This is a revival of #7490.
Quoting #7490:
The managed_bytes class now uses implicit linearization: outside LSA, data is never fragmented, and within LSA, data is linearized on-demand, as long as the code is running within with_linearized_managed_bytes() scope.
We would like to stop linearizing managed_bytes and keep it fragmented at all times, since linearization can require large contiguous chunks. Large contiguous allocations are hard to satisfy and cause latency spikes.
As a first step towards that, we remove all implicitly linearizing accessors and replace them with an explicit linearization accessor, with_linearized().
Some of the linearization happens long before use, by creating a bytes_view of the managed_bytes object and passing it onwards, perhaps storing it for later use. This does not work with with_linearized(), which creates a temporary linearized view, and does not work towards the longer term goal of never linearizing. As a substitute a managed_bytes_view class is introduced that acts as a view for managed_bytes (for interoperability it can also be a view for bytes and is compatible with bytes_view).
By the end of the series, all linearizations are temporary, within the scope of a with_linearized() call and can be converted to fragmented consumption of the data at leisure.
This has limited practical value directly, as current uses of managed_bytes are limited to keys (which are limited to 64k). However, it enables converting the atomic_cell layer back to managed_bytes (so we can remove IMR) and the CQL layer to managed_bytes/managed_bytes_view, removing contiguous allocations from the coordinator.
Closes#7820
* github.com:scylladb/scylla:
test: add hashers_test
memtable: fix accounting of managed_bytes in partition_snapshot_accounter
test: add managed_bytes_test
utils: fragment_range: add a fragment iterator for FragmentedView
keys: update comments after changes and remove an unused method
mutation_test: use the correct preferred_max_contiguous_allocation in measuring_allocator
row_cache: more indentation fixes
utils: remove unused linearization facilities in `managed_bytes` class
misc: fix indentation
treewide: remove remaining `with_linearized_managed_bytes` uses
memtable, row_cache: remove `with_linearized_managed_bytes` uses
utils: managed_bytes: remove linearizing accessors
keys, compound: switch from bytes_view to managed_bytes_view
sstables: writer: add write_* helpers for managed_bytes_view
compound_compat: transition legacy_compound_view from bytes_view to managed_bytes_view
types: change equal() to accept managed_bytes_view
types: add parallel interfaces for managed_bytes_view
types: add to_managed_bytes(const sstring&)
serializer_impl: handle managed_bytes without linearizing
utils: managed_bytes: add managed_bytes_view::operator[]
utils: managed_bytes: introduce managed_bytes_view
utils: fragment_range: add serialization helpers for FragmentedMutableView
bytes: implement std::hash using appending_hash
utils: mutable_view: add substr()
utils: fragment_range: add compare_unsigned
utils: managed_bytes: make the constructors from bytes and bytes_view explicit
utils: managed_bytes: introduce with_linearized()
utils: managed_bytes: constrain with_linearized_managed_bytes()
utils: managed_bytes: avoid internal uses of managed_bytes::data()
utils: managed_bytes: extract do_linearize_pure()
thrift: do not depend on implicit conversion of keys to bytes_view
clustering_bounds_comparator: do not depend on implicit conversion of keys to bytes_view
cql3: expression: linearize get_value_from_mutation() eariler
bytes: add to_bytes(bytes)
cql3: expression: mark do_get_value() as static
The min/max aggregators use aggregate_type_for comparators, and the
aggregate_type_for<timeuuid> is regular uuid. But that yields wrong
results; timeuuids should be compared as timestamps.
Fix it by changing aggregate_type_for<timeuuid> from uuid to timeuuid,
so aggregators can distinguish betwen the two. Then specialize the
aggregation utilities for timeuuid.
Add a cql-pytest and change some unit tests, which relied on naive
uuid comparators.
Fixes#7729.
Tests: unit (dev, debug)
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
Closes#7910
Replace two methods for unreversal (`as` and `self_or_reversed`) with
a new one (`without_reversed`). More flexible and better named.
Tests: unit (dev)
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
Closes#7889
bytes_view can convert to managed_bytes_view, so the change
is compatible with the existing representation and the next
patches, which change compound types to use managed_bytes_view.
When the clustering order is reversed on a set column, the column type
is reversed_type_impl, not set_type_impl. Therefore, we have to check
for both reversed type and set type in some places.
To make such checks easier, add convenience methods self_or_reversed()
and as() to abstract_type. Invoke those methods (instead of is_set()
and casts) enough to make test_clustering_key_reverse_frozen_set pass.
