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<tr class="field"><th class="field-name">GLEP:</th><td class="field-body">61</td> |
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</tr> |
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<tr class="field"><th class="field-name">Title:</th><td class="field-body">Manifest2 compression</td> |
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</tr> |
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<tr class="field"><th class="field-name">Version:</th><td class="field-body">1.1</td> |
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</tr> |
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<tr class="field"><th class="field-name">Last-Modified:</th><td class="field-body"><a class="reference external" href="http://www.gentoo.org/cgi-bin/viewcvs.cgi/xml/htdocs/proj/en/glep/glep-0061.txt?cvsroot=gentoo">2008/07/13 02:21:58</a></td> |
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<tr class="field"><th class="field-name">Author:</th><td class="field-body">Robin Hugh Johnson <robbat2 at gentoo.org></td> |
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</tr> |
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<tr class="field"><th class="field-name">Status:</th><td class="field-body">Draft</td> |
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<tr class="field"><th class="field-name">Type:</th><td class="field-body">Standards Track</td> |
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<tr class="field"><th class="field-name">Content-Type:</th><td class="field-body"><a class="reference external" href="glep-0002.html">text/x-rst</a></td> |
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<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><a class="reference external" href="http://www.gentoo.org/proj/en/glepglep-0044.html">44</a></td> |
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</tr> |
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<tr class="field"><th class="field-name">Created:</th><td class="field-body">July 2008</td> |
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<tr class="field"><th class="field-name">Updates:</th><td class="field-body">44</td> |
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</tbody> |
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</table> |
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<hr /> |
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<div class="contents topic" id="contents"> |
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<p class="topic-title first">Contents</p> |
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<ul class="simple"> |
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<li><a class="reference internal" href="#abstract" id="id1">Abstract</a></li> |
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<li><a class="reference internal" href="#motivation" id="id2">Motivation</a></li> |
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<li><a class="reference internal" href="#specification" id="id3">Specification</a></li> |
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<li><a class="reference internal" href="#backwards-compatibility" id="id4">Backwards Compatibility</a></li> |
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<li><a class="reference internal" href="#references" id="id5">References</a></li> |
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<li><a class="reference internal" href="#copyright" id="id6">Copyright</a></li> |
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</ul> |
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</div> |
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<div class="section" id="abstract"> |
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<h1><a class="toc-backref" href="#id1">Abstract</a></h1> |
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<p>Deals with compression of large Manifest2 files.</p> |
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</div> |
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<div class="section" id="motivation"> |
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<h1><a class="toc-backref" href="#id2">Motivation</a></h1> |
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<p>With the introduction of MetaManifest, and full-tree Manifest coverage, |
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we are faced with the possibility of having very large Manifests.</p> |
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<p>Preliminary experiments with MetaManifest, show that with just the |
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existing per-package Manifests, the full MetaManifest, for a tree |
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including metadata/, exceeds 8MiB in size. Applying common compression |
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can achieve a 50-60% reduction in this size.</p> |
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</div> |
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<div class="section" id="specification"> |
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<h1><a class="toc-backref" href="#id3">Specification</a></h1> |
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<p>When searching for a Manifest2 file, if the basename form does not |
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exist, the package manager should search in the same location using |
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common compressed suffixes, and use the compressed file in place of the |
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Manifest2.</p> |
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<p>gzip, bzip2, lzma should all be supported if available on the given |
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platform. In the case that multiple versions exist, the package manager |
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should simply pick one - they should be identical, differing only in |
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compression.</p> |
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<p>The Manifest generation process is required to ensure that inconsistent |
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compressed versions do not exist.</p> |
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</div> |
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<div class="section" id="backwards-compatibility"> |
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<h1><a class="toc-backref" href="#id4">Backwards Compatibility</a></h1> |
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<p>The package Manifests should also be maintained as ONLY uncompressed in |
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CVS.</p> |
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<p>For processing of all existing per-package Manifests, if compression is |
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used, it should be done in parallel to the existing Manifests, to |
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provide for a changeover period. Newer versions of Portage may later |
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choose to exclude all non-compressed Manifests during emerge --sync if |
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compressed versions are guaranteed to exist on the servers.</p> |
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<p>MetaManifests may come into existence as compressed from the start, as |
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do not have an backwards compatibility issues.</p> |
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<p>As a side note, this breaks all manual interaction with Manifests |
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such as grep, and so should only be applied to large Manifest2 files, |
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such as the MetaManifest. 384KiB is suggested as a arbitary cut-off |
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point to start generating compressed Manifest2 files.</p> |
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</div> |
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<div class="section" id="references"> |
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<h1><a class="toc-backref" href="#id5">References</a></h1> |
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<table class="docutils footnote" frame="void" id="glep44" rules="none"> |
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<colgroup><col class="label" /><col /></colgroup> |
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<tbody valign="top"> |
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<tr><td class="label">[1]</td><td>Mauch, M. (2005) GLEP44 - Manifest2 format. |
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<a class="reference external" href="http://www.gentoo.org/proj/en/glep/glep-0044.html">http://www.gentoo.org/proj/en/glep/glep-0044.html</a></td></tr> |
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</tbody> |
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</table> |
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</div> |
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<div class="section" id="copyright"> |
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<h1><a class="toc-backref" href="#id6">Copyright</a></h1> |
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<p>Copyright (c) 2007 by Robin Hugh Johnson. This material may be |
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distributed only subject to the terms and conditions set forth in the |
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Open Publication License, v1.0.</p> |
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<p>vim: tw=72 ts=2 expandtab:</p> |
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