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scylladb/data/value_view_impl.hh
Paweł Dziepak eec33fda14 data: introduce cell
This commit introduces cell serializers and views based on the in-memory
representation infrastructure. The code doesn't assume anything about
how the cells are stored, they can be either a part of another IMR
object (once the rows are converted to the IMR) or a separate objects
(just like current atomic_cell).
2018-05-31 15:51:11 +01:00

117 lines
3.3 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 "data/cell.hh"
namespace data {
template<mutable_view is_mutable>
inline typename basic_value_view<is_mutable>::iterator& basic_value_view<is_mutable>::iterator::operator++()
{
if (!_next) {
_view = fragment_type();
} else if (_left > maximum_external_chunk_length) {
cell::chunk_context ctx(_next);
auto v = cell::external_chunk::make_view(_next, ctx);
_next = static_cast<uint8_t*>(v.template get<cell::tags::chunk_next>(ctx).load());
_view = v.template get<cell::tags::chunk_data>(ctx);
_left -= cell::maximum_external_chunk_length;
} else {
cell::last_chunk_context ctx(_next);
auto v = cell::external_last_chunk::make_view(_next, ctx);
_view = v.template get<cell::tags::chunk_data>(ctx);
_next = nullptr;
}
return *this;
}
template<mutable_view is_mutable>
inline bool basic_value_view<is_mutable>::operator==(const basic_value_view& other) const noexcept
{
// We can assume that all values are fragmented exactly in the same way.
auto it1 = begin();
auto it2 = other.begin();
while (it1 != end() && it2 != other.end()) {
if (*it1 != *it2) {
return false;
}
++it1;
++it2;
}
return it1 == end() && it2 == other.end();
}
template<mutable_view is_mutable>
inline bool basic_value_view<is_mutable>::operator==(bytes_view bv) const noexcept
{
bool equal = true;
using boost::range::for_each;
for_each(*this, [&] (bytes_view fragment) {
if (fragment.size() > bv.size()) {
equal = false;
} else {
auto bv_frag = bv.substr(0, fragment.size());
equal = equal && fragment == bv_frag;
bv.remove_prefix(fragment.size());
}
});
return equal && bv.empty();
}
template<mutable_view is_mutable>
inline bytes basic_value_view<is_mutable>::linearize() const
{
bytes b(bytes::initialized_later(), size_bytes());
auto it = b.begin();
for (auto fragment : *this) {
it = boost::copy(fragment, it);
}
return b;
}
template<mutable_view is_mutable>
template<typename Function>
inline decltype(auto) basic_value_view<is_mutable>::with_linearized(Function&& fn) const
{
bytes b;
bytes_view bv;
if (is_fragmented()) {
b = linearize();
bv = b;
} else {
bv = _first_fragment;
}
return fn(bv);
}
inline std::ostream& operator<<(std::ostream& os, value_view vv)
{
using boost::range::for_each;
for_each(vv, [&os] (bytes_view fragment) {
os << fragment;
});
return os;
}
}