Currently, `sstable::estimated_keys_for_range` works by
checking what fraction of Summary is covered by the given
range, and multiplying this fraction to the number of all keys.
Since computing things on Summary doesn't involve I/O (because Summary
is always kept in RAM), this is synchronous.
In a later patch, we will modify `sstable::estimated_keys_for_range`
so that it can deal with sstables that don't have a Summary
(because they use BTI indexes instead of BIG indexes).
In that case, the function is going to compute the relevant fraction
by using the index instead of Summary. This will require making
the function asynchronous. This is what we do in this patch.
(The actual change to the logic of `sstable::estimated_keys_for_range`
will come in the next patch. In this one, we only make it asynchronous).
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
class clustering_range is a range of Clustering Key Prefixes implemented
as interval<clustering_key_prefix>. However, due to the nature of
Clustering Key Prefix, the ordering of clustering_range is complex and
does not satisfy the invariant of interval<>. To be more specific, as a
comment in interval<> implementation states: “The end bound can never be
smaller than the start bound”. As a range of CKP violates the invariant,
some algorithms, like intersection(), can return incorrect results.
For more details refer to scylladb#8157, scylladb#21604, scylladb#22817.
This commit:
- Add a WARNING comment to discourage usage of clustering_range
- Add WARNING comments to potentially incorrect uses of
interval<clustering_key_prefix> non-trivial methods
- Add a FIXME comment to incorrect use of
interval<clustering_key_prefix_view>::deoverlap and WARNING comments
to related interval<clustering_key_prefix_view> misuse.
Closesscylladb/scylladb#22913
Replace boost::make_iterator_range() with std::ranges::subrange.
This change improves code modernization and reduces external dependencies:
- Replace boost::make_iterator_range() with std::ranges::subrange
- Remove boost/range/iterator_range.hpp include
- Improve iterator type detection in interval.hh using std::ranges::const_iterator_t<Range>
This is part of ongoing efforts to modernize our codebase and minimize
external dependencies.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21787
now that we are allowed to use C++23. we now have the luxury of using
`std::views::transform`.
in this change, we:
- replace `boost::adaptors::transformed` with `std::views::transform`
- use `fmt::join()` when appropriate where `boost::algorithm::join()`
is not applicable to a range view returned by `std::view::transform`.
- use `std::ranges::fold_left()` to accumulate the range returned by
`std::view::transform`
- use `std::ranges::fold_left()` to get the maximum element in the
range returned by `std::view::transform`
- use `std::ranges::min()` to get the minimal element in the range
returned by `std::view::transform`
- use `std::ranges::equal()` to compare the range views returned
by `std::view::transform`
- remove unused `#include <boost/range/adaptor/transformed.hpp>`
- use `std::ranges::subrange()` instead of `boost::make_iterator_range()`,
to feed `std::views::transform()` a view range.
to reduce the dependency to boost for better maintainability, and
leverage standard library features for better long-term support.
this change is part of our ongoing effort to modernize our codebase
and reduce external dependencies where possible.
limitations:
there are still a couple places where we are still using
`boost::adaptors::transformed` due to the lack of a C++23 alternative
for `boost::join()` and `boost::adaptors::uniqued`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21700
now that we are allowed to use C++23. we now have the luxury of using
`std::ranges::find_if`.
in this change, we:
- replace `boost::find_if` with `std::ranges::find_if`
- remove all `#include <boost/range/algorithm/find_if.hpp>`
to reduce the dependency to boost for better maintainability, and
leverage standard library features for better long-term support.
this change is part of our ongoing effort to modernize our codebase
and reduce external dependencies where possible.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
To work with std::ranges, an iterator has to have a default constructor,
and be assignable. Add the default constructor and convert references
to pointers to support this.
Using the standard library is preffered over boost.
In cql3/expr/expression.cc to_sorted_vector got more of a
face-list and was modernized to use also std::unique
and while at it, to move its input range in the uniquely sorted
result vector.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
assert() is traditionally disabled in release builds, but not in
scylladb. This hasn't caused problems so far, but the latest abseil
release includes a commit [1] that causes a 1000 insn/op regression when
NDEBUG is not defined.
Clearly, we must move towards a build system where NDEBUG is defined in
release builds. But we can't just define it blindly without vetting
all the assert() calls, as some were written with the expectation that
they are enabled in release mode.
