91dab1d998
Version 5 of the native protocol for CQL [1] adds the `vint` and `unsigned vint` types. An unsigned integer encoded as a `vint` has a variable size based on the magnitude of the value. The first byte indicates the total number of bytes. For signed integers, a "zig-zag" encoding scheme ensures that small negative values are encoded as short-length `vint`s (0 -> 0, -1 -> 1, 1 -> 2, 2 -> 3, -2 -> 4, etc). [1] https://github.com/apache/cassandra/blob/trunk/doc/native_protocol_v5.spec
61 lines
1.6 KiB
C++
61 lines
1.6 KiB
C++
/*
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* Copyright 2017 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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//
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// For reference, see https://developers.google.com/protocol-buffers/docs/encoding#varints
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//
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#include "bytes.hh"
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#include <cstdint>
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using vint_size_type = bytes::size_type;
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struct unsigned_vint final {
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using value_type = uint64_t;
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struct deserialized_type final {
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value_type value;
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vint_size_type size;
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};
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static vint_size_type serialized_size(value_type) noexcept;
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static vint_size_type serialize(value_type, bytes::iterator out);
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static deserialized_type deserialize(bytes_view v);
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};
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struct signed_vint final {
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using value_type = int64_t;
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struct deserialized_type final {
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value_type value;
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vint_size_type size;
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};
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static vint_size_type serialized_size(value_type) noexcept;
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static vint_size_type serialize(value_type, bytes::iterator out);
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static deserialized_type deserialize(bytes_view v);
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};
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