Simplify AreaStore ID management

doc/lua_api.txt

@@ -2727,8 +2727,7 @@ If you chose the parameter-less constructor, a fast implementation will be autom
 * `get_area(id, include_borders, include_data)`: returns the area with the id `id`. (optional) Boolean values `include_borders` and `include_data` control what's copied.
 * `get_areas_for_pos(pos, include_borders, include_data)`: returns all areas that contain the position `pos`. (optional) Boolean values `include_borders` and `include_data` control what's copied.
 * `get_areas_in_area(edge1, edge2, accept_overlap, include_borders, include_data)`: returns all areas that contain all nodes inside the area specified by `edge1` and `edge2` (inclusive). If `accept_overlap` is true, also areas are returned that have nodes in common with the specified area. (optional) Boolean values `include_borders` and `include_data` control what's copied.
-* `insert_area(edge1, edge2, data)`: inserts an area into the store. Returns the id if successful, nil otherwise. The (inclusive) positions `edge1` and `edge2` describe the area, `data`
-is a string stored with the area.
+* `insert_area(edge1, edge2, data)`: inserts an area into the store. Returns the new area's ID, or nil if the insertion failed. The (inclusive) positions `edge1` and `edge2` describe the area, `data` is a string stored with the area.
 * `reserve(count)`: reserves resources for at most `count` many contained areas. Only needed for efficiency, and only some implementations profit.
 * `remove_area(id)`: removes the area with the given id from the store, returns success.
 * `set_cache_params(params)`: sets params for the included prefiltering cache. Calling invalidates the cache, so that its elements have to be newly generated.

src/areastore.cpp

@@ -49,21 +49,6 @@ u16 AreaStore::size() const
 	return areas_map.size();
 }
 
-u32 AreaStore::getFreeId(v3s16 minedge, v3s16 maxedge)
-{
-	int keep_on = 100;
-	while (keep_on--) {
-		m_highest_id++;
-		// Handle overflows, we dont want to return 0
-		if (m_highest_id == AREA_ID_INVALID)
-			m_highest_id++;
-		if (areas_map.find(m_highest_id) == areas_map.end())
-			return m_highest_id;
-	}
-	// search failed
-	return AREA_ID_INVALID;
-}
-
 const Area *AreaStore::getArea(u32 id) const
 {
 	const Area *res = NULL;
@@ -185,11 +170,17 @@ void AreaStore::getAreasForPos(std::vector<Area *> *result, v3s16 pos)
 ////
 
 
-void VectorAreaStore::insertArea(const Area &a)
+bool VectorAreaStore::insertArea(Area *a)
 {
-	areas_map[a.id] = a;
-	m_areas.push_back(&(areas_map[a.id]));
+	a->id = getNextId();
+	std::pair<std::map<u32, Area>::iterator, bool> res =
+			areas_map.insert(std::make_pair(a->id, *a));
+	if (!res.second)
+		// ID is not unique
+		return false;
+	m_areas.push_back(&res.first->second);
 	invalidateCache();
+	return true;
 }
 
 void VectorAreaStore::reserve(size_t count)
@@ -273,11 +264,15 @@ static inline SpatialIndex::Point get_spatial_point(const v3s16 pos)
 }
 
 
-void SpatialAreaStore::insertArea(const Area &a)
+bool SpatialAreaStore::insertArea(Area *a)
 {
-	areas_map[a.id] = a;
-	m_tree->insertData(0, NULL, get_spatial_region(a.minedge, a.maxedge), a.id);
+	a->id = getNextId();
+	if (!areas_map.insert(std::make_pair(a->id, *a)).second)
+		// ID is not unique
+		return false;
+	m_tree->insertData(0, NULL, get_spatial_region(a->minedge, a->maxedge), a->id);
 	invalidateCache();
+	return true;
 }
 
 bool SpatialAreaStore::removeArea(u32 id)

src/areastore.h

@@ -36,34 +36,14 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 	#include "util/serialize.h"
 #endif
 
