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Diffstat (limited to 'src/rocksdb/db/wide/wide_column_serialization.h')
-rw-r--r-- | src/rocksdb/db/wide/wide_column_serialization.h | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/src/rocksdb/db/wide/wide_column_serialization.h b/src/rocksdb/db/wide/wide_column_serialization.h new file mode 100644 index 000000000..f0ffbd392 --- /dev/null +++ b/src/rocksdb/db/wide/wide_column_serialization.h @@ -0,0 +1,77 @@ +// Copyright (c) Meta Platforms, Inc. and affiliates. +// This source code is licensed under both the GPLv2 (found in the +// COPYING file in the root directory) and Apache 2.0 License +// (found in the LICENSE.Apache file in the root directory). + +#pragma once + +#include <cstdint> +#include <string> + +#include "rocksdb/rocksdb_namespace.h" +#include "rocksdb/status.h" +#include "rocksdb/wide_columns.h" + +namespace ROCKSDB_NAMESPACE { + +class Slice; + +// Wide-column serialization/deserialization primitives. +// +// The two main parts of the layout are 1) a sorted index containing the column +// names and column value sizes and 2) the column values themselves. Keeping the +// index and the values separate will enable selectively reading column values +// down the line. Note that currently the index has to be fully parsed in order +// to find out the offset of each column value. +// +// Legend: cn = column name, cv = column value, cns = column name size, cvs = +// column value size. +// +// +----------+--------------+----------+-------+----------+---... +// | version | # of columns | cns 1 | cn 1 | cvs 1 | +// +----------+--------------+------------------+--------- +---... +// | varint32 | varint32 | varint32 | bytes | varint32 | +// +----------+--------------+----------+-------+----------+---... +// +// ... continued ... +// +// ...---+----------+-------+----------+-------+---...---+-------+ +// | cns N | cn N | cvs N | cv 1 | | cv N | +// ...---+----------+-------+----------+-------+---...---+-------+ +// | varint32 | bytes | varint32 | bytes | | bytes | +// ...---+----------+-------+----------+-------+---...---+-------+ + +class WideColumnSerialization { + public: + static Status Serialize(const WideColumns& columns, std::string& output); + static Status Serialize(const Slice& value_of_default, + const WideColumns& other_columns, + std::string& output); + + static Status Deserialize(Slice& input, WideColumns& columns); + + static WideColumns::const_iterator Find(const WideColumns& columns, + const Slice& column_name); + static Status GetValueOfDefaultColumn(Slice& input, Slice& value); + + static constexpr uint32_t kCurrentVersion = 1; + + private: + static Status SerializeImpl(const Slice* value_of_default, + const WideColumns& columns, std::string& output); +}; + +inline Status WideColumnSerialization::Serialize(const WideColumns& columns, + std::string& output) { + constexpr Slice* value_of_default = nullptr; + + return SerializeImpl(value_of_default, columns, output); +} + +inline Status WideColumnSerialization::Serialize( + const Slice& value_of_default, const WideColumns& other_columns, + std::string& output) { + return SerializeImpl(&value_of_default, other_columns, output); +} + +} // namespace ROCKSDB_NAMESPACE |