Add AreaStore data structure

1 files changed, 343 insertions, 0 deletions

diff --git a/src/areastore.cpp b/src/areastore.cpp
new file mode 100644
index 000000000..f9362c4a6
--- /dev/null
+++ b/src/areastore.cpp
@@ -0,0 +1,343 @@
+/*
+Minetest
+Copyright (C) 2015 est31 <mtest31@outlook.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "areastore.h"
+#include "util/serialize.h"
+#include "util/container.h"
+
+#if USE_SPATIAL
+	#include <spatialindex/SpatialIndex.h>
+	#include <spatialindex/RTree.h>
+	#include <spatialindex/Point.h>
+#endif
+
+#define AST_SMALLER_EQ_AS(p, q) (((p).X <= (q).X) && ((p).Y <= (q).Y) && ((p).Z <= (q).Z))
+
+#define AST_OVERLAPS_IN_DIMENSION(amine, amaxe, b, d) \
+	(!(((amine).d > (b)->maxedge.d) || ((amaxe).d < (b)->minedge.d)))
+
+#define AST_CONTAINS_PT(a, p) (AST_SMALLER_EQ_AS((a)->minedge, (p)) && \
+	AST_SMALLER_EQ_AS((p), (a)->maxedge))
+
+#define AST_CONTAINS_AREA(amine, amaxe, b)         \
+	(AST_SMALLER_EQ_AS((amine), (b)->minedge) \
+	&& AST_SMALLER_EQ_AS((b)->maxedge, (amaxe)))
+
+#define AST_AREAS_OVERLAP(amine, amaxe, b)                \
+	(AST_OVERLAPS_IN_DIMENSION((amine), (amaxe), (b), X) && \
+	AST_OVERLAPS_IN_DIMENSION((amine), (amaxe), (b), Y) &&  \
+	AST_OVERLAPS_IN_DIMENSION((amine), (amaxe), (b), Z))
+
+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;
+	std::map<u32, Area>::const_iterator itr = areas_map.find(id);
+	if (itr != areas_map.end()) {
+		res = &itr->second;
+	}
+	return res;
+}
+
+#if 0
+Currently, serialisation is commented out. This is because of multiple reasons:
+1. Why do we store the areastore into a file, why not into the database?
+2. We don't use libspatial's serialisation, but we should, or perhaps not, because
+	it would remove the ability to switch. Perhaps write migration routines?
+3. Various things need fixing, e.g. the size is serialized as
+	c++ implementation defined size_t
+bool AreaStore::deserialize(std::istream &is)
+{
+	u8 ver = readU8(is);
+	if (ver != 1)
+		return false;
+	u16 count_areas = readU16(is);
+	for (u16 i = 0; i < count_areas; i++) {
+		// deserialize an area
+		Area a;
+		a.id = readU32(is);
+		a.minedge = readV3S16(is);
+		a.maxedge = readV3S16(is);
+		a.datalen = readU16(is);
+		a.data = new char[a.datalen];
+		is.read((char *) a.data, a.datalen);
+		insertArea(a);
+	}
+	return true;
+}
+
+
+static bool serialize_area(void *ostr, Area *a)
+{
+	std::ostream &os = *((std::ostream *) ostr);
+	writeU32(os, a->id);
+	writeV3S16(os, a->minedge);
+	writeV3S16(os, a->maxedge);
+	writeU16(os, a->datalen);
+	os.write(a->data, a->datalen);
+
+	return false;
+}
+
+
+void AreaStore::serialize(std::ostream &os) const
+{
+	// write initial data
+	writeU8(os, 1); // serialisation version
+	writeU16(os, areas_map.size()); //DANGER: not platform independent
+	forEach(&serialize_area, &os);
+}
+
+#endif
+
+void AreaStore::invalidateCache()
+{
+	if (cache_enabled) {
+		m_res_cache.invalidate();
+	}
+}
+
+void AreaStore::setCacheParams(bool enabled, u8 block_radius, size_t limit)
+{
+	cache_enabled = enabled;
+	m_cacheblock_radius = MYMAX(block_radius, 16);
+	m_res_cache.setLimit(MYMAX(limit, 20));
+	invalidateCache();
+}
+
+void AreaStore::cacheMiss(void *data, const v3s16 &mpos, std::vector<Area *> *dest)
+{
+	AreaStore *as = (AreaStore *)data;
+	u8 r = as->m_cacheblock_radius;
+
+	// get the points at the edges of the mapblock
+	v3s16 minedge(mpos.X * r, mpos.Y * r, mpos.Z * r);
+	v3s16 maxedge(
+		minedge.X + r - 1,
+		minedge.Y + r - 1,
+		minedge.Z + r - 1);
+
+	as->getAreasInArea(dest, minedge, maxedge, true);
+
+	/* infostream << "Cache miss with " << dest->size() << " areas, between ("
+			<< minedge.X << ", " << minedge.Y << ", " << minedge.Z
+			<< ") and ("
+			<< maxedge.X << ", " << maxedge.Y << ", " << maxedge.Z
+			<< ")" << std::endl; // */
+}
+
+void AreaStore::getAreasForPos(std::vector<Area *> *result, v3s16 pos)
+{
+	if (cache_enabled) {
+		v3s16 mblock = getContainerPos(pos, m_cacheblock_radius);
+		const std::vector<Area *> *pre_list = m_res_cache.lookupCache(mblock);
+
+		size_t s_p_l = pre_list->size();
