#include <stdbool.h>
#include <assert.h>
#include "bigraph.h"
+#include "set.h"
-struct edgenode
+struct edge
{
- struct edgenode* next;
- struct vertex* this;
- struct vertex* other;
+ struct vertex* v1;
+ struct vertex* v2;
};
struct vertex
{
void* data;
- struct edgenode* connections;
int degree;
+ struct set edges;
};
static uint32_t edge_hash_function(void* key)
{
- struct edgenode* en = key;
+ struct edge* edge = key;
/* This will always return the same value, even if the two endpoints are swapped. */
- return standard_pointer_hash_function(en->this) ^ standard_pointer_hash_function(en->other);
+ return standard_pointer_hash_function(edge->v1) ^ standard_pointer_hash_function(edge->v2);
}
static bool edge_comparison_function(void* key1, void* key2)
{
- struct edgenode* en1 = key1;
- struct edgenode* en2 = key2;
+ struct edge* edge1 = key1;
+ struct edge* edge2 = key2;
- return ((en1->this == en2->this) && (en1->other == en2->other))
- || ((en1->this == en2->other) && (en1->other == en2->this));
+ return ((edge1->v1 == edge2->v1) && (edge1->v2 == edge2->v2))
+ || ((edge1->v1 == edge2->v2) && (edge1->v2 == edge2->v1));
}
static void lazy_init(struct graph* g)
{
- g->edges.hashfunction = edge_hash_function;
- g->edges.cmpfunction = edge_comparison_function;
+ g->edges.table.hashfunction = edge_hash_function;
+ g->edges.table.cmpfunction = edge_comparison_function;
}
void graph_reset(struct graph* g)
if (!vertex)
return;
- while (vertex->connections)
- {
- struct edgenode* next = vertex->connections->next;
- free(vertex->connections);
- vertex->connections = next;
- }
-
+ set_reset(&vertex->edges);
free(vertex);
}
+
+ for (;;)
+ {
+ struct edge* edge = set_pop(&g->edges);
+ free(edge);
+ }
}
bool graph_contains_vertex(struct graph* g, void* data)
{
lazy_init(g);
- return hashtable_contains(&g->vertices, data);
+ return !!hashtable_get(&g->vertices, data);
}
static struct vertex* find_or_add_vertex(struct graph* g, void* data)
return vertex;
}
-static struct edgenode** find_edgep(struct vertex* v1, struct vertex* v2)
-{
- struct edgenode** ep = &v1->connections;
-
- while (*ep)
- {
- if ((*ep)->other == v2)
- return ep;
- ep = &(*ep)->next;
- }
-
- return ep;
-}
-
bool graph_contains_edge(struct graph* g, void* data1, void* data2)
{
- struct vertex* v1 = find_or_add_vertex(g, data1);
- struct vertex* v2 = find_or_add_vertex(g, data2);
-
- if (!v1 || !v2)
- return false;
+ struct edge template;
- return *find_edgep(v1, v2) || *find_edgep(v2, v1);
-}
-
-static struct edgenode* add_edge(struct vertex* v1, struct vertex* v2)
-{
- struct edgenode** ep = find_edgep(v1, v2);
- if (!*ep)
- {
- *ep = calloc(1, sizeof(struct edgenode));
- (*ep)->this = v1;
- (*ep)->other = v2;
- v1->degree++;
- }
+ template.v1 = find_or_add_vertex(g, data1);
+ template.v2 = find_or_add_vertex(g, data2);
+ if (!template.v1 || !template.v2)
+ return false;
- return *ep;
+ return !!set_get(&g->edges, &template);
}
void graph_add_edge(struct graph* g, void* data1, void* data2)
{
- struct vertex* v1 = find_or_add_vertex(g, data1);
- struct vertex* v2 = find_or_add_vertex(g, data2);
- struct edgenode* e;
- struct edgenode template;
+ struct edge template;
+ struct edge* e;
- if (v1 == v2)
+ template.v1 = find_or_add_vertex(g, data1);
+ template.v2 = find_or_add_vertex(g, data2);
+ if (template.v1 == template.v2)
return;
- template.this = v1;
- template.other = v2;
- if (hashtable_contains(&g->edges, &template))
+ if (set_get(&g->edges, &template))
return;
- add_edge(v1, v2);
- e = add_edge(v2, v1);
+ e = calloc(1, sizeof(struct edge));
+ *e = template;
- hashtable_put(&g->edges, e, e);
-}
-
-static struct edgenode* remove_edge(struct vertex* v1, struct vertex* v2)
-{
- struct edgenode** ep = find_edgep(v1, v2);
-
- if (*ep)
- {
- struct edgenode* old = *ep;
- *ep = (*ep)->next;
- v1->degree--;
- return old;
- }
-
- return NULL;
+ set_add(&g->edges, e);
+ set_add(&template.v1->edges, e);
+ set_add(&template.v2->edges, e);
+ template.v1->degree++;
+ template.v2->degree++;
}
void graph_remove_edge(struct graph* g, void* data1, void* data2)
{
+ struct edge template;
struct vertex* v1 = find_or_add_vertex(g, data1);
struct vertex* v2 = find_or_add_vertex(g, data2);
- struct edgenode* e1 = remove_edge(v1, v2);
- struct edgenode* e2 = remove_edge(v2, v1);
- assert(!e1 == !e2);
+ template.v1 = find_or_add_vertex(g, data1);
+ template.v2 = find_or_add_vertex(g, data2);
+ if (template.v1 == template.v2)
+ return;
- if (e1)
- {
- /* e1 is a template; the actual object in the hashtable might actually
- * be e2 (as they compare the same). So, remove from the hashtable
- * before freeing anything. */
- hashtable_remove(&g->edges, e1);
- free(e1);
- }
- if (e2)
- free(e2);
+ set_remove(&template.v1->edges, &template);
+ set_remove(&template.v2->edges, &template);
+ free(set_remove(&g->edges, &template));
+ template.v1->degree--;
+ template.v2->degree--;
}
void graph_add_vertex(struct graph* g, void* data)
if (!vertex)
return;
- while (vertex->connections)
- {
- struct edgenode* next = vertex->connections->next;
- struct edgenode* e = remove_edge(vertex->connections->other, vertex);
- hashtable_remove(&g->edges, vertex->connections);
- free(e);
- free(vertex->connections);
- vertex->connections = next;
- }
-
+ for (;;)
+ {
+ struct vertex* other;
+ struct edge* e = set_pop(&vertex->edges);
+ if (!e)
+ break;
+
+ other = e->v1;
+ if (other == vertex)
+ other = e->v2;
+
+ set_remove(&other->edges, e);
+ other->degree--;
+ free(set_remove(&g->edges, e));
+ }
+
+ set_reset(&vertex->edges);
hashtable_remove(&g->vertices, data);
+ free(vertex);
}
int graph_get_vertex_degree(struct graph* g, void* data)
bool graph_next_edge(struct graph* g, struct edge_iterator* it)
{
- struct edgenode* e = hashtable_next(&g->edges, &it->hit);
+ struct edge* e = set_next(&g->edges, &it->sit);
if (e)
{
- it->left = e->this->data;
- it->right = e->other->data;
+ it->left = e->v1->data;
+ it->right = e->v2->data;
return true;
}
else
public / ack.git / commitdiff