Method Details

• getVersion

  public abstract String getVersion() throws IOException

  Reads the RRD file format version the export was written with.

  Returns:

  the version string, such as "008"

  Throws:

  IOException - if the export cannot be read

• getLastUpdateTime

  public abstract long getLastUpdateTime() throws IOException

  Reads the moment the RRD was last updated.

  Returns:

  a unix timestamp in seconds, aligned to the step boundary

  Throws:

  IOException - if the export cannot be read

• getStep

  public abstract long getStep() throws IOException

  Reads the base interval between two primary data points.

  Returns:

  the step size in seconds

  Throws:

  IOException - if the export cannot be read

• getDsCount

  public abstract int getDsCount() throws IOException

  Counts the data sources declared by the RRD.

  Returns:

  the number of data sources

  Throws:

  IOException - if the export cannot be read

• getArcCount

  public abstract int getArcCount() throws IOException

  Counts the archives (RRAs) declared by the RRD.

  Returns:

  the number of archives

  Throws:

  IOException - if the export cannot be read

• getDsName

  public abstract String getDsName(int dsIndex) throws IOException

  Reads the name of a data source.

  Parameters:

  dsIndex - zero-based index of the data source

  Returns:

  the data source name

  Throws:

  IOException - if the export cannot be read

• getDsType

  public abstract DsType getDsType(int dsIndex) throws IOException

  Reads the type of a data source.

  Parameters:

  dsIndex - zero-based index of the data source

  Returns:

  the type driving how consecutive samples are combined

  Throws:

  IOException - if the export cannot be read

• getHeartbeat

  public abstract long getHeartbeat(int dsIndex) throws IOException

  Reads the heartbeat of a data source.

  Parameters:

  dsIndex - zero-based index of the data source

  Returns:

  the maximum gap in seconds between two updates before the data source is declared dead

  Throws:

  IOException - if the export cannot be read

• getMinValue

  public abstract double getMinValue(int dsIndex) throws IOException

  Reads the lower bound a data source accepts.

  Parameters:

  dsIndex - zero-based index of the data source

  Returns:

  the minimum value, or NaN when unbounded

  Throws:

  IOException - if the export cannot be read

• getMaxValue

  public abstract double getMaxValue(int dsIndex) throws IOException

  Reads the upper bound a data source accepts.

  Parameters:

  dsIndex - zero-based index of the data source

  Returns:

  the maximum value, or NaN when unbounded

  Throws:

  IOException - if the export cannot be read

• getLastValue

  public abstract double getLastValue(int dsIndex) throws IOException

  Reads the last value recorded for a data source.

  Parameters:

  dsIndex - zero-based index of the data source

  Returns:

  the most recent value, unknown until the next update lands

  Throws:

  IOException - if the export cannot be read

• getAccumValue

  public abstract double getAccumValue(int dsIndex) throws IOException

  Reads the partial total a data source is carrying into the current step.

  Parameters:

  dsIndex - zero-based index of the data source

  Returns:

  the value accumulated so far for the step being built

  Throws:

  IOException - if the export cannot be read

• getNanSeconds

  public abstract long getNanSeconds(int dsIndex) throws IOException

  Reads when a data source last saw a usable sample.

  Parameters:

  dsIndex - zero-based index of the data source

  Returns:

  a unix timestamp in seconds of the last valid sample, or 0 if it never had one

  Throws:

  IOException - if the export cannot be read

• getConsolFun

  public abstract ConsolFun getConsolFun(int arcIndex) throws IOException

  Reads the consolidation function of an archive.

  Parameters:

  arcIndex - zero-based index of the archive

  Returns:

  the function folding primary data points into one row

  Throws:

  IOException - if the export cannot be read

• getXff

  public abstract double getXff(int arcIndex) throws IOException

  Reads the xfiles factor of an archive.

  Parameters:

  arcIndex - zero-based index of the archive

  Returns:

  the share of a step that an unknown value occupies, from 0 to 1

  Throws:

  IOException - if the export cannot be read

• getSteps

  public abstract int getSteps(int arcIndex) throws IOException

  Reads how many primary data points one archive row covers.

  Parameters:

  arcIndex - zero-based index of the archive

  Returns:

  the number of steps consolidated into a single row

  Throws:

  IOException - if the export cannot be read

• getRows

  public abstract int getRows(int arcIndex) throws IOException

  Counts the rows an archive currently holds.

  Parameters:

  arcIndex - zero-based index of the archive

  Returns:

  the number of archive rows stored, which bounds getValues(int, int) in length

  Throws:

  IOException - if the export cannot be read

• getStateAccumValue

  public abstract double getStateAccumValue(int arcIndex, int dsIndex) throws IOException

  Reads the value an archive is accumulating for one data source.

  Parameters:

  arcIndex - zero-based index of the archive

  dsIndex - zero-based index of the data source

  Returns:

  the accumulated value held in the archive state, waiting for the next step

  Throws:

  IOException - if the export cannot be read

• getStateNanSteps

  public abstract int getStateNanSteps(int arcIndex, int dsIndex) throws IOException

  Counts the unknown primary data points an archive is holding.

  Parameters:

  arcIndex - zero-based index of the archive

  dsIndex - zero-based index of the data source

  Returns:

  the number of unknown steps inside the archive state, waiting for the next step

  Throws:

  IOException - if the export cannot be read

• getValues

  public abstract double[] getValues(int arcIndex, int dsIndex) throws IOException

  Reads one data source's series from an archive.

  Parameters:

  arcIndex - zero-based index of the archive

  dsIndex - zero-based index of the data source

  Returns:

  the archive's stored values, oldest first, one per getRows(int) row

  Throws:

  IOException - if the export cannot be read

• getEstimatedSize

  protected long getEstimatedSize() throws IOException

  Estimates the byte length needed to hold everything this importer exposes.

  Returns:

  the file size in bytes to reserve before writing the RRD

  Throws:

  IOException - if the export cannot be read

• release

  void release() throws IOException

  Frees whatever the importer holds open; the default importer needs nothing.

  Throws:

  IOException - if the underlying source cannot be closed

• close

  public void close() throws IOException

  Releases the import source once the RRD has been written.

  Specified by:

  close in interface AutoCloseable

  Specified by:

  close in interface Closeable

  Throws:

  IOException - if the underlying source cannot be closed