node-hook-redis-lua

import redis lua scripts as a normal node module

Install

$ npm install --save hook-redis-lua

Usage

If you have a redis lua script in your project, you can load it and install it into ioredis clients, or any other client, as follows:

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

index.js:

const Redis = require('ioredis');
const fs = require('fs');
const { hook, unhook } = require('hook-redis-lua');

hook(); // Uses default redis-lua2js behavior for parsing name and numberOfKeys out of lua comments

const pdel = require('./pdel.lua');
const ioredis = new Redis();
ioredis.defineCommand(pdel.name, {
  lua: pdel.lua,
  numberOfKeys: pdel.numberOfKeys,
});

ioredis.pdel('*');

console.log(pdel.name); // pdel
console.log(pdel.numberOfKeys); // 1
console.log(pdel.lua); // the content of pdel.lua

unhook(); // can't require lua scripts from here

API

hook({ name, numberOfKeys })

Hooks .lua files to be parsed when called by require with redis-lua2js

name

Type: any | (filename: string, source: string) => any, default: undefined

How to determine the name of the lua script. If undefined, it will use the default redis-lua2js behavior of parsing lua comments for the name. If a constant is passed, it will use this constant for the name of all scripts. If a function is passed, it will be used to determine the name of the script. The function must be synchronous.

Example: (filename) => path.basename(filename, path.extname(filename))

numberOfKeys

Type: any | (filename: string, source: string) => any, default: undefined

How to determine the number of keys of the lua script. If undefined, it will use the default redis-lua2js behavior of parsing lua comments for the number of keys. If a constant is passed, it will use this constant for the number of keys of all scripts. If a function is passed, it will be used to determine the number of keys of the script. The function must be synchronous.

Example: (filename, source) => getNumberOfKeysSomehow(source)

unhook()

Removes .lua hooks from require

For details on the properties exported by the hook, check redis-lua2js.

Tests

npm test

License

See the LICENSE file for license rights and limitations (MIT).