Record MapBlock modification reasons as flags instead of strings

This improves performance of MapBlock::raiseModified by a factor of 6.
Also, clean up mapblock.h a bit and inline small functions.

6 files changed, 286 insertions, 233 deletions

diff --git a/src/environment.cpp b/src/environment.cpp
index 96353dffb..dc18fd58f 100644
--- a/src/environment.cpp
+++ b/src/environment.cpp
@@ -873,7 +873,7 @@ void ServerEnvironment::clearAllObjects()
 			if(block){
 				block->m_static_objects.remove(id);
 				block->raiseModified(MOD_STATE_WRITE_NEEDED,
-						"clearAllObjects");
+						MOD_REASON_CLEAR_ALL_OBJECTS);
 				obj->m_static_exists = false;
 			}
 		}
@@ -952,7 +952,7 @@ void ServerEnvironment::clearAllObjects()
 			block->m_static_objects.m_stored.clear();
 			block->m_static_objects.m_active.clear();
 			block->raiseModified(MOD_STATE_WRITE_NEEDED,
-					"clearAllObjects");
+				MOD_REASON_CLEAR_ALL_OBJECTS);
 			num_objs_cleared += num_stored + num_active;
 			num_blocks_cleared++;
 		}
@@ -1139,7 +1139,7 @@ void ServerEnvironment::step(float dtime)
 			// set block to be saved when it is unloaded
 			if(block->getTimestamp() > block->getDiskTimestamp() + 60)
 				block->raiseModified(MOD_STATE_WRITE_AT_UNLOAD,
-						"Timestamp older than 60s (step)");
+					MOD_REASON_BLOCK_EXPIRED);
 
 			// Run node timers
 			std::map<v3s16, NodeTimer> elapsed_timers =
@@ -1530,7 +1530,7 @@ u16 ServerEnvironment::addActiveObjectRaw(ServerActiveObject *object,
 
 			if(set_changed)
 				block->raiseModified(MOD_STATE_WRITE_NEEDED,
-						"addActiveObjectRaw");
+					MOD_REASON_ADD_ACTIVE_OBJECT_RAW);
 		} else {
 			v3s16 p = floatToInt(objectpos, BS);
 			errorstream<<"ServerEnvironment::addActiveObjectRaw(): "
@@ -1579,7 +1579,7 @@ void ServerEnvironment::removeRemovedObjects()
 			if (block) {
 				block->m_static_objects.remove(id);
 				block->raiseModified(MOD_STATE_WRITE_NEEDED,
-						"removeRemovedObjects/remove");
+					MOD_REASON_REMOVE_OBJECTS_REMOVE);
 				obj->m_static_exists = false;
 			} else {
 				infostream<<"Failed to emerge block from which an object to "
@@ -1604,7 +1604,7 @@ void ServerEnvironment::removeRemovedObjects()
 					block->m_static_objects.m_stored.push_back(i->second);
 					block->m_static_objects.m_active.erase(id);
 					block->raiseModified(MOD_STATE_WRITE_NEEDED,
-							"removeRemovedObjects/deactivate");
+						MOD_REASON_REMOVE_OBJECTS_DEACTIVATE);
 				}
 			} else {
 				infostream<<"Failed to emerge block from which an object to "
@@ -1690,8 +1690,7 @@ void ServerEnvironment::activateObjects(MapBlock *block, u32 dtime_s)
 		// Clear stored list
 		block->m_static_objects.m_stored.clear();
 		block->raiseModified(MOD_STATE_WRITE_NEEDED,
-				"stored list cleared in activateObjects due to "
-				"large amount of objects");
+			MOD_REASON_TOO_MANY_OBJECTS);
 		return;
 	}
 
@@ -1812,7 +1811,7 @@ void ServerEnvironment::deactivateFarObjects(bool force_delete)
 			block->m_static_objects.insert(id, s_obj);
 			obj->m_static_block = blockpos_o;
 			block->raiseModified(MOD_STATE_WRITE_NEEDED,
-					"deactivateFarObjects: Static data moved in");
+				MOD_REASON_STATIC_DATA_ADDED);
 
