mirror of
https://github.com/facebook/rocksdb.git
synced 2024-12-02 20:52:55 +00:00
e9c74bc474
Summary: The patch adds some low-level logic that can be used to serialize/deserialize a sorted vector of wide columns to/from a simple binary searchable string representation. Currently, there is no user-facing API; this will be implemented in subsequent stages. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9915 Test Plan: `make check` Reviewed By: siying Differential Revision: D35978076 Pulled By: ltamasi fbshipit-source-id: 33f5f6628ec3bcd8c8beab363b1978ac047a8788
56 lines
2.1 KiB
C++
56 lines
2.1 KiB
C++
// 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 Deserialize(Slice& input, WideColumns& columns);
|
|
|
|
static WideColumns::const_iterator Find(const WideColumns& columns,
|
|
const Slice& column_name);
|
|
|
|
static constexpr uint32_t kCurrentVersion = 1;
|
|
};
|
|
|
|
} // namespace ROCKSDB_NAMESPACE
|