moduleapi: Add module:shared(), a way to easily share data between multiple loaded modules

1 files changed, 23 insertions, 0 deletions

diff --git a/core/moduleapi.lua b/core/moduleapi.lua
index 44ae9a07..7a4d1fa6 100644
--- a/core/moduleapi.lua
+++ b/core/moduleapi.lua
@@ -129,6 +129,29 @@ function api:depends(name)
 	return mod;
 end
 
+-- Returns one or more shared tables at the specified virtual paths
+-- Intentionally does not allow the table at a path to be _set_, it
+-- is auto-created if it does not exist.
+function api:shared(...)
+	local paths = { n = select("#", ...), ... };
+	local data_array = {};
+	local default_path_components = { self.host, self.name };
+	for i = 1, paths.n do
+		local path = paths[i];
+		if path:sub(1,1) ~= "/" then -- Prepend default components
+			local n_components = select(2, path:gsub("/", "%1"));
+			path = (n_components<#default_path_components and "/" or "")..t_concat(default_path_components, "/", 1, #default_path_components-n_components).."/"..path;
+		end
+		local shared = shared_data[path];
+		if not shared then
+			shared = {};
+			shared_data[path] = shared;
+		end
+		t_insert(data_array, shared);
+	end
+	return unpack(data_array);
+end
+
 function api:get_option(name, default_value)
 	local value = config.get(self.host, self.name, name);
 	if value == nil then