1 | #pragma once |
2 | |
3 | #include <mutex> |
4 | |
5 | #include <ext/shared_ptr_helper.h> |
6 | |
7 | #include <Core/NamesAndTypes.h> |
8 | #include <Storages/IStorage.h> |
9 | #include <DataStreams/IBlockOutputStream.h> |
10 | |
11 | |
12 | namespace DB |
13 | { |
14 | |
15 | /** Implements storage in the RAM. |
16 | * Suitable for temporary data. |
17 | * It does not support keys. |
18 | * Data is stored as a set of blocks and is not stored anywhere else. |
19 | */ |
20 | class StorageMemory : public ext::shared_ptr_helper<StorageMemory>, public IStorage |
21 | { |
22 | friend class MemoryBlockInputStream; |
23 | friend class MemoryBlockOutputStream; |
24 | friend struct ext::shared_ptr_helper<StorageMemory>; |
25 | |
26 | public: |
27 | String getName() const override { return "Memory" ; } |
28 | String getTableName() const override { return table_name; } |
29 | String getDatabaseName() const override { return database_name; } |
30 | |
31 | size_t getSize() const { return data.size(); } |
32 | |
33 | BlockInputStreams read( |
34 | const Names & column_names, |
35 | const SelectQueryInfo & query_info, |
36 | const Context & context, |
37 | QueryProcessingStage::Enum processed_stage, |
38 | size_t max_block_size, |
39 | unsigned num_streams) override; |
40 | |
41 | BlockOutputStreamPtr write(const ASTPtr & query, const Context & context) override; |
42 | |
43 | void drop(TableStructureWriteLockHolder &) override; |
44 | |
45 | void truncate(const ASTPtr &, const Context &, TableStructureWriteLockHolder &) override; |
46 | |
47 | void rename(const String & /*new_path_to_db*/, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &) override |
48 | { |
49 | table_name = new_table_name; |
50 | database_name = new_database_name; |
51 | } |
52 | |
53 | private: |
54 | String database_name; |
55 | String table_name; |
56 | |
57 | /// The data itself. `list` - so that when inserted to the end, the existing iterators are not invalidated. |
58 | BlocksList data; |
59 | |
60 | std::mutex mutex; |
61 | |
62 | protected: |
63 | StorageMemory(String database_name_, String table_name_, ColumnsDescription columns_description_, ConstraintsDescription constraints_); |
64 | }; |
65 | |
66 | } |
67 | |