@startuml
  actor User as user
  participant SegmentWriter as segWriter
  participant DeltaCacheWriter as dcWriter
  participant Segment as segment

  user -> segWriter: put(key,value)

  alt delta cache writer is closed
    'open delta cache writer'
    segWriter -> dcWriter : open delta cache writer
    activate dcWriter
    dcWriter --> segWriter: done
    deactivate dcWriter
  end
  
  'put'
  segWriter -> dcWriter : put(key,value)
  activate dcWriter
  dcWriter --> segWriter: done
  deactivate dcWriter
  
  'isThereSpace'  
  segWriter -> dcWriter: get number of written keys
  activate dcWriter
  dcWriter --> segWriter: return result
  'is there more space in delta cache?'
  deactivate dcWriter
  
  alt there si no more space in delta cache
    'close'
    segWriter -> dcWriter: close delta cache writer
    activate dcWriter
    dcWriter --> segWriter: done
    deactivate dcWriter
 
    'compact'
    segWriter -> segment: compact segment
    activate segment
    note right
      There are some other operations
    end note
    segment -> dcWriter: evict all, delete files
    dcWriter --> segment
    segment --> segWriter: done
    deactivate segment
  end
  
  segWriter --> user

@enduml