 			// Delete from block where object was located
 			block = m_map->emergeBlock(old_static_block, false);
@@ -1825,7 +1824,7 @@ void ServerEnvironment::deactivateFarObjects(bool force_delete)
 			}
 			block->m_static_objects.remove(id);
 			block->raiseModified(MOD_STATE_WRITE_NEEDED,
-					"deactivateFarObjects: Static data moved out");
+				MOD_REASON_STATIC_DATA_REMOVED);
 			continue;
 		}
 
@@ -1890,8 +1889,7 @@ void ServerEnvironment::deactivateFarObjects(bool force_delete)
 					// Only mark block as modified if data changed considerably
 					if(shall_be_written)
 						block->raiseModified(MOD_STATE_WRITE_NEEDED,
-								"deactivateFarObjects: Static data "
-								"changed considerably");
+							MOD_REASON_STATIC_DATA_CHANGED);
 				}
 			}
 
@@ -1937,8 +1935,7 @@ void ServerEnvironment::deactivateFarObjects(bool force_delete)
 					// Only mark block as modified if data changed considerably
 					if(shall_be_written)
 						block->raiseModified(MOD_STATE_WRITE_NEEDED,
-								"deactivateFarObjects: Static data "
-								"changed considerably");
+							MOD_REASON_STATIC_DATA_CHANGED);
 
 					obj->m_static_exists = true;
 					obj->m_static_block = block->getPos();
diff --git a/src/map.cpp b/src/map.cpp
index 47c66055d..9974ff363 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -1436,7 +1436,7 @@ void Map::timerUpdate(float dtime, float unload_timeout,
 
 				// Save if modified
 				if (block->getModified() != MOD_STATE_CLEAN && save_before_unloading) {
-					modprofiler.add(block->getModifiedReason(), 1);
+					modprofiler.add(block->getModifiedReasonString(), 1);
 					if (!saveBlock(block))
 						continue;
 					saved_blocks_count++;
@@ -2412,7 +2412,7 @@ void ServerMap::finishBlockMake(BlockMakeData *data,
 			Set block as modified
 		*/
 		block->raiseModified(MOD_STATE_WRITE_NEEDED,
-				"finishBlockMake expireDayNightDiff");
+			MOD_REASON_EXPIRE_DAYNIGHTDIFF);
 	}
 
 	/*
@@ -2981,7 +2981,7 @@ void ServerMap::save(ModifiedState save_level)
 					save_started = true;
 				}
 
-				modprofiler.add(block->getModifiedReason(), 1);
+				modprofiler.add(block->getModifiedReasonString(), 1);
 
 				saveBlock(block);
 				block_count++;
diff --git a/src/mapblock.cpp b/src/mapblock.cpp
index ca80c39d7..7ad67c589 100644
--- a/src/mapblock.cpp
+++ b/src/mapblock.cpp
@@ -38,6 +38,30 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #define PP(x) "("<<(x).X<<","<<(x).Y<<","<<(x).Z<<")"
 
+static const char *modified_reason_strings[] = {
+	"initial",
+	"reallocate",
+	"setIsUnderground",
+	"setLightingExpired",
+	"setGenerated",
+	"setNode",
+	"setNodeNoCheck",
+	"setTimestamp",
+	"NodeMetaRef::reportMetadataChange",
+	"clearAllObjects",
+	"Timestamp expired (step)",
+	"addActiveObjectRaw",
+	"removeRemovedObjects/remove",
+	"removeRemovedObjects/deactivate",
+	"Stored list cleared in activateObjects due to overflow",
+	"deactivateFarObjects: Static data moved in",
+	"deactivateFarObjects: Static data moved out",
+	"deactivateFarObjects: Static data changed considerably",
+	"finishBlockMake: expireDayNightDiff"
+	"unknown",
+};
+
+
 /*
 	MapBlock
 */
@@ -47,8 +71,7 @@ MapBlock::MapBlock(Map *parent, v3s16 pos, IGameDef *gamedef, bool dummy):
 		m_pos(pos),
 		m_gamedef(gamedef),
 		m_modified(MOD_STATE_WRITE_NEEDED),
-		m_modified_reason("initial"),
-		m_modified_reason_too_long(false),
+		m_modified_reason(MOD_REASON_INITIAL),
 		is_underground(false),
 		m_lighting_expired(true),
 		m_day_night_differs(false),
@@ -112,6 +135,27 @@ MapNode MapBlock::getNodeParent(v3s16 p, bool *is_valid_position)
 	return data[p.Z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + p.Y*MAP_BLOCKSIZE + p.X];
 }
 
