osrm-backend/src/engine/routing_algorithms/routing_base.cpp
2017-03-03 16:02:12 +00:00

663 lines
25 KiB
C++

#include "engine/routing_algorithms/routing_base.hpp"
namespace osrm
{
namespace engine
{
namespace routing_algorithms
{
void routingStep(const datafacade::ContiguousInternalMemoryDataFacade<algorithm::CH> &facade,
SearchEngineData::QueryHeap &forward_heap,
SearchEngineData::QueryHeap &reverse_heap,
NodeID &middle_node_id,
EdgeWeight &upper_bound,
EdgeWeight min_edge_offset,
const bool forward_direction,
const bool stalling,
const bool force_loop_forward,
const bool force_loop_reverse)
{
const NodeID node = forward_heap.DeleteMin();
const EdgeWeight weight = forward_heap.GetKey(node);
if (reverse_heap.WasInserted(node))
{
const EdgeWeight new_weight = reverse_heap.GetKey(node) + weight;
if (new_weight < upper_bound)
{
// if loops are forced, they are so at the source
if ((force_loop_forward && forward_heap.GetData(node).parent == node) ||
(force_loop_reverse && reverse_heap.GetData(node).parent == node) ||
// in this case we are looking at a bi-directional way where the source
// and target phantom are on the same edge based node
new_weight < 0)
{
// check whether there is a loop present at the node
for (const auto edge : facade.GetAdjacentEdgeRange(node))
{
const auto &data = facade.GetEdgeData(edge);
bool forward_directionFlag = (forward_direction ? data.forward : data.backward);
if (forward_directionFlag)
{
const NodeID to = facade.GetTarget(edge);
if (to == node)
{
const EdgeWeight edge_weight = data.weight;
const EdgeWeight loop_weight = new_weight + edge_weight;
if (loop_weight >= 0 && loop_weight < upper_bound)
{
middle_node_id = node;
upper_bound = loop_weight;
}
}
}
}
}
else
{
BOOST_ASSERT(new_weight >= 0);
middle_node_id = node;
upper_bound = new_weight;
}
}
}
// make sure we don't terminate too early if we initialize the weight
// for the nodes in the forward heap with the forward/reverse offset
BOOST_ASSERT(min_edge_offset <= 0);
if (weight + min_edge_offset > upper_bound)
{
forward_heap.DeleteAll();
return;
}
// Stalling
if (stalling)
{
for (const auto edge : facade.GetAdjacentEdgeRange(node))
{
const auto &data = facade.GetEdgeData(edge);
const bool reverse_flag = ((!forward_direction) ? data.forward : data.backward);
if (reverse_flag)
{
const NodeID to = facade.GetTarget(edge);
const EdgeWeight edge_weight = data.weight;
BOOST_ASSERT_MSG(edge_weight > 0, "edge_weight invalid");
if (forward_heap.WasInserted(to))
{
if (forward_heap.GetKey(to) + edge_weight < weight)
{
return;
}
}
}
}
}
for (const auto edge : facade.GetAdjacentEdgeRange(node))
{
const auto &data = facade.GetEdgeData(edge);
bool forward_directionFlag = (forward_direction ? data.forward : data.backward);
if (forward_directionFlag)
{
const NodeID to = facade.GetTarget(edge);
const EdgeWeight edge_weight = data.weight;
BOOST_ASSERT_MSG(edge_weight > 0, "edge_weight invalid");
const EdgeWeight to_weight = weight + edge_weight;
// New Node discovered -> Add to Heap + Node Info Storage
if (!forward_heap.WasInserted(to))
{
forward_heap.Insert(to, to_weight, node);
}
// Found a shorter Path -> Update weight
else if (to_weight < forward_heap.GetKey(to))
{
// new parent
forward_heap.GetData(to).parent = node;
forward_heap.DecreaseKey(to, to_weight);
}
}
}
}
/**
* Unpacks a single edge (NodeID->NodeID) from the CH graph down to it's original non-shortcut
* route.
