/**
* Cursor must be closed before the transaction is aborted/commited.
* http://download.oracle.com/docs/cd/E17076_02/html/programmer_reference/transapp_cursor.html
*/
Bdb::ResponseCode Bdb::
update(const std::string& key, const std::string& value)
{
if (!inited_) {
fprintf(stderr, "insert called on uninitialized database");
return Error;
}
DbTxn* txn = NULL;
Dbc* cursor = NULL;
Dbt dbkey, dbdata;
dbkey.set_data(const_cast<char*>(key.c_str()));
dbkey.set_size(key.size());
dbdata.set_data(const_cast<char*>(value.c_str()));
dbdata.set_size(value.size());
Dbt currentData;
currentData.set_data(NULL);
currentData.set_ulen(0);
currentData.set_dlen(0);
currentData.set_doff(0);
currentData.set_flags(DB_DBT_USERMEM | DB_DBT_PARTIAL);
int rc = 0;
for (uint32_t idx = 0; idx < numRetries_; idx++) {
env_->txn_begin(NULL, &txn, 0);
(*db_).cursor(txn, &cursor, DB_READ_COMMITTED);
// move the cursor to the record.
rc = cursor->get(&dbkey, ¤tData, DB_SET | DB_RMW);
if (rc != 0) {
cursor->close();
txn->abort();
if (rc == DB_NOTFOUND) {
return KeyNotFound;
} else if (rc != DB_LOCK_DEADLOCK) {
fprintf(stderr, "Db::get() returned: %s", db_strerror(rc));
return Error;
}
continue;
}
// update the record.
rc = cursor->put(NULL, &dbdata, DB_CURRENT);
cursor->close();
if (rc == 0) {
txn->commit(DB_TXN_SYNC);
return Success;
} else {
txn->abort();
if (rc != DB_LOCK_DEADLOCK) {
fprintf(stderr, "Db::put() returned: %s", db_strerror(rc));
return Error;
}
}
}
fprintf(stderr, "update failed %d times", numRetries_);
return Error;
}
void Database::del(const RecordID& id)
{
Dbt key(id.data(), id.size());
// fetch children
std::vector<RecordID> childrenIds;
Dbc* pCursor = nullptr;
dbParentId_.cursor(NULL, &pCursor, 0);
assert(pCursor);
BOOST_SCOPE_EXIT(&pCursor)
{
if(pCursor) pCursor->close();
} BOOST_SCOPE_EXIT_END
Dbt keyChild;
Dbt record;
record.set_flags(DB_DBT_PARTIAL);
record.set_doff(0);
record.set_dlen(0);
int res = pCursor->pget(&key, &keyChild, &record, DB_SET);
while (res == 0)
{
childrenIds.push_back(RecordID(keyChild));
res = pCursor->pget(&key, &keyChild, &record, DB_NEXT_DUP);
}
if (res != DB_NOTFOUND)
{
throw DbException("Failed to obtain children ids", res);
}
pCursor->close();
pCursor = nullptr;
// delete children
for (const RecordID& childId : childrenIds)
{
del(childId);
}
// delete the record itself
const int err = dbMain_.del(nullptr, &key, /*flags*/0);
if (err && err != DB_NOTFOUND)
{
std::ostringstream ss;
ss << "Failed to delete record id='" << id << '\'';
throw DbException(ss.str().c_str(), err);
}
}
