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 void send_match(int f,int i)
90 static int matches[32];
91 static int match_count=0;
93 matches[match_count++] = i;
94 if (match_count == 32 || i==0) {
96 for (i=0;i<match_count;i++)
97 write_int(f,matches[i]);
102 static off_t last_match;
105 static void matched(int f,struct sum_struct *s,char *buf,off_t len,
108 int n = offset - last_match;
112 fprintf(stderr,"match at %d last_match=%d j=%d len=%d n=%d\n",
113 (int)offset,(int)last_match,i,(int)s->sums[i].len,n);
119 int n1 = MIN(CHUNK_SIZE,n-l);
120 write_buf(f,map_ptr(buf,last_match+l,n1),n1);
125 send_match(f,-(i+1));
127 last_match = offset + s->sums[i].len;
133 static void hash_search(int f,struct sum_struct *s,char *buf,off_t len)
137 char sum2[SUM_LENGTH];
142 fprintf(stderr,"hash search b=%d len=%d\n",s->n,(int)len);
146 map = map_ptr(buf,0,k);
148 sum = get_checksum1(map, k);
152 fprintf(stderr, "sum=%.8x k=%d\n", sum, k);
156 end = len + 1 - s->sums[s->count-1].len;
159 fprintf(stderr,"hash search s->n=%d len=%d count=%d\n",
160 s->n,(int)len,s->count);
163 tag t = gettag2(s1,s2);
166 fprintf(stderr,"offset=%d sum=%08x\n",
172 sum = (s1 & 0xffff) | (s2 << 16);
175 int i = targets[j].i;
177 if (sum == s->sums[i].sum1) {
179 fprintf(stderr,"potential match at %d target=%d %d sum=%08x\n",
183 int l = MIN(s->n,len-offset);
184 map = map_ptr(buf,offset,l);
185 get_checksum2(map,l,sum2);
188 if (memcmp(sum2,s->sums[i].sum2,csum_length) == 0) {
189 matched(f,s,buf,len,offset,i);
190 offset += s->sums[i].len - 1;
191 k = MIN((len-offset), s->n);
192 map = map_ptr(buf,offset,k);
193 sum = get_checksum1(map, k);
203 } while (j<s->count && targets[j].t == t);
206 /* Trim off the first byte from the checksum */
207 map = map_ptr(buf,offset,k+1);
211 /* Add on the next byte (if there is one) to the checksum */
212 if (k < (len-offset)) {
219 } while (++offset < end);
221 matched(f,s,buf,len,len,-1);
225 void match_sums(int f,struct sum_struct *s,char *buf,off_t len)
233 if (len > 0 && s->count>0) {
237 fprintf(stderr,"built hash table\n");
239 hash_search(f,s,buf,len);
242 fprintf(stderr,"done hash search\n");
244 matched(f,s,buf,len,len,-1);
253 fprintf(stderr, "false_alarms=%d tag_hits=%d matches=%d\n",
254 false_alarms, tag_hits, matches);
256 total_tag_hits += tag_hits;
257 total_false_alarms += false_alarms;
258 total_matches += matches;
259 total_data_transfer += data_transfer;
262 void match_report(void)
267 fprintf(am_server?stderr:stdout,
268 "total: matches=%d tag_hits=%d false_alarms=%d data=%d\n",
269 total_matches,total_tag_hits,
270 total_false_alarms,total_data_transfer);