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 a set of a few cosmetic changes in dht/token. Mostly some comments and a simplification of `midpoint()`.
Closes#8803
* github.com:scylladb/scylla:
dht: token: add a comment excusing the `const bytes&` constructor
dht: token: simplify midpoint()
dht: token: add a comment to normalize()
dht: token: use {read,write}_unaligned instead of std::copy_n
dht: token-sharding: fix a typo in a comment
Change token's tri_compare functions to return std::strong_ordering,
which is not convertible to bool and therefore not suspect to
being misused where a less-compare is expected.
Two of the users (ring_position and decorated_key) have to undo
the conversion, since they still return int. A follow up will
convert them too.
Ref #1449.
If the key type is int64_t and the less-comparator is "natural" (i.e. it's
literally 'a < b') we may use the SIMD instructions to search for the key
on a node. Before doing so, the maybe_key and the searcher should be prepared
for that, in particular:
1. maybe_key should set unused keys to the minimal value
2. the searcher for this case should call the gt() helper with
primitive types -- int64_t search key and array of int64_t values
To tell to B+ code that the key-less pair is such the less-er should define
the simplify_key() method converting search keys to int64_t-s.
This searcher is selected automatically, if any mismatch happens it silently
falls back to default one. Thus also add a static assertion to the row-cache
to mitigate this.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The <search-key>.token() is noexcept currently and will have
to be explicitly such for future optimized key searcher, so
restrict the constraint and update the related classes.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
In next patches the entries having token on-board will be
moved onto B+-tree rails. For this the int64_t value of the
token will be used as B+ key, so prepare for this.
One corner case -- the after_all_keys tokens must be resolved
to int64::max value to appear at the "end" of the tree. This
is not the same as "before_all_keys" case, which maps to the
int64::min value which is not allowed for regular tokens. But
for the sake of B+ switch this is OK, the conflicts of token
raw values are explicitly resolved in next patches.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
When we switched token representation to int64_t
we added some sanity checks that byte representation
is always 8 bytes long.
It turns out that for token_kind::before_all_keys and
token_kind::after_all_keys bytes can sometimes be empty
because for those tokens they are just ignored. The check
introduced with the change is too strict and sometimes
throws the exception for tokens before/after all keys
created with empty bytes.
This patch relaxes the condition of the check and always
uses 0 as value of _data for special before/after all keys
tokens.
Fixes#6131
Tests: unit(dev, sct)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Previously the tokens were stored as strings
because token could have been represented in multiple ways.
Now token representation is always int64_t so we can
store them as ints in cdc description as well.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Previously _data was stored as array of 8 bytes in
network byte order.
After this change it stores the same value in int64_t
in host byte order.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
It is save to do such change because we support only
Murmur3Partitioner which uses only tokens that are
8 bytes long.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