* @param from the node the CH edge starts at
* @param to the node the CH edge finishes at
* @param unpacked_path the sequence of original NodeIDs that make up the expanded CH edge
*/
void unpackEdge(const datafacade::ContiguousInternalMemoryDataFacade<algorithm::CH> &facade,
const NodeID from,
const NodeID to,
std::vector<NodeID> &unpacked_path)
{
std::array<NodeID, 2> path{{from, to}};
unpackPath(facade,
path.begin(),
path.end(),
[&unpacked_path](const std::pair<NodeID, NodeID> &edge, const auto & /* data */) {
unpacked_path.emplace_back(edge.first);
});
unpacked_path.emplace_back(to);
}
void retrievePackedPathFromHeap(const SearchEngineData::QueryHeap &forward_heap,
const SearchEngineData::QueryHeap &reverse_heap,
const NodeID middle_node_id,
std::vector<NodeID> &packed_path)
{
retrievePackedPathFromSingleHeap(forward_heap, middle_node_id, packed_path);
std::reverse(packed_path.begin(), packed_path.end());
packed_path.emplace_back(middle_node_id);
retrievePackedPathFromSingleHeap(reverse_heap, middle_node_id, packed_path);
}
void retrievePackedPathFromSingleHeap(const SearchEngineData::QueryHeap &search_heap,
const NodeID middle_node_id,
std::vector<NodeID> &packed_path)
{
NodeID current_node_id = middle_node_id;
// all initial nodes will have itself as parent, or a node not in the heap
// in case of a core search heap. We need a distinction between core entry nodes
// and start nodes since otherwise start node specific code that assumes
// node == node.parent (e.g. the loop code) might get actived.
while (current_node_id != search_heap.GetData(current_node_id).parent &&
search_heap.WasInserted(search_heap.GetData(current_node_id).parent))
{
current_node_id = search_heap.GetData(current_node_id).parent;
packed_path.emplace_back(current_node_id);
}
}
// assumes that heaps are already setup correctly.
// ATTENTION: This only works if no additional offset is supplied next to the Phantom Node
// Offsets.
// In case additional offsets are supplied, you might have to force a loop first.
// A forced loop might be necessary, if source and target are on the same segment.
// If this is the case and the offsets of the respective direction are larger for the source
// than the target
// then a force loop is required (e.g. source_phantom.forward_segment_id ==
// target_phantom.forward_segment_id
// && source_phantom.GetForwardWeightPlusOffset() > target_phantom.GetForwardWeightPlusOffset())
// requires
// a force loop, if the heaps have been initialized with positive offsets.
void search(const datafacade::ContiguousInternalMemoryDataFacade<algorithm::CH> &facade,
SearchEngineData::QueryHeap &forward_heap,
SearchEngineData::QueryHeap &reverse_heap,
EdgeWeight &weight,
std::vector<NodeID> &packed_leg,
const bool force_loop_forward,
const bool force_loop_reverse,
const EdgeWeight weight_upper_bound)
{
NodeID middle = SPECIAL_NODEID;
weight = weight_upper_bound;
// get offset to account for offsets on phantom nodes on compressed edges
const auto min_edge_offset = std::min(0, forward_heap.MinKey());
BOOST_ASSERT(min_edge_offset <= 0);
// we only every insert negative offsets for nodes in the forward heap
BOOST_ASSERT(reverse_heap.MinKey() >= 0);
// run two-Target Dijkstra routing step.
const constexpr bool STALLING_ENABLED = true;
while (0 < (forward_heap.Size() + reverse_heap.Size()))
{
if (!forward_heap.Empty())
{
routingStep(facade,
forward_heap,
reverse_heap,
middle,
weight,
min_edge_offset,
true,
STALLING_ENABLED,
force_loop_forward,
force_loop_reverse);
}
if (!reverse_heap.Empty())
{
routingStep(facade,
reverse_heap,
forward_heap,
middle,
weight,
min_edge_offset,
false,
STALLING_ENABLED,
force_loop_reverse,
force_loop_forward);
}
}
// No path found for both target nodes?
if (weight_upper_bound <= weight || SPECIAL_NODEID == middle)
{
weight = INVALID_EDGE_WEIGHT;
return;
}
// Was a paths over one of the forward/reverse nodes not found?
