these unused includes were identifier by clang-include-cleaner. after
auditing these source files, all of the reports have been confirmed.
please note, because quite a few source files relied on
`utils/to_string.hh` to pull in the specialization of
`fmt::formatter<std::optional<T>>`, after removing
`#include <fmt/std.h>` from `utils/to_string.hh`, we have to
include `fmt/std.h` directly.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
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
std::is_fundamental isn't a good constraint since it include nullptr_t
and void. Replace with std::integral which is sufficient. Use a concept
instead of enable_if to simplify the code.
Closes#8450
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>
"
This gives about 30% increase in tps in:
build/release/tests/perf/perf_simple_query -c1 --query-single-key
This patch switches query result format from a structured one to a
serialized one. The problems with structured format are:
- high level of indirection (vector of vectors of vectors of blobs), which
is not CPU cache friendly
- high allocation rate due to fine-grained object structure
On replica side, the query results are probably going to be serialized
in the transport layer anyway, so this change only subtracts
work. There is no processing of the query results on replica other
than concatenation in case of range queries. If query results are
collected in serialized form from different cores, we can concatenate
them without copying by simply appending the fragments into the
packet. This optimization is not implemented yet.
On coordinator side, the query results would have to be parsed from
the transport layer buffers anyway, so this also doesn't add work, but
again saves allocations and copying. The CQL server doesn't need
complex data structures to process the results, it just goes over it
linearly consuming it. This patch provides views, iterators and
visitors for consuming query results in serialized form. Currently the
iterators assume that the buffer is contiguous but we could easily
relax this in future so that we can avoid linearization of data
received from seastar sockets.
The coordinator side could be optimized even further for CQL queries
which do not need processing (eg. select * from cf where ...) we
could make the replica send the query results in the format which is
expected by the CQL binary protocol client. So in the typical case the
coordinator would just pass the data using zero-copy to the client,
prepending a header.
We do need structure for prefetched rows (needed by list
manipulations), and this change adds query result post-processing
which converts serialized query result into a structured one, tailored
particularly for prefetched rows needs.
This change also introduces partition_slice options. In some queries
(maybe even in typical ones), we don't need to send partition or
clustering keys back to the client, because they are already specified
in the query request, and not queried for. The query results hold now
keys as optional elements. Also, meta-data like cell timestamp and
ttl is now also optional. It is only needed if the query has
writetime() or ttl() functions in it, which it typically won't have.
bytes and sstring are distinct types, since their internal buffers are of
different length, but bytes_view is an alias of sstring_view, which makes
it possible of objects of different types to leak across the abstraction
boundary.
Fix this by making bytes a basic_sstring<int8_t, ...> instead of using char.
int8_t is a 'signed char', which is a distinct type from char, so now
bytes_view is a distinct type from sstring_view.
uint8_t would have been an even better choice, but that diverges from Origin
and would have required an audit.
