1#pragma once
2
3#include <ext/shared_ptr_helper.h>
4#include <Formats/FormatSettings.h>
5#include <Storages/IStorage.h>
6#include <Storages/MergeTree/MergeTreeData.h>
7
8
9namespace DB
10{
11
12class Context;
13
14struct StoragesInfo
15{
16 StoragePtr storage = nullptr;
17 TableStructureReadLockHolder table_lock;
18
19 String database;
20 String table;
21 String engine;
22
23 bool need_inactive_parts = false;
24 MergeTreeData * data = nullptr;
25
26 operator bool() const { return storage != nullptr; }
27 MergeTreeData::DataPartsVector getParts(MergeTreeData::DataPartStateVector & state, bool has_state_column) const;
28};
29
30/** A helper class that enumerates the storages that match given query. */
31class StoragesInfoStream
32{
33public:
34 StoragesInfoStream(const SelectQueryInfo & query_info, const Context & context);
35 StoragesInfo next();
36
37private:
38 String query_id;
39
40 ColumnPtr database_column;
41 ColumnPtr table_column;
42 ColumnPtr active_column;
43
44 size_t next_row;
45 size_t rows;
46
47 using StoragesMap = std::map<std::pair<String, String>, StoragePtr>;
48 StoragesMap storages;
49};
50
51/** Implements system table 'parts' which allows to get information about data parts for tables of MergeTree family.
52 */
53class StorageSystemPartsBase : public IStorage
54{
55public:
56 std::string getTableName() const override { return name; }
57 std::string getDatabaseName() const override { return "system"; }
58
59 NameAndTypePair getColumn(const String & column_name) const override;
60
61 bool hasColumn(const String & column_name) const override;
62
63 BlockInputStreams read(
64 const Names & column_names,
65 const SelectQueryInfo & query_info,
66 const Context & context,
67 QueryProcessingStage::Enum processed_stage,
68 size_t max_block_size,
69 unsigned num_streams) override;
70
71private:
72 const std::string name;
73
74 bool hasStateColumn(const Names & column_names) const;
75
76protected:
77 const FormatSettings format_settings;
78
79 StorageSystemPartsBase(std::string name_, NamesAndTypesList && columns_);
80
81 virtual void processNextStorage(MutableColumns & columns, const StoragesInfo & info, bool has_state_column) = 0;
82};
83
84}
85