Files
scylladb/sstables/exceptions.hh
Kefu Chai 168ade72f8 treewide: replace formatter<std::string_view> with formatter<string_view>
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>

Closes scylladb/scylladb#18299
2024-04-19 07:44:07 +03:00

72 lines
2.1 KiB
C++

/*
* Copyright (C) 2015-present ScyllaDB
*
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#pragma once
#include <concepts>
#include <seastar/core/print.hh>
#include "seastarx.hh"
namespace sstables {
class malformed_sstable_exception : public std::exception {
sstring _msg;
public:
malformed_sstable_exception(sstring msg, sstring filename)
: malformed_sstable_exception{format("{} in sstable {}", msg, filename)}
{}
malformed_sstable_exception(sstring s) : _msg(s) {}
const char *what() const noexcept {
return _msg.c_str();
}
};
struct bufsize_mismatch_exception : malformed_sstable_exception {
bufsize_mismatch_exception(size_t size, size_t expected) :
malformed_sstable_exception(format("Buffer improperly sized to hold requested data. Got: {:d}. Expected: {:d}", size, expected))
{}
};
class compaction_job_exception : public std::exception {
sstring _msg;
public:
compaction_job_exception(sstring msg) noexcept : _msg(std::move(msg)) {}
const char *what() const noexcept {
return _msg.c_str();
}
};
// Indicates that compaction was stopped via an external event,
// E.g. shutdown or api call.
class compaction_stopped_exception : public compaction_job_exception {
public:
compaction_stopped_exception(sstring ks, sstring cf, sstring reason)
: compaction_job_exception(format("Compaction for {}/{} was stopped due to: {}", ks, cf, reason)) {}
};
// Indicates that compaction hit an unrecoverable error
// and should be aborted.
class compaction_aborted_exception : public compaction_job_exception {
public:
compaction_aborted_exception(sstring ks, sstring cf, sstring reason)
: compaction_job_exception(format("Compaction for {}/{} was aborted due to: {}", ks, cf, reason)) {}
};
}
#if FMT_VERSION < 100000
// fmt v10 introduced formatter for std::exception
template <std::derived_from<sstables::malformed_sstable_exception> T>
struct fmt::formatter<T> : fmt::formatter<string_view> {
auto format(const T& e, fmt::format_context& ctx) const {
return fmt::format_to(ctx.out(), "{}", e.what());
}
};
#endif