Fixes#967
Frozen lists are just atomic cells. However, old code inserted the
frozen data directly as an atomic_cell_or_collection, which in turn
meant it lacked the header data of a cell. When in turn it was
handled by internal serialization (freeze), since the schema said
is was not a (non-frozen) collection, we tried to look at frozen
list data as cell header -> most likely considered dead.
Message-Id: <1457432538-28836-1-git-send-email-calle@scylladb.com>
We want the format of query results to be eventually defined in the
IDL and be independent of the format we use in memory to represent
collections. This change is a step in this direction.
The change decouples format of collection cells in query results from
our in-memory representation. We currently use collection_mutation_view,
after the change we will use CQL binary protocol format. We use that because
it requires less transformations on the coordinator side.
One complication is that some list operations need to retrieve keys
used in list cells, not only values. To satisfy this need, new query
option was added called "collections_as_maps" which will cause lists
and sets to be reinterpreted as maps matching their underlying
representation. This allows the coordinator to generate mutations
referencing existing items in lists.
List operations and prefetching were not handling static columns
correctly. One issue was that prefetching was attaching static column
data to row data using ids which might overlap with clustered columns.
Another problem was that list operations were always constructing
clustering key even if they worked on a static column. For static
columns the key would be always empty and lookup would fail.
The effect was that list operations which depend on curent state had
no effect. Similar problem could be observed on C* 2.1.9, but not on 2.2.3.
Fixes#903.
We use boost::any to convert to and from database values (stored in
serlialized form) and native C++ values. boost::any captures information
about the data type (how to copy/move/delete etc.) and stores it inside
the boost::any instance. We later retrieve the real value using
boost::any_cast.
However, data_value (which has a boost::any member) already has type
information as a data_type instance. By teaching data_type intances about
the corresponding native type, we can elimiante the use of boost::any.
While boost::any is evil and eliminating it improves efficiency somewhat,
the real goal is growing native type support in data_type. We will use that
later to store native types in the cache, enabling O(log n) access to
collections, O(1) access to tuples, and more efficient large blob support.
Store values as bytes view when possible. This improves the CQL protocol
option parsing path by avoiding allocating memory and copying individual
values as "bytes" objects.
Please note that we retain the non-view version for internal queries
where performance is not as important.
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
any_cast<X> is supposed to return X, but boost 1.55's any_cast<X> returns
X&&. This means the lifetime-extending construct
auto&& x = boost::any_cast<X>(...);
will not work, because the result of the expression is an rvalue reference,
not a true temporary.
Fix by using a temporary, not a lifetime-extending reference.
Fixes#163.
Encapsulate the '_values' vector to make it easier to switch the
underlying type from bytes_opt to bytes_view_opt.
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
Before this patch the tombstone created in setter::execute() was never
applied if the new collection value was null.
Signed-off-by: Paweł Dziepak <pdziepak@cloudius-systems.com>
Also replace derived types (map_type, collection_type, etc.).
As we'll change data_type's definition, this reduces the number of places
that need to be modified later, and is more readable.
To prepare a user-defined type, we need to look up its name in the keyspace.
While we get the keyspace name as an argument to prepare(), it is useless
without the database instance.
Fix the problem by passing a database reference along with the keyspace.
This precolates through the class structure, so most cql3 raw types end up
receiving this treatment.
Origin gets along without it by using a singleton. We can't do this due
to sharding (we could use a thread-local instance, but that's ugly too).
Hopefully the transition to a visitor will clean this up.
A tuple is a multi_item_terminal that can contain NULLs, so we need to
return a vector of bytes_opt, not bytes.
Unfortunately the lists code needs to be uglified as a result.
bytes and sstring are distinct types, since their internal buffers are of
different length, but bytes_view is an alias of sstring_view, which makes
it possible of objects of different types to leak across the abstraction
boundary.
Fix this by making bytes a basic_sstring<int8_t, ...> instead of using char.
int8_t is a 'signed char', which is a distinct type from char, so now
bytes_view is a distinct type from sstring_view.
uint8_t would have been an even better choice, but that diverges from Origin
and would have required an audit.
The list cell may be not set, in which case we should reurn an error
to the user. Current implementation of get_prefetched_list() was
returning collection_mutaion::view in this case, which had an empty
view. Deserialization is not prepared to get an empty view though. I
think we can stick with having non-empty views in the general case and
return an optional in get_prefetched_list().
