update_parameters::prefetch_data is used for some list updates (which
need a read-before-write to determine the key to update) and for
LWT compare-and-swap. Currently they use a custom structure for
representing a read row.
Switch to the same structure that is used in evaluation_inputs (and
in SELECT statement evaluation) to the expression machinery can be reused.
The expression representation is irregular (with different fields for
the keys and regular/static columns), so we introduce an old_row
structure to hold both the clustering key and the regular row values
for cas_request.
A nice bonus is that we can use get_non_pk_values() to read the data
into the format expected by evaluation_inputs, but on the other hand
we have to adjust get_prefetched_list() to fix up the type of
the returned list (we return it as a map, not a list, so list updates
can access the index).
After fcb8d040 ("treewide: use Software Package Data Exchange
(SPDX) license identifiers"), many dual-licensed files were
left with empty comments on top. Remove them to avoid visual
noise.
Closes#10562
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
This is just a plain move of the code from `modification_statement`
to `cas_request` without changes in the logic, which will further
help to refactor `build_cas_result_set` behavior to include a row
for each LWT statement and order rows in the order of statements
in a batch.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Factor out little helper function which finds a pre-existing
row for a given `cas_row_update` (matching the primary key).
Used in `cas_request::applies_to`.
Will be used in a subsequent patch to move
`modification_statement::build_cas_result_set` into `cas_request`.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
This field will replace max size which is currently passed once per
established rpc connection via the CLIENT_ID verb and stored as an
auxiliary value on the client_info. For now it is unused, but we update
all sites creating a read command to pass the correct value to it. In the
next patch we will phase out the old max size and use this field to pass
max size on each verb instead.
Change the way query result is passed from getting a reference to a
result to getting a foreign_ptr<lw_shared_ptr<query::result>>. This will
allow cas_request to keep it without copying.
cql_statement is a class representing a prepared statement in Scylla.
It is used concurrently during execution, so it is important that its
change is not changed by execution.
Add const qualifier to the execution methods family, throghout the
cql hierarchy.
Mark a few places which do mutate prepared statement state during
execution as mutable. While these are not affecting production today,
as code ages, they may become a source of latent bugs and should be
moved out of the prepared state or evaluated at prepare eventually:
cf_property_defs::_compaction_strategy_class
list_permissions_statement::_resource
permission_altering_statement::_resource
property_definitions::_properties
select_statement::_opts
Support single-statement conditional updates and as well as batches.
This patch almost fully rewrites column_condition.cc, implementing
is_satisfied_by().
Most of the remaining complications in column_condition implementation
come from the need to properly handle frozen and multi-cell
collection in predicates - up until now it was not possible
to compare entire collection values between each other. This is further
complicated since multi-cell lists and sets are returned as maps.
We can no longer assume that the columns fetched by prefetch operation
are non-frozen collections. IF EXISTS/IF NOT EXISTS condition
fetches all columns, besides, a column may be needed to check other
condition.
When fetching the old row for LWT or to apply updates on list/columns,
we now calculate precisely the list of columns to fetch.
The primary key columns are also included in CAS batch result set,
and are thus also prefetched (the user needs them to figure out which
statements failed to apply).
The patch is cross-checked for compatibility with cassandra-3.11.4-1545-g86812fa502
but does deviate from the origin in handling of conditions on static
row cells. This is addressed in future series.