To solve the conundrum, change all assert() calls to a new SCYLLA_ASSERT()
macro in utils/assert.hh. This macro is always defined and is not conditional
on NDEBUG, so we can later (after vetting Seastar) enable NDEBUG in release
mode.
[1] 66ef711d68Closesscylladb/scylladb#20006
The is_minimum/is_maximum predicates are more
efficient than comparing the the m{minimum,maximum}_token
values, respectrively. since the is_* functions
need to check only the token kind.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
flat_mutation_reader_v2 was introduced in a pair of commits in 2021:
e3309322c3 "Clone flat_mutation_reader related classes into v2 variants"
08b5773c12 "Adapt flat_mutation_reader_v2 to the new version of the API"
as a replacement for flat_mutation_reader, using range_tombstone_change
instead of range_tombstone to represent represent range tombstones. See
those commits for more information.
The transition was incremental; the last use of the original
flat_mutation_reader was removed in 2022 in commit
026f8cc1e7 "db: Use mutation_partition_v2 in mvcc"
In turn, flat_mutation_reader was introduced in 2017 in commit
748205ca75 "Introduce flat_mutation_reader"
To transition from a mutation_reader that nested rows within
a partition in a separate stream, to a flat reader that streamed
partitions and rows in the same stream.
Here, we reclaim the original name and rename the awkward
flat_mutation_reader_v2 to mutation_reader.
Note that mutation_fragment_v2 remains since we still use the original
for compatibilty, sometimes.
Some notes about the transition:
- files were also renamed. In one case (flat_mutation_reader_test.cc), the
rename target already existed, so we rename to
mutation_reader_another_test.cc.
- a namespace 'mutation_reader' with two definitions existed (in
mutation_reader_fwd.hh). Its contents was folded into the mutation_reader
class. As a result, a few #includes had to be adjusted.
Closesscylladb/scylladb#19356
range.hh was deprecated in bd794629f9 (2020) since its names
conflict with the C++ library concept of an iterator range. The name
::range also mapped to the dangerous wrapping_interval rather than
nonwrapping_interval.
Complete the deprecation by removing range.hh and replacing all the
aliases by the names they point to from the interval library. Note
this now exposes uses of wrapping intervals as they are now explicit.
The unit tests are renamed and range.hh is deleted.
Closesscylladb/scylladb#17428
This is in order to prevent new incorrect uses of dht::shard_of() to
be accidentally added. Also, makes sure that all current uses are
caught by the compiler and require an explicit rename.
In https://github.com/scylladb/scylladb/pull/13482 we renamed the reader permit states to more descriptive names. That PR however only covered only the states themselves and their usages, as well as the documentation in `docs/dev`.
This PR is a followup to said PR, completing the name changes: renaming all symbols, names, comments etc, so all is consistent and up-to-date.
Closes#13573
* github.com:scylladb/scylladb:
reader_concurrency_semaphore: misc updates w.r.t. recent permit state name changes
reader_concurrency_semaphore: update permit members w.r.t. recent permit state name changes
reader_concurrency_semaphore: update RAII state guard classes w.r.t. recent permit state name changes
reader_concurrency_semaphore: update API w.r.t. recent permit state name changes
reader_concurrency_semaphore: update stats w.r.t. recent permit state name changes
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
Move mutation-related files to a new mutation/ directory. The names
are kept in the global namespace to reduce churn; the names are
unambiguous in any case.
mutation_reader remains in the readers/ module.
mutation_partition_v2.cc was missing from CMakeLists.txt; it's added in this
patch.
This is a step forward towards librarization or modularization of the
source base.
Closes#12788
Now all callers have system_keyspace reference at hand. This removes one
more user of the global qctx object
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This method static calls system_keyspace::get_local_tokens(). Having the
system_keyspace reference will make this method non-static
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The s._e._v._reader::fill_buffer() method needs system keyspace to get
node's local tokens. Now it's a static method, having system_keyspace
reference will make it non-static
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The flat_mutation_reader files were conflated and contained multiple
readers, which were not strictly necessary. Splitting optimizes both
iterative compilation times, as touching rarely used readers doesn't
recompile large chunks of codebase. Total compilation times are also
improved, as the size of flat_mutation_reader.hh and
flat_mutation_reader_v2.hh have been reduced and those files are
included by many file in the codebase.
