java.lang.Object
org.rrd4j.core.jrrd.RRDatabase
All Implemented Interfaces:
Closeable, AutoCloseable
public class RRDatabaseextends Object implements Closeable
Instances of this class model Round Robin Database (RRD) files.

  • Field Details

    • rrdFile

      final RRDFile rrdFile
      The RRD file

    • name

      private final String name
      The RRD file's name.

    • dataSources

      private final ArrayList<DataSource> dataSources
      The file's data sources.

    • archives

      private final ArrayList<Archive> archives
      The file's archives.

    • lastUpdate

      final Date lastUpdate
      Timestamp of last data modification

    • nameindex

      private final Map<String,Integer> nameindex
      Data source name to index

  • Constructor Details

    • RRDatabase

      public RRDatabase(String name) throws IOException
      Creates a database to read from.
      Parameters:
      name - the filename of the file to read from.
      Throws:
      IOException - if an I/O error occurs.

    • RRDatabase

      public RRDatabase(File file) throws IOException
      Creates a database to read from.
      Parameters:
      file - the file to read from.
      Throws:
      IOException - if an I/O error occurs.

  • Method Details

    • getHeader

      public Header getHeader()
      Returns the Header for this database.
      Returns:
      the Header for this database.

    • getDataSourcesName

      public Set<String> getDataSourcesName()
      Returns the names of the data sources defined in the database header.
      Returns:
      a Set object.

    • getLastUpdate

      public Date getLastUpdate()
      Returns the date this database was last updated. To convert this date to the form returned by rrdtool last call Date.getTime() and divide the result by 1000.
      Returns:
      the date this database was last updated.

    • getDataSource

      public DataSource getDataSource(int index)
      Returns the DataSource at the specified position in this database.
      Parameters:
      index - index of DataSource to return.
      Returns:
      the DataSource at the specified position in this database

    • getDataSources

      public Iterator<DataSource> getDataSources()
      Returns an iterator over the data sources in this database in proper sequence.
      Returns:
      an iterator over the data sources in this database in proper sequence.

    • getArchive

      public Archive getArchive(int index)
      Returns the Archive at the specified position in this database.
      Parameters:
      index - index of Archive to return.
      Returns:
      the Archive at the specified position in this database.

    • getArchive

      public Archive getArchive(String name)
      Look up an archive by its name.
      Parameters:
      name - a String object.
      Returns:
      a Archive object.

    • getArchives

      public Iterator<Archive> getArchives()
      Returns an iterator over the archives in this database in proper sequence.
      Returns:
      an iterator over the archives in this database in proper sequence.

    • getNumArchives

      public int getNumArchives()
      Returns the number of archives in this database.
      Returns:
      the number of archives in this database.

    • getArchives

      public Iterator<Archive> getArchives(ConsolidationFunctionType type)
      Returns an iterator over the archives in this database of the given type in proper sequence.
      Parameters:
      type - the consolidation function that should have been applied to the data.
      Returns:
      an iterator over the archives in this database of the given type in proper sequence.

    • getArchiveList

      ArrayList<Archive> getArchiveList(ConsolidationFunctionType type)
      Collect the archives consolidated with the given function, in definition order.
      Parameters:
      type - the consolidation function whose archives to collect
      Returns:
      the matching archives, empty if the database holds none

    • close

      public void close() throws IOException
      Closes this database stream and releases any associated system resources.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Throws:
      IOException - if an I/O error occurs.

    • printInfo

      public void printInfo(PrintStream s)
      Outputs the header information of the database to the given print stream using the default number format. The default format for double is 0.0000000000E0.
      Parameters:
      s - the PrintStream to print the header information to.

    • getData

      public DataChunk getData(ConsolidationFunctionType type) throws IOException
      Returns data from the database corresponding to the given consolidation function and a step size of 1.
      Parameters:
      type - the consolidation function that should have been applied to the data.
      Returns:
      the raw data.
      Throws:
      IllegalArgumentException - if there was a problem locating a data archive with the requested consolidation function.
      IOException - if there was a problem reading data from the database.

    • getData

      public DataChunk getData(ConsolidationFunctionType type, Date startDate, Date endDate, long step) throws IOException
      Returns data from the database corresponding to the given consolidation function.
      Parameters:
      type - the consolidation function that should have been applied to the data.
      startDate - a Date object.
      endDate - a Date object.
      step - the step size to use.
      Returns:
      the raw data.
      Throws:
      IllegalArgumentException - if there was a problem locating a data archive with the requested consolidation function.
      IOException - if there was a problem reading data from the database.

    • getData

      public DataChunk getData(ConsolidationFunctionType type, long startTime, long endTime, long stepSeconds) throws IOException
      Read consolidated data over a time range at a given step.
      Parameters:
      type - a ConsolidationFunctionType object.
      startTime - seconds since epoch
      endTime - seconds since epoch
      stepSeconds - resolution of the returned data, in seconds
      Returns:
      a DataChunk object.
      Throws:
      IOException - if the archive cannot be read

    • findBestArchive

      private Archive findBestArchive(long start, long end, long step, ArrayList<Archive> archives)
      Chooses the archive that answers a request most accurately, almost a verbatim copy of the original C code by Tobias Oetiker.
      Parameters:
      start - the requested start time
      end - the requested end time
      step - the requested resolution
      archives - the archives to choose from
      Returns:
      the archive that fits best

    • printInfo

      public void printInfo(PrintStream s, NumberFormat numberFormat)
      Outputs the header information of the database to the given print stream using the given number format. The format is almost identical to that produced by rrdtool info
      Parameters:
      s - the PrintStream to print the header information to.
      numberFormat - the format to print doubles as.

    • toXml

      public void toXml(PrintStream s)
      Outputs the content of the database to the given print stream as a stream of XML. The XML format is almost identical to that produced by rrdtool dump

      A flush is issued at the end of the XML generation, so auto flush of the PrintStream can be set to false

      Parameters:
      s - the PrintStream to send the XML to.

    • toString

      public String toString()
      Returns a summary the contents of this database.
      Overrides:
      toString in class Object
      Returns:
      a summary of the information contained in this database.