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use case. This will help to avoid having a too large number of files in any single folder.

=head1 METHODS

=head2 new

    $store = File::UStore->new( 
        path => "/home/shantanu/.teststore", 
        prefix => "prefix_", depth  => 5 
    );

This constructor  returns a new C<File::UStore>  object encapsulating a
specific store. The path specifies  where the UStore is located on the
filesystem.  If the  path  is  not specified,  the  path ~/.ustore  is
used. The $prefix is an extension to specify the prefix appended before 
unique file name.

=head2 add

    my $id = $store->add($filename)

The $filename is the path of the file to be added in the  store. The return value
is the uuid ($id) of the file stored. From this point on the user 
will only be able to refer to this file using $id.

Returns undef on error. 

=head2 remove

    $store->remove($id)

The $id is the uuid of the file to be removed from the store. 

Returns false on success and undef on error.

=head2 get

    $store->get($id)

Returns the file handle of the file from its uuid.
Returns undef on error.

=head2 getPath

    $store->getPath($id)

Returns the filesystem location of the file from its uuid.
Returns undef on error.

=head1 NOTES

  * An Analysis of Compare-by-hash - for reasons why a UUID based storage 
  maybe preferred over hash based solution in certain cases.
  http://www.usenix.org/events/hotos03/tech/full_papers/henson/henson.pdf

=head1 USE CASE FOR THIS MODULE IN LIEU OF A HASH BASED STORAGE

File::HStore is a similar module that
provides File Hash based storage. However due to the nature of File
Hashing, File::HStore doesn't allow duplicates. If the same file is
stored a second time using File::HStore it transparently returns the
same hash it had returned last time as an id without adding any new 
file in storage due to inherent character of hash based storage, while 
this is useful if a user doesn't want any duplicates occurring in a
storage, this apparently trivial difference is risky in the use case
where two processes upload a duplicate file to the store and both
processes want to do file handling on these files simultaneously, only 
one of the processes will be able to get a lock(deletion,manipulation 
etc.) on the file at a time and if the first process deletes the file 
referred to by its ID, the second process will never know what happened 
to the file it added. However in circumstances where filename based
deduplication is desired you must use LE<lt>File::HStoreE<gt> instead.

Hence to serve this unique use case I wrote this module for a UUID 
based storage solution which is not hostage to auto de-duping features 
of HStore. This module returns a unique file id each time a file is 
uploaded even if its a duplicate of existing file previously uploaded. 
This allows multiple processes handling data from a common file dump to 
access the same file. This module also expands on the Hstore to allow 
the user flexibility of choosing the depth of storage to optimize the
performance for the users application. Depth of storage allows users
to make the balance between average "number of files in a folder"
and folder depth.

=head1 ACKNOWLEDGEMENTS

Thanks to Alexandre Dulaunoy for the excellent File::HStore module which along with my own special need provided the idea behind this module.

=for :stopwords cpan testmatrix url annocpan anno bugtracker rt cpants kwalitee diff irc mailto metadata placeholders metacpan

=head1 SUPPORT

=head2 Bugs / Feature Requests

Please report any bugs or feature requests through github at 
L<https://github.com/shantanubhadoria/perl-file-ustore/issues>.
You will be notified automatically of any progress on your issue.

=head2 Source Code

This is open source software.  The code repository is available for
public review and contribution under the terms of the license.

L<https://github.com/shantanubhadoria/perl-file-ustore>

  git clone git://github.com/shantanubhadoria/perl-file-ustore.git

=head1 AUTHOR

Shantanu Bhadoria <shantanu@cpan.org>

=head1 CONTRIBUTORS

=for stopwords Shantanu Bhadoria

=over 4

=item *

Shantanu Bhadoria <shantanu.bhadoria@gmail.com>