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
Convert read_vint() to a concept. The explicitly deleted version
is no longer needed since wrongly-typed inputs will be rejected
by the constraint. Similarly the static assert can be dropped
for the same reason.
Move bound_kind_m's formatter to the same header file where
is is defined. This prevents cases where the compiler decays
the type (an enum) to the underlying integral type because it
does not see the formatter declaration, resulting in the wrong
output.
Fix runtime error: signed integer overflow
introduced by 2dc3776407
Delta-encoded values may wrap around if the encoded value is
less than the base value. This could happen in two places:
In the mc-format serialization header itself, where the base values are implicit
Cassandra epoch time, and in the sstables data files, where the base values
are taken from the encoding_stats (later written to the serialization_header).
In these cases, when the calculation is done using signed integer/long we may see
"runtime error: signed integer overflow" messages in debug mode
(with -fsanitize=undefined / -fsanitize=signed-integer-overflow).
Overflow here is expected and harmless since we do not gurantee that
neither the base values in the serialization header are greater than
or equal to Cassandra's epoch now that the delta-encoded values are
always greater than or equal to the respective base values in
the serialization header.
To prevent these warnings, the subtraction/addition should be done with unsigned
(two's complement) arithmetic and the result converted to the signed type.
Note that to keep the code simple where possible, when also rely on implicit
conversion of signed integers to unsigned when either one of added value is unsigned
and the other is signed.
Fixes: #4098
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20190120142950.15776-1-bhalevy@scylladb.com>
This allows to store expired liveness info in SSTables 3.x format
without introducing a possible conflict with real TTL values.
As per Cassandra, TTL cannot exceed 20 years so taking the maximum value
as a special value for indicating expired liveness info is safe.
Signed-off-by: Vladimir Krivopalov <vladimir@scylladb.com>
Before this fix, the code was a potential undefined behaviour and crash
because it would add a large value to a const char* and try to create a
std::string out of it.
Signed-off-by: Vladimir Krivopalov <vladimir@scylladb.com>
Internally, timestamps are represented as signed integers (int64_t) but
stored as unsigned ones. So it is quite possible to store data with
timestamp that is represented as a number larger than the max value of
int64_t type.
One such example is api::min_timestamp() that is used when generating
system schema tables ("keyspaces"). When cast to uint64_t, it turns into
a large value.
Signed-off-by: Vladimir Krivopalov <vladimir@scylladb.com>
There previously was an inconsistency in treating min values stored in a
serialization_header. They are written to or read from a Statistics.db
as deltas against fixed bases, but when we parse timeouts from the data
file, we need the full bases, not just deltas.
This inconsistency causes wrong timestamp values if we write an sstable
and then read from it using one and the same sstable object because we
turn min values into bases on write and then don't adjust them back
because we already have them in memory.
Signed-off-by: Vladimir Krivopalov <vladimir@scylladb.com>
