" "member2"

• Remove Elements from a Set:

  SREM myset "member1"

• Check for Membership in a Set:

  SISMEMBER myset "member2"

• Get the Intersection of Multiple Sets:

  SINTER myset1 myset2

• Get the Cardinality of a Set:

  SCARD myset

Sorted Set Operations

• Add Elements to a Sorted Set:

  ZADD myzset 1 "member1" 2 "member2"

• Remove Elements from a Sorted Set:

  ZREM myzset "member1"

• Get the Score of an Element in a Sorted Set:

  ZSCORE myzset "member2"

• Get the Rank of an Element in a Sorted Set:

  ZRANK myzset "member2"

• Get a Range of Elements from a Sorted Set:

  ZRANGE myzset 0 -1

Pub/Sub Operations

• Subscribe to a Channel:

  SUBSCRIBE mychannel

• Unsubscribe from a Channel:

  UNSUBSCRIBE mychannel

• Publish a Message to a Channel:

  PUBLISH mychannel "Hello, Subscribers!"

Replication

Start the server on a different port as a replica:

npm start -- --port 6380 --replicaof 127.0.0.1 6379

Persistence

Place an RDB file in the specified directory, and it will be loaded upon server start:

npm start -- --dir ./data --dbfilename dump.rdb

Project Structure

• src/: Contains all the TypeScript source code.

• dist/: Contains the compiled JavaScript files.

• test/: Tests for the various functionalities.

Contributing

Contributions are welcome! Please open an issue or submit a pull request with your changes. Ensure that your code is well-tested and documented.

License

This project is licensed under the MIT License.

Author

Vivek Shah

• LinkedIn: Vivek Shah
• GitHub: Vivek-C-Shah
• Twitter: @ShVivek25