in in {fmt} before v10, it provides the specialization of `fmt::formatter<..>`
for `std::string_view` as well as the specialization of `fmt::formatter<..>`
for `fmt::string_view` which is an implementation builtin in {fmt} for
compatibility of pre-C++17. and this type is used even if the code is
compiled with C++ stadandard greater or equal to C++17. also, before v10,
the `fmt::formatter<std::string_view>::format()` is defined so it accepts
`std::string_view`. after v10, `fmt::formatter<std::string_view>` still
exists, but it is now defined using `format_as()` machinery, so it's
`format()` method does not actually accept `std::string_view`, it
accepts `fmt::string_view`, as the former can be converted to
`fmt::string_view`.
this is why we can inherit from `fmt::formatter<std::string_view>` and
use `formatter<std::string_view>::format(foo, ctx);` to implement the
`format()` method with {fmt} v9, but we cannot do this with {fmt} v10,
and we would have following compilation failure:
```
FAILED: service/CMakeFiles/service.dir/RelWithDebInfo/topology_state_machine.cc.o
/home/kefu/.local/bin/clang++ -DFMT_DEPRECATED_OSTREAM -DFMT_SHARED -DSCYLLA_BUILD_MODE=release -DSEASTAR_API_LEVEL=7 -DSEASTAR_LOGGER_COMPILE_TIME_FMT -DSEASTAR_LOGGER_TYPE_STDOUT -DSEASTAR_SCHEDULING_GROUPS_COUNT=16 -DSEASTAR_SSTRING -DXXH_PRIVATE_API -DCMAKE_INTDIR=\"RelWithDebInfo\" -I/home/kefu/dev/scylladb -I/home/kefu/dev/scylladb/build/gen -I/home/kefu/dev/scylladb/seastar/include -I/home/kefu/dev/scylladb/build/seastar/gen/include -I/home/kefu/dev/scylladb/build/seastar/gen/src -ffunction-sections -fdata-sections -O3 -g -gz -std=gnu++20 -fvisibility=hidden -Wall -Werror -Wextra -Wno-error=deprecated-declarations -Wimplicit-fallthrough -Wno-c++11-narrowing -Wno-deprecated-copy -Wno-mismatched-tags -Wno-missing-field-initializers -Wno-overloaded-virtual -Wno-unsupported-friend -Wno-enum-constexpr-conversion -Wno-unused-parameter -ffile-prefix-map=/home/kefu/dev/scylladb=. -march=westmere -mllvm -inline-threshold=2500 -fno-slp-vectorize -U_FORTIFY_SOURCE -Werror=unused-result -MD -MT service/CMakeFiles/service.dir/RelWithDebInfo/topology_state_machine.cc.o -MF service/CMakeFiles/service.dir/RelWithDebInfo/topology_state_machine.cc.o.d -o service/CMakeFiles/service.dir/RelWithDebInfo/topology_state_machine.cc.o -c /home/kefu/dev/scylladb/service/topology_state_machine.cc
/home/kefu/dev/scylladb/service/topology_state_machine.cc:254:41: error: no matching member function for call to 'format'
254 | return formatter<std::string_view>::format(it->second, ctx);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
/usr/include/fmt/core.h:2759:22: note: candidate function template not viable: no known conversion from 'seastar::basic_sstring<char, unsigned int, 15>' to 'const fmt::basic_string_view<char>' for 1st argument
2759 | FMT_CONSTEXPR auto format(const T& val, FormatContext& ctx) const
| ^ ~~~~~~~~~~~~
```
because the inherited `format()` method actually comes from
`fmt::formatter<fmt::string_view>`. to reduce the confusion, in this
change, we just inherit from `fmt::format<string_view>`, where
`string_view` is actually `fmt::string_view`. this follows
the document at
https://fmt.dev/latest/api.html#formatting-user-defined-types,
and since there is less indirection under the hood -- we do not
use the specialization created by `FMT_FORMAT_AS` which inherit
from `formatter<fmt::string_view>`, hopefully this can improve
the compilation speed a little bit. also, this change addresses
the build failure with {fmt} v10.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#18299
before this change, we rely on the default-generated fmt::formatter
created from operator<<, but fmt v10 dropped the default-generated
formatter.
