22d193ba9f
It is needed for noexcept destruction, which we need for exception safety in higher layers. According to [1], erase() only throws if key comparison throws, and in our case it doesn't. [1] http://en.cppreference.com/w/cpp/container/unordered_map/erase
51 lines
1.5 KiB
C++
51 lines
1.5 KiB
C++
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/*
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* Copyright 2015 ScyllaDB
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*/
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/*
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* This file is part of Scylla.
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*
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* Scylla is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Scylla is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "managed_bytes.hh"
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thread_local managed_bytes::linearization_context managed_bytes::_linearization_context;
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void
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managed_bytes::linearization_context::forget(const blob_storage* p) noexcept {
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_state.erase(p);
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}
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const bytes_view::value_type*
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managed_bytes::do_linearize() const {
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auto& lc = _linearization_context;
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assert(lc._nesting);
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auto b = _u.ptr;
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auto i = lc._state.find(b);
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if (i == lc._state.end()) {
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auto data = std::unique_ptr<bytes_view::value_type[]>(new bytes_view::value_type[b->size]);
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auto e = data.get();
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while (b) {
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e = std::copy_n(b->data, b->frag_size, e);
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b = b->next;
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}
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i = lc._state.emplace(_u.ptr, std::move(data)).first;
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}
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return i->second.get();
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}
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