feat(prometheus-exporter): add metrics-pole for power metrics

prometheus-exporter/control.lua

@@ -1,83 +1,55 @@
--- Config
-local steps_per_tick = 1      -- process 1 surface×force per tick
-local flush_interval_ticks = 60 * 15  -- flush every n ticks
+local metrics = require("utils.metrics")
 
--- State
+-- config
+local flush_interval_ticks = 60 -- flush every n ticks
+
+-- state
+--- @type table<number, fun()>
 local queue = {}
-local buffer = {}
-local last_flush_tick = 0
 
--- Initialize queue with all surface×force pairs
+--- @type table<number, string>
+local buffer = {}
+local last_reset = 0
+
+-- queue operations to perform for each round of metric processing
+-- that way, avoid doing too much work in a single game tick and causing UPS inconsistencies
 local function prepare_queue()
     queue = {}
-    for surface_name, _ in pairs(game.surfaces) do
-        for force_name, _ in pairs(game.forces) do
-            table.insert(queue, {surface_name = surface_name, force_name = force_name})
+    for _, surface in pairs(game.surfaces) do
+        for _, force in pairs(game.forces) do
+            table.insert(queue, metrics.calc_item_production_statistics(buffer, surface, force))
+            table.insert(queue, metrics.calc_fluid_production_statistics(buffer, surface, force))
         end
+        table.insert(queue, metrics.calc_power_statistics(buffer, surface))
     end
 end
 
--- Process a few items from the queue each tick
 local function process_queue()
-    for i = 1, steps_per_tick do
-        local entry = table.remove(queue, 1)
-        if not entry then break end
-
-        local surface_name, force_name = entry.surface_name, entry.force_name
-        local force = game.forces[force_name]
-
-        -- Items
-        local item_stats = force.get_item_production_statistics(surface_name)
-        for item, count in pairs(item_stats.input_counts) do
-            table.insert(buffer, string.format(
-                "factorio_production_total{type=\"item\",surface=\"%s\",force=\"%s\",name=\"%s\"} %d",
-                surface_name, force_name, item, count
-            ))
-        end
-        for item, count in pairs(item_stats.output_counts) do
-            table.insert(buffer, string.format(
-                "factorio_consumption_total{type=\"item\",surface=\"%s\",force=\"%s\",name=\"%s\"} %d",
-                surface_name, force_name, item, count
-            ))
-        end
-
-        -- Fluids
-        local fluid_stats = force.get_fluid_production_statistics(surface_name)
-        for fluid, count in pairs(fluid_stats.input_counts) do
-            table.insert(buffer, string.format(
-                "factorio_production_total{type=\"fluid\",surface=\"%s\",force=\"%s\",name=\"%s\"} %d",
-                surface_name, force_name, fluid, count
-            ))
-        end
-        for fluid, count in pairs(fluid_stats.output_counts) do
-            table.insert(buffer, string.format(
-                "factorio_consumption_total{type=\"fluid\",surface=\"%s\",force=\"%s\",name=\"%s\"} %d",
-                surface_name, force_name, fluid, count
-            ))
-        end
+    local entry = table.remove(queue, 1)
+    if entry then
+        entry()
     end
 end
 
--- Flush buffer to file periodically
-local function maybe_flush()
-    if #queue == 0 and game.tick - last_flush_tick >= flush_interval_ticks then
-        if #buffer > 0 then
-            helpers.write_file("metrics.prom", table.concat(buffer, "\n"), false)
-            buffer = {}
-        end
-        last_flush_tick = game.tick
-        prepare_queue()
-    end
-end
-
--- Main tick handler
-script.on_event(defines.events.on_tick, function()
+local function tick()
     process_queue()
-    maybe_flush()
-end)
 
--- Bootstrap
+    if #queue == 0 and #buffer > 0 then
+        helpers.write_file("metrics.prom", table.concat(buffer, "\n"), false)
+        buffer = {}
+    end
+
+    if #queue == 0 and game.tick - last_reset >= flush_interval_ticks then
+        prepare_queue()
+        last_reset = game.tick
+    end
+end
+
+-- main tick handler
+script.on_event(defines.events.on_tick, tick)
+
+-- startup
 script.on_init(function()
-    last_flush_tick = game.tick
+    last_reset = game.tick
     prepare_queue()
 end)