in this change, we define formatters for `db::functions::function`.
please note, because we use `std::ostream` as the parameter of
the polymorphism implementation of `function::print()`.
without an intrusive change, we have to use `fmt::ostream_formatter`
or at least use similar technique to format the `function` instance
into an instance of `ostream` first. so instead of implementing
a "native" `fmt::formatter`, in this change, we just use
`fmt::ostream_formatter`.
Refs #13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#17832
Fixes some typos as found by codespell run on the code.
In this commit, I was hoping to fix only comments, not user-visible alerts, output, etc.
Follow-up commits will take care of them.
Refs: https://github.com/scylladb/scylladb/issues/16255
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
this is a part of a series to migrating from `operator<<(ostream&, ..)`
based formatting to fmtlib based formatting. the goal here is to enable
fmtlib to print `function_name` without the help of `operator<<`.
the corresponding `operator<<()` are dropped dropped in this change,
as all its callers are now using fmtlib for formatting now.
Refs #13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closes#13608
Spans are more flexible and can be constructed from any contiguous
container (such as small_vector), or a subrange of such a container.
This can save allocations, so change the signature to accept a span.
Spans cannot be constructed from std::initializer_list, so one such
call site is changed to use construct a span directly from the single
argument.
Now that stateless_aggregate_function is directly exposed by
aggregate_function, we can use it directly, avoiding the intermediary
aggregate_function::aggregate, which is removed.
Now that all aggregate functions are derived from
stateless_aggregate_function_adapter, we can just fold its functionality
into the base class. This exposes stateless_aggregate_function to
all users of aggregate_function, so they can begin to benefit from
the transformation, though this patch doesn't touch those users.
The aggregate_function base class is partiallly devirtualized since
there is just a single implementation now.
Currently, aggregate functions are implemented in a statefull manner.
The accumulator is stored internally in an aggregate_function::aggregate,
requiring each query to instantiate new instances (see
aggregate_function_selector's constructor, and note how it's called
from selector::new_instance()).
This makes aggregates hard to use in expressions, since expressions
are stateless (with state only provided to evaluate()). To facilitate
migration towards stateless expressions, we define a
stateless_aggregate_function (modelled after user-defined aggregates,
which are already stateless). This new struct defines the aggregate
in terms of three scalar functions: one to aggregate a new input into
an accumulator (provided in the first parameter), one to finalize an
accumulator into a result, and one to reduce two accumulators for
parallelized aggregation.
An adapter of the new struct to the aggregate_function interface is
also provided, to allow for incremental migration in the following
patches.
Previously, we moved cql3::functions::function to the
db::functions namespace, since functions are a part of the
data dictionary, which is independent of cql3. We do the
same now for scalar_function, since we wish to make use
of it in a new db::functions::stateless_aggregate_function.
A stub remains in cql3/functions to avoid churn.
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
Now that we don't accept cql protocol version 1 or 2, we can
drop cql_serialization format everywhere, except when in the IDL
(since it's part of the inter-node protocol).
A few functions had duplicate versions, one with and one without
a cql_serialization_format parameter. They are deduplicated.
Care is taken that `partition_slice`, which communicates
the cql_serialization_format across nodes, still presents
a valid cql_serialization_format to other nodes when
transmitting itself and rejects protocol 1 and 2 serialization\
format when receiving. The IDL is unchanged.
One test checking the 16-bit serialization format is removed.
Moving `function`, `function_name` and `aggregate_function` into
db namespace to avoid including cql3 namespace into query-request.
For now, only minimal subset of cql3 function was moved to db.