Leave other invocations of is_set() and *_cast<set_type_impl>() as
they are; some are protected by callers from being invoked on reverse
types, but some are quite possibly bugs untriggered by existing tests.
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
It turns out that `cql_table_large_data_handler::record_large_rows`
and `cql_table_large_data_handler::record_large_cells` were broken
for reporting static cells and static rows from the very beginning:
In case a large static cell or a large static row is encountered,
it tries to execute `db::try_record` with `nullptr` additional values,
denoting that there is no clustering key to be recorded.
These values are next passed to `qctx.execute_cql()`, which
creates `data_value` instances for each statement parameter,
hence invoking `data_value(nullptr)`.
This uses `const char*` overload which delegates to
`std::string_view` ctor overload. It is UB to pass `nullptr`
pointer to `std::string_view` ctor. Hence leading to
segmentation faults in the aforementioned large data reporting
code.
What we want here is to make a null `data_value` instead, so
just add an overload specifically for `std::nullptr_t`, which
will create a null `data_value` with `text` type.
A regression test is provided for the issue (written in
`cql-pytest` framework).
Tests: test/cql-pytest/test_large_cells_rows.py
Fixes: #6780
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20201223204552.61081-1-pa.solodovnikov@scylladb.com>
A sequel to #7692.
This series gets rid of linearization when validating collections and tuple types. (Other types were already validated without linearizing).
The necessary helpers for reading from fragmented buffers were introduced in #7692. All this series does is put them to use in `validate()`.
Refs: #6138Closes#7770
* github.com:scylladb/scylla:
types: add single-fragment optimization in validate()
utils: fragment_range: add with_simplified()
cql3: statements: select_statement: remove unnecessary use of with_linearized
cql3: maps: remove unnecessary use of with_linearized
cql3: lists: remove unnecessary use of with_linearized
cql3: tuples: remove unnecessary use of with_linearized
cql3: sets: remove unnecessary use of with_linearized
cql3: tuples: remove unnecessary use of with_linearized
cql3: attributes: remove unnecessary uses of with_linearized
types: validate lists without linearizing
types: validate tuples without linearizing
types: validate sets without linearizing
types: validate maps without linearizing
types: template abstract_type::validate on FragmentedView
types: validate_visitor: transition from FragmentRange to FragmentedView
utils: fragmented_temporary_buffer: add empty() to FragmentedView
utils: fragmented_temporary_buffer: don't add to null pointer
This is primarily a stylistic change. It makes the interface more consistent
with deserialize(). It will also allow us to call `validate()` for collection
elements in `validate_aux()`.
Verify that the input types are iterators and their value types are compatible
with the compare function.
Because some of the inputs were not actually valid iterators, they are adjusted
too.
Closes#7631
* github.com:scylladb/scylla:
types: add constraint on lexicographical_tri_compare()
composite: make composite::iterator a real input_iterator
compound: make compount_type::iterator a real input_iterator
Values usually come in a single fragment, but we pay the cost of fragmented
deserialization nevertheless: bigger view objects (4 words instead of 2 words)
more state to keep updated (i.e. total view size in addition to current fragment
size) and more branches.
This patch adds a special case for single-fragment buffers to
abstract_type::deserialize. They are converted to a single_fragmented_view
before doing anything else. Templates instantiated with single_fragmented_view
should compile to better code than their multi-fragmented counterparts. If
abstract_type::deserialize is inlined, this patch should completely prevent any
performance penalties for switching from with_linearized to fragmented
deserialization.
The final part of the transition of deserialize from bytes_view to
FragmentedView.
Adds a FragmentedView overload to abstract_type::deserialize and
switches deserialize_visitor from bytes_view to FragmentedView, allowing
deserialization of all types with no intermediate linearization.
Instead of eagerly linearizing all values as they are passed to
validate(), defer linearization to those validators that actually need
linearized values. Linearizing large values puts pressure on the memory
allocator with large contiguous allocation requests. This is something
we are trying to actively avoid, especially if it is not really neaded.
Turns out the types, whose validators really want linearized values are
a minority, as most validators just look at the size of the value, and
some like bytes don't need validation at all, while usually having large
values.
This is achieved by templating the validator struct on the view and
using the FragmentedRange concept to treat all passed in views
(`bytes_view` and `fragmented_temporary_buffer_view`) uniformly.
This patch makes no attempt at converting existing validators to work
with fragmented buffers, only trivial cases are converted. The major
offenders still left are ascii/utf8 and collections.