+std::string MapBlock::getModifiedReasonString()
+{
+	std::string reason;
+
+	const u32 ubound = MYMIN(sizeof(m_modified_reason) * CHAR_BIT,
+		ARRLEN(modified_reason_strings));
+
+	for (u32 i = 0; i != ubound; i++) {
+		if ((m_modified_reason & (1 << i)) == 0)
+			continue;
+
+		reason += modified_reason_strings[i];
+		reason += ", ";
+	}
+
+	if (reason.length() > 2)
+		reason.resize(reason.length() - 2);
+
+	return reason;
+}
+
 /*
 	Propagates sunlight down through the block.
 	Doesn't modify nodes that are not affected by sunlight.
diff --git a/src/mapblock.h b/src/mapblock.h
index 3c0ae9cd7..9e36fe113 100644
--- a/src/mapblock.h
+++ b/src/mapblock.h
@@ -97,21 +97,46 @@ public:
 };
 #endif
 
-/*
-	MapBlock itself
-*/
+////
+//// MapBlock modified reason flags
+////
+
+#define MOD_REASON_INITIAL                   (1 << 0)
+#define MOD_REASON_REALLOCATE                (1 << 1)
+#define MOD_REASON_SET_IS_UNDERGROUND        (1 << 2)
+#define MOD_REASON_SET_LIGHTING_EXPIRED      (1 << 3)
+#define MOD_REASON_SET_GENERATED             (1 << 4)
+#define MOD_REASON_SET_NODE                  (1 << 5)
+#define MOD_REASON_SET_NODE_NO_CHECK         (1 << 6)
+#define MOD_REASON_SET_TIMESTAMP             (1 << 7)
+#define MOD_REASON_REPORT_META_CHANGE        (1 << 8)
+#define MOD_REASON_CLEAR_ALL_OBJECTS         (1 << 9)
+#define MOD_REASON_BLOCK_EXPIRED             (1 << 10)
+#define MOD_REASON_ADD_ACTIVE_OBJECT_RAW     (1 << 11)
+#define MOD_REASON_REMOVE_OBJECTS_REMOVE     (1 << 12)
+#define MOD_REASON_REMOVE_OBJECTS_DEACTIVATE (1 << 13)
+#define MOD_REASON_TOO_MANY_OBJECTS          (1 << 14)
+#define MOD_REASON_STATIC_DATA_ADDED         (1 << 15)
+#define MOD_REASON_STATIC_DATA_REMOVED       (1 << 16)
+#define MOD_REASON_STATIC_DATA_CHANGED       (1 << 17)
+#define MOD_REASON_EXPIRE_DAYNIGHTDIFF       (1 << 18)
+#define MOD_REASON_UNKNOWN                   (1 << 19)
+
+////
+//// MapBlock itself
+////
 
 class MapBlock /*: public NodeContainer*/
 {
 public:
 	MapBlock(Map *parent, v3s16 pos, IGameDef *gamedef, bool dummy=false);
 	~MapBlock();
-	
+
 	/*virtual u16 nodeContainerId() const
 	{
 		return NODECONTAINER_ID_MAPBLOCK;
 	}*/
-	
+
 	Map * getParent()
 	{
 		return m_parent;
@@ -119,150 +144,125 @@ public:
 
 	void reallocate()
 	{
-		if(data != NULL)
-			delete[] data;
-		u32 l = MAP_BLOCKSIZE * MAP_BLOCKSIZE * MAP_BLOCKSIZE;
-		data = new MapNode[l];
-		for(u32 i=0; i<l; i++){
-			//data[i] = MapNode();
+		delete[] data;
+		u32 datasize = MAP_BLOCKSIZE * MAP_BLOCKSIZE * MAP_BLOCKSIZE;
+		data = new MapNode[datasize];
+		for (u32 i = 0; i < datasize; i++)
 			data[i] = MapNode(CONTENT_IGNORE);
-		}
-		raiseModified(MOD_STATE_WRITE_NEEDED, "reallocate");
-	}
-
-	/*
-		Flags
-	*/
 
