tests/test-hgweb-descend-empties.t

localrepo: add branchtip() method for faster single-branch lookups

For the PyPy repo with 744 branches and 843 branch heads, this brings
hg log -r default over NFS from:

   CallCount    Recursive    Total(ms)   Inline(ms) module:lineno(function)
        3249            0      1.3222      1.3222   <open>
        3244            0      0.6211      0.6211   <method 'close' of 'file' objects>
        3243            0      0.0800      0.0800   <method 'read' of 'file' objects>
        3241            0      0.0660      0.0660   <method 'seek' of 'file' objects>
        3905            0      0.0476      0.0476   <zlib.decompress>
        3281            0      2.6756      0.0472   mercurial.changelog:182(read)
       +3281            0      2.5256      0.0453   +mercurial.revlog:881(revision)
       +3276            0      0.0389      0.0196   +mercurial.changelog:28(decodeextra)
       +6562            0      0.0123      0.0123   +<method 'split' of 'str' objects>
       +6562            0      0.0408      0.0073   +mercurial.encoding:61(tolocal)
       +3281            0      0.0054      0.0054   +<method 'index' of 'str' objects>
        3241            0      2.2464      0.0456   mercurial.revlog:818(_loadchunk)
       +3241            0      0.6205      0.6205   +<method 'close' of 'file' objects>
       +3241            0      0.0765      0.0765   +<method 'read' of 'file' objects>
       +3241            0      0.0660      0.0660   +<method 'seek' of 'file' objects>
       +3241            0      1.4209      0.0135   +mercurial.store:374(__call__)
       +3241            0      0.0122      0.0107   +mercurial.revlog:810(_addchunk)
        3281            0      2.5256      0.0453   mercurial.revlog:881(revision)
       +3280            0      0.0175      0.0175   +mercurial.revlog:305(rev)
       +3281            0      2.2819      0.0119   +mercurial.revlog:847(_chunkraw)
       +3281            0      0.0603      0.0083   +mercurial.revlog:945(_checkhash)
       +3281            0      0.0051      0.0051   +mercurial.revlog:349(flags)
       +3281            0      0.0040      0.0040   +<mercurial.mpatch.patches>
       13682            0      0.0479      0.0248   <method 'decode' of 'str' objects>
       +7418            0      0.0228      0.0076   +encodings.utf_8:15(decode)
          +1            0      0.0003      0.0000   +encodings:71(search_function)
        3248            0      1.3995      0.0246   mercurial.scmutil:218(__call__)
       +3248            0      1.3222      1.3222   +<open>
       +3248            0      0.0235      0.0184   +os.path:80(split)
       +3248            0      0.0084      0.0068   +mercurial.scmutil:92(__call__)
Time: real 2.750 secs (user 0.680+0.000 sys 0.360+0.000)

down to:

   CallCount    Recursive    Total(ms)   Inline(ms) module:lineno(function)
          55           31      0.0197      0.0163   <__import__>
          +1            0      0.0006      0.0002   +mercurial.context:8(<module>)
          +1            0      0.0042      0.0001   +mercurial.revlog:12(<module>)
          +1            0      0.0002      0.0001   +mercurial.match:8(<module>)
          +1            0      0.0003      0.0001   +mercurial.dirstate:7(<module>)
          +1            0      0.0057      0.0001   +mercurial.changelog:8(<module>)
           1            0      0.0117      0.0032   mercurial.localrepo:525(_readbranchcache)
        +844            0      0.0015      0.0015   +<binascii.unhexlify>
        +845            0      0.0010      0.0010   +<method 'split' of 'str' objects>
        +843            0      0.0045      0.0009   +mercurial.encoding:61(tolocal)
        +843            0      0.0004      0.0004   +<method 'setdefault' of 'dict' objects>
          +1            0      0.0003      0.0003   +<method 'close' of 'file' objects>
           3            0      0.0029      0.0029   <method 'read' of 'file' objects>
           9            0      0.0018      0.0018   <open>
         990            0      0.0017      0.0017   <binascii.unhexlify>
          53            0      0.0016      0.0016   mercurial.demandimport:43(__init__)
         862            0      0.0015      0.0015   <_codecs.utf_8_decode>
         862            0      0.0037      0.0014   <method 'decode' of 'str' objects>
        +862            0      0.0023      0.0008   +encodings.utf_8:15(decode)
         981            0      0.0011      0.0011   <method 'split' of 'str' objects>
         861            0      0.0046      0.0009   mercurial.encoding:61(tolocal)
        +861            0      0.0037      0.0014   +<method 'decode' of 'str' objects>
         862            0      0.0023      0.0008   encodings.utf_8:15(decode)
        +862            0      0.0015      0.0015   +<_codecs.utf_8_decode>
           4            0      0.0008      0.0008   <method 'close' of 'file' objects>
         179          154      0.0202      0.0004   mercurial.demandimport:83(__getattribute__)
         +36           11      0.0199      0.0003   +mercurial.demandimport:55(_load)
         +72            0      0.0001      0.0001   +mercurial.demandimport:83(__getattribute__)
         +36            0      0.0000      0.0000   +<getattr>
           1            0      0.0015      0.0004   mercurial.tags:148(_readtagcache)
Time: real 0.060 secs (user 0.030+0.000 sys 0.010+0.000)

