Package org.orekit.data

Class UnixCompressFilter

java.lang.Object
org.orekit.data.UnixCompressFilter
All Implemented Interfaces:
DataFilter
public class UnixCompressFilter extends Object implements DataFilter
Filter for Unix compressed data.
Since:
9.2
Author:
Luc Maisonobe

  • Constructor Details

    • UnixCompressFilter

      public UnixCompressFilter()
      Empty constructor.

      This constructor is not strictly necessary, but it prevents spurious javadoc warnings with JDK 18 and later.

      Since:
      12.0

  • Method Details

    • filter

      public DataSource filter(DataSource original)
      Filter the data source.

      Filtering is often based on suffix. For example a gzip compressed file will have an original name of the form base.ext.gz when the corresponding uncompressed file will have a filtered name base.ext.

      A filter must never open the DataSource by itself, regardless of the fact it will return the original instance or a filtered instance. The rationale is that it is the upper layer that will decide to open (or not) the returned value and that a DataSource can be opened only once; this is the core principle of lazy-opening provided by DataSource.

      Beware that as the data providers manager will attempt to pile all filters in a stack as long as their implementation of this method returns a value different from the original parameter. This implies that the filter, must perform some checks to see if it must be applied or not. If for example there is a need for a deciphering filter to be applied once to all data, then the filter should for example check for a suffix in the name and create a new filtered DataSource instance only if the suffix is present, removing the suffix from the filtered instance. Failing to do so and simply creating a filtered instance with one deciphering layer without changing the name would result in an infinite stack of deciphering filters being built, until a stack overflow or memory exhaustion exception occurs.

      Specified by:
      filter in interface DataFilter
      Parameters:
      original - original data source
      Returns:
      filtered data source, or original if this filter does not apply to this data source