-	bool isDummy()
-	{
-		return (data == NULL);
-	}
-	void unDummify()
-	{
-		assert(isDummy()); // Pre-condition
-		reallocate();
+		raiseModified(MOD_STATE_WRITE_NEEDED, MOD_REASON_REALLOCATE);
 	}
-	
-	// m_modified methods
-	void raiseModified(u32 mod, const std::string &reason="unknown")
-	{
-		if(mod > m_modified){
-			m_modified = mod;
-			m_modified_reason = reason;
-			m_modified_reason_too_long = false;
 
-			if(m_modified >= MOD_STATE_WRITE_AT_UNLOAD){
-				m_disk_timestamp = m_timestamp;
-			}
-		} else if(mod == m_modified){
-			if(!m_modified_reason_too_long){
-				if(m_modified_reason.size() < 40)
-					m_modified_reason += ", " + reason;
-				else{
-					m_modified_reason += "...";
-					m_modified_reason_too_long = true;
-				}
-			}
-		}
-	}
-	void raiseModified(u32 mod, const char *reason)
+	////
+	//// Modification tracking methods
+	////
+	void raiseModified(u32 mod, u32 reason=MOD_REASON_UNKNOWN)
 	{
-		if (mod > m_modified){
+		if (mod > m_modified) {
 			m_modified = mod;
 			m_modified_reason = reason;
-			m_modified_reason_too_long = false;
-
-			if (m_modified >= MOD_STATE_WRITE_AT_UNLOAD){
+			if (m_modified >= MOD_STATE_WRITE_AT_UNLOAD)
 				m_disk_timestamp = m_timestamp;
-			}
-		}
-		else if (mod == m_modified){
-			if (!m_modified_reason_too_long){
-				if (m_modified_reason.size() < 40)
-					m_modified_reason += ", " + std::string(reason);
-				else{
-					m_modified_reason += "...";
-					m_modified_reason_too_long = true;
-				}
-			}
+		} else if (mod == m_modified) {
+			m_modified_reason |= reason;
 		}
 	}
 
-	u32 getModified()
+	inline u32 getModified()
 	{
 		return m_modified;
 	}
-	std::string getModifiedReason()
+
+	inline u32 getModifiedReason()
 	{
 		return m_modified_reason;
 	}
-	void resetModified()
+
+	std::string getModifiedReasonString();
+
+	inline void resetModified()
 	{
 		m_modified = MOD_STATE_CLEAN;
-		m_modified_reason = "none";
-		m_modified_reason_too_long = false;
+		m_modified_reason = 0;
 	}
-	
+
+	////
+	//// Flags
+	////
+
+	inline bool isDummy()
+	{
+		return (data == NULL);
+	}
+
+	inline void unDummify()
+	{
+		assert(isDummy()); // Pre-condition
+		reallocate();
+	}
+
 	// is_underground getter/setter
-	bool getIsUnderground()
+	inline bool getIsUnderground()
 	{
 		return is_underground;
 	}
-	void setIsUnderground(bool a_is_underground)
+
+	inline void setIsUnderground(bool a_is_underground)
 	{
 		is_underground = a_is_underground;
-		raiseModified(MOD_STATE_WRITE_NEEDED, "setIsUnderground");
+		raiseModified(MOD_STATE_WRITE_NEEDED, MOD_REASON_SET_IS_UNDERGROUND);
 	}
 
-	void setLightingExpired(bool expired)
+	inline void setLightingExpired(bool expired)
 	{
-		if(expired != m_lighting_expired){
+		if (expired != m_lighting_expired){
 			m_lighting_expired = expired;
-			raiseModified(MOD_STATE_WRITE_NEEDED, "setLightingExpired");
+			raiseModified(MOD_STATE_WRITE_NEEDED, MOD_REASON_SET_LIGHTING_EXPIRED);
 		}
 	}
-	bool getLightingExpired()
+
+	inline bool getLightingExpired()
 	{
 		return m_lighting_expired;
 	}
 