  $ "$TESTDIR/hghave" serve || exit 80

Test chains of near empty directories, terminating 3 different ways:
- a1: file at level 4 (deepest)
- b1: two dirs at level 3
- e1: file at level 2

Set up the repo

  $ hg init test
  $ cd test
  $ mkdir -p a1/a2/a3/a4
  $ mkdir -p b1/b2/b3/b4
  $ mkdir -p b1/b2/c3/c4
  $ mkdir -p d1/d2/d3/d4
  $ echo foo > a1/a2/a3/a4/foo
  $ echo foo > b1/b2/b3/b4/foo
  $ echo foo > b1/b2/c3/c4/foo
  $ echo foo > d1/d2/d3/d4/foo
  $ echo foo > d1/d2/foo
  $ hg ci -Ama
  adding a1/a2/a3/a4/foo
  adding b1/b2/b3/b4/foo
  adding b1/b2/c3/c4/foo
  adding d1/d2/d3/d4/foo
  adding d1/d2/foo
  $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -E errors.log
  $ cat hg.pid >> $DAEMON_PIDS

manifest with descending

  $ "$TESTDIR/get-with-headers.py" 127.0.0.1:$HGPORT '/file'
  200 Script output follows
  
  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
  <head>
  <link rel="icon" href="/static/hgicon.png" type="image/png" />
  <meta name="robots" content="index, nofollow" />
  <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
  <script type="text/javascript" src="/static/mercurial.js"></script>
  
  <title>test: 9087c84a0f5d /</title>
  </head>
  <body>
  
  <div class="container">
  <div class="menu">
  <div class="logo">
  <a href="http://mercurial.selenic.com/">
  <img src="/static/hglogo.png" alt="mercurial" /></a>
  </div>
  <ul>
  <li><a href="/shortlog/9087c84a0f5d">log</a></li>
  <li><a href="/graph/9087c84a0f5d">graph</a></li>
  <li><a href="/tags">tags</a></li>
  <li><a href="/bookmarks">bookmarks</a></li>
  <li><a href="/branches">branches</a></li>
  </ul>
  <ul>
  <li><a href="/rev/9087c84a0f5d">changeset</a></li>
  <li class="active">browse</li>
  </ul>
  <ul>
  
  </ul>
  <ul>
   <li><a href="/help">help</a></li>
  </ul>
  </div>
  
  <div class="main">
  <h2><a href="/">test</a></h2>
  <h3>directory / @ 0:9087c84a0f5d <span class="tag">tip</span> </h3>
  
  <form class="search" action="/log">
  
  <p><input name="rev" id="search1" type="text" size="30" /></p>
  <div id="hint">find changesets by author, revision,
  files, or words in the commit message</div>
  </form>
  
  <table class="bigtable">
  <tr>
    <th class="name">name</th>
    <th class="size">size</th>
    <th class="permissions">permissions</th>
  </tr>
  <tr class="fileline parity0">
    <td class="name"><a href="/file/9087c84a0f5d/">[up]</a></td>
    <td class="size"></td>
    <td class="permissions">drwxr-xr-x</td>
  </tr>
  
  <tr class="fileline parity1">
  <td class="name">
  <a href="/file/9087c84a0f5d/a1">
  <img src="/static/coal-folder.png" alt="dir."/> a1/
  </a>
  <a href="/file/9087c84a0f5d/a1/a2/a3/a4">
  a2/a3/a4
  </a>
  </td>
  <td class="size"></td>
  <td class="permissions">drwxr-xr-x</td>
  </tr>
  <tr class="fileline parity0">
  <td class="name">
  <a href="/file/9087c84a0f5d/b1">
  <img src="/static/coal-folder.png" alt="dir."/> b1/
  </a>
  <a href="/file/9087c84a0f5d/b1/b2">
  b2
  </a>
  </td>
  <td class="size"></td>
  <td class="permissions">drwxr-xr-x</td>
  </tr>
  <tr class="fileline parity1">
  <td class="name">
  <a href="/file/9087c84a0f5d/d1">
  <img src="/static/coal-folder.png" alt="dir."/> d1/
  </a>
  <a href="/file/9087c84a0f5d/d1/d2">
  d2
  </a>
  </td>
  <td class="size"></td>
  <td class="permissions">drwxr-xr-x</td>
  </tr>
  
  </table>
  </div>
  </div>
  <script type="text/javascript">process_dates()</script>
  
  
  </body>
  </html>
  

  $ cat errors.log