Fixes: #7318
Tests: unit(dev)
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20201007054524.909420-1-bdenes@scylladb.com>
So that nested exceptions are not lost. Also, marshal exceptions, the
ones we have in these places, already have a backtrace, so might as well
use that, instead of creating a new one, loosing unwound frames.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200507091405.244544-1-bdenes@scylladb.com>
This produces more compact code and avoids the anti-pattern of
building a map with statically known values. If the values are given
to GCC via a switch statement it can do a much better job at compile
time than libstdc++ can at runtime.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20200422224905.198794-1-espindola@scylladb.com>
Currently we call `on_internal_error()` if `tri_compare()` throws
`marshal_exception`. Some compare paths however might go around
`tri_compare()` and call `abstract_type::compare()` directly. Move the
check there to cover these cases too.
Tests: dev
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200403162530.1175801-1-bdenes@scylladb.com>
This is just a trivial wrapper over initialized_later when using
sstring, but also works when std::string is used.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
This reduces the number of translation units that depend on
boost/multiprecision from 354 to 30, and reduces the size of
database.i (as an example) from 406160 to 382933 (smaller
files will benefit more, relatively).
Ref #1
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.
With this we can construct a data_value from any string type. This
also avoids a few sstring copies.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Since a data_value can contain a null value, returning bytes from
serialize() was losing information as it was mapping null to empty.
This also introduces a serialize_nonnull that still returns bytes, but
results in an internal error if called with a null value.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
I found these mismatched types while converting some member functions
to standalone functions, since they have to use the public API that
has more type checks.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20191120181213.111758-4-espindola@scylladb.com>
"
This patch series adds only UDF support, UDA will be in the next patch series.
With this all CQL types are mapped to Lua. Right now we setup a new
lua state and copy the values for each argument and return. This will
be optimized once profiled.
We require --experimental to enable UDF in case there is some change
to the table format.
"
* 'espindola/udf-only-v4' of https://github.com/espindola/scylla: (65 commits)
Lua: Document the conversions between Lua and CQL
Lua: Implement decimal subtraction
Lua: Implement decimal addition
Lua: Implement support for returning decimal
Lua: Implement decimal to string conversion
Lua: Implement decimal to floating point conversion
Lua: Implement support for decimal arguments
Lua: Implement support for returning varint
Lua: Implement support for returning duration
Lua: Implement support for duration arguments
Lua: Implement support for returning inet
Lua: Implement support for inet arguments
Lua: Implement support for returning time
Lua: Implement support for time arguments
Lua: Implement support for returning timeuuid
Lua: Implement support for returning uuid
Lua: Implement support for uuid and timeuuid arguments
Lua: Implement support for returning date
Lua: Implement support for date arguments
Lua: Implement support for returning timestamp
...
This is a simple wrapper that allows code that is not in the types
hierarchy to visit a data_value.
Will be used by UDF.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
is_value_compatible_with_internal and update_user_type were generalized
to the non-frozen case.
For now, all user_type_impls in the code are non-multi-cell (frozen).
This will be changed in future commits.
In modification_statement/batch_statement, we need to prefetch data to
1) apply list operations
2) evaluate CAS conditions
3) return CAS result set.
Boost update_parameters::prefetch_data to serve as a single result set
for all of the above. In case of a batch, store multiple rows for
multiple clustering keys involved in the batch.
Use an ordered set for columns and rows to make sure 3) CAS result set
is returned to the client in an ordered manner.
Deserialize the primary key and add it to result set rows since
it is returned to the client as part of CAS result set.
Index columns using ordinal_id - this allows having a single
set for all columns and makes columns easy to look up.
Remove an extra memcpy to build view objects when looking
up a cell by primary key, use partition_key/clustering_key
objects for lookup.
Now that we know that anything expecting a date_type has been
converted to date_type_native_type, switch to using
db_clock::time_point when we want a timestamp_type.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
This also moves every user to date_type_native_type. A followup patch
will convert to timestamp_type when appropriate.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
date_type was replaced with timestamp_type, but it was very easy to
create a date_type instead of a timestamp_type by accident.
This patch changes the code so that a date_type is no longer
implicitly used when constructing a data_value. All existing code that
was depending on this is converted to explicitly using
date_type_native_type. A followup patch will convert to timestamp_type
when appropriate.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
They are somewhat expensive (in code size at least) and not needed
everywhere.
Inside the getter the variables are 'const data_type&', so we can
return that. Everything still works when a copy is needed, but in code
that just wants to check a property we avoid the copy.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
