Class StandardFitsTableSerializer

java.lang.Object
uk.ac.starlink.fits.StandardFitsTableSerializer
All Implemented Interfaces:
FitsTableSerializer
Direct Known Subclasses:
VariableFitsTableSerializer

public class StandardFitsTableSerializer extends Object implements FitsTableSerializer
Class which knows how to do the various bits of serializing a StarTable to FITS BINTABLE format. A normal (row-oriented) organisation of the data is used. Array-valued columns are all written as fixed size arrays. This class does the hard work for FitsTableWriter.

When writing tables that are marked up using the headers defined in HealpixTableInfo, this serializer will attempt to insert FITS headers corresponding to the HEALPix-FITS convention.

Author:
Mark Taylor (Starlink)
See Also:
  • Constructor Details

    • StandardFitsTableSerializer

      public StandardFitsTableSerializer(FitsTableSerializerConfig config, uk.ac.starlink.table.StarTable table) throws IOException
      Constructor.
      Parameters:
      config - configuration
      table - table to serialize
      Throws:
      IOException - if it won't be possible to write the given table
  • Method Details

    • getConfig

      public FitsTableSerializerConfig getConfig()
      Returns the configuration information for this serializer.
      Returns:
      config
    • getHeader

      public CardImage[] getHeader()
      Description copied from interface: FitsTableSerializer
      Returns header cards suitable for the HDU which will contain the table. Additional metadata and an END marker will be added after these cards, so the returned array must not contain the END card.
      Specified by:
      getHeader in interface FitsTableSerializer
      Returns:
      header cards
    • writeData

      public void writeData(DataOutput strm) throws IOException
      Description copied from interface: FitsTableSerializer
      Writes the HDU data for the table to an output stream. This is only intended to be called once following creation of this object. Subsequent calls result in undefined behaviour.
      Specified by:
      writeData in interface FitsTableSerializer
      Parameters:
      strm - destination stream
      Throws:
      IOException
    • writeDataOnly

      public long writeDataOnly(DataOutput strm) throws IOException
      Writes the table data content without any trailing padding.
      Parameters:
      strm - destination stream
      Returns:
      number of bytes written
      Throws:
      IOException
    • getFormatChar

      public char getFormatChar(int icol)
      Description copied from interface: FitsTableSerializer
      Returns the FITS TFORM letter which describes the type of data output for a given column. This is as described by the FITS standard - 'J' for 4-byte integer, 'A' for characters, etc. If the column is not being output, (char)0 will be returned.
      Specified by:
      getFormatChar in interface FitsTableSerializer
      Parameters:
      icol - column to query
      Returns:
      format letter for data in column icol, or 0 for a column being skipped
    • getDimensions

      public int[] getDimensions(int icol)
      Description copied from interface: FitsTableSerializer
      Returns the dimensions of the items which will be output for a given column. This will be null only if that column is not being output. Otherwise it will be a zero-element array for a scalar, 1-element array for a vector, etc.
      Specified by:
      getDimensions in interface FitsTableSerializer
      Parameters:
      icol - column to query
      Returns:
      dimensions array for data in column icol or null for a column being skipped
    • getBadValue

      public String getBadValue(int icol)
      Description copied from interface: FitsTableSerializer
      Returns the bad value (text of the TNULLnn card), if any, used for a given column.
      Specified by:
      getBadValue in interface FitsTableSerializer
      Parameters:
      icol - column to query
      Returns:
      blank value string, or null if there is none or the column is being skipped
    • getRowCount

      public long getRowCount()
      Description copied from interface: FitsTableSerializer
      Returns the number of rows which will be output.
      Specified by:
      getRowCount in interface FitsTableSerializer
      Returns:
      row count
    • getHealpixHeaders

      protected CardImage[] getHealpixHeaders(uk.ac.starlink.table.HealpixTableInfo hpxInfo) throws uk.ac.starlink.table.TableFormatException
      Returns FITS headers specific for a table containing a HEALPix map. If this method is called the assumption is that the table looks like it should be a HEALPix map of some sort. If there are problems with the metadata that prevent a consistent set of headers from being generated, a TableFormatException with an informative message should be thrown.
      Parameters:
      hpxInfo - non-null healpix description
      Returns:
      array of FITS headers describing healpix information
      Throws:
      uk.ac.starlink.table.TableFormatException