The expression system uses managed_bytes_opt for values, but result_set
uses bytes_opt. This means that processing values from the result set
in expressions requires a copy.
Out of the two, managed_bytes_opt is the better choice, since it prevents
large contiguous allocations for large blobs. So we switch result_set
to use managed_bytes_opt. Users of the result_set API are adjusted.
The db::function interface is not modified to limit churn; instead we
convert the types on entry and exit. This will be adjusted in a following
patch.
in C++20, compiler generate operator!=() if the corresponding
operator==() is already defined, the language now understands
that the comparison is symmetric in the new standard.
fortunately, our operator!=() is always equivalent to
`! operator==()`, this matches the behavior of the default
generated operator!=(). so, in this change, all `operator!=`
are removed.
in addition to the defaulted operator!=, C++20 also brings to us
the defaulted operator==() -- it is able to generated the
operator==() if the member-wise lexicographical comparison.
under some circumstances, this is exactly what we need. so,
in this change, if the operator==() is also implemented as
a lexicographical comparison of all memeber variables of the
class/struct in question, it is implemented using the default
generated one by removing its body and mark the function as
`default`. moreover, if the class happen to have other comparison
operators which are implemented using lexicographical comparison,
the default generated `operator<=>` is used in place of
the defaulted `operator==`.
sometimes, we fail to mark the operator== with the `const`
specifier, in this change, to fulfil the need of C++ standard,
and to be more correct, the `const` specifier is added.
also, to generate the defaulted operator==, the operand should
be `const class_name&`, but it is not always the case, in the
class of `version`, we use `version` as the parameter type, to
fulfill the need of the C++ standard, the parameter type is
changed to `const version&` instead. this does not change
the semantic of the comparison operator. and is a more idiomatic
way to pass non-trivial struct as function parameters.
please note, because in C++20, both operator= and operator<=> are
symmetric, some of the operators in `multiprecision` are removed.
they are the symmetric form of the another variant. if they were
not removed, compiler would, for instance, find ambiguous
overloaded operator '=='.
this change is a cleanup to modernize the code base with C++20
features.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closes#13687
they are part of the CQL type system, and are "closer" to types.
let's move them into "types" directory.
the building systems are updated accordingly.
the source files referencing `types.hh` were updated using following
command:
```
find . -name "*.{cc,hh}" -exec sed -i 's/\"types.hh\"/\"types\/types.hh\"/' {} +
```
the source files under sstables include "types.hh", which is
indeed the one located under "sstables", so include "sstables/types.hh"
instea, so it's more explicit.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closes#12926
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
contains_collection() and contains_set_or_map() used to be calculated on each call().
Now the result is calculated only once during type creation.
Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>
This patch switches the type used to store collection elements inside the
intermediate form used in lists::value, tuples::value etc. from bytes
to managed_bytes. After this patch, tuple and list elements are only linearized
in from_serialized, which will be corrected soon.
This commit introduces some additional copies in expression.cc, which
will be dealt with in a future commit.
In preparation for removing linearization from abstract_type::compare,
add options to avoid linearization in tuple_deserializing_iterator.
Signed-off-by: Wojciech Mitros <wojciech.mitros@scylladb.com>
We may want to store a tuple in a fragmented buffer. To split it
into a vector of optional bytes, tuple_type_impl::split can be used.
To split a contiguous buffer(bytes_view), simply pass
single_fragmented_view(bytes_view).
Signed-off-by: Wojciech Mitros <wojciech.mitros@scylladb.com>
is_value_compatible_with_internal and update_user_type were generalized
to the non-frozen case.
For now, all user_type_impls in the code are non-multi-cell (frozen).
This will be changed in future commits.
The type walking is similar to what the find function does, but
refactoring it doesn't seem worth it if these are the only two uses.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
The type hierarchy is closed, so we can give each leaf an enum value.
This will be used to implement a visitor pattern and reduce code
duplication.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Currently to_string takes raw bytes. This means that to print a
data_value it has to first be serialized to be passed to to_string,
which will then deserializes it.
This patch adds a virtual to_string_impl that takes a data_value and
implements a now non virtual to_sting on top of it.
I don't expect this to have a performance impact. It mostly documents
how to access a data_value without converting it to bytes.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20190620183449.64779-3-espindola@scylladb.com>
The to_json_string utility implementation was based on const references
instead of views, which can be a source of unnecessary memory copying.
This patch migrates all to_json_string to use bytes_view and leaves
the const reference version as a thin wrapper.
Message-Id: <2bf9f1951b862f8e8a2211cb4e83852e7ac70c67.1559654014.git.sarna@scylladb.com>
Both cql3_type and abstract_type are normally used inside
shared_ptr. This creates a problem when an abstract_type needs to refer
to a cql3_type as that creates a cycle.
To avoid warnings from asan, we were using a std::unordered_map to
store one of the edges of the cycle. This avoids the warning, but
wastes even more memory.
Even before this patch cql3_type was a fairly light weight
structure. This patch pushes in that direction and now cql3_type is a
struct with a single member variable, a data_type.
This avoids the reference cycle and is easier to understand IMHO.
Tests: unit (dev)
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
