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
Validate ascii string by ORing all bytes and check if 7-th bit is 0.
Compared with original std::any_of(), which checks ascii string byte
by byte, this new approach validates input in 8 bytes and two
independent streams. Performance is much higher for normal cases,
though slightly slower when string is very short. See table below.
Speed(MB/s) of ascii string validation
+---------------+-------------+---------+
| String length | std::any_of | u64 x 2 |
+---------------+-------------+---------+
| 9 bytes | 1691 | 1635 |
+---------------+-------------+---------+
| 31 bytes | 2923 | 3181 |
+---------------+-------------+---------+
| 129 bytes | 3377 | 15110 |
+---------------+-------------+---------+
| 1039 bytes | 3357 | 31815 |
+---------------+-------------+---------+
| 16385 bytes | 3448 | 47983 |
+---------------+-------------+---------+
| 1048576 bytes | 3394 | 31391 |
+---------------+-------------+---------+
Signed-off-by: Yibo Cai <yibo.cai@arm.com>
Message-Id: <1544669646-31881-1-git-send-email-yibo.cai@arm.com>
