2 Copyright (C) Andrew Tridgell 1996
3 Copyright (C) Paul Mackerras 1996
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 extern int csum_length;
27 typedef unsigned short tag;
29 #define TABLESIZE (1<<16)
30 #define NULL_TAG ((tag)-1)
32 static int false_alarms;
35 static int data_transfer;
37 static int total_false_alarms=0;
38 static int total_tag_hits=0;
39 static int total_matches=0;
40 static int total_data_transfer=0;
48 static struct target *targets=NULL;
50 static tag *tag_table = NULL;
52 #define gettag2(s1,s2) (((s1) + (s2)) & 0xFFFF)
53 #define gettag(sum) gettag2((sum)&0xFFFF,(sum)>>16)
55 static int compare_targets(struct target *t1,struct target *t2)
57 return(t1->t - t2->t);
61 static void build_hash_table(struct sum_struct *s)
66 tag_table = (tag *)malloc(sizeof(tag)*TABLESIZE);
68 targets = (struct target *)malloc(sizeof(targets[0])*s->count);
69 if (!tag_table || !targets)
70 out_of_memory("build_hash_table");
72 for (i=0;i<s->count;i++) {
74 targets[i].t = gettag(s->sums[i].sum1);
77 qsort(targets,s->count,sizeof(targets[0]),(int (*)())compare_targets);
79 for (i=0;i<TABLESIZE;i++)
80 tag_table[i] = NULL_TAG;
82 for (i=s->count-1;i>=0;i--) {
83 tag_table[targets[i].t] = i;
88 static off_t last_match;
91 static void matched(int f,struct sum_struct *s,char *buf,off_t len,
94 int n = offset - last_match;
98 fprintf(FERROR,"match at %d last_match=%d j=%d len=%d n=%d\n",
99 (int)offset,(int)last_match,i,(int)s->sums[i].len,n);
101 send_token(f,i,buf,last_match,n);
106 last_match = offset + s->sums[i].len;
109 last_match = offset + s->sums[i].len;
115 static void hash_search(int f,struct sum_struct *s,char *buf,off_t len)
119 char sum2[SUM_LENGTH];
124 fprintf(FERROR,"hash search b=%d len=%d\n",s->n,(int)len);
128 map = map_ptr(buf,0,k);
130 sum = get_checksum1(map, k);
134 fprintf(FERROR, "sum=%.8x k=%d\n", sum, k);
138 end = len + 1 - s->sums[s->count-1].len;
141 fprintf(FERROR,"hash search s->n=%d len=%d count=%d\n",
142 s->n,(int)len,s->count);
145 tag t = gettag2(s1,s2);
148 fprintf(FERROR,"offset=%d sum=%08x\n",
154 sum = (s1 & 0xffff) | (s2 << 16);
157 int i = targets[j].i;
159 if (sum == s->sums[i].sum1) {
161 fprintf(FERROR,"potential match at %d target=%d %d sum=%08x\n",
165 int l = MIN(s->n,len-offset);
166 map = map_ptr(buf,offset,l);
167 get_checksum2(map,l,sum2);
170 if (memcmp(sum2,s->sums[i].sum2,csum_length) == 0) {
171 matched(f,s,buf,len,offset,i);
172 offset += s->sums[i].len - 1;
173 k = MIN((len-offset), s->n);
174 map = map_ptr(buf,offset,k);
175 sum = get_checksum1(map, k);
185 } while (j<s->count && targets[j].t == t);
188 /* Trim off the first byte from the checksum */
189 map = map_ptr(buf,offset,k+1);
193 /* Add on the next byte (if there is one) to the checksum */
194 if (k < (len-offset)) {
201 } while (++offset < end);
203 matched(f,s,buf,len,len,-1);
207 void match_sums(int f,struct sum_struct *s,char *buf,off_t len)
215 if (len > 0 && s->count>0) {
219 fprintf(FERROR,"built hash table\n");
221 hash_search(f,s,buf,len);
224 fprintf(FERROR,"done hash search\n");
226 matched(f,s,buf,len,len,-1);
235 fprintf(FERROR, "false_alarms=%d tag_hits=%d matches=%d\n",
236 false_alarms, tag_hits, matches);
238 total_tag_hits += tag_hits;
239 total_false_alarms += false_alarms;
240 total_matches += matches;
241 total_data_transfer += data_transfer;
244 void match_report(void)
250 "total: matches=%d tag_hits=%d false_alarms=%d data=%d\n",
251 total_matches,total_tag_hits,
252 total_false_alarms,total_data_transfer);