C++ Dbc::put方法代码示例

void LoginDB::change(string user, string pass)
{
    openDb();

    Dbc *cursorp;
    Dbt key(const_cast<char*> (user.data()), user.size());
    Dbt data;

    // Get a cursor
    db->cursor(NULL, &cursorp, 0);

    // Position the cursor
    int ret = cursorp->get(&key, &data, DB_SET);
    if (ret == 0)
        {
            data.set_data(const_cast<char*>(pass.data()));
            data.set_size(pass.size());
            cursorp->put(&key, &data, DB_CURRENT);
        }
    if (cursorp != NULL)
        cursorp->close();

    closeDb();

}

void AvailableGroups::slotDeleteServer(quint16 serverId)
{
	Dbt key, data;
	memset(&key, 0, sizeof(key));
	memset(&data, 0, sizeof(data));
    Dbc *cursor = 0;
	int ret;
	groupDb->cursor(0, &cursor, DB_WRITECURSOR);

	while ((ret=cursor->get(&key, &data, DB_NEXT)) != DB_NOTFOUND)
	{
        g=new AvailableGroup((char*)data.get_data());

		g->removeServerPresence(serverId);
		//resave the group...
		const char *p=g->data();
		memset(&data, 0, sizeof(data));
		data.set_data((void*)p);
		data.set_size(g->size());
		if (g->noServerPresence())
		{
			ret=cursor->del(0);
			if (ret != 0)
				quban->getLogAlertList()->logMessage(LogAlertList::Error, tr("Cannot delete server ") + servers->value(serverId)->getHostName() + tr(" group record"));

		}
		else if ((ret=cursor->put(&key, &data, DB_CURRENT)) != 0)
			quban->getLogAlertList()->logMessage(LogAlertList::Error, tr("Cannot update group record. Error: ") + dbEnv->strerror(ret));

        Q_DELETE(p);
	}
	cursor->close();

	reloadData();
}

/**
 * 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, &currentData, 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;
}

//
// XXX Figure out the appropriate way to pick out IDs.
//
int
TpcbExample::txn(Db *adb, Db *bdb, Db *tdb, Db *hdb,
		 int accounts, int branches, int tellers)
{
	Dbc *acurs = NULL;
	Dbc *bcurs = NULL;
	Dbc *tcurs = NULL;
	DbTxn *t = NULL;

	db_recno_t key;
	Defrec rec;
	Histrec hrec;
	int account, branch, teller, ret;

	Dbt d_dbt;
	Dbt d_histdbt;
	Dbt k_dbt;
	Dbt k_histdbt(&key, sizeof(key));

	// !!!
	// This is sample code -- we could move a lot of this into the driver
	// to make it faster.
	//
	account = random_id(ACCOUNT, accounts, branches, tellers);
	branch = random_id(BRANCH, accounts, branches, tellers);
	teller = random_id(TELLER, accounts, branches, tellers);

	k_dbt.set_size(sizeof(int));

	d_dbt.set_flags(DB_DBT_USERMEM);
	d_dbt.set_data(&rec);
	d_dbt.set_ulen(sizeof(rec));

	hrec.aid = account;
	hrec.bid = branch;
	hrec.tid = teller;
	hrec.amount = 10;
	// Request 0 bytes since we're just positioning.
	d_histdbt.set_flags(DB_DBT_PARTIAL);

	// START PER-TRANSACTION TIMING.
	//
	// Technically, TPCB requires a limit on response time, you only get
	// to count transactions that complete within 2 seconds.  That's not
	// an issue for this sample application -- regardless, here's where
	// the transaction begins.
	if (txn_begin(NULL, &t, 0) != 0)
		goto err;

	if (adb->cursor(t, &acurs, 0) != 0 ||
	    bdb->cursor(t, &bcurs, 0) != 0 ||
	    tdb->cursor(t, &tcurs, 0) != 0)
		goto err;

	try {
		// Account record
		k_dbt.set_data(&account);
		if (acurs->get(&k_dbt, &d_dbt, DB_SET) != 0)
			goto err;
		rec.balance += 10;
		if (acurs->put(&k_dbt, &d_dbt, DB_CURRENT) != 0)
			goto err;

		// Branch record
		k_dbt.set_data(&branch);
		if (bcurs->get(&k_dbt, &d_dbt, DB_SET) != 0)
			goto err;
		rec.balance += 10;
		if (bcurs->put(&k_dbt, &d_dbt, DB_CURRENT) != 0)
			goto err;

		// Teller record
		k_dbt.set_data(&teller);
		if (tcurs->get(&k_dbt, &d_dbt, DB_SET) != 0)
			goto err;
		rec.balance += 10;
		if (tcurs->put(&k_dbt, &d_dbt, DB_CURRENT) != 0)
			goto err;

		// History record
		d_histdbt.set_flags(0);
		d_histdbt.set_data(&hrec);
		d_histdbt.set_ulen(sizeof(hrec));
		if (hdb->put(t, &k_histdbt, &d_histdbt, DB_APPEND) != 0)
			goto err;
	} catch (DbDeadlockException e) {
		goto err;
	}

	if (acurs->close() != 0 || bcurs->close() != 0 || tcurs->close() != 0)
		goto err;

	ret = t->commit(0);
	t = NULL;
	if (ret != 0)
		goto err;

//.........这里部分代码省略.........