With changes
real 29m14.051s
user 168m39.071s
sys 5m13.443s
Without changes
real 30m36.203s
user 175m43.354s
sys 5m26.376s
Closes#10194
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
Move replica-oriented classes to the replica namespace. The main
classes moved are ::database, ::keyspace, and ::table, but a few
ancillary classes are also moved. There are certainly classes that
should be moved but aren't (like distributed_loader) but we have
to start somewhere.
References are adjusted treewide. In many cases, it is obvious that
a call site should not access the replica (but the data_dictionary
instead), but that is left for separate work.
scylla-gdb.py is adjusted to look for both the new and old names.
The database, keyspace, and table classes represent the replica-only
part of the objects after which they are named. Reading from a table
doesn't give you the full data, just the replica's view, and it is not
consistent since reconciliation is applied on the coordinator.
As a first step in acknowledging this, move the related files to
a replica/ subdirectory.
As part of changing the codebase to flat_mutation_reader_v2,
change size_estimates_virtual_reader.
Since the bulk of the work is done by
make_flat_mutation_reader_from_mutations() (which is unchanged),
only glue code is affected. It is also not performance sensitive,
so the extra conversions are unimportant.
Test: unit (dev)
Closes#9707
Add schema parameter so that:
* Caller has better control over schema -- especially relevant for
reverse reads where it is not possible to follow the convention of
passing the query schema which is reversed compared to that of the
mutations.
* Now that we don't depend on the mutations for the schema, we can lift
the restriction on mutations not being empty: this leads to safer
code. When the mutations parameter is empty, an empty reader is
created.
Add "make_" prefix to follow convention of similar reader factory
functions.
Tests: unit(dev)
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20211115155614.363663-1-bdenes@scylladb.com>
The interval template member functions mostly accept
tri-comparators but a few functions accept less-comparators.
To reduce the chance of error, and to provide better error
messages, constrain comparator parameters to the expected
signature.
In one case (db/size_estimates_virtual_reader.cc) the caller
had to be adjusted. The comparator supported comparisons
of the interval value type against other types, but not
against itself. To simplify things, we add that signature too,
even though it will never be called.
Closes#9291
The get_next_partition uses global proxy instance to get
the local database reference. Now it's available in the
reader object itself, so it's possible to remove this
call for global storage proxy.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This reader uses local databse instance in its get_next_partition
method to find keyspaces to work with
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
When getting local ranges, an assumption is made that
if a range does not contain an end or when its end is a maximum token,
then it must contain a start. This assumption proven not true
during manual tests, so it's now fortified with an additional check.
Here's a gdb output for a set of local ranges which causes an assertion
failure when calling `get_local_ranges` on it:
(gdb) p ranges
$1 = std::vector of length 2, capacity 2 = {{_interval = {_start = std::optional<interval_bound<dht::token>> = {[contained value] = {_value = {_kind = dht::token_kind::before_all_keys,
_data = 0}, _inclusive = false}}, _end = std::optional<interval_bound<dht::token>> [no contained value], _singular = false}}, {_interval = {
_start = std::optional<interval_bound<dht::token>> [no contained value], _end = std::optional<interval_bound<dht::token>> = {[contained value] = {_value = {
_kind = dht::token_kind::before_all_keys, _data = 0}, _inclusive = true}}, _singular = false}}}
Closes#7764
The main user of this method, the one which required this method to
return the collective buffer size of the entire reader tree, is now
gone. The remaining two users just use it to check the size of the
reader instance they are working with.
So de-virtualize this method and reduce its responsibility to just
returning the buffer size of the current reader instance.
Not used yet, this patch does all the churn of propagating a permit
to each impl.
In the next patch we will use it to track to track the memory
consumption of `_buffer`.
This reader was probably created in ancient times, when readers didn't
yet have a _schema member of their own. But now that they do, it is not
necessary to store the schema in the reader implementation, there is one
available in the parent class.
While at it also move the schema into the class when calling the
constructor.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Reviewed-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20200821070358.33937-1-bdenes@scylladb.com>
and replace all calls to dht::global_partitioner().get_token
dht::get_token is better because it takes schema and uses it
to obtain partitioner instead of using a global partitioner.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
