/*
open source routing machine
Copyright (C) Dennis Luxen, others 2010
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU AFFERO General Public License as published by
the Free Software Foundation; either version 3 of the License, or
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 General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
or see http://www.gnu.org/licenses/agpl.txt.
*/
#ifndef CONTRACTIONCLEANUP_H_INCLUDED
#define CONTRACTIONCLEANUP_H_INCLUDED
#include <algorithm>
#ifndef _WIN32
#include <sys/time.h>
#endif
#include "Contractor.h"
class ContractionCleanup {
private:
struct _CleanupHeapData {
NodeID parent;
_CleanupHeapData( NodeID p ) {
parent = p;
}
};
typedef BinaryHeap< NodeID, NodeID, int, _CleanupHeapData > _Heap;
struct _ThreadData {
_Heap* _heapForward;
_Heap* _heapBackward;
_ThreadData( NodeID nodes ) {
_heapBackward = new _Heap(nodes);
_heapForward = new _Heap(nodes);
}
~_ThreadData() {
delete _heapBackward;
delete _heapForward;
}
};
public:
struct Edge {
NodeID source;
NodeID target;
struct EdgeData {
NodeID via;
unsigned nameID;
int distance;
short turnInstruction;
bool shortcut:1;
bool forward:1;
bool backward:1;
} data;
bool operator<( const Edge& right ) const {
if ( source != right.source )
return source < right.source;
return target < right.target;
}
//sorts by source and other attributes
static bool CompareBySource( const Edge& left, const Edge& right ) {
if ( left.source != right.source )
return left.source < right.source;
int l = ( left.data.forward ? -1 : 0 ) + ( left.data.backward ? -1 : 0 );
int r = ( right.data.forward ? -1 : 0 ) + ( right.data.backward ? -1 : 0 );
if ( l != r )
return l < r;
if ( left.target != right.target )
return left.target < right.target;
return left.data.distance < right.data.distance;
}
bool operator== ( const Edge& right ) const {
return ( source == right.source && target == right.target && data.distance == right.data.distance &&
data.shortcut == right.data.shortcut && data.forward == right.data.forward && data.backward == right.data.backward
&& data.via == right.data.via && data.nameID == right.data.nameID
);
}
};
ContractionCleanup( int numNodes, const std::vector< Edge >& edges ) {
_graph = edges;
_numNodes = numNodes;
}
~ContractionCleanup() {
}
void Run() {
RemoveUselessShortcuts();
}
template< class EdgeT >
void GetData( std::vector< EdgeT >& edges ) {
for ( int edge = 0, endEdges = ( int ) _graph.size(); edge != endEdges; ++edge ) {
if(_graph[edge].data.forward || _graph[edge].data.backward) {
EdgeT newEdge;
newEdge.source = _graph[edge].source;
newEdge.target = _graph[edge].target;
newEdge.data = _graph[edge].data;
edges.push_back( newEdge );
}
}
sort( edges.begin(), edges.end() );
}
private:
double _Timestamp() {
struct timeval tp;
gettimeofday(&tp, NULL);
return double(tp.tv_sec) + tp.tv_usec / 1000000.;
}
void BuildOutgoingGraph() {
//sort edges by source
sort( _graph.begin(), _graph.end(), Edge::CompareBySource );
try {
_firstEdge.resize( _numNodes + 1 );
} catch(...) {
ERR("Not enough RAM on machine");
return;
}
_firstEdge[0] = 0;
for ( NodeID i = 0, node = 0; i < ( NodeID ) _graph.size(); i++ ) {
while ( _graph[i].source != node )
_firstEdge[++node] = i;
if ( i == ( NodeID ) _graph.size() - 1 )
while ( node < _numNodes )
_firstEdge[++node] = ( int ) _graph.size();
}
}
void RemoveUselessShortcuts() {
int maxThreads = omp_get_max_threads();
std::vector < _ThreadData* > threadData;
for ( int threadNum = 0; threadNum < maxThreads; ++threadNum ) {
threadData.push_back( new _ThreadData( _numNodes ) );
}
INFO("Scanning for useless shortcuts");
BuildOutgoingGraph();
/*
#pragma omp parallel for
for ( int i = 0; i < ( int ) _graph.size(); i++ ) {
//only remove shortcuts
if ( !_graph[i].data.shortcut )
continue;
if ( _graph[i].data.forward ) {
int result = _ComputeDistance( _graph[i].source, _graph[i].target, threadData[omp_get_thread_num()] );
if ( result < _graph[i].data.distance ) {
_graph[i].data.forward = false;
}
}
if ( _graph[i].data.backward ) {
int result = _ComputeDistance( _graph[i].target, _graph[i].source, threadData[omp_get_thread_num()] );
if ( result < _graph[i].data.distance ) {
_graph[i].data.backward = false;
}
}
}
*/
INFO("Removing edges");
int useful = 0;
for ( int i = 0; i < ( int ) _graph.size(); i++ ) {
if ( !_graph[i].data.forward && !_graph[i].data.backward && _graph[i].data.shortcut ) {
continue;
}
_graph[useful] = _graph[i];
useful++;
}
INFO("Removed " << _graph.size() - useful << " useless shortcuts");
_graph.resize( useful );
for ( int threadNum = 0; threadNum < maxThreads; ++threadNum ) {
delete threadData[threadNum];
}
}
void _ComputeStep( _Heap* heapForward, _Heap* heapBackward, bool forwardDirection, NodeID* middle, int* targetDistance ) {
const NodeID node = heapForward->DeleteMin();
const int distance = heapForward->GetKey( node );
if ( distance > *targetDistance ) {
heapForward->DeleteAll();
return;
}
if ( heapBackward->WasInserted( node ) ) {
const int newDistance = heapBackward->GetKey( node ) + distance;
if ( newDistance < *targetDistance ) {
*middle = node;
*targetDistance = newDistance;
}
}
for ( int edge = _firstEdge[node], endEdges = _firstEdge[node + 1]; edge != endEdges; ++edge ) {
const NodeID to = _graph[edge].target;
const int edgeWeight = _graph[edge].data.distance;
assert( edgeWeight > 0 );
const int toDistance = distance + edgeWeight;
if ( (forwardDirection ? _graph[edge].data.forward : _graph[edge].data.backward ) ) {
//New Node discovered -> Add to Heap + Node Info Storage
if ( !heapForward->WasInserted( to ) )
heapForward->Insert( to, toDistance, node );
//Found a shorter Path -> Update distance
else if ( toDistance < heapForward->GetKey( to ) ) {
heapForward->DecreaseKey( to, toDistance );
//new parent
heapForward->GetData( to ) = node;
}
}
}
}
int _ComputeDistance( NodeID source, NodeID target, _ThreadData * data ) {
data->_heapForward->Clear();
data->_heapBackward->Clear();
//insert source into heap
data->_heapForward->Insert( source, 0, source );
data->_heapBackward->Insert( target, 0, target );
int targetDistance = std::numeric_limits< int >::max();
NodeID middle = std::numeric_limits<NodeID>::max();
while ( data->_heapForward->Size() + data->_heapBackward->Size() > 0 ) {
if ( data->_heapForward->Size() > 0 ) {
_ComputeStep( data->_heapForward, data->_heapBackward, true, &middle, &targetDistance );
}
if ( data->_heapBackward->Size() > 0 ) {
_ComputeStep( data->_heapBackward, data->_heapForward, false, &middle, &targetDistance );
}
}
return targetDistance;
}
NodeID _numNodes;
std::vector< Edge > _graph;
std::vector< unsigned > _firstEdge;
};
#endif // CONTRACTIONCLEANUP_H_INCLUDED