Resource data storage

Resource data storage

Server-side; since 0.1.4.

Three resource-scoped persistence functions support map saves and Lua exports. They do not expose arbitrary filesystem paths or MySQL connections.

Function	Return	File in the calling resource
readResourceData(key)	JSON text string, or false for missing/invalid/unreadable data	.storage/data-KEY.json
writeResourceData(key, json)	boolean success; json must be a nonempty valid JSON string	.storage/data-KEY.json
writeResourceText(key, text)	boolean success; writes nonempty text without validating/executing Lua	.storage/data-KEY.lua

Keys contain 1-64 ASCII letters, digits, underscores or hyphens. Pass a key only, not a path, prefix data- or extension. Each resource can access only its own storage root. readResourceData reads JSON only; it does not read a writeResourceText Lua export. No matching generic Lua-text read function is exposed here.

Example

local json = toJSON({format="my-layout", version=1, objects={}})
if json and writeResourceData("layout", json) then
    outputDebugString("Layout saved")
else
    outputDebugString("Layout save failed", 1)
end
local saved = readResourceData("layout")
local layout = saved and fromJSON(saved)
-- Validate your own schema before using layout; JSON validity is not a schema check.

local exported = writeResourceText("layout_export", "MapScene = {}\n")
-- This only writes text. It neither starts a resource nor executes that text.

Safety and limits

Maximum payload size: 1048576 bytes (1 MiB) per file. Before writing, the current storage directory is checked: a write is refused if existing regular files already total more than 64 MiB or their count exceeds 512; backups/temp files also count. These are pre-write admission checks, not a reservation of space for the incoming file and backup. Filesystem errors can also cause false. The map editor adds a stricter 1000000-byte transfer limit.

Writes use a temporary file and replacement, retaining one .bak copy when overwriting an existing destination. Keep independent backups; this is not a database transaction across multiple keys or an unlimited revision archive. Path traversal and symlink/junction escapes are rejected. Never accept untrusted client text as executable exported Lua; writeResourceText does not validate its content for you.

The functions validate storage/JSON, not gameplay permissions: server scripts must authorize who may submit data, validate schema and bound request sizes/rates. The editor implements those checks and a named-map session lock. See Map editor for its filenames and Map scene deployment for the explicit publication step.