feat: expose production/consumption metrics as metrics.prom

control.lua

@@ -0,0 +1,83 @@
+-- Config
+local steps_per_tick = 1      -- process 1 surface×force per tick
+local flush_interval_ticks = 60 * 15  -- flush every n ticks
+
+-- State
+local queue = {}
+local buffer = {}
+local last_flush_tick = 0
+
+-- Initialize queue with all surface×force pairs
+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})
+        end
+    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(
+                "production{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(
+                "consumption{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(
+                "production{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(
+                "consumption{type=\"fluid\",surface=\"%s\",force=\"%s\",name=\"%s\"} %d",
+                surface_name, force_name, fluid, count
+            ))
+        end
+    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()
+    process_queue()
+    maybe_flush()
+end)
+
+-- Bootstrap
+script.on_init(function()
+    last_flush_tick = game.tick
+    prepare_queue()
+end)