Add more Prometheus metrics (#12274)

src/emerge.h

@@ -24,6 +24,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "network/networkprotocol.h"
 #include "irr_v3d.h"
 #include "util/container.h"
+#include "util/metricsbackend.h"
 #include "mapgen/mapgen.h" // for MapgenParams
 #include "map.h"
 
@@ -69,6 +70,14 @@ enum EmergeAction {
 	EMERGE_GENERATED,
 };
 
+const static std::string emergeActionStrs[] = {
+	"cancelled",
+	"errored",
+	"from_memory",
+	"from_disk",
+	"generated",
+};
+
 // Callback
 typedef void (*EmergeCompletionCallback)(
 	v3s16 blockpos, EmergeAction action, void *param);
@@ -138,7 +147,7 @@ public:
 	MapSettingsManager *map_settings_mgr;
 
 	// Methods
-	EmergeManager(Server *server);
+	EmergeManager(Server *server, MetricsBackend *mb);
 	~EmergeManager();
 	DISABLE_CLASS_COPY(EmergeManager);
 
@@ -197,6 +206,9 @@ private:
 	u32 m_qlimit_diskonly;
 	u32 m_qlimit_generate;
 
+	// Emerge metrics
+	MetricCounterPtr m_completed_emerge_counter[5];
+
 	// Managers of various map generation-related components
 	// Note that each Mapgen gets a copy(!) of these to work with
 	BiomeGen *biomegen;
@@ -218,5 +230,7 @@ private:
 
 	bool popBlockEmergeData(v3s16 pos, BlockEmergeData *bedata);
 
+	void reportCompletedEmerge(EmergeAction action);
+
 	friend class EmergeThread;
 };