-	bool isGenerated()
+	inline bool isGenerated()
 	{
 		return m_generated;
 	}
-	void setGenerated(bool b)
+
+	inline void setGenerated(bool b)
 	{
-		if(b != m_generated){
-			raiseModified(MOD_STATE_WRITE_NEEDED, "setGenerated");
+		if (b != m_generated) {
+			raiseModified(MOD_STATE_WRITE_NEEDED, MOD_REASON_SET_GENERATED);
 			m_generated = b;
 		}
 	}
 
-	bool isValid()
+	inline bool isValid()
 	{
-		if(m_lighting_expired)
+		if (m_lighting_expired)
 			return false;
-		if(data == NULL)
+		if (data == NULL)
 			return false;
 		return true;
 	}
 
-	/*
-		Position stuff
-	*/
+	////
+	//// Position stuff
+	////
 
-	v3s16 getPos()
+	inline v3s16 getPos()
 	{
 		return m_pos;
 	}
-		
-	v3s16 getPosRelative()
+
+	inline v3s16 getPosRelative()
 	{
 		return m_pos * MAP_BLOCKSIZE;
 	}
-		
-	core::aabbox3d<s16> getBox()
+
+	inline core::aabbox3d<s16> getBox()
 	{
 		return core::aabbox3d<s16>(getPosRelative(),
 				getPosRelative()
@@ -270,140 +270,135 @@ public:
 				- v3s16(1,1,1));
 	}
 
-	/*
-		Regular MapNode get-setters
-	*/
-	
-	bool isValidPosition(s16 x, s16 y, s16 z)
+	////
+	//// Regular MapNode get-setters
+	////
+
+	inline bool isValidPosition(s16 x, s16 y, s16 z)
 	{
 		return data != NULL
-				&& x >= 0 && x < MAP_BLOCKSIZE
-				&& y >= 0 && y < MAP_BLOCKSIZE
-				&& z >= 0 && z < MAP_BLOCKSIZE;
+			&& x >= 0 && x < MAP_BLOCKSIZE
+			&& y >= 0 && y < MAP_BLOCKSIZE
+			&& z >= 0 && z < MAP_BLOCKSIZE;
 	}
 
-	bool isValidPosition(v3s16 p)
+	inline bool isValidPosition(v3s16 p)
 	{
 		return isValidPosition(p.X, p.Y, p.Z);
 	}
 
-	MapNode getNode(s16 x, s16 y, s16 z, bool *valid_position)
+	inline MapNode getNode(s16 x, s16 y, s16 z, bool *valid_position)
 	{
 		*valid_position = isValidPosition(x, y, z);
 
 		if (!*valid_position)
 			return MapNode(CONTENT_IGNORE);
 
-		return data[z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + y*MAP_BLOCKSIZE + x];
+		return data[z * MAP_BLOCKSIZE * MAP_BLOCKSIZE + y * MAP_BLOCKSIZE + x];
 	}
-	
-	MapNode getNode(v3s16 p, bool *valid_position)
+
+	inline MapNode getNode(v3s16 p, bool *valid_position)
 	{
 		return getNode(p.X, p.Y, p.Z, valid_position);
 	}
-	
-	MapNode getNodeNoEx(v3s16 p)
+
+	inline MapNode getNodeNoEx(v3s16 p)
 	{
 		bool is_valid;
 		MapNode node = getNode(p.X, p.Y, p.Z, &is_valid);
 		return is_valid ? node : MapNode(CONTENT_IGNORE);
 	}
-	
-	void setNode(s16 x, s16 y, s16 z, MapNode & n)
+
+	inline void setNode(s16 x, s16 y, s16 z, MapNode & n)
 	{
-		if(data == NULL)
+		if (!isValidPosition(x, y, z))
 			throw InvalidPositionException();
-		if(x < 0 || x >= MAP_BLOCKSIZE) throw InvalidPositionException();
-		if(y < 0 || y >= MAP_BLOCKSIZE) throw InvalidPositionException();
-		if(z < 0 || z >= MAP_BLOCKSIZE) throw InvalidPositionException();
-		data[z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + y*MAP_BLOCKSIZE + x] = n;
-		raiseModified(MOD_STATE_WRITE_NEEDED, "setNode");
+
+		data[z * zstride + y * ystride + x] = n;
+		raiseModified(MOD_STATE_WRITE_NEEDED, MOD_REASON_SET_NODE);
 	}
-	
-	void setNode(v3s16 p, MapNode & n)
+
+	inline void setNode(v3s16 p, MapNode & n)
 	{
 		setNode(p.X, p.Y, p.Z, n);
 	}
 
