/*
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 DYNAMICGRAPH_H_INCLUDED
#define DYNAMICGRAPH_H_INCLUDED
#include <vector>
#include <algorithm>
#include <limits>
#include "../DataStructures/DeallocatingVector.h"
template< typename EdgeDataT>
class DynamicGraph {
public:
typedef EdgeDataT EdgeData;
typedef unsigned NodeIterator;
typedef unsigned EdgeIterator;
class InputEdge {
public:
NodeIterator source;
NodeIterator target;
EdgeDataT data;
bool operator<( const InputEdge& right ) const {
if ( source != right.source )
return source < right.source;
return target < right.target;
}
};
//Constructs an empty graph with a given number of nodes.
DynamicGraph( int nodes ) : m_numNodes(nodes), m_numEdges(0) {
m_nodes.reserve( m_numNodes );
m_nodes.resize( m_numNodes );
m_edges.reserve( m_numNodes * 1.1 );
m_edges.resize( m_numNodes );
}
template<class ContainerT>
DynamicGraph( const int nodes, const ContainerT &graph )
{
m_numNodes = nodes;
m_numEdges = ( EdgeIterator ) graph.size();
m_nodes.reserve( m_numNodes );
m_nodes.resize( m_numNodes );
EdgeIterator edge = 0;
EdgeIterator position = 0;
for ( NodeIterator node = 0; node < m_numNodes; ++node ) {
EdgeIterator lastEdge = edge;
while ( edge < m_numEdges && graph[edge].source == node ) {
++edge;
}
m_nodes[node].firstEdge = position;
m_nodes[node].edges = edge - lastEdge;
position += m_nodes[node].edges;
}
m_edges.reserve( position * 1.1 );
m_edges.resize( position );
edge = 0;
for ( NodeIterator node = 0; node < m_numNodes; ++node ) {
for ( EdgeIterator i = m_nodes[node].firstEdge, e = m_nodes[node].firstEdge + m_nodes[node].edges; i != e; ++i ) {
m_edges[i].target = graph[edge].target;
m_edges[i].data = graph[edge].data;
GUARANTEE(graph[edge].data.distance > 0, "edge: " << edge << "(" << graph[edge].source << "," << graph[edge].target << ")=" << graph[edge].data.distance);
++edge;
}
}
}
~DynamicGraph(){ }
unsigned GetNumberOfNodes() const
{
return m_numNodes;
}
unsigned GetNumberOfEdges() const
{
return m_numEdges;
}
unsigned GetOutDegree( const NodeIterator &n ) const
{
return m_nodes[n].edges;
}
NodeIterator GetTarget( const EdgeIterator &e ) const
{
return NodeIterator( m_edges[e].target );
}
EdgeDataT &GetEdgeData( const EdgeIterator &e )
{
return m_edges[e].data;
}
const EdgeDataT &GetEdgeData( const EdgeIterator &e ) const
{
return m_edges[e].data;
}
EdgeIterator BeginEdges( const NodeIterator &n ) const
{
//assert( EndEdges( n ) - EdgeIterator( _nodes[n].firstEdge ) <= 100 );
return EdgeIterator( m_nodes[n].firstEdge );
}
EdgeIterator EndEdges( const NodeIterator &n ) const
{
return EdgeIterator( m_nodes[n].firstEdge + m_nodes[n].edges );
}
//adds an edge. Invalidates edge iterators for the source node
EdgeIterator InsertEdge( const NodeIterator &from, const NodeIterator &to, const EdgeDataT &data )
{
Node &node = m_nodes[from];
EdgeIterator newFirstEdge = node.edges + node.firstEdge;
if ( newFirstEdge >= m_edges.size() || !isDummy( newFirstEdge ) ) {
if ( node.firstEdge != 0 && isDummy( node.firstEdge - 1 ) ) {
node.firstEdge--;
m_edges[node.firstEdge] = m_edges[node.firstEdge + node.edges];
} else {
EdgeIterator newFirstEdge = ( EdgeIterator ) m_edges.size();
unsigned newSize = node.edges * 1.1 + 2;
EdgeIterator requiredCapacity = newSize + m_edges.size();
EdgeIterator oldCapacity = m_edges.capacity();
if ( requiredCapacity >= oldCapacity ) {
m_edges.reserve( requiredCapacity * 1.1 );
}
m_edges.resize( m_edges.size() + newSize );
for ( EdgeIterator i = 0; i < node.edges; ++i ) {
m_edges[newFirstEdge + i ] = m_edges[node.firstEdge + i];
makeDummy( node.firstEdge + i );
}
for ( EdgeIterator i = node.edges + 1; i < newSize; ++i )
makeDummy( newFirstEdge + i );
node.firstEdge = newFirstEdge;
}
}
Edge &edge = m_edges[node.firstEdge + node.edges];
edge.target = to;
edge.data = data;
++m_numEdges;
++node.edges;
return EdgeIterator( node.firstEdge + node.edges );
}
//removes an edge. Invalidates edge iterators for the source node
void DeleteEdge( const NodeIterator source, const EdgeIterator &e ) {
Node &node = m_nodes[source];
--m_numEdges;
--node.edges;
const unsigned last = node.firstEdge + node.edges;
//swap with last edge
m_edges[e] = m_edges[last];
makeDummy( last );
}
//removes all edges (source,target)
int DeleteEdgesTo( const NodeIterator source, const NodeIterator target )
{
int deleted = 0;
for ( EdgeIterator i = BeginEdges( source ), iend = EndEdges( source ); i < iend - deleted; ++i ) {
if ( m_edges[i].target == target ) {
do {
deleted++;
m_edges[i] = m_edges[iend - deleted];
makeDummy( iend - deleted );
} while ( i < iend - deleted && m_edges[i].target == target );
}
}
#pragma omp atomic
m_numEdges -= deleted;
m_nodes[source].edges -= deleted;
return deleted;
}
//searches for a specific edge
EdgeIterator FindEdge( const NodeIterator &from, const NodeIterator &to ) const
{
for ( EdgeIterator i = BeginEdges( from ), iend = EndEdges( from ); i != iend; ++i ) {
if ( m_edges[i].target == to ) {
return i;
}
}
return EndEdges( from );
}
protected:
bool isDummy( EdgeIterator edge ) const
{
return m_edges[edge].target == (std::numeric_limits< NodeIterator >::max)();
}
void makeDummy( EdgeIterator edge )
{
m_edges[edge].target = (std::numeric_limits< NodeIterator >::max)();
}
struct Node {
//index of the first edge
EdgeIterator firstEdge;
//amount of edges
unsigned edges;
};
struct Edge {
NodeIterator target;
EdgeDataT data;
};
NodeIterator m_numNodes;
EdgeIterator m_numEdges;
DeallocatingVector< Node > m_nodes;
DeallocatingVector< Edge > m_edges;
};
#endif // DYNAMICGRAPH_H_INCLUDED