-#define AST_EXTREMIFY(min, max, pa, pb) \
-	(min).X = MYMIN((pa).X, (pb).X);    \
-	(min).Y = MYMIN((pa).Y, (pb).Y);    \
-	(min).Z = MYMIN((pa).Z, (pb).Z);    \
-	(max).X = MYMAX((pa).X, (pb).X);    \
-	(max).Y = MYMAX((pa).Y, (pb).Y);    \
-	(max).Z = MYMAX((pa).Z, (pb).Z);
-
-#define AREA_ID_INVALID 0
 
 struct Area {
-	Area(const v3s16 &minedge, const v3s16 &maxedge)
-	{
-		this->minedge = minedge;
-		this->maxedge = maxedge;
-	}
-
 	Area() {}
-
-	void extremifyEdges()
+	Area(const v3s16 &mine, const v3s16 &maxe)
 	{
-		v3s16 nminedge;
-		v3s16 nmaxedge;
-
-		AST_EXTREMIFY(nminedge, nmaxedge, minedge, maxedge)
-
-		maxedge = nmaxedge;
-		minedge = nminedge;
+		minedge = mine;
+		maxedge = maxe;
+		sortBoxVerticies(minedge, maxedge);
 	}
 
 	u32 id;
@@ -76,13 +56,16 @@ std::vector<std::string> get_areastore_typenames();
 
 class AreaStore {
 protected:
-	// TODO change to unordered_map when we can
-	std::map<u32, Area> areas_map;
 	void invalidateCache();
 	virtual void getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos) = 0;
+	u32 getNextId() { return m_next_id++; }
+
+	// TODO change to unordered_map when we can
+	std::map<u32, Area> areas_map;
 	bool cache_enabled; // don't write to this from subclasses, only read.
 public:
-	virtual void insertArea(const Area &a) = 0;
+	// Updates the area's ID
+	virtual bool insertArea(Area *a) = 0;
 	virtual void reserve(size_t count) {};
 	virtual bool removeArea(u32 id) = 0;
 	void getAreasForPos(std::vector<Area *> *result, v3s16 pos);
@@ -103,13 +86,12 @@ public:
 		cache_enabled(true),
 		m_cacheblock_radius(64),
 		m_res_cache(1000, &cacheMiss, this),
-		m_highest_id(0)
+		m_next_id(0)
 	{
 	}
 
 	void setCacheParams(bool enabled, u8 block_radius, size_t limit);
 
-	u32 getFreeId(v3s16 minedge, v3s16 maxedge);
 	const Area *getArea(u32 id) const;
 	u16 size() const;
 #if 0
@@ -120,7 +102,7 @@ private:
 	static void cacheMiss(void *data, const v3s16 &mpos, std::vector<Area *> *dest);
 	u8 m_cacheblock_radius; // if you modify this, call invalidateCache()
 	LRUCache<v3s16, std::vector<Area *> > m_res_cache;
-	u32 m_highest_id;
+	u32 m_next_id;
 
 };
 
@@ -129,7 +111,7 @@ class VectorAreaStore : public AreaStore {
 protected:
 	virtual void getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos);
 public:
-	virtual void insertArea(const Area &a);
+	virtual bool insertArea(Area *a);
 	virtual void reserve(size_t count);
 	virtual bool removeArea(u32 id);
 	virtual void getAreasInArea(std::vector<Area *> *result,
@@ -146,7 +128,7 @@ protected:
 	virtual void getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos);
 public:
 	SpatialAreaStore();
-	virtual void insertArea(const Area &a);
+	virtual bool insertArea(Area *a);
 	virtual bool removeArea(u32 id);
 	virtual void getAreasInArea(std::vector<Area *> *result,
 		v3s16 minedge, v3s16 maxedge, bool accept_overlap);

src/script/lua_api/l_areastore.cpp

@@ -159,26 +159,15 @@ int LuaAreaStore::l_insert_area(lua_State *L)
 	LuaAreaStore *o = checkobject(L, 1);
 	AreaStore *ast = o->as;
 
