From bda9c466182c5917c12405e834c5e3967a7692a9 Mon Sep 17 00:00:00 2001
From: fc_botelho <fc_botelho>
Date: Mon, 3 Jan 2005 20:47:21 +0000
Subject: [PATCH] using less space to store the used_edges and critical_nodes
arrays
---
src/bmz.c | 26 +++++++++++++++++---------
src/graph.c | 36 ++++++++++++++++++++----------------
2 files changed, 37 insertions(+), 25 deletions(-)
diff --git a/src/bmz.c b/src/bmz.c
index 61a1b5b..c0bfd0c 100644
--- a/src/bmz.c
+++ b/src/bmz.c
@@ -16,10 +16,16 @@
static uint32 UNDEFINED = UINT_MAX;
+static const char bitmask[8] = { 1, 1 << 1, 1 << 2, 1 << 3, 1 << 4, 1 << 5, 1 << 6, 1 << 7 };
+#define GETBIT(array, i) (array[(i) / 8] & bitmask[(i) % 8])
+#define SETBIT(array, i) (array[(i) / 8] |= bitmask[(i) % 8])
+#define UNSETBIT(array, i) (array[(i) / 8] &= (~(bitmask[(i) % 8])))
+
static int bmz_gen_edges(mph_t *mph);
static void bmz_traverse_critical_nodes(bmz_mph_data_t *bmz, uint32 v, uint32 * biggest_g_value, uint32 * biggest_edge_value, uint8 * used_edges);
static void bmz_traverse_non_critical_nodes(bmz_mph_data_t *bmz, uint8 * used_edges);
+
mph_t *bmz_mph_new(key_source_t *key_source)
{
mph_t *mph = NULL;
@@ -70,7 +76,6 @@ mphf_t *bmz_mph_create(mph_t *mph, float bmz_c)
uint32 i;
uint32 iterations = 10;
uint8 *used_edges = NULL;
- uint32 unused_edge_index = 0;
uint32 biggest_g_value = 0;
uint32 biggest_edge_value = 1;
DEBUGP("bmz_c: %f\n", bmz_c);
@@ -131,12 +136,13 @@ mphf_t *bmz_mph_create(mph_t *mph, float bmz_c)
// Searching step
if (mph->verbosity)
{
- fprintf(stderr, "Starting Searching step\n");
+ fprintf(stderr, "Starting Searching step.\n");
fprintf(stderr, "\tTraversing critical vertices.\n");
}
DEBUGP("Searching step\n");
- used_edges = (uint8 *)malloc(bmz->m*sizeof(uint8));
- memset(used_edges, 0, bmz->m);
+
+ used_edges = (uint8 *)malloc((bmz->m*sizeof(uint8))/8 + 1);
+ memset(used_edges, 0, bmz->m/8 + 1);
free(bmz->g);
bmz->g = malloc(bmz->n * sizeof(uint32));
assert(bmz->g);
@@ -211,7 +217,7 @@ static void bmz_traverse_critical_nodes(bmz_mph_data_t *bmz, uint32 v, uint32 *
if (graph_node_is_critical(bmz->graph, lav) && (bmz->g[lav] != UNDEFINED))
{
assert(next_g + bmz->g[lav] < bmz->m);
- if (used_edges[next_g + bmz->g[lav]])
+ if (GETBIT(used_edges, next_g + bmz->g[lav]))
{
collision = 1;
break;
@@ -226,7 +232,7 @@ static void bmz_traverse_critical_nodes(bmz_mph_data_t *bmz, uint32 v, uint32 *
{
if (graph_node_is_critical(bmz->graph, lav) && (bmz->g[lav] != UNDEFINED))
{
- used_edges[next_g + bmz->g[lav]] = 1;
+ SETBIT(used_edges,next_g + bmz->g[lav]);
if(next_g + bmz->g[lav] > *biggest_edge_value) *biggest_edge_value = next_g + bmz->g[lav];
}
}
@@ -245,7 +251,7 @@ static uint32 next_unused_edge(bmz_mph_data_t *bmz, uint8 * used_edges, uint32 u
while(1)
{
assert(unused_edge_index < bmz->m);
- if(used_edges[unused_edge_index]) unused_edge_index ++;
+ if(GETBIT(used_edges, unused_edge_index)) unused_edge_index ++;
else break;
}
return unused_edge_index;
@@ -259,16 +265,18 @@ static void bmz_traverse(bmz_mph_data_t *bmz, uint8 * used_edges, uint32 v, uint
{
DEBUGP("Visiting neighbor %u\n", neighbor);
if(bmz->g[neighbor] != UNDEFINED) continue;
- *unused_edge_index = next_unused_edge(bmz, used_edges, *unused_edge_index + 1);
+ *unused_edge_index = next_unused_edge(bmz, used_edges, *unused_edge_index);
bmz->g[neighbor] = *unused_edge_index - bmz->g[v];
+ (*unused_edge_index)++;
bmz_traverse(bmz, used_edges, neighbor, unused_edge_index);
+
}
}
static void bmz_traverse_non_critical_nodes(bmz_mph_data_t *bmz, uint8 * used_edges)
{
- uint32 i, v1, v2, unused_edge_index = -1;
+ uint32 i, v1, v2, unused_edge_index = 0;
DEBUGP("Labelling non critical vertices\n");
for(i = 0; i < bmz->m; i++)