+		for (size_t i = 0; i < s_p_l; i++) {
+			Area *b = (*pre_list)[i];
+			if (AST_CONTAINS_PT(b, pos)) {
+				result->push_back(b);
+			}
+		}
+	} else {
+		return getAreasForPosImpl(result, pos);
+	}
+}
+
+
+////
+// VectorAreaStore
+////
+
+
+void VectorAreaStore::insertArea(const Area &a)
+{
+	areas_map[a.id] = a;
+	m_areas.push_back(&(areas_map[a.id]));
+	invalidateCache();
+}
+
+void VectorAreaStore::reserve(size_t count)
+{
+	m_areas.reserve(count);
+}
+
+bool VectorAreaStore::removeArea(u32 id)
+{
+	std::map<u32, Area>::iterator itr = areas_map.find(id);
+	if (itr != areas_map.end()) {
+		size_t msiz = m_areas.size();
+		for (size_t i = 0; i < msiz; i++) {
+			Area * b = m_areas[i];
+			if (b->id == id) {
+				areas_map.erase(itr);
+				m_areas.erase(m_areas.begin() + i);
+				invalidateCache();
+				return true;
+			}
+		}
+		// we should never get here, it means we did find it in map,
+		// but not in the vector
+	}
+	return false;
+}
+
+void VectorAreaStore::getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos)
+{
+	size_t msiz = m_areas.size();
+	for (size_t i = 0; i < msiz; i++) {
+		Area *b = m_areas[i];
+		if (AST_CONTAINS_PT(b, pos)) {
+			result->push_back(b);
+		}
+	}
+}
+
+void VectorAreaStore::getAreasInArea(std::vector<Area *> *result,
+		v3s16 minedge, v3s16 maxedge, bool accept_overlap)
+{
+	size_t msiz = m_areas.size();
+	for (size_t i = 0; i < msiz; i++) {
+		Area * b = m_areas[i];
+		if (accept_overlap ? AST_AREAS_OVERLAP(minedge, maxedge, b) :
+				AST_CONTAINS_AREA(minedge, maxedge, b)) {
+			result->push_back(b);
+		}
+	}
+}
+
+#if 0
+bool VectorAreaStore::forEach(bool (*callback)(void *args, Area *a), void *args) const
+{
+	size_t msiz = m_areas.size();
+	for (size_t i = 0; i < msiz; i++) {
+		if (callback(args, m_areas[i])) {
+			return true;
+		}
+	}
+	return false;
+}
+#endif
+
+#if USE_SPATIAL
+
+static inline SpatialIndex::Region get_spatial_region(const v3s16 minedge,
+		const v3s16 maxedge)
+{
+	const double p_low[] = {(double)minedge.X,
+		(double)minedge.Y, (double)minedge.Z};
+	const double p_high[] = {(double)maxedge.X, (double)maxedge.Y,
+		(double)maxedge.Z};
+	return SpatialIndex::Region(p_low, p_high, 3);
+}
+
+static inline SpatialIndex::Point get_spatial_point(const v3s16 pos)
+{
+	const double p[] = {(double)pos.X, (double)pos.Y, (double)pos.Z};
+	return SpatialIndex::Point(p, 3);
+}
+
+
+void SpatialAreaStore::insertArea(const Area &a)
+{
+	areas_map[a.id] = a;
+	m_tree->insertData(0, NULL, get_spatial_region(a.minedge, a.maxedge), a.id);
+	invalidateCache();
+}
+
+bool SpatialAreaStore::removeArea(u32 id)
+{
+	std::map<u32, Area>::iterator itr = areas_map.find(id);
+	if (itr != areas_map.end()) {
+		Area *a = &itr->second;
+		bool result = m_tree->deleteData(get_spatial_region(a->minedge,
+			a->maxedge), id);
+		invalidateCache();
+		return result;
+	} else {
+		return false;
+	}
+}
+
+void SpatialAreaStore::getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos)
+{
+	VectorResultVisitor visitor(result, this);
+	m_tree->pointLocationQuery(get_spatial_point(pos), visitor);
+}
+
+void SpatialAreaStore::getAreasInArea(std::vector<Area *> *result,
+		v3s16 minedge, v3s16 maxedge, bool accept_overlap)
+{
+	VectorResultVisitor visitor(result, this);
+	if (accept_overlap) {
+		m_tree->intersectsWithQuery(get_spatial_region(minedge, maxedge),
+			visitor);
+	} else {
+		m_tree->containsWhatQuery(get_spatial_region(minedge, maxedge), visitor);
+	}
+}
+
+#if 0
+bool SpatialAreaStore::forEach(bool (*callback)(void *args, Area *a), void *args) const
+{
+	// TODO ?? (this is only needed for serialisation, but libspatial has its own serialisation)
+	return false;
+}
+#endif
+
+SpatialAreaStore::~SpatialAreaStore()
+{
+	delete m_tree;
+}
+
+SpatialAreaStore::SpatialAreaStore()
+{
+	m_storagemanager =
+		SpatialIndex::StorageManager::createNewMemoryStorageManager();
+	SpatialIndex::id_type id;
+	m_tree = SpatialIndex::RTree::createNewRTree(
+		*m_storagemanager,
+		.7, // Fill factor
+		100, // Index capacity
+		100, // Leaf capacity
+		3, // dimension :)
+		SpatialIndex::RTree::RV_RSTAR,
+		id);
+}
+
+#endif