NAME

       Lucy::Index::Snapshot - Point-in-time index file list.

SYNOPSIS

           my $snapshot = Lucy::Index::Snapshot->new;
           $snapshot->read_file( folder => $folder );    # load most recent snapshot
           my $files = $snapshot->list;
           print "$_\n" for @$files;

DESCRIPTION

       A Snapshot is list of index files and folders.  Because index files, once written, are
       never modified, a Snapshot defines a point-in-time view of the data in an index.

       IndexReader objects interpret the data associated with a single Snapshot.

CONSTRUCTORS

   new()
           my $snapshot = Lucy::Index::Snapshot->new;

       Constructor.  Takes no arguments.

METHODS

   list()
       Return an array of all entries.

   num_entries()
       Return the number of entries (including directories).

   add_entry(entry)
       Add a filepath to the snapshot.

   delete_entry(entry)
       Delete a filepath from the snapshot.

       Returns: true if the entry existed and was successfully deleted, false otherwise.

   read_file( [labeled params] )
       Decode a snapshot file and initialize the object to reflect its contents.

       •   folder - A Folder.

       •   path - The location of the snapshot file.  If not supplied, the most recent snapshot
           file in the base directory will be chosen.

       Returns: the object, allowing an assignment idiom.

   write_file( [labeled params] )
       Write a snapshot file.  The caller must lock the index while this operation takes place,
       and the operation will fail if the snapshot file already exists.

       •   folder - A Folder.

       •   path - The path of the file to write.  If undef, a file name will be chosen which
           supersedes the latest snapshot file in the index folder.

   set_path(path)
       Set the path to the file that the Snapshot object serves as a proxy for.

   get_path()
       Get the path to the snapshot file.  Initially undef; updated by read_file(), write_file(),
       and set_path().

INHERITANCE

       Lucy::Index::Snapshot isa Lucy::Object::Obj.