C++ (Cpp) ValueBuffer::get_data示例

示例#1

ValueBuffer*
UnqliteCursor::get_key(int key_len, pyunqlite::UserCallback* callback)
{
	ValueBuffer* value = 0;
	int rc;
	if (callback)
	{
		rc = unqlite_kv_cursor_key_callback(
			this->_cursor,
			callback->get_unqlite_callback_function(),
			callback->get_unqlite_callback_data()
		);
	}
	else
	{
		int nBytes = 0;
		unqlite_kv_cursor_key(this->_cursor, 0, &nBytes);

		// create the buffer
		value = new ValueBuffer(false, nBytes);
		if (!value)
			throw UnqliteException(UNQLITE_NOMEM);

		rc = unqlite_kv_cursor_key(this->_cursor, value->get_data(), &nBytes);
	}

	if (callback && (rc == UNQLITE_ABORT))
		callback->process_exception();
	else if (rc != UNQLITE_OK)
		throw UnqliteException(rc, this->_db);

	return value;
}

示例#2

ValueBuffer*
UnqliteCursor::get_data(
	bool as_binary,
	sxi64 value_len,
	pyunqlite::UserCallback* callback,
	pyunqlite::ValueBuffer* direct_buffer
)
{
	ValueBuffer* value = 0;

	// setup the buffer for retrieving data
	if (direct_buffer) {
		if (value_len < 0)
			value_len = direct_buffer->get_data_len();
		else if (direct_buffer->get_data_len() < value_len)
			throw UnqliteException(UNQLITE_INVALID);

		value = new ValueBuffer(*direct_buffer);
	}
	else if (!callback) {
		// determine the size of the stored data if it is unknown
		if (value_len < 0)
			value_len = get_data_len();

		// create a new buffer
		value = new ValueBuffer(as_binary, value_len);
		if (!value)
			throw UnqliteException(UNQLITE_NOMEM);
	}

	int rc;
	if (callback) {
		rc = unqlite_kv_cursor_data_callback(
			this->_cursor,
			callback->get_unqlite_callback_function(),
			callback->get_unqlite_callback_data()
		);
	}
	else {
		rc = unqlite_kv_cursor_data(this->_cursor, value->get_data(), &value_len);
	}

	if (callback && (rc == UNQLITE_ABORT))
		callback->process_exception();
	else if (rc != UNQLITE_OK)
		throw UnqliteException(rc, this->_db);

	return value;
}