346055a9ea
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/13168 The patch moves `WideColumnSerialization::Find` to `WideColumnsHelper` to facilitate reuse in non-serialization-related contexts. It also generalizes the method to take a range of iterators, and templatizes it on the iterator type to enable using it with both `const` and non-`const` iterators. Finally, it adds an assertion to ensure the method is called with a properly sorted range, which is a precondition for binary search. Reviewed By: jaykorean Differential Revision: D66602558 fbshipit-source-id: 841a885af31e183edeb7e3314167c55f8ed53ff1
55 lines
2 KiB
C++
55 lines
2 KiB
C++
// Copyright (c) Meta Platforms, Inc. and affiliates.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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#pragma once
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#include <cstdint>
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#include <string>
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#include "rocksdb/rocksdb_namespace.h"
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#include "rocksdb/status.h"
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#include "rocksdb/wide_columns.h"
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namespace ROCKSDB_NAMESPACE {
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class Slice;
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// Wide-column serialization/deserialization primitives.
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//
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// The two main parts of the layout are 1) a sorted index containing the column
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// names and column value sizes and 2) the column values themselves. Keeping the
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// index and the values separate will enable selectively reading column values
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// down the line. Note that currently the index has to be fully parsed in order
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// to find out the offset of each column value.
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//
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// Legend: cn = column name, cv = column value, cns = column name size, cvs =
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// column value size.
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//
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// +----------+--------------+----------+-------+----------+---...
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// | version | # of columns | cns 1 | cn 1 | cvs 1 |
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// +----------+--------------+------------------+--------- +---...
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// | varint32 | varint32 | varint32 | bytes | varint32 |
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// +----------+--------------+----------+-------+----------+---...
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//
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// ... continued ...
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//
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// ...---+----------+-------+----------+-------+---...---+-------+
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// | cns N | cn N | cvs N | cv 1 | | cv N |
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// ...---+----------+-------+----------+-------+---...---+-------+
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// | varint32 | bytes | varint32 | bytes | | bytes |
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// ...---+----------+-------+----------+-------+---...---+-------+
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class WideColumnSerialization {
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public:
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static Status Serialize(const WideColumns& columns, std::string& output);
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static Status Deserialize(Slice& input, WideColumns& columns);
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static Status GetValueOfDefaultColumn(Slice& input, Slice& value);
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static constexpr uint32_t kCurrentVersion = 1;
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};
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} // namespace ROCKSDB_NAMESPACE
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