-	/*
-		Non-checking variants of the above
-	*/
+	////
+	//// Non-checking variants of the above
+	////
 
-	MapNode getNodeNoCheck(s16 x, s16 y, s16 z, bool *valid_position)
+	inline MapNode getNodeNoCheck(s16 x, s16 y, s16 z, bool *valid_position)
 	{
 		*valid_position = data != NULL;
-		if(!valid_position)
+		if (!valid_position)
 			return MapNode(CONTENT_IGNORE);
 
-		return data[z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + y*MAP_BLOCKSIZE + x];
+		return data[z * zstride + y * ystride + x];
 	}
-	
-	MapNode getNodeNoCheck(v3s16 p, bool *valid_position)
+
+	inline MapNode getNodeNoCheck(v3s16 p, bool *valid_position)
 	{
 		return getNodeNoCheck(p.X, p.Y, p.Z, valid_position);
 	}
-	
-	void setNodeNoCheck(s16 x, s16 y, s16 z, MapNode & n)
+
+	inline void setNodeNoCheck(s16 x, s16 y, s16 z, MapNode & n)
 	{
-		if(data == NULL)
+		if (data == NULL)
 			throw InvalidPositionException();
-		data[z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + y*MAP_BLOCKSIZE + x] = n;
-		raiseModified(MOD_STATE_WRITE_NEEDED, "setNodeNoCheck");
+
+		data[z * zstride + y * ystride + x] = n;
+		raiseModified(MOD_STATE_WRITE_NEEDED, MOD_REASON_SET_NODE_NO_CHECK);
 	}
-	
-	void setNodeNoCheck(v3s16 p, MapNode & n)
+
+	inline void setNodeNoCheck(v3s16 p, MapNode & n)
 	{
 		setNodeNoCheck(p.X, p.Y, p.Z, n);
 	}
 
-	/*
-		These functions consult the parent container if the position
-		is not valid on this MapBlock.
-	*/
+	// These functions consult the parent container if the position
+	// is not valid on this MapBlock.
 	bool isValidPositionParent(v3s16 p);
 	MapNode getNodeParent(v3s16 p, bool *is_valid_position = NULL);
 	void setNodeParent(v3s16 p, MapNode & n);
 
-	void drawbox(s16 x0, s16 y0, s16 z0, s16 w, s16 h, s16 d, MapNode node)
+	inline void drawbox(s16 x0, s16 y0, s16 z0, s16 w, s16 h, s16 d, MapNode node)
 	{
-		for(u16 z=0; z<d; z++)
-			for(u16 y=0; y<h; y++)
-				for(u16 x=0; x<w; x++)
-					setNode(x0+x, y0+y, z0+z, node);
+		for (u16 z = 0; z < d; z++)
+		for (u16 y = 0; y < h; y++)
+		for (u16 x = 0; x < w; x++)
+			setNode(x0 + x, y0 + y, z0 + z, node);
 	}
 
 	// See comments in mapblock.cpp
-	bool propagateSunlight(std::set<v3s16> & light_sources,
-			bool remove_light=false, bool *black_air_left=NULL);
-	
+	bool propagateSunlight(std::set<v3s16> &light_sources,
+		bool remove_light=false, bool *black_air_left=NULL);
+
 	// Copies data to VoxelManipulator to getPosRelative()
 	void copyTo(VoxelManipulator &dst);
+
 	// Copies data from VoxelManipulator getPosRelative()
 	void copyFrom(VoxelManipulator &dst);
 
-	/*
-		Update day-night lighting difference flag.
-		Sets m_day_night_differs to appropriate value.
-		These methods don't care about neighboring blocks.
-	*/
+	// Update day-night lighting difference flag.
+	// Sets m_day_night_differs to appropriate value.
+	// These methods don't care about neighboring blocks.
 	void actuallyUpdateDayNightDiff();
-	/*
-		Call this to schedule what the previous function does to be done
-		when the value is actually needed.
-	*/
+
+	// Call this to schedule what the previous function does to be done
+	// when the value is actually needed.
 	void expireDayNightDiff();
 
