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<div class="section" id="initial-push-pull">
<h1>Initial push / pull<a class="headerlink" href="#initial-push-pull" title="Permalink to this headline">¶</a></h1>
<div class="section" id="optimal-case">
<h2>Optimal case<a class="headerlink" href="#optimal-case" title="Permalink to this headline">¶</a></h2>
<p>(a motivating example of ultimate performance)
Assume there is a file with exactly the right data in compressed form. This
may be a tarred branch, a bundle, or a blob format. Performance in this case
scales with the size of the file.</p>
</div>
<div class="section" id="disk-case">
<h2>Disk case<a class="headerlink" href="#disk-case" title="Permalink to this headline">¶</a></h2>
<p>Assume current repo format. Attempt to achieve parity with <code class="docutils literal notranslate"><span class="pre">cp</span> <span class="pre">-r</span></code>. Read
each file only 1 time.</p>
<ul class="simple">
<li>read knit graph for revisions</li>
<li>write filtered copy of revision knit O(d+a)</li>
<li>write filtered copy of knit index O(d)</li>
<li>Open knit index for inventory</li>
<li>Write a filtered copy of inventory knit and simultaneously not all referenced
file-ids O(b+d)</li>
<li>Write filtered copy of inventory knit index O(d)</li>
<li>For each referenced file-id:<ul>
<li>Open knit index for each file knit O(e)</li>
<li>If acceptable threshold of irrelevant data hard-link O(f)</li>
<li>Otherwise write filtered copy of text knit and simultaneously write
the fulltext to tree transform O(h)</li>
</ul>
</li>
<li>Write format markers O(1)</li>
</ul>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">a:</th><td class="field-body">size of aggregate revision metadata</td>
</tr>
<tr class="field-even field"><th class="field-name">b:</th><td class="field-body">size of inventory changes for all revisions</td>
</tr>
<tr class="field-odd field"><th class="field-name">c:</th><td class="field-body">size of text changes for all files and all revisions (e * g)</td>
</tr>
<tr class="field-even field"><th class="field-name">d:</th><td class="field-body">number of relevant revisions</td>
</tr>
<tr class="field-odd field"><th class="field-name">e:</th><td class="field-body">number of relevant versioned files</td>
</tr>
<tr class="field-even field"><th class="field-name">f:</th><td class="field-body">size of the particular versioned file knit index</td>
</tr>
<tr class="field-odd field"><th class="field-name">g:</th><td class="field-body">size of the filtered versioned file knit</td>
</tr>
<tr class="field-even field"><th class="field-name">h:</th><td class="field-body">size of the versioned file fulltext</td>
</tr>
<tr class="field-odd field"><th class="field-name">i:</th><td class="field-body">size of the largest file fulltext</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="smart-network-case">
<h2>Smart Network Case<a class="headerlink" href="#smart-network-case" title="Permalink to this headline">¶</a></h2>
<div class="section" id="phase-1">
<h3>Phase 1<a class="headerlink" href="#phase-1" title="Permalink to this headline">¶</a></h3>
<p>Push: ask if there is a repository, and if not, what formats are okay
Pull: Nothing</p>
</div>
<div class="section" id="phase-2">
<h3>Phase 2<a class="headerlink" href="#phase-2" title="Permalink to this headline">¶</a></h3>
<p>Push: send initial push command, streaming data in acceptable format, following
disk case strategy
Pull: receive initial pull command, specifying format</p>
<p>Pull client complexity: O(a), memory cost O(1)
Push client complexity: procesing and memory cost same as disk case</p>
</div>
</div>
<div class="section" id="dumb-network-case">
<h2>Dumb Network Case<a class="headerlink" href="#dumb-network-case" title="Permalink to this headline">¶</a></h2>
<p>Pull: same as disk case, but request all file knit indices at once and request
al file knits at once.
Push: same as disk case, but write all files at once.</p>
</div>
<div class="section" id="wants">
<h2>Wants<a class="headerlink" href="#wants" title="Permalink to this headline">¶</a></h2>
<ul class="simple">
<li>Read partial graph</li>
<li>Read multiple segments of multiple files on HTTP and SFTP</li>
<li>Write multiple files over SFTP</li>
</ul>
</div>
</div>
</div>
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<h3><a href="index.html">Table of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">Initial push / pull</a><ul>
<li><a class="reference internal" href="#optimal-case">Optimal case</a></li>
<li><a class="reference internal" href="#disk-case">Disk case</a></li>
<li><a class="reference internal" href="#smart-network-case">Smart Network Case</a><ul>
<li><a class="reference internal" href="#phase-1">Phase 1</a></li>
<li><a class="reference internal" href="#phase-2">Phase 2</a></li>
</ul>
</li>
<li><a class="reference internal" href="#dumb-network-case">Dumb Network Case</a></li>
<li><a class="reference internal" href="#wants">Wants</a></li>
</ul>
</li>
</ul>
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