BOOST_ASSERT_MSG((SPECIAL_NODEID != middle && INVALID_EDGE_WEIGHT != weight), "no path found");
// make sure to correctly unpack loops
if (weight != forward_heap.GetKey(middle) + reverse_heap.GetKey(middle))
{
// self loop makes up the full path
packed_leg.push_back(middle);
packed_leg.push_back(middle);
}
else
{
retrievePackedPathFromHeap(forward_heap, reverse_heap, middle, packed_leg);
}
}
// assumes that heaps are already setup correctly.
// A forced loop might be necessary, if source and target are on the same segment.
// If this is the case and the offsets of the respective direction are larger for the source
// than the target
// then a force loop is required (e.g. source_phantom.forward_segment_id ==
// target_phantom.forward_segment_id
// && source_phantom.GetForwardWeightPlusOffset() > target_phantom.GetForwardWeightPlusOffset())
// requires
// a force loop, if the heaps have been initialized with positive offsets.
void search(const datafacade::ContiguousInternalMemoryDataFacade<algorithm::CoreCH> &facade,
SearchEngineData::QueryHeap &forward_heap,
SearchEngineData::QueryHeap &reverse_heap,
SearchEngineData::QueryHeap &forward_core_heap,
SearchEngineData::QueryHeap &reverse_core_heap,
EdgeWeight &weight,
std::vector<NodeID> &packed_leg,
const bool force_loop_forward,
const bool force_loop_reverse,
EdgeWeight weight_upper_bound)
{
NodeID middle = SPECIAL_NODEID;
weight = weight_upper_bound;
using CoreEntryPoint = std::tuple<NodeID, EdgeWeight, NodeID>;
std::vector<CoreEntryPoint> forward_entry_points;
std::vector<CoreEntryPoint> reverse_entry_points;
// get offset to account for offsets on phantom nodes on compressed edges
const auto min_edge_offset = std::min(0, forward_heap.MinKey());
// we only every insert negative offsets for nodes in the forward heap
BOOST_ASSERT(reverse_heap.MinKey() >= 0);
const constexpr bool STALLING_ENABLED = true;
// run two-Target Dijkstra routing step.
while (0 < (forward_heap.Size() + reverse_heap.Size()))
{
if (!forward_heap.Empty())
{
if (facade.IsCoreNode(forward_heap.Min()))
{
const NodeID node = forward_heap.DeleteMin();
const EdgeWeight key = forward_heap.GetKey(node);
forward_entry_points.emplace_back(node, key, forward_heap.GetData(node).parent);
}
else
{
routingStep(facade,
forward_heap,
reverse_heap,
middle,
weight,
min_edge_offset,
true,
STALLING_ENABLED,
force_loop_forward,
force_loop_reverse);
}
}
if (!reverse_heap.Empty())
{
if (facade.IsCoreNode(reverse_heap.Min()))
{
const NodeID node = reverse_heap.DeleteMin();
const EdgeWeight key = reverse_heap.GetKey(node);
reverse_entry_points.emplace_back(node, key, reverse_heap.GetData(node).parent);
}
else
{
routingStep(facade,
reverse_heap,
forward_heap,
middle,
weight,
min_edge_offset,
false,
STALLING_ENABLED,
force_loop_reverse,
force_loop_forward);
}
}
}
const auto insertInCoreHeap = [](const CoreEntryPoint &p,
SearchEngineData::QueryHeap &core_heap) {
NodeID id;
EdgeWeight weight;
NodeID parent;
// TODO this should use std::apply when we get c++17 support
std::tie(id, weight, parent) = p;
core_heap.Insert(id, weight, parent);
};
forward_core_heap.Clear();
for (const auto &p : forward_entry_points)
