bundle2: inline changegroup.readexactly()
Profiling reveals this loop is pretty tight. Literally any
function call elimination can make a big difference.
This commit inlines the relatively trivial changegroup.readexactly()
method inside the loop.
The results with `hg perfbundleread` on a bundle of the Firefox repo
speak for themselves:
! read(8k)
! wall 0.679730 comb 0.680000 user 0.140000 sys 0.540000 (best of 15)
! read(16k)
! wall 0.577228 comb 0.570000 user 0.080000 sys 0.490000 (best of 17)
! read(32k)
! wall 0.516060 comb 0.520000 user 0.040000 sys 0.480000 (best of 20)
! read(128k)
! wall 0.496378 comb 0.490000 user 0.010000 sys 0.480000 (best of 20)
! bundle2 iterparts()
! wall 3.460903 comb 3.460000 user 2.760000 sys 0.700000 (best of 3)
! wall 3.056811 comb 3.050000 user 2.340000 sys 0.710000 (best of 4)
! bundle2 iterparts() seekable
! wall 4.312722 comb 4.310000 user 3.480000 sys 0.830000 (best of 3)
! wall 4.007676 comb 4.000000 user 3.170000 sys 0.830000 (best of 3)
! bundle2 part seek()
! wall 6.754764 comb 6.740000 user 3.970000 sys 2.770000 (best of 3)
! wall 6.267110 comb 6.250000 user 3.480000 sys 2.770000 (best of 3)
! bundle2 part read(8k)
! wall 3.668004 comb 3.660000 user 2.960000 sys 0.700000 (best of 3)
! wall 3.404164 comb 3.400000 user 2.650000 sys 0.750000 (best of 3)
! bundle2 part read(16k)
! wall 3.489196 comb 3.480000 user 2.750000 sys 0.730000 (best of 3)
! wall 3.197972 comb 3.200000 user 2.490000 sys 0.710000 (best of 4)
! bundle2 part read(32k)
! wall 3.388569 comb 3.380000 user 2.640000 sys 0.740000 (best of 3)
! wall 3.060557 comb 3.060000 user 2.340000 sys 0.720000 (best of 4)
! bundle2 part read(128k)
! wall 3.276415 comb 3.270000 user 2.560000 sys 0.710000 (best of 4)
! wall 2.952209 comb 2.950000 user 2.230000 sys 0.720000 (best of 4)
Differential Revision: https://phab.mercurial-scm.org/D1392
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<!-- This is the second screen displayed during the install. -->
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta http-equiv="Content-Style-Type" content="text/css">
<title>Read Me - Important Information</title>
<style type="text/css">
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Helvetica}
p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px}
p.p3 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica}
p.p4 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; color: #000fed}
span.s1 {text-decoration: underline}
span.s2 {font: 12.0px Courier}
</style>
</head>
<body>
<p class="p1"><b>Before you install</b></p>
<p class="p2"><br></p>
<p class="p3">This is an OS X version of Mercurial that depends on the default Python installation.</p>
<p class="p2"><br></p>
<p class="p1"><b>After you install</b></p>
<p class="p2"><br></p>
<p class="p3">This package installs the <span class="s2">hg</span> executable as <span class="s2">/usr/local/bin/hg</span>. See <span class="s2">hg debuginstall</span> for more info on file locations.</p>
<p class="p2"><br></p>
<p class="p1"><b>Documentation</b></p>
<p class="p2"><br></p>
<p class="p3">Visit the <a href="https://mercurial-scm.org/">Mercurial web site and wiki</a></p>
<p class="p2"><br></p>
<p class="p3">There's also a free book, <a href="https://book.mercurial-scm.org/">Distributed revision control with Mercurial</a></p>
<p class="p2"><br></p>
<p class="p1"><b>Reporting problems</b></p>
<p class="p2"><br></p>
<p class="p3">If you run into any problems, please file a bug online:</p>
<p class="p3"><a href="https://bz.mercurial-scm.org/">https://bz.mercurial-scm.org/</a></p>
</body>
</html>