/*
* __wt_bloom_insert --
* Adds the given key to the Bloom filter.
*/
int
__wt_bloom_insert(WT_BLOOM *bloom, WT_ITEM *key)
{
uint64_t h1, h2;
uint32_t i;
h1 = __wt_hash_fnv64(key->data, key->size);
h2 = __wt_hash_city64(key->data, key->size);
for (i = 0; i < bloom->k; i++, h1 += h2) {
__bit_set(bloom->bitstring, h1 % bloom->m);
}
return (0);
}
/*
* __txn_rollback_to_stable_btree --
* Called for each open handle - choose to either skip or wipe the commits
*/
static int
__txn_rollback_to_stable_btree(
WT_SESSION_IMPL *session, const char *cfg[])
{
WT_DECL_RET;
WT_DECL_TIMESTAMP(rollback_timestamp)
WT_BTREE *btree;
WT_TXN_GLOBAL *txn_global;
WT_UNUSED(cfg);
btree = S2BT(session);
txn_global = &S2C(session)->txn_global;
/*
* Immediately durable files don't get their commits wiped. This case
* mostly exists to support the semantic required for the oplog in
* MongoDB - updates that have been made to the oplog should not be
* aborted. It also wouldn't be safe to roll back updates for any
* table that had it's records logged, since those updates would be
* recovered after a crash making them inconsistent.
*/
if (__wt_btree_immediately_durable(session)) {
/*
* Add the btree ID to the bitstring, so we can exclude any
* lookaside entries for this btree.
*/
__bit_set(
S2C(session)->stable_rollback_bitstring, btree->id);
return (0);
}
/* There is never anything to do for checkpoint handles */
if (session->dhandle->checkpoint != NULL)
return (0);
/* There is nothing to do on an empty tree. */
if (btree->root.page == NULL)
return (0);
if (btree->type != BTREE_ROW)
WT_RET_MSG(session, EINVAL, "rollback_to_stable "
"is only supported for row store btrees");
/*
* Copy the stable timestamp, otherwise we'd need to lock it each time
* it's accessed. Even though the stable timestamp isn't supposed to be
* updated while rolling back, accessing it without a lock would
* violate protocol.
*/
__wt_readlock(session, &txn_global->rwlock);
__wt_timestamp_set(&rollback_timestamp, &txn_global->stable_timestamp);
__wt_readunlock(session, &txn_global->rwlock);
/*
* Ensure the eviction server is out of the file - we don't
* want it messing with us. This step shouldn't be required, but
* it simplifies some of the reasoning about what state trees can
* be in.
*/
WT_RET(__wt_evict_file_exclusive_on(session));
ret = __txn_rollback_to_stable_btree_walk(
session, &rollback_timestamp);
__wt_evict_file_exclusive_off(session);
return (ret);
}
