no need to use `size - 1` for accessing the last element in a vector,
let's just use `vector::back()` for more compacted code.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Scylla's Bloom filter implementation has a minimal false-positive rate
that it can support (6.71e-5). When setting bloom_filter_fp_chance any
lower than that, the compute_bloom_spec() function, which writes the bloom
filter, throws an exception. However, this is too late - it only happens
while flushing the memtable to disk, and a failure at that point causes
Scylla to crash.
Instead, we should refuse the table creation with the unsupported
bloom_filter_fp_chance. This is also what Cassandra did six years ago -
see CASSANDRA-11920.
This patch also includes a regression test, which crashes Scylla before
this patch but passes after the patch (and also passes on Cassandra).
Fixes#11524.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#11576
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
Recently, coordinator_result was introduced as an alternative for
exceptions. It was placed in the main "exceptions/exceptions.hh" header,
which virtually every single source file in Scylla includes.
But unfortunately, it brings in some heavy header files and templates,
leading to a lot of wasted build time - ClangBuildAnalyzer measured that
we include exceptions.hh in 323 source files, taking almost two seconds
each on average.
In this patch, we split the coordinator_result feature into a separate
header file, "exceptions/coordinator_result", and only the few places
which need it include the header file. Unfortunately, some of these
few places are themselves header, so the new header file ends up being
included in 100 source files - but 100 is still much less than 323 and
perhaps we can reduce this number 100 later.
After this patch, the total Scylla object-file size is reduced by 6.5%
(the object size is a proxy for build time, which I didn't directly
measure). ClangBuildAnalyzer reports that now each of the 323 includes
of exceptions.hh only takes 80ms, coordinator_result.hh is only included
100 times, and virtually all the cost to include it comes from Boost's
result.hh (400ms per inclusion).
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220228204323.1427012-1-nyh@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
sprint() recently became more strict, throwing on sprint("%s", 5). Replace
with the more modern format().
Mechanically converted with https://github.com/avikivity/unsprint.