{
diff --git a/src/graph.c b/src/graph.c
index a2a927a..00b3fca 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -10,6 +10,11 @@
//#define DEBUG
#include "debug.h"
+static const char bitmask[8] = { 1, 1 << 1, 1 << 2, 1 << 3, 1 << 4, 1 << 5, 1 << 6, 1 << 7 };
+#define GETBIT(array, i) (array[(i) / 8] & bitmask[(i) % 8])
+#define SETBIT(array, i) (array[(i) / 8] |= bitmask[(i) % 8])
+#define UNSETBIT(array, i) (array[(i) / 8] &= (~(bitmask[(i) % 8])))
+
#define abs_edge(e, i) (e % g->nedges + i * g->nedges)
struct __graph_t
@@ -172,7 +177,7 @@ static int find_degree1_edge(graph_t *g, uint32 v, char *deleted, uint32 *e)
char found = 0;
DEBUGP("Checking degree of vertex %u\n", v);
if (edge == EMPTY) return 0;
- else if (!deleted[abs_edge(edge, 0)])
+ else if (!(GETBIT(deleted, abs_edge(edge, 0))))
{
found = 1;
*e = edge;
@@ -181,7 +186,7 @@ static int find_degree1_edge(graph_t *g, uint32 v, char *deleted, uint32 *e)
{
edge = g->next[edge];
if (edge == EMPTY) break;
- if (deleted[abs_edge(edge, 0)]) continue;
+ if (GETBIT(deleted, abs_edge(edge, 0))) continue;
if (found) return 0;
DEBUGP("Found first edge\n");
*e = edge;
@@ -203,7 +208,7 @@ static void cyclic_del_edge(graph_t *g, uint32 v, char *deleted)
while(1)
{
DEBUGP("Deleting edge %u (%u->%u)\n", e, g->edges[abs_edge(e, 0)], g->edges[abs_edge(e, 1)]);
- deleted[abs_edge(e, 0)] = 1;
+ SETBIT(deleted, abs_edge(e, 0));
v2 = g->edges[abs_edge(e, 0)];
if (v2 == v1) v2 = g->edges[abs_edge(e, 1)];
@@ -223,8 +228,8 @@ int graph_is_cyclic(graph_t *g)
{
uint32 i;
uint32 v;
- char *deleted = (char *)malloc(g->nedges*sizeof(char));
- memset(deleted, 0, g->nedges);
+ char *deleted = (char *)malloc((g->nedges*sizeof(char))/8 + 1);
+ memset(deleted, 0, g->nedges/8 + 1);
DEBUGP("Looking for cycles in graph with %u vertices and %u edges\n", g->nnodes, g->nedges);
for (v = 0; v < g->nnodes; ++v)
@@ -233,7 +238,7 @@ int graph_is_cyclic(graph_t *g)
}
for (i = 0; i < g->nedges; ++i)
{
- if (!(deleted[i]))
+ if (!(GETBIT(deleted, i)))
{
DEBUGP("Edge %u %u->%u was not deleted\n", i, g->edges[i], g->edges[i + g->nedges]);
free(deleted);
@@ -246,17 +251,16 @@ int graph_is_cyclic(graph_t *g)
uint8 graph_node_is_critical(graph_t * g, uint32 v) /* included -- Fabiano */
{
- return g->critical_nodes[v];
+ return GETBIT(g->critical_nodes,v);
}
void graph_obtain_critical_nodes(graph_t *g) /* included -- Fabiano*/
{
uint32 i;
uint32 v;
- char *deleted = (char *)malloc(g->nedges*sizeof(char));
- memset(deleted, 0, g->nedges);
-/* g->critical_nodes = (uint8 *)malloc((size_t)(ceil(g->nnodes*sizeof(uint8)/8.))); */
- g->critical_nodes = (uint8 *)malloc(g->nnodes*sizeof(uint8));
+ char *deleted = (char *)malloc((g->nedges*sizeof(char))/8+1);
+ memset(deleted, 0, g->nedges/8 + 1);
+ g->critical_nodes = (uint8 *)malloc((g->nnodes*sizeof(uint8))/8 + 1);
g->ncritical_nodes = 0;
DEBUGP("Looking for the 2-core in graph with %u vertices and %u edges\n", g->nnodes, g->nedges);
for (v = 0; v < g->nnodes; ++v)
@@ -266,18 +270,18 @@ void graph_obtain_critical_nodes(graph_t *g) /* included -- Fabiano*/
for (i = 0; i < g->nedges; ++i)
{
- if (!(deleted[i]))
+ if (!(GETBIT(deleted,i)))
{
DEBUGP("Edge %u %u->%u belongs to the 2-core\n", i, g->edges[i], g->edges[i + g->nedges]);
- if(!(g->critical_nodes[g->edges[i]]))
+ if(!(GETBIT(g->critical_nodes,g->edges[i])))
{
g->ncritical_nodes ++;
- g->critical_nodes[g->edges[i]] = 1;
+ SETBIT(g->critical_nodes,g->edges[i]);
}
- if(!(g->critical_nodes[g->edges[i + g->nedges]]))
+ if(!(GETBIT(g->critical_nodes,g->edges[i + g->nedges])))
{
g->ncritical_nodes ++;
- g->critical_nodes[g->edges[i + g->nedges]] = 1;
+ SETBIT(g->critical_nodes,g->edges[i + g->nedges]);
}
}
}