{
insertInCoreHeap(p, forward_core_heap);
}
reverse_core_heap.Clear();
for (const auto &p : reverse_entry_points)
{
insertInCoreHeap(p, reverse_core_heap);
}
// get offset to account for offsets on phantom nodes on compressed edges
EdgeWeight min_core_edge_offset = 0;
if (forward_core_heap.Size() > 0)
{
min_core_edge_offset = std::min(min_core_edge_offset, forward_core_heap.MinKey());
}
if (reverse_core_heap.Size() > 0 && reverse_core_heap.MinKey() < 0)
{
min_core_edge_offset = std::min(min_core_edge_offset, reverse_core_heap.MinKey());
}
BOOST_ASSERT(min_core_edge_offset <= 0);
// run two-target Dijkstra routing step on core with termination criterion
const constexpr bool STALLING_DISABLED = false;
while (0 < forward_core_heap.Size() && 0 < reverse_core_heap.Size() &&
weight > (forward_core_heap.MinKey() + reverse_core_heap.MinKey()))
{
routingStep(facade,
forward_core_heap,
reverse_core_heap,
middle,
weight,
min_core_edge_offset,
true,
STALLING_DISABLED,
force_loop_forward,
force_loop_reverse);
routingStep(facade,
reverse_core_heap,
forward_core_heap,
middle,
weight,
min_core_edge_offset,
false,
STALLING_DISABLED,
force_loop_reverse,
force_loop_forward);
}
// No path found for both target nodes?
if (weight_upper_bound <= weight || SPECIAL_NODEID == middle)
{
weight = INVALID_EDGE_WEIGHT;
return;
}
// Was a paths over one of the forward/reverse nodes not found?
BOOST_ASSERT_MSG((SPECIAL_NODEID != middle && INVALID_EDGE_WEIGHT != weight), "no path found");
// we need to unpack sub path from core heaps
if (facade.IsCoreNode(middle))
{
if (weight != forward_core_heap.GetKey(middle) + reverse_core_heap.GetKey(middle))
{
// self loop
BOOST_ASSERT(forward_core_heap.GetData(middle).parent == middle &&
reverse_core_heap.GetData(middle).parent == middle);
packed_leg.push_back(middle);
packed_leg.push_back(middle);
}
else
{
std::vector<NodeID> packed_core_leg;
retrievePackedPathFromHeap(
forward_core_heap, reverse_core_heap, middle, packed_core_leg);
BOOST_ASSERT(packed_core_leg.size() > 0);
retrievePackedPathFromSingleHeap(forward_heap, packed_core_leg.front(), packed_leg);
std::reverse(packed_leg.begin(), packed_leg.end());
packed_leg.insert(packed_leg.end(), packed_core_leg.begin(), packed_core_leg.end());
retrievePackedPathFromSingleHeap(reverse_heap, packed_core_leg.back(), packed_leg);
}
}
else
{
if (weight != forward_heap.GetKey(middle) + reverse_heap.GetKey(middle))
{
// self loop
BOOST_ASSERT(forward_heap.GetData(middle).parent == middle &&
reverse_heap.GetData(middle).parent == middle);
packed_leg.push_back(middle);
packed_leg.push_back(middle);
}
else
{
retrievePackedPathFromHeap(forward_heap, reverse_heap, middle, packed_leg);
}
}
}
bool needsLoopForward(const PhantomNode &source_phantom, const PhantomNode &target_phantom)
{
return source_phantom.forward_segment_id.enabled && target_phantom.forward_segment_id.enabled &&
source_phantom.forward_segment_id.id == target_phantom.forward_segment_id.id &&
source_phantom.GetForwardWeightPlusOffset() >
target_phantom.GetForwardWeightPlusOffset();
}
bool needsLoopBackwards(const PhantomNode &source_phantom, const PhantomNode &target_phantom)
