1 | #pragma once |
2 | |
3 | #include <Processors/ISource.h> |
4 | |
5 | |
6 | namespace DB |
7 | { |
8 | |
9 | class ReadBuffer; |
10 | |
11 | /** Input format is a source, that reads data from ReadBuffer. |
12 | */ |
13 | class IInputFormat : public ISource |
14 | { |
15 | protected: |
16 | |
17 | /// Skip GCC warning: ‘maybe_unused’ attribute ignored |
18 | #pragma GCC diagnostic push |
19 | #pragma GCC diagnostic ignored "-Wattributes" |
20 | |
21 | ReadBuffer & in [[maybe_unused]]; |
22 | |
23 | #pragma GCC diagnostic pop |
24 | |
25 | public: |
26 | IInputFormat(Block , ReadBuffer & in_); |
27 | |
28 | /** In some usecase (hello Kafka) we need to read a lot of tiny streams in exactly the same format. |
29 | * The recreating of parser for each small stream takes too long, so we introduce a method |
30 | * resetParser() which allow to reset the state of parser to continue reading of |
31 | * source stream w/o recreating that. |
32 | * That should be called after current buffer was fully read. |
33 | */ |
34 | virtual void resetParser(); |
35 | |
36 | virtual const BlockMissingValues & getMissingValues() const |
37 | { |
38 | static const BlockMissingValues none; |
39 | return none; |
40 | } |
41 | }; |
42 | |
43 | } |
44 | |