Fossil SCM
Add the /hash-collisions webpage.
Commit
43e2aff58ae2bc0c59742038fd7eeefcb1d22f44
Parent
1fee0377e4fb76b…
1 file changed
+52
+52
| --- src/name.c | ||
| +++ src/name.c | ||
| @@ -1058,5 +1058,57 @@ | ||
| 1058 | 1058 | */ |
| 1059 | 1059 | void test_phatoms_cmd(void){ |
| 1060 | 1060 | db_find_and_open_repository(0,0); |
| 1061 | 1061 | describe_artifacts_to_stdout("IN (SELECT rid FROM blob WHERE size<0)", 0); |
| 1062 | 1062 | } |
| 1063 | + | |
| 1064 | +/* | |
| 1065 | +** WEBPAGE: hash-collisions | |
| 1066 | +** | |
| 1067 | +** Show the number of hash collisions for hash prefixes of various lengths. | |
| 1068 | +*/ | |
| 1069 | +void hash_collisions_webpage(void){ | |
| 1070 | + int i; | |
| 1071 | + int nHash = 0; | |
| 1072 | + Stmt q; | |
| 1073 | + char zPrev[UUID_SIZE+1]; | |
| 1074 | + struct { | |
| 1075 | + int cnt; | |
| 1076 | + char z[UUID_SIZE+1]; | |
| 1077 | + } aCollide[UUID_SIZE+1]; | |
| 1078 | + login_check_credentials(); | |
| 1079 | + if( !g.perm.Read ){ login_needed(); return; } | |
| 1080 | + memset(aCollide, 0, sizeof(aCollide)); | |
| 1081 | + memset(zPrev, 0, sizeof(zPrev)); | |
| 1082 | + db_prepare(&q, | |
| 1083 | + "SELECT tkt_uuid FROM ticket\n" | |
| 1084 | + "UNION ALL\n" | |
| 1085 | + "SELECT substr(tagname,7) FROM tag WHERE tagname GLOB 'event-*'\n" | |
| 1086 | + "UNION ALL\n" | |
| 1087 | + "SELECT uuid FROM blob\n" | |
| 1088 | + "ORDER BY 1" | |
| 1089 | + ); | |
| 1090 | + while( db_step(&q)==SQLITE_ROW ){ | |
| 1091 | + const char *zUuid = db_column_text(&q,0); | |
| 1092 | + int n = db_column_bytes(&q,0); | |
| 1093 | + int i; | |
| 1094 | + nHash++; | |
| 1095 | + for(i=0; zPrev[i] && zPrev[i]==zUuid[i]; i++){} | |
| 1096 | + memcpy(zPrev, zUuid, n+1); | |
| 1097 | + if( i>0 && i<=UUID_SIZE ){ | |
| 1098 | + aCollide[i].cnt++; | |
| 1099 | + if( aCollide[i].z[0]==0 ) memcpy(aCollide[i].z, zPrev, n+1); | |
| 1100 | + } | |
| 1101 | + } | |
| 1102 | + db_finalize(&q); | |
| 1103 | + style_header("Hash Prefix Collisions"); | |
| 1104 | + @ <table border=1><thead> | |
| 1105 | + @ <tr><th>Length<th>Instances<th>First Instance</tr> | |
| 1106 | + @ </thead><tbody> | |
| 1107 | + for(i=1; i<UUID_SIZE; i++){ | |
| 1108 | + if( aCollide[i].cnt==0 ) continue; | |
| 1109 | + @ <tr><td>%d(i)<td>%d(aCollide[i].cnt)<td>%h(aCollide[i].z)</tr> | |
| 1110 | + } | |
| 1111 | + @ </tbody></table> | |
| 1112 | + @ <p>Total number of hashes: %d(nHash)</p> | |
| 1113 | + style_footer(); | |
| 1114 | +} | |
| 1063 | 1115 |
| --- src/name.c | |
| +++ src/name.c | |
| @@ -1058,5 +1058,57 @@ | |
| 1058 | */ |
| 1059 | void test_phatoms_cmd(void){ |
| 1060 | db_find_and_open_repository(0,0); |
| 1061 | describe_artifacts_to_stdout("IN (SELECT rid FROM blob WHERE size<0)", 0); |
| 1062 | } |
| 1063 |
| --- src/name.c | |
| +++ src/name.c | |
| @@ -1058,5 +1058,57 @@ | |
| 1058 | */ |
| 1059 | void test_phatoms_cmd(void){ |
| 1060 | db_find_and_open_repository(0,0); |
| 1061 | describe_artifacts_to_stdout("IN (SELECT rid FROM blob WHERE size<0)", 0); |
| 1062 | } |
| 1063 | |
| 1064 | /* |
| 1065 | ** WEBPAGE: hash-collisions |
| 1066 | ** |
| 1067 | ** Show the number of hash collisions for hash prefixes of various lengths. |
| 1068 | */ |
| 1069 | void hash_collisions_webpage(void){ |
| 1070 | int i; |
| 1071 | int nHash = 0; |
| 1072 | Stmt q; |
| 1073 | char zPrev[UUID_SIZE+1]; |
| 1074 | struct { |
| 1075 | int cnt; |
| 1076 | char z[UUID_SIZE+1]; |
| 1077 | } aCollide[UUID_SIZE+1]; |
| 1078 | login_check_credentials(); |
| 1079 | if( !g.perm.Read ){ login_needed(); return; } |
| 1080 | memset(aCollide, 0, sizeof(aCollide)); |
| 1081 | memset(zPrev, 0, sizeof(zPrev)); |
| 1082 | db_prepare(&q, |
| 1083 | "SELECT tkt_uuid FROM ticket\n" |
| 1084 | "UNION ALL\n" |
| 1085 | "SELECT substr(tagname,7) FROM tag WHERE tagname GLOB 'event-*'\n" |
| 1086 | "UNION ALL\n" |
| 1087 | "SELECT uuid FROM blob\n" |
| 1088 | "ORDER BY 1" |
| 1089 | ); |
| 1090 | while( db_step(&q)==SQLITE_ROW ){ |
| 1091 | const char *zUuid = db_column_text(&q,0); |
| 1092 | int n = db_column_bytes(&q,0); |
| 1093 | int i; |
| 1094 | nHash++; |
| 1095 | for(i=0; zPrev[i] && zPrev[i]==zUuid[i]; i++){} |
| 1096 | memcpy(zPrev, zUuid, n+1); |
| 1097 | if( i>0 && i<=UUID_SIZE ){ |
| 1098 | aCollide[i].cnt++; |
| 1099 | if( aCollide[i].z[0]==0 ) memcpy(aCollide[i].z, zPrev, n+1); |
| 1100 | } |
| 1101 | } |
| 1102 | db_finalize(&q); |
| 1103 | style_header("Hash Prefix Collisions"); |
| 1104 | @ <table border=1><thead> |
| 1105 | @ <tr><th>Length<th>Instances<th>First Instance</tr> |
| 1106 | @ </thead><tbody> |
| 1107 | for(i=1; i<UUID_SIZE; i++){ |
| 1108 | if( aCollide[i].cnt==0 ) continue; |
| 1109 | @ <tr><td>%d(i)<td>%d(aCollide[i].cnt)<td>%h(aCollide[i].z)</tr> |
| 1110 | } |
| 1111 | @ </tbody></table> |
| 1112 | @ <p>Total number of hashes: %d(nHash)</p> |
| 1113 | style_footer(); |
| 1114 | } |
| 1115 |