//
// XXX Figure out the appropriate way to pick out IDs.
//
int
TpcbExample::txn(Db *adb, Db *bdb, Db *tdb, Db *hdb,
		 int accounts, int branches, int tellers)
{
	Dbc *acurs = NULL;
	Dbc *bcurs = NULL;
	Dbc *tcurs = NULL;
	DbTxn *t = NULL;

	db_recno_t key;
	Defrec rec;
	Histrec hrec;
	int account, branch, teller;

	Dbt d_dbt;
	Dbt d_histdbt;
	Dbt k_dbt;
	Dbt k_histdbt(&key, sizeof(key));

	//
	// XXX We could move a lot of this into the driver to make this
	// faster.
	//
	account = random_id(ACCOUNT, accounts, branches, tellers);
	branch = random_id(BRANCH, accounts, branches, tellers);
	teller = random_id(TELLER, accounts, branches, tellers);

	k_dbt.set_size(sizeof(int));

	d_dbt.set_flags(DB_DBT_USERMEM);
	d_dbt.set_data(&rec);
	d_dbt.set_ulen(sizeof(rec));

	hrec.aid = account;
	hrec.bid = branch;
	hrec.tid = teller;
	hrec.amount = 10;
	// Request 0 bytes since we're just positioning.
	d_histdbt.set_flags(DB_DBT_PARTIAL);

	// START TIMING
	if (txn_begin(NULL, &t, 0) != 0)
		goto err;

	if (adb->cursor(t, &acurs, 0) != 0 ||
	    bdb->cursor(t, &bcurs, 0) != 0 ||
	    tdb->cursor(t, &tcurs, 0) != 0)
		goto err;

	// Account record
	k_dbt.set_data(&account);
	if (acurs->get(&k_dbt, &d_dbt, DB_SET) != 0)
		goto err;
	rec.balance += 10;
	if (acurs->put(&k_dbt, &d_dbt, DB_CURRENT) != 0)
		goto err;

	// Branch record
	k_dbt.set_data(&branch);
	if (bcurs->get(&k_dbt, &d_dbt, DB_SET) != 0)
		goto err;
	rec.balance += 10;
	if (bcurs->put(&k_dbt, &d_dbt, DB_CURRENT) != 0)
		goto err;

	// Teller record
	k_dbt.set_data(&teller);
	if (tcurs->get(&k_dbt, &d_dbt, DB_SET) != 0)
		goto err;
	rec.balance += 10;
	if (tcurs->put(&k_dbt, &d_dbt, DB_CURRENT) != 0)
		goto err;

	// History record
	d_histdbt.set_flags(0);
	d_histdbt.set_data(&hrec);
	d_histdbt.set_ulen(sizeof(hrec));
	if (hdb->put(t, &k_histdbt, &d_histdbt, DB_APPEND) != 0)
		goto err;

	if (acurs->close() != 0 || bcurs->close() != 0 ||
	    tcurs->close() != 0)
		goto err;

	if (t->commit(0) != 0)
		goto err;

	// END TIMING
	return (0);

err:
	if (acurs != NULL)
		(void)acurs->close();
	if (bcurs != NULL)
		(void)bcurs->close();
	if (tcurs != NULL)
		(void)tcurs->close();
//.........这里部分代码省略.........

// Modify or create a part based on the following information
MultiPartHeader::Add_Code MultiPartHeader::modifyPart(Db* pdb, quint16 partNo, RawHeader *rh, quint16 hostId)
{
	//qDebug() << "Entering modifyPart";
    Add_Code retCode = New_Part;
	int ret = 0;
	bool createPart = false;
	Header* h = 0;
    char *phead = 0;
    Dbc *cursorp = 0;

	Dbt key;
	Dbt data;

	//qDebug() << "Creating part for key " << multiPartKey;

	key.set_data(&multiPartKey);
	key.set_size(sizeof(quint64));

	data.set_data(&partNo);
	data.set_size(sizeof(quint16));

	// Get a cursor
	pdb->cursor(NULL, &cursorp, DB_WRITECURSOR);
	//qDebug("1");

	// Position the cursor to the first record in the database whose
	// key matches the search key and whose data begins with the search
	// data.
	ret = cursorp->get(&key, &data, DB_GET_BOTH);
	if  (ret == 0)
	{
		//qDebug("2");
	    // update the data
		h = new Header((char*)data.get_data(), (char*)key.get_data());
		//qDebug("3");

		if (h->isHeldByServer(hostId))
		{
			retCode = Duplicate_Part;
		}
		else
			retCode = Updated_Part;

        // qDebug() << "Found an update for part " << partNo << ", existing part " << h->getPartNo() << ", existing msgid " << h->getMessageId() << ", new msgid " << rh->m_mid;

		// Always update the article number
		h->setServerPartNum(hostId, rh->m_num);

		//qDebug("4");
		phead=h->data();

		data.set_data(phead);
		data.set_size(h->getRecordSize());

		//qDebug("5");
		cursorp->put(&key, &data, DB_CURRENT);
		//qDebug("6");
        Q_DELETE_ARRAY(phead);
	}
	else if (ret == DB_NOTFOUND) // create the part
	{
		//qDebug("7");
		createPart = true;
	}
	else // encountered an error
	{
		qDebug() << "Unable to find part " << partNo << " for key " << multiPartKey << ", result = " << ret;
		retCode = Error_Part;
	}

	// Close the cursor
	if (cursorp != NULL)
	    cursorp->close();

	if (createPart == true)
	{
		//qDebug("8");
		quint32 partSize = rh->m_bytes.toULong();
		h = new Header(multiPartKey, partNo, partSize);

		//qDebug("9");

		h->setMessageId(rh->m_mid);
		h->setServerPartNum(hostId, rh->m_num);

		//save in the parts db
		phead=h->data();

		data.set_data(phead);
		data.set_size(h->getRecordSize());

		//qDebug("10");

		ret = pdb->put(0, &key, &data, 0);
		if (ret)
		{
		    qDebug() << "Unable to create part " << partNo << " for key " << multiPartKey << ", result = " << ret;
		    retCode = Error_Part;
		}
//.........这里部分代码省略.........