Redis-lua2js NPM

redis-lua2js

convert redis lua scripts to a useful node module

Install

$ npm install --save-dev redis-lua2js

Usage

This module is not meant to be used on its own, but rather as part of another module, such as gulp-redis-lua2js or hook-redis-lua. In here, I will demonstrate the usage with the help of module-from-string:

index.js:

import { readFileSync } from 'node:fs';
import { join } from 'node:path';
import Redis from 'ioredis';
import lua2js from 'redis-lua2js';
import { requireFromString } from 'module-from-string';

const ioredis = new Redis();
const lua = readFileSync(join(__dirname, 'pdel.lua'));
const js = lua2js(lua); // This is a node module string, the template of which you can see in src/lua.js
const pdel = requireFromString(js); // Parse the module as a string

ioredis.defineCommand(pdel.name, {
  lua: pdel.lua,
  numberOfKeys: pdel.numberOfKeys,
});
ioredis.pdel('*');

pdel.lua:

--!/usr/bin/env lua
-- name pdel
-- nkeys 1

local function deleteKeys (keys)
  for i, name in ipairs(keys) do
    redis.call("DEL", name)
  end
end

if type(redis.replicate_commands) == 'function' and redis.replicate_commands() then -- Redis 3.2+
  local count = 0
  local cursor = "0"
  local keys

  repeat
    cursor, keys = unpack(redis.call("SCAN", cursor, "MATCH", KEYS[1]))
    count = count + #keys
    deleteKeys(keys)
  until cursor == "0"

  return count
else
  local keys = redis.call("KEYS", KEYS[1])
  deleteKeys(keys)
  return #keys
end

API

lua2js(lua, { name, numberOfKeys, type = "commonjs" })

Takes the contents of a lua script and outputs a node module, as a string, which can be used to load the script into a redis client such as ioredis easily.