{
return source_phantom.reverse_segment_id.enabled && target_phantom.reverse_segment_id.enabled &&
source_phantom.reverse_segment_id.id == target_phantom.reverse_segment_id.id &&
source_phantom.GetReverseWeightPlusOffset() >
target_phantom.GetReverseWeightPlusOffset();
}
double getPathDistance(const datafacade::ContiguousInternalMemoryDataFacade<algorithm::CH> &facade,
const std::vector<NodeID> &packed_path,
const PhantomNode &source_phantom,
const PhantomNode &target_phantom)
{
std::vector<PathData> unpacked_path;
PhantomNodes nodes;
nodes.source_phantom = source_phantom;
nodes.target_phantom = target_phantom;
unpackPath(facade, packed_path.begin(), packed_path.end(), nodes, unpacked_path);
using util::coordinate_calculation::detail::DEGREE_TO_RAD;
using util::coordinate_calculation::detail::EARTH_RADIUS;
double distance = 0;
double prev_lat = static_cast<double>(toFloating(source_phantom.location.lat)) * DEGREE_TO_RAD;
double prev_lon = static_cast<double>(toFloating(source_phantom.location.lon)) * DEGREE_TO_RAD;
double prev_cos = std::cos(prev_lat);
for (const auto &p : unpacked_path)
{
const auto current_coordinate = facade.GetCoordinateOfNode(p.turn_via_node);
const double current_lat =
static_cast<double>(toFloating(current_coordinate.lat)) * DEGREE_TO_RAD;
const double current_lon =
static_cast<double>(toFloating(current_coordinate.lon)) * DEGREE_TO_RAD;
const double current_cos = std::cos(current_lat);
const double sin_dlon = std::sin((prev_lon - current_lon) / 2.0);
const double sin_dlat = std::sin((prev_lat - current_lat) / 2.0);
const double aharv = sin_dlat * sin_dlat + prev_cos * current_cos * sin_dlon * sin_dlon;
const double charv = 2. * std::atan2(std::sqrt(aharv), std::sqrt(1.0 - aharv));
distance += EARTH_RADIUS * charv;
prev_lat = current_lat;
prev_lon = current_lon;
prev_cos = current_cos;
}
const double current_lat =
static_cast<double>(toFloating(target_phantom.location.lat)) * DEGREE_TO_RAD;
const double current_lon =
static_cast<double>(toFloating(target_phantom.location.lon)) * DEGREE_TO_RAD;
const double current_cos = std::cos(current_lat);
const double sin_dlon = std::sin((prev_lon - current_lon) / 2.0);
const double sin_dlat = std::sin((prev_lat - current_lat) / 2.0);
const double aharv = sin_dlat * sin_dlat + prev_cos * current_cos * sin_dlon * sin_dlon;
const double charv = 2. * std::atan2(std::sqrt(aharv), std::sqrt(1.0 - aharv));
distance += EARTH_RADIUS * charv;
return distance;
}
// Requires the heaps for be empty
// If heaps should be adjusted to be initialized outside of this function,
// the addition of force_loop parameters might be required
double
getNetworkDistance(const datafacade::ContiguousInternalMemoryDataFacade<algorithm::CoreCH> &facade,
SearchEngineData::QueryHeap &forward_heap,
SearchEngineData::QueryHeap &reverse_heap,
SearchEngineData::QueryHeap &forward_core_heap,
SearchEngineData::QueryHeap &reverse_core_heap,
const PhantomNode &source_phantom,
const PhantomNode &target_phantom,
EdgeWeight weight_upper_bound)
{
forward_heap.Clear();
reverse_heap.Clear();
forward_core_heap.Clear();
reverse_core_heap.Clear();