-	Area a;
-
-	a.minedge = check_v3s16(L, 2);
-	a.maxedge = check_v3s16(L, 3);
-
-	a.extremifyEdges();
-	a.id = ast->getFreeId(a.minedge, a.maxedge);
-
-	if (a.id == AREA_ID_INVALID) {
-		// couldn't get free id
-		lua_pushnil(L);
-		return 1;
-	}
+	Area a(check_v3s16(L, 2), check_v3s16(L, 3));
 
 	size_t d_len;
 	const char *data = luaL_checklstring(L, 4, &d_len);
 
 	a.data = std::string(data, d_len);
 
-	ast->insertArea(a);
+	if (!ast->insertArea(&a))
+		return 0;
 
 	lua_pushnumber(L, a.id);
 	return 1;

src/unittest/test_areastore.cpp

@@ -62,18 +62,15 @@ void TestAreaStore::testSpatialStore()
 void TestAreaStore::genericStoreTest(AreaStore *store)
 {
 	Area a(v3s16(-10, -3, 5), v3s16(0, 29, 7));
-	a.id = 1;
 	Area b(v3s16(-5, -2, 5), v3s16(0, 28, 6));
-	b.id = 2;
 	Area c(v3s16(-7, -3, 6), v3s16(-1, 27, 7));
-	c.id = 3;
 	std::vector<Area *> res;
 
 	UASSERTEQ(size_t, store->size(), 0);
 	store->reserve(2); // sic
-	store->insertArea(a);
-	store->insertArea(b);
-	store->insertArea(c);
+	store->insertArea(&a);
+	store->insertArea(&b);
+	store->insertArea(&c);
 	UASSERTEQ(size_t, store->size(), 3);
 
 	store->getAreasForPos(&res, v3s16(-1, 0, 6));
@@ -81,20 +78,18 @@ void TestAreaStore::genericStoreTest(AreaStore *store)
 	res.clear();
 	store->getAreasForPos(&res, v3s16(0, 0, 7));
 	UASSERTEQ(size_t, res.size(), 1);
-	UASSERTEQ(u32, res[0]->id, 1);
 	res.clear();
 
-	store->removeArea(1);
+	store->removeArea(a.id);
 
 	store->getAreasForPos(&res, v3s16(0, 0, 7));
 	UASSERTEQ(size_t, res.size(), 0);
 	res.clear();
 
-	store->insertArea(a);
+	store->insertArea(&a);
 
 	store->getAreasForPos(&res, v3s16(0, 0, 7));
 	UASSERTEQ(size_t, res.size(), 1);
-	UASSERTEQ(u32, res[0]->id, 1);
 	res.clear();
 
 	store->getAreasInArea(&res, v3s16(-10, -3, 5), v3s16(0, 29, 7), false);
@@ -109,21 +104,20 @@ void TestAreaStore::genericStoreTest(AreaStore *store)
 	UASSERTEQ(size_t, res.size(), 3);
 	res.clear();
 
-	store->removeArea(1);
-	store->removeArea(2);
-	store->removeArea(3);
+	store->removeArea(a.id);
+	store->removeArea(b.id);
+	store->removeArea(c.id);
 
 	Area d(v3s16(-100, -300, -200), v3s16(-50, -200, -100));
-	d.id = 4;
 	d.data = "Hi!";
-	store->insertArea(d);
+	store->insertArea(&d);
 
 	store->getAreasForPos(&res, v3s16(-75, -250, -150));
 	UASSERTEQ(size_t, res.size(), 1);
-	UASSERTEQ(u32, res[0]->id, 4);
 	UASSERTEQ(u16, res[0]->data.size(), 3);
 	UASSERT(strncmp(res[0]->data.c_str(), "Hi!", 3) == 0);
 	res.clear();
 
-	store->removeArea(4);
+	store->removeArea(d.id);
 }
+