-	bool getDayNightDiff()
+	inline bool getDayNightDiff()
 	{
-		if(m_day_night_differs_expired)
+		if (m_day_night_differs_expired)
 			actuallyUpdateDayNightDiff();
 		return m_day_night_differs;
 	}
 
-	/*
-		Miscellaneous stuff
-	*/
-	
+	////
+	//// Miscellaneous stuff
+	////
+
 	/*
 		Tries to measure ground level.
 		Return value:
@@ -414,84 +409,99 @@ public:
 	*/
 	s16 getGroundLevel(v2s16 p2d);
 
-	/*
-		Timestamp (see m_timestamp)
-		NOTE: BLOCK_TIMESTAMP_UNDEFINED=0xffffffff means there is no timestamp.
-	*/
-	void setTimestamp(u32 time)
+	////
+	//// Timestamp (see m_timestamp)
+	////
+
+	// NOTE: BLOCK_TIMESTAMP_UNDEFINED=0xffffffff means there is no timestamp.
+
+	inline void setTimestamp(u32 time)
 	{
 		m_timestamp = time;
-		raiseModified(MOD_STATE_WRITE_AT_UNLOAD, "setTimestamp");
+		raiseModified(MOD_STATE_WRITE_AT_UNLOAD, MOD_REASON_SET_TIMESTAMP);
 	}
-	void setTimestampNoChangedFlag(u32 time)
+
+	inline void setTimestampNoChangedFlag(u32 time)
 	{
 		m_timestamp = time;
 	}
-	u32 getTimestamp()
+
+	inline u32 getTimestamp()
 	{
 		return m_timestamp;
 	}
-	u32 getDiskTimestamp()
+
+	inline u32 getDiskTimestamp()
 	{
 		return m_disk_timestamp;
 	}
-	
-	/*
-		See m_usage_timer
-	*/
-	void resetUsageTimer()
+
+	////
+	//// Usage timer (see m_usage_timer)
+	////
+
+	inline void resetUsageTimer()
 	{
 		m_usage_timer = 0;
 	}
-	void incrementUsageTimer(float dtime)
+
+	inline void incrementUsageTimer(float dtime)
 	{
 		m_usage_timer += dtime;
 	}
-	float getUsageTimer()
+
+	inline float getUsageTimer()
 	{
 		return m_usage_timer;
 	}
 
-	/*
-		See m_refcount
-	*/
-	void refGrab()
+	////
+	//// Reference counting (see m_refcount)
+	////
+
+	inline void refGrab()
 	{
 		m_refcount++;
 	}
-	void refDrop()
+
+	inline void refDrop()
 	{
 		m_refcount--;
 	}
-	int refGet()
+
+	inline int refGet()
 	{
 		return m_refcount;
 	}
-	
-	/*
-		Node Timers
-	*/
-	// Get timer
-	NodeTimer getNodeTimer(v3s16 p){ 
+
+	////
+	//// Node Timers
+	////
+
+	inline NodeTimer getNodeTimer(v3s16 p)
+	{
 		return m_node_timers.get(p);
 	}
-	// Deletes timer
-	void removeNodeTimer(v3s16 p){
+
+	inline void removeNodeTimer(v3s16 p)
+	{
 		m_node_timers.remove(p);
 	}
-	// Deletes old timer and sets a new one
-	void setNodeTimer(v3s16 p, NodeTimer t){
+
+	inline void setNodeTimer(v3s16 p, NodeTimer t)
+	{
 		m_node_timers.set(p,t);
 	}
-	// Deletes all timers
-	void clearNodeTimers(){
+
+	inline void clearNodeTimers()
+	{
 		m_node_timers.clear();
 	}
 
-	/*
-		Serialization
-	*/
-	
+	////
+	//// Serialization
+	///
+
 	// These don't write or read version by itself
 	// Set disk to true for on-disk format, false for over-the-network format
 	// Precondition: version >= SER_FMT_CLIENT_VER_LOWEST
@@ -514,16 +524,15 @@ private:
 		Used only internally, because changes can't be tracked
 	*/
 
