LSQ-Cache NPM module

Develop and deploy applications with the LSQ Cache module, the module provides first-class TypeScript support and makes it easy to call LSQ Cache API services.

Getting Started

Assuming that you have Node JS (Recommended is 16.x or 18.x) setup on your machine, install lsq-cache by running below command

npm install lsq-cache

Usage

• For LSQ Lapp development, import the lsq-cache before the main method as shown below.

const CacheApp = require('lsq-cache').CacheApp;

function main(queryString, body, callback) {
  (async function () {
    try {
      const myCacheApp = new CacheApp(
        '<cache token here>', // refer 'Initialize the module' section to obtain the token
        '21', // values could be 1, 11, 21, 31
      );
      const setItemRes = await myCacheApp.item.set('k1', 'v1', 60 * 20);
      console.log(setItemRes);

      const getItemRes = await myCacheApp.item.get('k1');
      console.log(getItemRes);

      callback(null, {
        setItemRes,
        getItemRes,
      });
    } catch (error) {
      console.log(error);
    }
  })();
}

• For non lapp development, please import the module to create a new instance of the cache app.

const CacheApp = require('lsq-cache').CacheApp;

async function main() {
  try {
    const myCacheApp = new CacheApp(
      '<cache token here>', // refer 'Initialize the module' section to obtain the token
      '21', // values could be 1, 11, 21, 31
    );
    const setItemRes = await myCacheApp.item.set('k1', 'v1', 60 * 20);
    console.log(setItemRes);

    const getItemRes = await myCacheApp.item.get('k1');
    console.log(getItemRes);
  } catch (error) {
    console.log(error);
  }
}

main();

Initialize the module

To use the module, user is required to pass the following arguments to the CacheApp class constructor:

• Token - Please contact the LeadSquared support team for enabling cache service for the tenant and obtaining the token.
• Region - Valid values are 1, 11, 21, 31 (1 for SGP, 11 for US, 21 for MUM and 31 for IR)

Data Types

Item

get(key_name)

For the key, gets the value if it exists or else returns null

Arguments

• key_name (string | number): Name of the key

Example:

myCacheApp.item.get('key_name'); // returns string

set(key_name, key_value, ttl)

For the key, sets (overrides if already present) a value, Optionally a time to live (TTL) attribute can be set to automatically expire the key and its value

Arguments

• key_name (string | number): Name of the key
• key_value (any): Value of the key
• ttl (number): Time to live (seconds), this argument is optional

Example:

myCacheApp.item.set('key_name', 'key_value'); // returns boolean

// with TTL
myCacheApp.item.set('key_name', 'key_value', 600); // returns boolean

exists(key_name)

For the key, checks if a value exists by returning 1 or else returns 0

Arguments

• key_name (string | number): Name of the key

Example:

myCacheApp.item.exists('key_name'); // returns 0 if key doesnt exist else 1

getExpiry(key_name)

For the key, gets the expiry lifetime (in seconds) for it

Arguments

• key_name (string | number): Name of the key

Example:

myCacheApp.item.getExpiry('key_name'); // returns number

setExpireAt(key_name, ttl)

For the key, sets the expiry lifetime (in seconds) for it

Arguments

• key_name (string | number): Name of the key
• ttl (number): Time to live (seconds)

Example:

myCacheApp.item.setExpireAt('key_name', 600); // returns boolean

increment(key_name, incrBy)

For the key, increments the value and returns the incremented value. Optionally a custom increment value can be provided or else the default value is 1

Arguments

• key_name (string | number): Name of the key
• incrBy (number): Increment, this argument is optional

Example:

myCacheApp.item.increment('key_name'); // returns number

// with custom incrBy
myCacheApp.item.increment('key_name', 3); // returns number

decrement(key_name, decrBy)

For the key, decrements the value and returns the decremented value. Optionally a custom decrement value can be provided or else the default is 1

Arguments

• key_name (string | number): Name of the key
• decrBy (number): Decrement, this argument is optional

Example:

myCacheApp.item.decrement('key_name'); // returns number

// with custom decrBy
myCacheApp.item.decrement('key_name', 3); // returns number

delete(key_name)

