Introduction

Explanatory article: https://medium.com/@kyberneees/introducing-item-store-redis-a-high-performance-redis-based-item-store-for-efficient-data-4510d4e9fcf9

This module provides classes that implement repositories for storing and retrieving data in a Redis database:

• ItemRepository: The class provides basic functionality for storing and retrieving individual items, as well as querying all items or a subset of items in a paginated manner. The items are stored in Redis using a key-value data model with expiration support.
• SortedItemRepository: The class provides a more advanced functionality for storing and retrieving items in a sorted manner. The items are sorted based on a numeric score, and can be queried in a paginated manner as well. The items are stored in Redis using a sorted set data model, making it more performant and efficient at scale (see demos/benchmark.ts). However, this model does not supports automatic expiration.

import { ItemRepository, SortedItemRepository, IItem } from 'item-store-redis'

Class ItemRepository

Constructor

constructor (name: string, redis?: Redis | Cluster)

Usage

import { ItemRepository } from 'item-store-redis'
import Redis from 'ioredis'

const redis = new Redis({ host: 'localhost', port: 6379 })
const repository = new ItemRepository<T>('my-unsorted-repo', redis)
...

Interface

interface IItemRepository<T> {
  name: string
  redis: Redis | Cluster
  set: (item: IItem<T>, expirationInSeconds?: number) => Promise<void>
  getById: (id: string) => Promise<IItem<T> | null>
  getAll: () => Promise<IItem<T>[]>
  getPaginated: (page: number, pageSize: number) => Promise<IPaginatedItems<T>>
  hasItem: (id: string) => Promise<boolean>
  deleteById: (id: string) => Promise<void>
  deleteAll: () => Promise<void>
  count: () => Promise<number>
}

Class SortedItemRepository

Constructor

constructor (name: string, redis?: Redis | Cluster)

Usage

import { SortedItemRepository, SortedItem } from 'item-store-redis'
import Redis from 'ioredis'

const redis = new Redis({ host: 'localhost', port: 6379 })
const repository = new SortedItemRepository<T>('my-sorted-repo', redis)
...

Interface

/**
 * ISortedItemRepository is an interface that defines the methods for interacting with a
 * sorted item repository that uses Redis as the storage system.
 */
export interface ISortedItemRepository<T> {
  name: string
  redis: Redis | Cluster

  /**
   * Sets an item in the repository.
   * @param item - The item to be added.
   */
  set: (item: IItem<T>) => Promise<void>

  /**
   * Retrieves an item from the repository by its ID.
   * @param id - The ID of the item to retrieve.
   * @returns The item if found, null otherwise.
   */
  getById: (id: string) => Promise<IItem<T> | null>

  /**
   * Retrieves all items from the repository.
   * @returns An array of all items in the repository.
   */
  getAll: () => Promise<IItem<T>[]>

  /**
   * Retrieves a paginated set of items from the repository.
   * @param page - The page number to retrieve.
   * @param pageSize - The number of items per page.
   * @returns An object containing the paginated items and the total count of items.
   */
  getPaginated: (page: number, pageSize: number) => Promise<IPaginatedItems<T>>

  /**
   * Retrieves the score of an item by its ID.
   * @param id - The ID of the item.
   * @returns The score of the item if found, null otherwise.
   */
  getItemScoreById: (id: string) => Promise<number | null>

  /**
   * Retrieves items by their scores within a specified range.
   * @param min - The minimum score value.
   * @param max - The maximum score value.
   * @returns An array of items with scores within the specified range.
   */
  getItemsByScore: (min: number, max: number) => Promise<IItem<T>[]>

  /**
   * Deletes a page of items from the repository.
   * @param page - The page number of items to delete.
   * @param pageSize - The number of items per page.
   */
  deletePage: (page: number, pageSize: number) => Promise<void>

  /**
   * Checks if an item exists in the repository by its ID.
   * @param id - The ID of the item.
   * @returns A boolean indicating whether the item exists.
   */
  hasItem: (id: string) => Promise<boolean>

  /**
   * Deletes an item from the repository by its ID.
   * @param id - The ID of the item to delete.
   */
  deleteById: (id: string) => Promise<void>

  /**
   * Deletes all items from the repository.
   */
  deleteAll: () => Promise<void>

  /**
   * Retrieves the count of items in the repository.
   * @returns The count of items.
   */
  count: () => Promise<number>

  /**
   * Retrieves the first N items from the repository.
   * @param n - The number of items to retrieve.
   * @returns An array of the first N items.
   */
  getFirstNItems: (n: number) => Promise<IItem<T>[]>

  /**
   * Retrieves the last N items from the repository.
   * @param n - The number of items to retrieve.
   * @returns An array of the last N items.
   */
  getLastNItems: (n: number) => Promise<IItem<T>[]>

  /**
   * Retrieves items within a specified index range.
   * @param start - The starting index.
   * @param end - The ending index.
   *
   * @returns An array of items within the specified index range.
   */
  getItemsInRange: (start: number, end: number) => Promise<IItem<T>[]>

  /**
   *
   * Checks if any items exist within a specified score range.
   * @param min - The minimum score value.
   * @param max - The maximum score value.
   * @returns A boolean indicating whether any items exist within the specified score range.
   */
  existsInRange: (min: number, max: number) => Promise<boolean>

  /**
   *
   * Retrieves the next N items with scores greater than a specified score.
   * @param score - The score to compare.
   * @param n - The number of items to retrieve.
   * @returns An array of the next N items with scores greater than the specified score.
   */
  getNextNItemsGreaterThanScore: (score: number, n: number) => Promise<IItem<T>[]>
}

License

MIT License

Copyright (c) 2023 21no.de

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