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139 lines
3.6 KiB
C
139 lines
3.6 KiB
C
/*
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* Graph data structure.
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*
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* --
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* Copyright (C) 2016 Cumulus Networks, Inc.
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*
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* This file is part of GNU Zebra.
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*
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* GNU Zebra is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2, or (at your option) any
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* later version.
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*
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* GNU Zebra is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU Zebra; see the file COPYING. If not, write to the Free
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* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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* 02111-1307, USA.
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*/
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#include <zebra.h>
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#include "graph.h"
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#include "memory.h"
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DEFINE_MTYPE_STATIC(LIB, GRAPH, "Graph")
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DEFINE_MTYPE_STATIC(LIB, GRAPH_NODE, "Graph Node")
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struct graph *
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graph_new ()
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{
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struct graph *graph = XCALLOC (MTYPE_GRAPH, sizeof(struct graph));
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graph->nodes = vector_init (VECTOR_MIN_SIZE);
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return graph;
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}
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struct graph_node *
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graph_new_node (struct graph *graph, void *data, void (*del) (void*))
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{
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struct graph_node *node =
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XCALLOC(MTYPE_GRAPH_NODE, sizeof(struct graph_node));
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node->from = vector_init (VECTOR_MIN_SIZE);
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node->to = vector_init (VECTOR_MIN_SIZE);
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node->data = data;
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node->del = del;
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vector_set (graph->nodes, node);
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return node;
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}
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static void
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vector_remove (vector v, unsigned int ix)
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{
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vector_unset (v, ix);
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if (ix == vector_active (v)) return;
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for (; ix < vector_active (v) - 1; ix++)
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v->index[ix] = v->index[ix+1];
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v->active--;
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}
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void
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graph_delete_node (struct graph *graph, struct graph_node *node)
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{
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if (!node) return;
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// an adjacent node
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struct graph_node *adj;
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// remove all edges from other nodes to us
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vector edges = vector_copy (node->from);
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for (unsigned int i = 0; i < vector_active (edges); i++)
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{
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adj = vector_slot (edges, i);
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graph_remove_edge (adj, node);
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}
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vector_free (edges);
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// remove all edges from us to other nodes
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edges = vector_copy (node->to);
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for (unsigned int i = 0; i < vector_active (edges); i++)
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{
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adj = vector_slot (edges, i);
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graph_remove_edge (node, adj);
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}
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vector_free (edges);
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// if there is a deletion callback, call it
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if (node->del && node->data)
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(*node->del) (node->data);
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// free adjacency lists
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vector_free (node->to);
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vector_free (node->from);
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// remove node from graph->nodes
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for (unsigned int i = 0; i < vector_active (graph->nodes); i++)
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if (vector_slot (graph->nodes, i) == node)
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vector_remove (graph->nodes, i);
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// free the node itself
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XFREE (MTYPE_GRAPH_NODE, node);
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}
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struct graph_node *
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graph_add_edge (struct graph_node *from, struct graph_node *to)
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{
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vector_set (from->to, to);
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vector_set (to->from, from);
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return to;
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}
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void
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graph_remove_edge (struct graph_node *from, struct graph_node *to)
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{
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// remove from from to->from
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for (unsigned int i = 0; i < vector_active (to->from); i++)
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if (vector_slot (to->from, i) == from)
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vector_remove (to->from, i);
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// remove to from from->to
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for (unsigned int i = 0; i < vector_active (from->to); i++)
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if (vector_slot (from->to, i) == to)
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vector_remove (from->to, i);
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}
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void
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graph_delete_graph (struct graph *graph)
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{
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// delete each node in the graph
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for (unsigned int i = 0; i < vector_active (graph->nodes); i++)
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graph_delete_node (graph, vector_slot (graph->nodes, i));
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vector_free (graph->nodes);
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XFREE (MTYPE_GRAPH, graph);
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}
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