A negative scale was being passed an a positive value to
boost::multiprecision::pow, which would never finish.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Big decimals are, among other use cases, used as a main number
type for alternator, and as such can appear on the fast path.
Parsing big decimals was performed via std::regex, which is not
precisely famous for its speeds, and also enforces unnecessary
string copying. Therefore, the implementation is replaced
with an open-coded version based on string_views.
One previous iteration of this series also included
a hand-coded state machine implementation, but it proved
to be slower than the slightly naive string_view one.
Overall, execution time is reduced by 61.6% according to
microbenchmarks, which sounds like a promising improvement.
Perf results:
test iterations median mad min max
Regex (original):
big_decimal_test.from_string 88895 11.228us 25.891ns 11.202us 11.510us
String view (new):
big_decimal_test.from_string 232334 4.303us 21.660ns 4.282us 4.736us
State machine (experimental, ditched):
big_decimal_test.from_string 148318 6.723us 51.896ns 6.672us 6.877us
Tests: unit(dev + release(big_decimal_test))
The goal is to forward-declare utils::multiprecision_int, something
beyond my capabilities for boost::multiprecision::cpp_int, to reduce
compile time bloat.
The patch is mostly search-and-replace, with a few casts added to
disambiguate conversions the compiler had trouble with.
Different versions of boost have different rules for what conversions
from cpp_int to smaller intergers are allowed.
We already had a function that worked with all supported versions, but
it was not being use by lua.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20200104041028.215153-1-espindola@scylladb.com>
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>
* seastar d59fcef...b924495 (2):
> build: Fix protobuf generation rules
> Merge "Restructure files" from Jesse
Includes fixup patch from Jesse:
"
Update Seastar `#include`s to reflect restructure
All Seastar header files are now prefixed with "seastar" and the
configure script reflects the new locations of files.
Signed-off-by: Jesse Haber-Kucharsky <jhaberku@scylladb.com>
Message-Id: <5d22d964a7735696fb6bb7606ed88f35dde31413.1542731639.git.jhaberku@scylladb.com>
"
sprint() recently became more strict, throwing on sprint("%s", 5). Replace
with the more modern format().
Mechanically converted with https://github.com/avikivity/unsprint.
