This method can cause performance regressions if used in the wrong place
-- namely if it is used to abort reads by throwing the abort exception.
Exceptions should be propagated during reads without throwing them,
otherwise they cause extra CPU load, making a bad situation worse.
Remove this method, so it doesn't accidentally get more users, migrate
remaining users to get_abort_exception().
Use coroutine::try_future() to avoid exceptions taking flight and
triggering expensive stack-unwinding.
Especially bad for common exceptions like timeouts.
Will replace check_abort(). The latter throws an exception which is
something we want to avoid when a read is aborted, in particular when it
times out.
Also add a convenience get_abort_exception() method to mutation_reader.
Add precompiled header support to CMakeLists.txt and configure.py -
it improves compilation time by approximately 10%.
New header `stdafx.hh` is added, don't include it manually -
the compiler will include it for you. The header contains includes from
external libraries used by Scylla - seastar, standard library,
linux headers and zlib.
The feature is enabled by default, use CMake option `Scylla_USE_PRECOMPILED_HEADER`
or configure.py --disable-precompiled-header to disable.
The feature should be disabled, when trying to check headers - otherwise
you might get false negatives on missing includes from seastar / abseil and so on.
Note: following configuration needs to be added to ccache.conf:
sloppiness = pch_defines,time_macros,include_file_mtime,include_file_ctime
Closesscylladb/scylladb#26617
As requested in #22120, moved the files and fixed other includes and build system.
Moved files:
- query.cc
- query-request.hh
- query-result.hh
- query-result-reader.hh
- query-result-set.cc
- query-result-set.hh
- query-result-writer.hh
- query_id.hh
- query_result_merger.hh
Fixes: #22120
This is a cleanup, no need to backport
Closesscylladb/scylladb#25105
Add precompiled header support to CMakeLists.txt and configure.py -
it improves compilation time by approximately 10%.
New header `stdafx.hh` is added, don't include it manually -
the compiler will include it for you. The header contains includes from
external libraries used by Scylla - seastar, standard library,
linux headers and zlib.
The feature is enabled by default, use CMake option `Scylla_USE_PRECOMPILED_HEADER`
or configure.py --disable-precompiled-header to disable.
The feature should be disabled, when trying to check headers - otherwise
you might get false negatives on missing includes from seastar / abseil and so on.
Note: following configuration needs to be added to ccache.conf:
sloppiness = pch_defines,time_macros
Closes#25182
As requested in #22102, #22103 and #22105 moved the files and fixed other includes and build system.
Moved files:
- clustering_bounds_comparator.hh
- keys.cc
- keys.hh
- clustering_interval_set.hh
- clustering_key_filter.hh
- clustering_ranges_walker.hh
- compound_compat.hh
- compound.hh
- full_position.hh
Fixes: #22102Fixes: #22103Fixes: #22105Closesscylladb/scylladb#25082
As requested in #22114, moved the files and fixed other includes and build system.
Moved files:
- interval.hh
- Map_difference.hh
Fixes: #22114
This is a cleanup, no need to backport
Closesscylladb/scylladb#25095
C++20 introduced two new attributes--likely and unlikely--that
function as a built-in replacement for __builtin_expect implemented
in various compilers. Since it makes code easier to read and it's
an integral part of the language, there's no reason to not use it
instead.
Closesscylladb/scylladb#24786
Extends the make_compacting_reader funtion and the constructor of
the compacting_reader, in order to accept an optional pointer to
the tombstone purge statistics structure that is later passed
further down to compact_mutation_state.
The idea behind readers/ is that each reader has its minimal header with
just a factory method declaration. The delegating reader is defined in
the factory header because it has a derived class in row_cache_test.cc.
Move the definition to delegating_impl.hh so users not interested in
deriving from it don't pay the price in header include cost.
Instead of raising std::runtime_error("Dangling queue_reader_handle_v2")
unconditionally. push() already raises _ex if set, best to be
consistent.
Unconditionally raising std::runtime_error can cause an error to be
logged, when aborting an operation involving a queue reader.
Although the original exception passed to
queue_reader_handle_v2::abort() is most likely handled by higher level
code (not logged), the generic std::runtime_error raised is not and
therefore is logged.
Fixes: #23550Closesscylladb/scylladb#23554
these unused includes were identified by clang-include-cleaner. after
auditing these source files, all of the reports have been confirmed.
in which, instead of using `seastarx.hh`, `readers/mutation_reader.hh`,
use `using seastar::future` to include `future` in the global namespace,
this makes `readers/mutation_reader.hh` a header exposing `future<>`,
but this is not a good practice, because, unlike `seastarx.hh` or
`seastar/core/future.hh`, `reader/mutation_reader.hh` is not
responsible for exposing seastar declarations. so, we trade the
using statement for `#include "seastarx.hh"` in that file to decouple
the source files including it from this header because of this statement.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22439
these unused includes are identified by clang-include-cleaner. after
auditing the source files, all of the reports have been confirmed.
please note, because `mutation/mutation.hh` does not include
`seastar/coroutine/maybe_yield.hh` anymore, and quite a few source
files were relying on this header to bring in the declaration of
`maybe_yield()`, we have to include this header in the places where
this symbol is used. the same applies to `seastar/core/when_all.hh`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
std::ranges::{push,pop}_heap() will only generate default comparator if
the compared types are fully ordered. So we need to pass std::less<>
explicitely as comparator for the code to compile.
From boost::iterator_range<>. One return in maybe_produce_batch() had to
be adjusted because it used a strange initialization of
boost::iterator_range<>, which should not even had compiled.
Calculate a buffer fill hint and pass it to
shard_reader_v2::fill_buffer(), so the underlying buffer-fill can be
optimized to avoid multiple cross shard round-trips, as well as possible
evict-recreate cycles.
The buffer hint mechanism is opt-in, enabled via the new
multishard_reader_buffer_hint parameter.
When the hint is provided, respect it: make sure the returned buffer is
of the requested size, stopping early if the stop_token is seen.
To reduce the amount of possible eviction-recreate cycles while the
buffer is filled, disable auto-pause for the duration of the
fill_reader_buffer() call. For this purpose, auto_pause_disable_guard is
added to evictable_reader_v2.
The hint will tell the shard reader exactly how much data to produce, to
avoid multiple cross-shard round-trips and possible evict-recreate
cycles.
The hint is neither used yet or calculated yet, this is coming in the
next patches.
