1#include <stdio.h>
2#include <stdlib.h>
3#include <unistd.h>
4#include <fcntl.h>
5#include <kvm.h>
6#include <nlist.h>
7#include <sysexits.h>
8#include <sys/uio.h>
9#include <sys/namei.h>
10#include <sys/param.h>
11#include <sys/queue.h>
12#include <sys/time.h>
13#include <sys/vnode.h>
14/*----------------------------------*/
15static u_int crc16_table[16] = {
16    0x0000, 0xCC01, 0xD801, 0x1400,
17    0xF001, 0x3C00, 0x2800, 0xE401,
18    0xA001, 0x6C00, 0x7800, 0xB401,
19    0x5000, 0x9C01, 0x8801, 0x4400
20};
21
22/* XXX Taken from sys/kern/vfs_cache.c */
23struct	namecache {
24	LIST_ENTRY(namecache) nc_hash;
25	LIST_ENTRY(namecache) nc_src;
26	TAILQ_ENTRY(namecache) nc_dst;
27	struct	vnode *nc_dvp;
28	struct	vnode *nc_vp;
29	u_char	nc_flag;
30	u_char	nc_nlen;
31	char	nc_name[0];
32};
33
34static u_short
35wlpsacrc(u_char *buf, u_int len)
36{
37    u_short     crc = 0;
38    int         i, r1;
39
40    for (i = 0; i < len; i++, buf++) {
41        /* lower 4 bits */
42        r1 = crc16_table[crc & 0xF];
43        crc = (crc >> 4) & 0x0FFF;
44        crc = crc ^ r1 ^ crc16_table[*buf & 0xF];
45
46        /* upper 4 bits */
47        r1 = crc16_table[crc & 0xF];
48        crc = (crc >> 4) & 0x0FFF;
49        crc = crc ^ r1 ^ crc16_table[(*buf >> 4) & 0xF];
50    }
51    return(crc);
52}
53
54/*----------------------------------*/
55struct nlist nl[] = {
56	{ "_nchash", 0},
57	{ "_nchashtbl", 0},
58	{ 0, 0 },
59};
60
61int histo[2047];
62int histn[2047];
63int *newbucket;
64
65int
66main(int argc, char **argv)
67{
68	int nchash, i, j, k, kn;
69	int nb, p1, p2;
70	u_long p;
71	LIST_HEAD(nchashhead, namecache) *nchashtbl;
72	struct namecache *nc;
73	struct vnode vn;
74
75	kvm_t *kvm = kvm_open(NULL, NULL, NULL, O_RDONLY, argv[0]);
76	if (kvm == NULL)
77		return(EX_OSERR);
78
79	printf("kvm: %p\n", kvm);
80	printf("kvm_nlist: %d\n", kvm_nlist(kvm, nl));
81	kvm_read(kvm, nl[0].n_value, &nchash, sizeof nchash);
82	nchash++;
83	nchashtbl = malloc(nchash * sizeof *nchashtbl);
84	nc = malloc(sizeof *nc + NAME_MAX);
85	newbucket = malloc(nchash * sizeof (int));
86	memset(newbucket, 0, nchash * sizeof (int));
87	kvm_read(kvm, nl[1].n_value, &p, sizeof p);
88	kvm_read(kvm, p, nchashtbl, nchash * sizeof *nchashtbl);
89	for (i=0; i < nchash; i++) {
90#if 0
91		printf("%d\n", i);
92#endif
93		nb=0;
94		p = (u_long)LIST_FIRST(nchashtbl+i);
95		while (p) {
96			nb++;
97			kvm_read(kvm, p, nc, sizeof *nc + NAME_MAX);
98			kvm_read(kvm, (u_long)nc->nc_dvp, &vn, sizeof vn);
99			nc->nc_name[nc->nc_nlen] = '\0';
100			for (j=k=kn=0;nc->nc_name[j];j++) {
101				k+= nc->nc_name[j];
102				kn <<= 1;
103				kn+= nc->nc_name[j];
104			}
105			/*
106			kn = k;
107			*/
108			kn = wlpsacrc(nc->nc_name,nc->nc_nlen);
109
110			/* kn += (u_long)vn.v_data >> 8;  */
111			/* kn += (u_long)nc->nc_dvp >> 7;    */
112			kn += vn.v_id;
113			kn &= (nchash - 1);
114			newbucket[kn]++;
115#if 1
116			printf("%4d  dvp %08x  hash %08x  vp %08x  id %08x  name <%s>\n",
117				i,nc->nc_dvp, k, nc->nc_vp, vn.v_id, nc->nc_name);
118#endif
119			p = (u_long)LIST_NEXT(nc, nc_hash);
120		}
121		histo[nb]++;
122	}
123	for (i=0; i < nchash; i++) {
124		histn[newbucket[i]]++;
125	}
126	p1=p2 = 0;
127	for (i=0;i<30;i++) {
128		p1 += histo[i] * i;
129		p2 += histn[i] * i;
130		if (histo[i] || histn[i])
131			printf("H%02d %4d %4d / %4d %4d\n",i,histo[i], p1 , histn[i], p2);
132	}
133
134	return (0);
135}
136
137