1 | #pragma once |
2 | |
3 | #include <DataStreams/IBlockOutputStream.h> |
4 | #include <Core/Types.h> |
5 | #include <DataTypes/IDataType.h> |
6 | |
7 | namespace DB |
8 | { |
9 | |
10 | class WriteBuffer; |
11 | class CompressedWriteBuffer; |
12 | |
13 | |
14 | /** Serializes the stream of blocks in their native binary format (with names and column types). |
15 | * Designed for communication between servers. |
16 | * |
17 | * A stream can be specified to write the index. The index contains offsets to each part of each column. |
18 | * If an `append` is made to an existing file, and you need to write the index, then specify `initial_size_of_file`. |
19 | */ |
20 | class NativeBlockOutputStream : public IBlockOutputStream |
21 | { |
22 | public: |
23 | /** If non-zero client_revision is specified, additional block information can be written. |
24 | */ |
25 | NativeBlockOutputStream( |
26 | WriteBuffer & ostr_, UInt64 client_revision_, const Block & , bool remove_low_cardinality_ = false, |
27 | WriteBuffer * index_ostr_ = nullptr, size_t initial_size_of_file_ = 0); |
28 | |
29 | Block () const override { return header; } |
30 | void write(const Block & block) override; |
31 | void flush() override; |
32 | |
33 | static void writeData(const IDataType & type, const ColumnPtr & column, WriteBuffer & ostr, UInt64 offset, UInt64 limit); |
34 | |
35 | String getContentType() const override { return "application/octet-stream" ; } |
36 | |
37 | private: |
38 | WriteBuffer & ostr; |
39 | UInt64 client_revision; |
40 | Block ; |
41 | WriteBuffer * index_ostr; |
42 | size_t initial_size_of_file; /// The initial size of the data file, if `append` done. Used for the index. |
43 | /// If you need to write index, then `ostr` must be a CompressedWriteBuffer. |
44 | CompressedWriteBuffer * ostr_concrete = nullptr; |
45 | |
46 | bool remove_low_cardinality; |
47 | }; |
48 | |
49 | } |
50 | |