Commons Compress
  1. Commons Compress
  2. COMPRESS-115

Imploded entry decompression for Zip archives (method 6)

    Details

    • Type: New Feature New Feature
    • Status: Resolved
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: 1.0
    • Fix Version/s: 1.7
    • Component/s: Archivers
    • Labels:

      Description

      This is a RFE to implement the decompression of zip file entries using the imploded compression method (aka method 6). This method is found in archives created with old versions of PKZip. Only the decompression operation is really useful since this method is less efficient than deflate.

      Some links with technical information about this format:

      http://www.pkware.com/documents/casestudies/APPNOTE.TXT

      http://en.wikipedia.org/wiki/Shannon%E2%80%93Fano_coding

      http://en.wikipedia.org/wiki/LZ77

      http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/unzip/explode.c

      1. explode.c
        24 kB
        Emmanuel Bourg
      2. imploding-8Kdict-3trees.zip
        4 kB
        Emmanuel Bourg
      3. imploding-4Kdict-2trees.zip
        0.7 kB
        Emmanuel Bourg

        Issue Links

          Activity

          Transition Time In Source Status Execution Times Last Executer Last Execution Date
          Open Open Resolved Resolved
          1288d 17h 5m 1 Emmanuel Bourg 19/Dec/13 16:10
          Emmanuel Bourg made changes -
          Status Open [ 1 ] Resolved [ 5 ]
          Fix Version/s 1.7 [ 12325345 ]
          Resolution Fixed [ 1 ]
          Emmanuel Bourg made changes -
          Assignee Emmanuel Bourg [ ebourg ]
          Emmanuel Bourg made changes -
          Comment [ InfoZIP explode implementation ]
          Emmanuel Bourg made changes -
          Attachment explode.c [ 12618010 ]
          Stefan Bodewig made changes -
          Labels zip
          Sebb made changes -
          Component/s Archivers [ 12313595 ]
          Show
          Emmanuel Bourg added a comment - - edited Alternative explode implementation in ClamAV: https://github.com/vrtadmin/clamav-devel/blob/master/libclamav/explode.h https://github.com/vrtadmin/clamav-devel/blob/master/libclamav/explode.c
          Emmanuel Bourg made changes -
          Link This issue is blocked by COMPRESS-93 [ COMPRESS-93 ]
          Emmanuel Bourg made changes -
          Field Original Value New Value
          Attachment imploding-4Kdict-2trees.zip [ 12446727 ]
          Attachment imploding-8Kdict-3trees.zip [ 12446728 ]
          Hide
          Emmanuel Bourg added a comment -

          Here are 2 test files covering the variants of the imploded format (4K or 8K sliding dictionary, 2 or 3 Shannon-Fano trees)

          Show
          Emmanuel Bourg added a comment - Here are 2 test files covering the variants of the imploded format (4K or 8K sliding dictionary, 2 or 3 Shannon-Fano trees)
          Emmanuel Bourg created issue -

            People

            • Assignee:
              Emmanuel Bourg
              Reporter:
              Emmanuel Bourg
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              Dates

              • Created:
                Updated:
                Resolved:

                Development