Packages

•  package root

  Definition Classes

  root

•  package io

  Definition Classes

  root

•  package sqooba

  Definition Classes

  io

•  package oss

  Definition Classes

  sqooba

•  package timeseries

  Definition Classes

  oss

•  package archive

  Provides abstraction and tools for compressing/archiving time series data.

  Provides abstraction and tools for compressing/archiving time series data. The compression used is Gorilla TSC encoding implemented by the Java library fi.iki.yak.ts.compression.gorilla.

  These are the main types:

  • io.sqooba.oss.timeseries.archive.GorillaArray: a simple byte array that represents a compressed/encoded map of (timestamp, value) tuples.
  • io.sqooba.oss.timeseries.archive.GorillaBlock: the representation of a compressed/encoded TimeSeries as defined in this library.
  • io.sqooba.oss.timeseries.archive.GorillaSuperBlock: groups many GorillaBlocks of the same TimeSeries into a larger binary format. This allows compression of a timeseries that spans a very long range of time.
  • io.sqooba.oss.timeseries.archive.MultiSeriesBlock: a large block of many indexed GorillaSuperBlocks. This format can be used to store all the data of a certain time period into one single binary blob.

  Definition Classes

  timeseries

  Note

  The only supported type for the values of the TSEntries at the moment is Double. This can lead to precision problems if you have very high long values that you convert to double and pass to the compression.

•  object GorillaSuperBlock extends Serializable

  A GorillaSuperBlock is a binary format for storing a long io.sqooba.oss.timeseries.TimeSeries composed of many GorillaBlocks.

  A GorillaSuperBlock is a binary format for storing a long io.sqooba.oss.timeseries.TimeSeries composed of many GorillaBlocks. It uses a sequential layout with an index to permit quick look-up of individual blocks by timestamp.

  GorillaSuperBlock Format +-------+-------+ ... +----- -+-------+---+----------+---+

  block	block		block	Index	L	Thrift	L

  +-------+-------+ ... +-------+-------+---+----------+---+

  LT: length of Thrift block, LI: length of index

  The Gorilla blocks are lined up one after another, ordered by timestamp. They all have different lengths that can be recovered from the offsets stored in the index.

  At the end of the stream there is a footer composed of an additional Gorilla array containing the index and a block of thrift managed metadata. The index maps the start timestamp of each GorillaBlock to its offset from the beginning of the blob (in bytes). The last entry in the index points to the start of the footer.

  The lengths of the index and of the thrift block are written as 4 byte integers just after the respective blocks. In that manner a user can first read the footer, decode the index and then do fast look-ups for blocks by timestamp.

  Definition Classes

  archive

• Writer

io.sqooba.oss.timeseries.archive.GorillaSuperBlock

Writer