/****************
* Flush the cache. This cannot be used while in a transaction.
*/
int
tdbio_sync()
{
CACHE_CTRL r;
int did_lock = 0;
if( db_fd == -1 )
open_db();
if( in_transaction )
log_bug("tdbio: syncing while in transaction\n");
if( !cache_is_dirty )
return 0;
if (!take_write_lock ())
did_lock = 1;
for( r = cache_list; r; r = r->next ) {
if( r->flags.used && r->flags.dirty ) {
int rc = write_cache_item( r );
if( rc )
return rc;
}
}
cache_is_dirty = 0;
if (did_lock)
release_write_lock ();
return 0;
}
/****************
* Flush the cache. This cannot be used while in a transaction.
*/
int
tdbio_sync()
{
CACHE_CTRL r;
int did_lock = 0;
if( db_fd == -1 )
open_db();
if( in_transaction )
log_bug("tdbio: syncing while in transaction\n");
if( !cache_is_dirty )
return 0;
if( !is_locked ) {
if( make_dotlock( lockhandle, -1 ) )
log_fatal("can't acquire lock - giving up\n");
else
is_locked = 1;
did_lock = 1;
}
for( r = cache_list; r; r = r->next ) {
if( r->flags.used && r->flags.dirty ) {
int rc = write_cache_item( r );
if( rc )
return rc;
}
}
cache_is_dirty = 0;
if( did_lock && !opt.lock_once ) {
if( !release_dotlock( lockhandle ) )
is_locked = 0;
}
return 0;
}
/****************
* Put data into the cache. This function may flush the
* some cache entries if there is not enough space available.
*/
int
put_record_into_cache( ulong recno, const char *data )
{
CACHE_CTRL r, unused;
int dirty_count = 0;
int clean_count = 0;
/* see whether we already cached this one */
for( unused = NULL, r = cache_list; r; r = r->next ) {
if( !r->flags.used ) {
if( !unused )
unused = r;
}
else if( r->recno == recno ) {
if( !r->flags.dirty ) {
/* Hmmm: should we use a a copy and compare? */
if( memcmp(r->data, data, TRUST_RECORD_LEN ) ) {
r->flags.dirty = 1;
cache_is_dirty = 1;
}
}
memcpy( r->data, data, TRUST_RECORD_LEN );
return 0;
}
if( r->flags.used ) {
if( r->flags.dirty )
dirty_count++;
else
clean_count++;
}
}
/* not in the cache: add a new entry */
if( unused ) { /* reuse this entry */
r = unused;
r->flags.used = 1;
r->recno = recno;
memcpy( r->data, data, TRUST_RECORD_LEN );
r->flags.dirty = 1;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
/* see whether we reached the limit */
if( cache_entries < MAX_CACHE_ENTRIES_SOFT ) { /* no */
r = xmalloc( sizeof *r );
r->flags.used = 1;
r->recno = recno;
memcpy( r->data, data, TRUST_RECORD_LEN );
r->flags.dirty = 1;
r->next = cache_list;
cache_list = r;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
/* cache is full: discard some clean entries */
if( clean_count ) {
int n = clean_count / 3; /* discard a third of the clean entries */
if( !n )
n = 1;
for( unused = NULL, r = cache_list; r; r = r->next ) {
if( r->flags.used && !r->flags.dirty ) {
if( !unused )
unused = r;
r->flags.used = 0;
cache_entries--;
if( !--n )
break;
}
}
assert( unused );
r = unused;
r->flags.used = 1;
r->recno = recno;
memcpy( r->data, data, TRUST_RECORD_LEN );
r->flags.dirty = 1;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
/* no clean entries: have to flush some dirty entries */
if( in_transaction ) {
/* but we can't do this while in a transaction
* we increase the cache size instead */
if( cache_entries < MAX_CACHE_ENTRIES_HARD ) { /* no */
if( opt.debug && !(cache_entries % 100) )
log_debug("increasing tdbio cache size\n");
r = xmalloc( sizeof *r );
r->flags.used = 1;
r->recno = recno;
memcpy( r->data, data, TRUST_RECORD_LEN );
r->flags.dirty = 1;
r->next = cache_list;
cache_list = r;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
log_info(_("trustdb transaction too large\n"));
return G10ERR_RESOURCE_LIMIT;
}
if( dirty_count ) {
int n = dirty_count / 5; /* discard some dirty entries */
if( !n )
n = 1;
if( !is_locked ) {
if( make_dotlock( lockhandle, -1 ) )
log_fatal("can't acquire lock - giving up\n");
else
is_locked = 1;
}
for( unused = NULL, r = cache_list; r; r = r->next ) {
if( r->flags.used && r->flags.dirty ) {
int rc = write_cache_item( r );
if( rc )
return rc;
if( !unused )
unused = r;
r->flags.used = 0;
cache_entries--;
if( !--n )
break;
}
}
if( !opt.lock_once ) {
if( !release_dotlock( lockhandle ) )
is_locked = 0;
}
assert( unused );
r = unused;
r->flags.used = 1;
r->recno = recno;
memcpy( r->data, data, TRUST_RECORD_LEN );
r->flags.dirty = 1;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
BUG();
}
/*
* Put data into the cache. This function may flush
* some cache entries if the cache is filled up.
