Files
scylladb/digester.hh
Avi Kivity 19ffc9455d Merge "Don't expose exact collection from range_tombstone_list" from Pavel E
"
The range_tombstone_list provides an abstraction to work with
sorted list of range tombstones with methods to add/retrive
them. However, there's a tombstones() method that just returns
modifiable reference to the used collection (boost::intrusive_set)
which makes it hard to track the exact usage of it.

This set encapsulates the collaction of range tombstones inside
the mentioned ..._list class.

tests: unit(dev)
"

* 'br-range-tombstone-encapsulate-collection' of https://github.com/xemul/scylla:
  range_tombstone_list: Do not expose internal collection
  range_tombstone_list: Introduce and use pop-and-lock helper
  range_tombstone_list: Introduce and use pop_as<>()
  flat_mutation_reader: Use range_tombstone_list begin/end API
  repair: Mark some partition_hasher methods noexcept
  hashers: Mark hash updates noexcept
2020-09-15 10:09:15 +02:00

82 lines
2.3 KiB
C++

/*
* Copyright (C) 2018 ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "digest_algorithm.hh"
#include "hashers.hh"
#include "xx_hasher.hh"
#include <type_traits>
#include <variant>
namespace query {
struct noop_hasher {
void update(const char* ptr, size_t length) noexcept { }
std::array<uint8_t, 16> finalize_array() { return std::array<uint8_t, 16>(); };
};
class digester final {
std::variant<noop_hasher, md5_hasher, xx_hasher, legacy_xx_hasher_without_null_digest> _impl;
public:
explicit digester(digest_algorithm algo) {
switch (algo) {
case digest_algorithm::MD5:
_impl = md5_hasher();
break;
case digest_algorithm::xxHash:
_impl = xx_hasher();
break;
case digest_algorithm::legacy_xxHash_without_null_digest:
_impl = legacy_xx_hasher_without_null_digest();
break;
case digest_algorithm ::none:
_impl = noop_hasher();
break;
}
}
template<typename T, typename... Args>
void feed_hash(const T& value, Args&&... args) {
std::visit([&] (auto& hasher) noexcept -> void {
::feed_hash(hasher, value, std::forward<Args>(args)...);
}, _impl);
};
std::array<uint8_t, 16> finalize_array() {
return std::visit([&] (auto& hasher) {
return hasher.finalize_array();
}, _impl);
}
};
using default_hasher = xx_hasher;
template<typename Hasher>
using using_hash_of_hash = std::negation<std::disjunction<std::is_same<Hasher, md5_hasher>, std::is_same<Hasher, noop_hasher>>>;
template<typename Hasher>
inline constexpr bool using_hash_of_hash_v = using_hash_of_hash<Hasher>::value;
}