Clarify setting CompressionOptions::max_dict_bytes > 0 will charge block cache (#9119)

Summary:
Add it to the API comment.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9119

Reviewed By: hx235

Differential Revision: D32124238

Pulled By: ajkr

fbshipit-source-id: d1f82037417d883f2000f2d62995a7708dda77c6
This commit is contained in:
Andrew Kryczka 2021-11-02 21:42:31 -07:00 committed by Facebook GitHub Bot
parent 82afa01815
commit 67a7b74b7f

View File

@ -105,9 +105,14 @@ struct CompressionOptions {
//
// When compression dictionary is disabled, we compress and write each block
// before buffering data for the next one. When compression dictionary is
// enabled, we buffer all SST file data in-memory so we can sample it, as data
// enabled, we buffer SST file data in-memory so we can sample it, as data
// can only be compressed and written after the dictionary has been finalized.
// So users of this feature may see increased memory usage.
//
// The amount of data buffered can be limited by `max_dict_buffer_bytes`. This
// buffered memory is charged to the block cache when there is a block cache.
// If block cache insertion fails with `Status::Incomplete` (i.e., it is
// full), we finalize the dictionary with whatever data we have and then stop
// buffering.
//
// Default: 0.
uint32_t max_dict_bytes;