--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ueda/uschem-netlist/nets.c	Mon Jul 20 00:24:37 2015 +0000
@@ -0,0 +1,127 @@
+/*
+ * Working with struct net objects (netheads)
+ */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <strings.h>
+#include "netlist.h"
+
+extern char *malloc();
+
+#define	HASH_SIZE	1103
+
+static struct net *named_net_hash[HASH_SIZE];
+int total_named_nets;
+
+struct net **sorted_named_nets;
+
+struct net *unnamed_net_list;
+int total_unnamed_nets;
+
+struct net noconnect_pseudo_net = {"NO_CONNECT", NULL, 0, NULL};
+
+static int
+hash_netname(str)
+	char *str;
+{
+	register u_long accum = 0;
+	register char *cp;
+	register int c, i;
+
+	for (cp = str, i = 1; c = *cp; cp++, i++)
+		accum += c * i;
+	return(accum % HASH_SIZE);
+}
+
+struct net *
+alloc_nethead()
+{
+	register struct net *n;
+
+	n = (struct net *) malloc(sizeof(struct net));
+	if (!n) {
+		perror("malloc");
+		exit(1);
+	}
+	bzero(n, sizeof(struct net));
+	return(n);
+}
+
+struct net *
+get_nethead_for_netname(netname)
+	register char *netname;
+{
+	register struct net *n, **np;
+
+	for (np = named_net_hash + hash_netname(netname); n = *np;
+	     np = &n->next)
+		if (!strcmp(n->netname, netname))
+			return(n);
+	n = alloc_nethead();
+	n->netname = netname;
+	*np = n;
+	total_named_nets++;
+	return(n);
+}
+
+report_named_net_hash_quality()
+{
+	int maxchain;
+	register int hb, curchain;
+	register struct net *n;
+
+	for (hb = 0, maxchain = 0; hb < HASH_SIZE; hb++) {
+		for (n = named_net_hash[hb], curchain = 0; n; n = n->next)
+			curchain++;
+		if (curchain > maxchain)
+			maxchain = curchain;
+	}
+	printf("Total named nets: %d\n", total_named_nets);
+	printf("Longest hash chain: %d\n", maxchain);
+}
+
+named_net_forall(callback)
+	int (*callback)();
+{
+	register struct net *n, **hb;
+	register int i;
+
+	for (hb = named_net_hash, i = 0; i < HASH_SIZE; hb++, i++)
+		for (n = *hb; n; n = n->next)
+			callback(n);
+}
+
+static
+netname_sort_compare(net1, net2)
+	struct net **net1, **net2;
+{
+	return(strcmp((*net1)->netname, (*net2)->netname));
+}
+
+sort_named_nets()
+{
+	register struct net *n, **hb, **op;
+	register int i;
+
+	sorted_named_nets =
+		(struct net **) malloc(sizeof(struct net *) * total_named_nets);
+	if (!sorted_named_nets) {
+		perror("malloc");
+		exit(1);
+	}
+	op = sorted_named_nets;
+	for (hb = named_net_hash, i = 0; i < HASH_SIZE; hb++, i++)
+		for (n = *hb; n; n = n->next)
+			*op++ = n;
+	qsort(sorted_named_nets, total_named_nets, sizeof(struct net *),
+		netname_sort_compare);
+}
+
+add_unnamed_net(n)
+	register struct net *n;
+{
+	n->next = unnamed_net_list;
+	unnamed_net_list = n;
+	total_unnamed_nets++;
+}