Some initial setmap and effect set operations

effect_set.lua

@@ -0,0 +1,170 @@
+
+-- Defines the relational data structure used for storing status effects.
+--
+--
+-- Effects
+--
+-- A single effect record has these components:
+--
+--   A unique ID (uid)
+--
+--   A boolean, whether it is dynamic (dynamic)
+--
+--   The effect type name (effect_type)
+--
+--   A set of names of players it applies to (players)
+--
+--   A set of tags it has (tags)
+--
+--   A set of monoids it belongs to (monoids)
+--
+--   A table from monoid names to monoidal values (values), if it is dynamic
+--
+--   A duration (duration), either the string "perm" or a number of seconds
+--
+--   The time it started (time_started)
+--
+--
+-- Effect Set
+--
+-- An effect set represents a many-to-many relation by holding for each index a
+-- map from indices to a set of records it indexes. Since the unique ID should be
+-- unique, a set of records can instead be represented by a map from IDs to
+-- records. The ID table can instead be a simple map to records, since each
+-- effect can only have one ID.
+--
+-- Currently, it has index tables:
+--
+-- id_table (one-to-one)
+-- player_table (many-to-many)
+-- tag_table (many-to-many)
+-- monoid_table (many-to-many)
+-- name_table (one-to-many)
+-- perm_table (one-to-many)
+--
+--
+-- To serialize, it suffices to just serialize the ID-indexed table, since all
+-- records have an ID.
+--
+-- It also keeps track of the next unique ID in next_id
+--
+--
+-- Setmap
+--
+-- A set map is a map from indices to sets of records. They are used to represent
+-- many-to-many and one-to-many relations.
+
+
+-- Returns a set of results
+local function setmap_get(setmap, index)
+	return setmap[index]
+end
+
+
+local function setmap_insert(setmap, indices, record)
+	local uid = record.uid
+
+	for k, index in pairs(indices) do
+		local set = setmap[index]
+		
+		if (not set) then
+			set = {}
+			setmap[index] = set
+		end
+
+		setmap[index][uid] = record
+	end
+end
+
+
+local function setmap_delete(setmap, indices, record)
+	local uid = record.uid
+
+	for k, index in pairs(indices) do
+		local set = setmap[index]
+
+		if set ~= nil then
+			set[uid] = nil
+
+			-- If the set is empty we should clean it up to prevent
+			-- leaks
+			if next(set) == nil then
+				setmap[index] = nil
+			end
+		end
+	end
+end
+
+
+monoidal_effects.static = 1
+monoidal_effects.dynamic = 2
+
+
+local function record(id, dyn, effect_type, players, tags, monoids, dur, values)
+
+	return { uid = id,
+		 dynamic = dyn,
+		 effect_type = effect_type,
+		 players = players,
+		 tags = tags,
+		 monoids = monoids
+		 values = values,
+		 duration = dur,
+		 time_started = os.time()
+	}
+end
+
+
+-- Prepares for serialization.
+local function prep_record(record, cur_time)
+
+	-- Save the amount of time left
+	if (record.duration ~= "perm") then
+		record.duration = record.duration - (cur_time - record.time_started)
+	end
+
+	record.time_started = nil
+end
+
+
+-- Sets the time_started nicely.
+local function unprep_record(record, cur_time)
+	record.time_started = cur_time
+end
+
+
+local function make_db()
+
+	local db = {}
+
+	db.next_id = 0
+
+	db.uid_table = {}
+	db.player_table = {}
+	db.tag_table = {}
+	db.monoid_table = {}
+	db.name_table = {}
+	db.perm_table = {}
+end
+
+
+-- Mutates the table to have the new record
+local function insert_record(db, record)
+	local uid = record.uid
+	
+	db.uid_table[uid] = record
+	setmap_insert(db.player_table, record.players, record)
+	setmap_insert(db.tag_table, record.tags, record)
+	setmap_insert(db.monoid_table, record.monoids, record)
+	setmap_insert(db.name_table, {record.effect_type}, record)
+
+	local perm
+
+	if (record.duration == "perm") then
+		perm = true
+	else
+		perm = false
+	end
+	
+	setmap_insert(db.name_table, {perm}, record)
+end