Class FileDataStore

  • All Implemented Interfaces:
    DataStore, MultiDataStoreAware

    public class FileDataStore
    extends AbstractDataStore
    implements MultiDataStoreAware
    Simple file-based data store. Data records are stored as normal files named using a message digest of the contained binary stream. Configuration:
     <DataStore class="">
         <param name="path" value="/data/datastore"/>
         <param name="minRecordLength" value="1024"/>

    If the directory is not set, the directory <repository home>/repository/datastore is used.

    A three level directory structure is used to avoid placing too many files in a single directory. The chosen structure is designed to scale up to billions of distinct records.

    This implementation relies on the underlying file system to support atomic O(1) move operations with Files.move(Path, Path, CopyOption...).

    • Constructor Detail

      • FileDataStore

        public FileDataStore()
    • Method Detail

      • init

        public void init​(String homeDir)
        Initialized the data store. If the path is not set, <repository home>/repository/datastore is used. This directory is automatically created if it does not yet exist.
        Specified by:
        init in interface DataStore
        homeDir -
      • addRecord

        public DataRecord addRecord​(InputStream input)
                             throws DataStoreException
        Creates a new data record. The stream is first consumed and the contents are saved in a temporary file and the AbstractDataStore.DIGEST message digest of the stream is calculated. If a record with the same AbstractDataStore.DIGEST digest (and length) is found then it is returned. Otherwise the temporary file is moved in place to become the new data record that gets returned.
        Specified by:
        addRecord in interface DataStore
        input - binary stream
        data record that contains the given stream
        DataStoreException - if the record could not be created
      • updateModifiedDateOnAccess

        public void updateModifiedDateOnAccess​(long before)
        Description copied from interface: DataStore
        From now on, update the modified date of an object even when accessing it. Usually, the modified date is only updated when creating a new object, or when a new link is added to an existing object. When this setting is enabled, even getLength() will update the modified date.
        Specified by:
        updateModifiedDateOnAccess in interface DataStore
        before - - update the modified date to the current time if it is older than this value
      • deleteAllOlderThan

        public int deleteAllOlderThan​(long min)
        Description copied from interface: DataStore
        Delete objects that have a modified date older than the specified date.
        Specified by:
        deleteAllOlderThan in interface DataStore
        min - the minimum time
        the number of data records deleted
      • clearInUse

        public void clearInUse()
        Description copied from interface: DataStore
        Clear the in-use list. This is only used for testing to make the the garbage collection think that objects are no longer in use.
        Specified by:
        clearInUse in interface DataStore
      • getPath

        public String getPath()
        Get the name of the directory where this data store keeps the files.
        the full path name
      • setPath

        public void setPath​(String directoryName)
        Set the name of the directory where this data store keeps the files.
        directoryName - the path name
      • getMinRecordLength

        public int getMinRecordLength()
        Description copied from interface: DataStore
        Get the minimum size of an object that should be stored in this data store. Depending on the overhead and configuration, each store may return a different value.
        Specified by:
        getMinRecordLength in interface DataStore
        the minimum size in bytes
      • setMinRecordLength

        public void setMinRecordLength​(int minRecordLength)
        Set the minimum object length.
        minRecordLength - the length
      • close

        public void close()
        Description copied from interface: DataStore
        Close the data store
        Specified by:
        close in interface DataStore
      • getOrCreateReferenceKey

        protected byte[] getOrCreateReferenceKey()
                                          throws DataStoreException
        Description copied from class: AbstractDataStore
        Returns the reference key of this data store. If one does not already exist, it is automatically created in an implementation-specific way. The default implementation simply creates a temporary random key that's valid only until the data store gets restarted. Subclasses can override and/or decorate this method to support a more persistent reference key.

        This method is called only once during the lifetime of a data store instance and the return value is cached in memory, so it's no problem if the implementation is slow.

        getOrCreateReferenceKey in class AbstractDataStore
        reference key
        DataStoreException - if the key is not available