For the key, deletes the key if it exists and returns 1 if key is deleted else 0

Arguments

• key_name (string | number): Name of the key

Example:

myCacheApp.item.delete('key_name'); // returns number

scan(page_index)

For the page index, returns the list of keys created in the namespace along with the page index of the next set of results

NOTE:

1. The first page will begin with pageIndex 0
2. This method should be called recursively until you get the same page index consecutively to get the complete list of items

Arguments

• page_index (number): Page Index

Example:

myCacheApp.item.scan(10); // returns { "nextIndex": number, "resultSet": string[] }

Set

add(key_name, key_value)

For the key, adds an item (i.e. the key_value argument) to a cache app set data structure

NOTE: Sets cannot contain duplicate records

Arguments

• key_name (string | number): Name of the set
• key_value (any): Item to be added to the set

Example:

myCacheApp.set.add('key_name', 'key_value'); // returns number

get(key_name)

For the key, gets all the items in the form of a array of string (i.e. a list data structure is returned)

Arguments

• key_name (string | number): Name of the set

Example:

myCacheApp.set.get('key_name'); // returns list (array of string)

exists(key_name, key_value)

For the key, checks if the key_value is a member in the cache app set data structure

Arguments

• key_name (string | number): Name of the key
• key_value (any): Item to be added to the set

Example:

myCacheApp.set.exists('key_name', 'key_value'); // returns boolean

delete(key_name, key_value)

For the key, removes the key_value from the cache app set data structure if it exists

Arguments

• key_name (string | number): Name of the key
• key_value (any): Item to be removed fromthe set

Example:

myCacheApp.set.delete('key_name', 'key_value'); // returns number

Hashset

add(key_name, key_value)

For the key, creates a hashset for it from a given dictionary data structure (i.e from key_value argument)

NOTE: The dictionary must be valid in the format {“key”: ”value”, ...}

Arguments

• key_name (string | number): Name of the hashset
• key_value (object): JS object i.e Dictionary data structure

Example:

myCacheApp.hashSet.add('key_name', { field1: 'value1', field2: 'value2' }); // returns boolean

addOrUpdateField(key_name, field_name, field_value)

For the key, if the field (i.e the field_name argument) is already present in the hashset then it will be updated with the field value (i.e the field_value argument) or else the field (i.e the field_name argument) with the field value (i.e the field_value argument) will be added to the existing hashset

NOTE:

1. If the key is not present then a new hashset will be created
2. The field_value will always be of stored as string or number type in the cache app

Arguments

• key_name (string | number): Name of the hashset
• field_name (string | number): Name of the field in the hashset
• field_value (any): Value of the field in the hashset

Example:

myCacheApp.hashSet.add_field('key_name', 'field1', 'field_value_1'); // returns number

get(key_name, field_name)

For the key, retrieves the hashset for it, optionally if the field name (i.e the field_name argument) can be passed to get its field value

Arguments

• key_name (string | number): Name of the hashset
• field_name (string | number): Name of the field in the hashset, this is an optional argument

Example:

myCacheApp.hashSet.get('key_name'); // returns complete JS object i.e dictionary data structure

myCacheApp.hashSet.get('key_name', 'field_name1'); // returns string

delete(key_name, field_name)

For the key, deletes a field (i.e. the field_name argument) from the hashset if it exists and returns 1 or else returns 0

NOTE: To delete the entire hashset, use myCacheApp.item.delete(key_name)

Arguments

• key_name (string | number): Name of the hashset
• field_name (string | number): Name of the field in the hashset

Example:

myCacheApp.hashSet.delete('key_name', 'field_name1'); // returns number

Info

getMemory(key_name)

For the key, gets the memory (in bytes) consumed by it and its corresponding value

Arguments

• key_name (string | number): Name of the key

Example:

myCacheApp.info.getMemory('key_name'); // returns number

getType(key_name)

For the key, gets the data type of its corresponding key

Arguments

• key_name (string | number): Name of the key

Example:

myCacheApp.info.getType('key_name'); // returns string