Package thredds.inventory

Interface CollectionManager

  • All Superinterfaces:
    AutoCloseable, Closeable, MCollection
    All Known Implementing Classes:
    CollectionManagerAbstract, CollectionManagerCatalog, MFileCollectionManager
    public interface CollectionManager
extends MCollection
    Manages a dynamic collection of MFile objects. You must call scan() first. This is the older stuff used by FMRC. GRIB uses lighter weight MCollection. An MFile must have the property that 
       NetcdfDatasets.open(MFile.getPath, ...);
    should work.

    A CollectionManager implements the element.

    collection element

    A collection element defines the collection of datasets. 

     <collection spec="/data/ldm/pub/native/satellite/3.9/WEST-CONUS_4km/WEST-CONUS_4km_3.9_#yyyyMMdd_HHmm#.gini$"
            name="WEST-CONUS_4km" olderThan="1 min" olderThan="15 min" />
    The XML Schema: 
    <xsd:complexType name="collectionType">
  1)  <xsd:attribute name="spec" type="xsd:string" use="required"/>
  2)  <xsd:attribute name="name" type="xsd:token"/>
  3)  <xsd:attribute name="olderThan" type="xsd:string" />
  5)  <xsd:attribute name="dateFormatMark" type="xsd:string"/>
  6)  <xsd:attribute name="timePartition" type="xsd:string"/>
</xsd:complexType>

    where

    1. spec: collection specification string (required).
    2. name: collection name must be unique in all of your TDS catalogs. This is used for external triggers and as an easy to read identifier for indexing, logging and debugging. If missing, the spec string is used (not a good idea in the context of the TDS).
    3. olderThan (optional): Only files whose lastModified date is older than this are included. This excludes files that are in the process of being written. However, it only applies to newly found files, that is, once a file is in the collection it is not removed because it got updated.
    4. dateFormatMark (optional): the collection specification string can only extract dates from the file name, as opposed to the file path, which includes all of the parent directory names. Use the dateFormatMark in order to extract the date from the full path. Use this OR a date extrator in the specification string, but not both.
    5. timePartition (optional):: experimental, not complete yet.
    Since:
    Jan 19, 2010

    • Method Detail

      • isStatic

        boolean isStatic()
        static means doesnt need to be monitored for changes; can be externally triggered, or read in at startup. true if no recheckAfter and no update.rescan
        Returns:
        if static

      • getLastScanned

        long getLastScanned()
        Get the last time scanned
        Returns:
        msecs since 1970

      • getLastChanged

        long getLastChanged()
        Get the last time the collection changed
        Returns:
        msecs since 1970

      • getRecheck

        TimeDuration getRecheck()
        Get how often to rescan
        Returns:
        time duration of rescan period, or null if none.

      • isScanNeeded

        boolean isScanNeeded()
        Compute whether rescan is needed, based on getRecheck(), and the LastScanned value.
        Returns:
        true if rescan is needed.

      • scanIfNeeded

        boolean scanIfNeeded()
              throws IOException
        If isScanNeeded(), do a scan. Do not send an event.
        Returns:
        true if scan was done, and anything changed.
        Throws:
        IOException - on io error

      • scan

        boolean scan​(boolean sendEvent)
      throws IOException
        Scan the collection. Files may have been deleted or added since last time. If the MFile already exists in the current list, leave it in the list. If anything changes, send TriggerEvent(TriggerType.update) and return true Get the results from getFiles()
        Returns:
        true if anything actually changed.
        Throws:
        IOException - on I/O error