if (source_phantom.forward_segment_id.enabled)
{
forward_heap.Insert(source_phantom.forward_segment_id.id,
-source_phantom.GetForwardWeightPlusOffset(),
source_phantom.forward_segment_id.id);
}
if (source_phantom.reverse_segment_id.enabled)
{
forward_heap.Insert(source_phantom.reverse_segment_id.id,
-source_phantom.GetReverseWeightPlusOffset(),
source_phantom.reverse_segment_id.id);
}
if (target_phantom.forward_segment_id.enabled)
{
reverse_heap.Insert(target_phantom.forward_segment_id.id,
target_phantom.GetForwardWeightPlusOffset(),
target_phantom.forward_segment_id.id);
}
if (target_phantom.reverse_segment_id.enabled)
{
reverse_heap.Insert(target_phantom.reverse_segment_id.id,
target_phantom.GetReverseWeightPlusOffset(),
target_phantom.reverse_segment_id.id);
}
const bool constexpr DO_NOT_FORCE_LOOPS =
false; // prevents forcing of loops, since offsets are set correctly
EdgeWeight weight = INVALID_EDGE_WEIGHT;
std::vector<NodeID> packed_path;
search(facade,
forward_heap,
reverse_heap,
forward_core_heap,
reverse_core_heap,
weight,
packed_path,
DO_NOT_FORCE_LOOPS,
DO_NOT_FORCE_LOOPS,
weight_upper_bound);
double distance = std::numeric_limits<double>::max();
if (weight != INVALID_EDGE_WEIGHT)
{
return getPathDistance(facade, packed_path, source_phantom, target_phantom);
}
return distance;
}
// Requires the heaps for be empty
// If heaps should be adjusted to be initialized outside of this function,
// the addition of force_loop parameters might be required
double
getNetworkDistance(const datafacade::ContiguousInternalMemoryDataFacade<algorithm::CH> &facade,
SearchEngineData::QueryHeap &forward_heap,
SearchEngineData::QueryHeap &reverse_heap,
const PhantomNode &source_phantom,
const PhantomNode &target_phantom,
EdgeWeight weight_upper_bound)
{
forward_heap.Clear();
reverse_heap.Clear();
if (source_phantom.forward_segment_id.enabled)
{
forward_heap.Insert(source_phantom.forward_segment_id.id,
-source_phantom.GetForwardWeightPlusOffset(),
source_phantom.forward_segment_id.id);
}
if (source_phantom.reverse_segment_id.enabled)
{
forward_heap.Insert(source_phantom.reverse_segment_id.id,
-source_phantom.GetReverseWeightPlusOffset(),
source_phantom.reverse_segment_id.id);
}
if (target_phantom.forward_segment_id.enabled)
{
reverse_heap.Insert(target_phantom.forward_segment_id.id,
target_phantom.GetForwardWeightPlusOffset(),
target_phantom.forward_segment_id.id);
}
if (target_phantom.reverse_segment_id.enabled)
{
reverse_heap.Insert(target_phantom.reverse_segment_id.id,
target_phantom.GetReverseWeightPlusOffset(),
target_phantom.reverse_segment_id.id);
}
const bool constexpr DO_NOT_FORCE_LOOPS =
false; // prevents forcing of loops, since offsets are set correctly
EdgeWeight weight = INVALID_EDGE_WEIGHT;
std::vector<NodeID> packed_path;
search(facade,
forward_heap,
reverse_heap,
weight,
packed_path,
DO_NOT_FORCE_LOOPS,
DO_NOT_FORCE_LOOPS,
weight_upper_bound);
if (weight == INVALID_EDGE_WEIGHT)
{
return std::numeric_limits<double>::max();
}
return getPathDistance(facade, packed_path, source_phantom, target_phantom);
}
} // namespace routing_algorithms
} // namespace engine
} // namespace osrm