*
* Returns: 0 on success or an error code.
*/
static int
put_record_into_cache (ulong recno, const char *data)
{
CACHE_CTRL r, unused;
int dirty_count = 0;
int clean_count = 0;
/* See whether we already cached this one. */
for (unused = NULL, r = cache_list; r; r = r->next)
{
if (!r->flags.used)
{
if (!unused)
unused = r;
}
else if (r->recno == recno)
{
if (!r->flags.dirty)
{
/* Hmmm: should we use a copy and compare? */
if (memcmp (r->data, data, TRUST_RECORD_LEN))
{
r->flags.dirty = 1;
cache_is_dirty = 1;
}
}
memcpy (r->data, data, TRUST_RECORD_LEN);
return 0;
}
if (r->flags.used)
{
if (r->flags.dirty)
dirty_count++;
else
clean_count++;
}
}
/* Not in the cache: add a new entry. */
if (unused)
{
/* Reuse this entry. */
r = unused;
r->flags.used = 1;
r->recno = recno;
memcpy (r->data, data, TRUST_RECORD_LEN);
r->flags.dirty = 1;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
/* See whether we reached the limit. */
if (cache_entries < MAX_CACHE_ENTRIES_SOFT)
{
/* No: Put into cache. */
r = xmalloc (sizeof *r);
r->flags.used = 1;
r->recno = recno;
memcpy (r->data, data, TRUST_RECORD_LEN);
r->flags.dirty = 1;
r->next = cache_list;
cache_list = r;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
/* Cache is full: discard some clean entries. */
if (clean_count)
{
int n;
/* We discard a third of the clean entries. */
n = clean_count / 3;
if (!n)
n = 1;
for (unused = NULL, r = cache_list; r; r = r->next)
{
if (r->flags.used && !r->flags.dirty)
{
if (!unused)
unused = r;
r->flags.used = 0;
cache_entries--;
if (!--n)
break;
}
}
/* Now put into the cache. */
assert (unused);
r = unused;
r->flags.used = 1;
r->recno = recno;
memcpy (r->data, data, TRUST_RECORD_LEN);
r->flags.dirty = 1;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
/* No clean entries: We have to flush some dirty entries. */
if (in_transaction)
{
/* But we can't do this while in a transaction. Thus we
* increase the cache size instead. */
if (cache_entries < MAX_CACHE_ENTRIES_HARD)
{
if (opt.debug && !(cache_entries % 100))
log_debug ("increasing tdbio cache size\n");
r = xmalloc (sizeof *r);
r->flags.used = 1;
r->recno = recno;
memcpy (r->data, data, TRUST_RECORD_LEN);
r->flags.dirty = 1;
r->next = cache_list;
cache_list = r;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
/* Hard limit for the cache size reached. */
log_info (_("trustdb transaction too large\n"));
return GPG_ERR_RESOURCE_LIMIT;
}
if (dirty_count)
{
int n;
/* Discard some dirty entries. */
n = dirty_count / 5;
if (!n)
n = 1;
take_write_lock ();
for (unused = NULL, r = cache_list; r; r = r->next)
{
if (r->flags.used && r->flags.dirty)
{
int rc;
rc = write_cache_item (r);
if (rc)
return rc;
if (!unused)
unused = r;
r->flags.used = 0;
cache_entries--;
if (!--n)
break;
}
}
release_write_lock ();
/* Now put into the cache. */
assert (unused);
r = unused;
r->flags.used = 1;
r->recno = recno;
memcpy (r->data, data, TRUST_RECORD_LEN);
r->flags.dirty = 1;
cache_is_dirty = 1;
cache_entries++;
return 0;
}
/* We should never reach this. */
BUG();
}
