cc-memdb

A distributed key/value caching system for computercraft inspired by memcached that uses ecnet2 for secure client/server communication

There is a terminal client client.lua and a programmatic client api_client.lua

To get started using it run the installer with

wget run https://raw.githubusercontent.com/GabrielleAkers/cc-memdb/refs/heads/main/install.lua
cd memdb

then run server.lua and take note of the address that prints in the terminal. dont forget to set the server chunk to forceload

to setup clients do the same steps as above and also create a file in the memdb directory called .memdb.client.config like this

{
  server = "theaddressstring",
  client_id = "mysupersecretclientid"
}

fill in the server address you noted down and come up with a client id. clients that share a client id will be able to share state.

when setting up the computers that will run both the server and client make sure to attach the modem to the top -- although this could be changed in the client.lua and server.lua files respectively.

example terminal client usage:

with the server running start the client and use it like this to set/get data:

memdb> client
memdb connection established
set name 'Gabby'
get name
VALUE "Gabby"
del name
get name
ERROR path does not exist

both set and get also support paths instead of plain keys

set c {d=1}
get c
VALUE {
  d = 1,
}
set c.d 2
get c.d
VALUE 2

you can also set an expiration time on the data like this

set temp_val {a=1} 10
get temp_val
VALUE {
  a = 1,
}

the number after the key and value is the lifetime, in this case 10 seconds. so 10 seconds later you might try

get temp_val
ERROR path does not exist

the value has been forgotten. if you dont pass a lifetime or set it to 0 then it will be infinite. if the lifetime exceeds 30 days then it's treated as the number of seconds since the epoch so you can set an exact expiration date and time for long lived values.

using get_id you can get a unique identifier for the path you give it

set a 'someval'
get_id a
VALUE "954352a765d1012e6f52a7413dad44caaaaa18ff3e9074c50118638937a1bf90"

you can use this id with the safe_set command to only set the new value if the id wasnt changed -- like by another client messing with the data at the same path in between you setting it the first time and now

set a 'some other val'
get a
VALUE "some other val"
safe_set a 7 954352a765d1012e6f52a7413dad44caaaaa18ff3e9074c50118638937a1bf90
get a
VALUE "some other val"

you can also do things like append/prepend to lists:

set mylist {1}
get mylist
VALUE {
  1,
}
append mylist 2
get mylist
VALUE {
  1,
  2
}
prepend mylist 'this one has spaces'
get mylist
VALUE {
  "this one has spaces",
  1,
  2
}

or incr/decr numbers:

set mynumber 6
get mynumber
VALUE 6
incr mynumber 2.2
get mynumber
VALUE 8.2
decr mynumber 1.5
get mynumber
VALUE 6.7

to view a list of all available commands use list_cmd and you can get help with a command using help <command>