-	MapNode & getNodeRef(s16 x, s16 y, s16 z)
+	inline MapNode &getNodeRef(s16 x, s16 y, s16 z)
 	{
-		if(data == NULL)
+		if (!isValidPosition(x, y, z))
 			throw InvalidPositionException();
-		if(x < 0 || x >= MAP_BLOCKSIZE) throw InvalidPositionException();
-		if(y < 0 || y >= MAP_BLOCKSIZE) throw InvalidPositionException();
-		if(z < 0 || z >= MAP_BLOCKSIZE) throw InvalidPositionException();
-		return data[z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + y*MAP_BLOCKSIZE + x];
+
+		return data[z * zstride + y * ystride + x];
 	}
-	MapNode & getNodeRef(v3s16 &p)
+
+	inline MapNode &getNodeRef(v3s16 &p)
 	{
 		return getNodeRef(p.X, p.Y, p.Z);
 	}
@@ -536,11 +545,14 @@ public:
 #ifndef SERVER // Only on client
 	MapBlockMesh *mesh;
 #endif
-	
+
 	NodeMetadataList m_node_metadata;
 	NodeTimerList m_node_timers;
 	StaticObjectList m_static_objects;
 
+	static const u32 ystride = MAP_BLOCKSIZE;
+	static const u32 zstride = MAP_BLOCKSIZE * MAP_BLOCKSIZE;
+
 private:
 	/*
 		Private member variables
@@ -552,12 +564,12 @@ private:
 	v3s16 m_pos;
 
 	IGameDef *m_gamedef;
-	
+
 	/*
 		If NULL, block is a dummy block.
 		Dummy blocks are used for caching not-found-on-disk blocks.
 	*/
-	MapNode * data;
+	MapNode *data;
 
 	/*
 		- On the server, this is used for telling whether the
@@ -565,8 +577,7 @@ private:
 		- On the client, this is used for nothing.
 	*/
 	u32 m_modified;
-	std::string m_modified_reason;
-	bool m_modified_reason_too_long;
+	u32 m_modified_reason;
 
 	/*
 		When propagating sunlight and the above block doesn't exist,
@@ -586,13 +597,13 @@ private:
 		If this is true, lighting might be wrong or right.
 	*/
 	bool m_lighting_expired;
-	
+
 	// Whether day and night lighting differs
 	bool m_day_night_differs;
 	bool m_day_night_differs_expired;
 
 	bool m_generated;
-	
+
 	/*
 		When block is removed from active blocks, this is set to gametime.
 		Value BLOCK_TIMESTAMP_UNDEFINED=0xffffffff means there is no timestamp.
diff --git a/src/rollback_interface.cpp b/src/rollback_interface.cpp
index c35ad5781..028bd0424 100644
--- a/src/rollback_interface.cpp
+++ b/src/rollback_interface.cpp
@@ -178,7 +178,7 @@ bool RollbackAction::applyRevert(Map *map, InventoryManager *imgr, IGameDef *gam
 				MapBlock *block = map->getBlockNoCreateNoEx(blockpos);
 				if (block) {
 					block->raiseModified(MOD_STATE_WRITE_NEEDED,
-						"NodeMetaRef::reportMetadataChange");
+						MOD_REASON_REPORT_META_CHANGE);
 				}
 			} catch (InvalidPositionException &e) {
 				infostream << "RollbackAction::applyRevert(): "
diff --git a/src/script/lua_api/l_nodemeta.cpp b/src/script/lua_api/l_nodemeta.cpp
index 4f20e56f9..906cc3172 100644
--- a/src/script/lua_api/l_nodemeta.cpp
+++ b/src/script/lua_api/l_nodemeta.cpp
@@ -63,9 +63,10 @@ void NodeMetaRef::reportMetadataChange(NodeMetaRef *ref)
 	ref->m_env->getMap().dispatchEvent(&event);
 	// Set the block to be saved
 	MapBlock *block = ref->m_env->getMap().getBlockNoCreateNoEx(blockpos);
-	if(block)
+	if (block) {
 		block->raiseModified(MOD_STATE_WRITE_NEEDED,
-				"NodeMetaRef::reportMetadataChange");
+			MOD_REASON_REPORT_META_CHANGE);
+	}
 }
 
 // Exported functions