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Keyhash usage streamlining, historydb_cleanup routine 

git-svn-id: http://repo.ham.fi/svn/aprsc/trunk@201 3ce903b1-3385-4e86-93cd-f9a4a239f7ac
This commit is contained in:
Matti Aarnio 2008-03-21 14:39:04 +00:00
parent e5e04a23bd
commit 7254b3cda5
2 changed files with 51 additions and 10 deletions
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59
src/historydb.c
View File

@ -101,12 +101,10 @@ void historydb_nointerest(void) {}
void historydb_hashmatch(void) {}
void historydb_keymatch(void) {}
uint32_t historydb_hash1(const char *s, int keylen)
{
return keyhash((const void *)s, keylen, 0); // TODO: find a better hash function ?
}
/*
* The historydb_atend() does exist primarily to make valgrind
* happy about lost memory object tracking.
*/
void historydb_atend(void)
{
int i;
@ -211,7 +209,7 @@ int historydb_load(FILE *fp)
continue; // Too old, forget it.
keylen = strlen(keybuf);
h1 = historydb_hash1(keybuf, keylen);
h1 = keyhash(keybuf, keylen, 0);
h2 = h1;
h2 ^= (h2 >> 16); /* Fold hash bits.. */
i = h2 % HISTORYDB_HASH_MODULO;
@ -340,7 +338,7 @@ int historydb_insert(struct pbuf_t *pb)
++historydb_inserts;
h1 = historydb_hash1(keybuf, keylen);
h1 = keyhash(keybuf, keylen, 0);
h2 = h1;
h2 ^= (h2 >> 16); /* Fold hash bits.. */
i = h2 % HISTORYDB_HASH_MODULO;
@ -362,7 +360,7 @@ int historydb_insert(struct pbuf_t *pb)
}
if ( (cp->hash1 == h1)) {
// Hash match, compare the key
historydb_hashmatch(); // debug thing -- a profiling counter
historydb_hashmatch(); // debug thing -- a profiling counter
if ((strcmp(cp->key, keybuf) == 0) ) {
// Key match!
historydb_keymatch(); // debug thing -- a profiling counter
@ -429,7 +427,7 @@ int historydb_lookup(const char *keybuf, const int keylen, struct history_cell_t
++historydb_lookups;
h1 = historydb_hash1(keybuf, keylen);
h1 = keyhash(keybuf, keylen, 0);
h2 = h1;
h2 ^= (h2 >> 16); /* Fold hash bits.. */
i = h2 % HISTORYDB_HASH_MODULO;
@ -471,3 +469,44 @@ int historydb_lookup(const char *keybuf, const int keylen, struct history_cell_t
return 1;
}
/*
* The historydb_cleanup() exists to purge too old data out of
* the database at regular intervals. Call this about once a minute.
*/
void historydb_cleanup(void)
{
struct history_cell_t **hp, *cp;
int i, cleancount = 0;
// validity is 5 minutes shorter than expiration time..
time_t expirytime = now - lastposition_storetime;
for (i = 0; i < HISTORYDB_HASH_MODULO; ++i) {
hp = &historydb_hash[i];
// multiple locks ? one for each bucket, or for a subset of buckets ?
// .. or should we just lock outside the for(i ...) loop ?
rwl_wrlock(&historydb_rwlock);
while (( cp = *hp )) {
if (cp->arrivaltime < expirytime) {
// OLD...
*hp = cp->next;
cp->next = NULL;
historydb_free(cp);
++cleancount;
continue;
}
/* No expiry, just advance the pointer */
hp = &(cp -> next);
}
// Free the lock
rwl_wrunlock(&historydb_rwlock);
}
hlog(LOG_DEBUG, "historydb_cleanup() removed %d entries", cleancount);
}

2
src/historydb.h
View File

@ -69,6 +69,8 @@ extern void historydb_init(void);
extern void historydb_dump(FILE *fp);
extern int historydb_load(FILE *fp);
extern void historydb_cleanup(void);
extern void historydb_atend(void);
/* insert and lookup... interface yet unspecified */