1 | #include <Storages/MarkCache.h> |
2 | #include <Storages/MergeTree/MarkRange.h> |
3 | #include <Storages/MergeTree/MergeTreeData.h> |
4 | #include <Storages/MergeTree/MergeTreeRangeReader.h> |
5 | #include <Storages/MergeTree/MergeTreeIndexGranularityInfo.h> |
6 | #include <Compression/CachedCompressedReadBuffer.h> |
7 | #include <Compression/CompressedReadBufferFromFile.h> |
8 | |
9 | |
10 | namespace DB |
11 | { |
12 | |
13 | /// Class for reading a single column (or index). |
14 | class MergeTreeReaderStream |
15 | { |
16 | public: |
17 | MergeTreeReaderStream( |
18 | const String & path_prefix_, const String & data_file_extension_, size_t marks_count_, |
19 | const MarkRanges & all_mark_ranges, |
20 | MarkCache * mark_cache, bool save_marks_in_cache, |
21 | UncompressedCache * uncompressed_cache, |
22 | size_t file_size, size_t aio_threshold, size_t max_read_buffer_size, |
23 | const MergeTreeIndexGranularityInfo * index_granularity_info_, |
24 | const ReadBufferFromFileBase::ProfileCallback & profile_callback, clockid_t clock_type); |
25 | |
26 | void seekToMark(size_t index); |
27 | |
28 | void seekToStart(); |
29 | |
30 | ReadBuffer * data_buffer; |
31 | |
32 | private: |
33 | /// NOTE: lazily loads marks from the marks cache. |
34 | const MarkInCompressedFile & getMark(size_t index); |
35 | |
36 | void loadMarks(); |
37 | |
38 | std::string path_prefix; |
39 | std::string data_file_extension; |
40 | |
41 | size_t marks_count; |
42 | |
43 | MarkCache * mark_cache; |
44 | bool save_marks_in_cache; |
45 | MarkCache::MappedPtr marks; |
46 | |
47 | const MergeTreeIndexGranularityInfo * index_granularity_info; |
48 | |
49 | std::unique_ptr<CachedCompressedReadBuffer> cached_buffer; |
50 | std::unique_ptr<CompressedReadBufferFromFile> non_cached_buffer; |
51 | }; |
52 | } |
53 | |