Replace stdx::optional and stdx::string_view with the C++ std
counterparts.
Some instances of boost::variant were also replaced with std::variant,
namely those that called seastar::visit.
Scylla now requires GCC 8 to compile.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20190108111141.5369-1-duarte@scylladb.com>
_value_views is the authoritative data structure for the
client-specified values. Indeed, the ctor called
transport::request::read_options() leaves _values completely empty.
In query_options::prepare() we were, however, using _values to
associated values to the client-specified column names, and not
_value_views. Fix this by using _value_views instead.
As for the reasons we didn't see this bug earlier, I assume it's
because very few drivers set the 0x04 query options flag, which means
column names are omitted. This is the right thing to do since most
drivers have enough information to correctly position the values.
Fixes#3688
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20180814234605.14775-1-duarte@scylladb.com>
A raw value can be in one of three states: a valid value, an unset
value, a null value. When translating raw_values to their views, we
were treating both unset and null values are null raw_value_views.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20180814231051.14385-1-duarte@scylladb.com>
Some code in the CQL3 layer requires bytes_view and it is fairly
reasonable to assume that it won't deal with large buffers (e.g.
statement restrictions). query_options already has make_temporary()
which takes ownership of a cql3::raw_value so that the rest of the code
can use cql3::raw_value_view. This patch adds similar linearize()
function which, if necessary, linearises a cql3::raw_value_view and
returns a bytes_view with lifetime tied to the life or query_options.
bytes_ostream is going to be more efficient than
std::vector<std::vector<char>> since it can put multiple small values in
a single buffer thus reducing the number of memory allocations.
query_options object cannot be changed after it was created. For
internal uses, like internal query paging, it is needed to create a new
object based on some of the data from an existing one with a new paging
state.
This patch adds a constructor from a unique_ptr and paging state.
using unique_ptr behave similar to move modify constructor.
Signed-off-by: Amnon Heiman <amnon@scylladb.com>
Currently, the code is using bytes_opt and bytes_view_opt to represent
CQL values, which can hold a value or null. In preparation for
supporting a third state, unset value introduced in CQL v4, introduce
new raw_value and raw_value_view types and use them instead.
The new types are based on boost::variant<> and are capable of holding
null, unset values, and blobs that represent a value.
query_options::prepare() changes the values array, but this is not the
one used by query_options internally (e.g., in get_value_at). So we
need to also recalculate the value_views after prepare() is called.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Having both the values and value_views arguments in the query_options
ctor is confusing, since query_options uses only the value_views field
but that is not communicated to the caller.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
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>
query_options is needlessy organized as a class hierarchy, even though it's
really a simple value type.
Fix by folding all the derived classes into it.
