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   9                         <h1>Dscho's Git log</h1>
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  11                         <table width=400px bgcolor=#e0e0e0 border=0>
  12                         <tr><th>Table of contents:</th></tr>
  13                         <tr><td>
  14                         <p><ul>
  15                         <li><a href=#1254868748>07 Oct 2009 GitTogether in Berlin</a>
  16                         <li><a href=#1249835938>09 Aug 2009 The dilemma of being correct</a>
  17                         <li><a href=#1245419588>19 Jun 2009 The GraphGUI project</a>
  18                         <li><a href=#1242408298>15 May 2009 Wasting way too much time on msysGit</a>
  19                         <li><a href=#1241995759>11 May 2009 Working on jgit diff</a>
  20                         <li><a href=#1239975597>17 Apr 2009 No time for Git</a>
  21                         <li><a href=#1238970571>06 Apr 2009 How to recover from a hackathon</a>
  22                         <li><a href=#1236554268>09 Mar 2009 So, what is missing from my <i>rebase-i-p</i> branch?</a>
  23                         <li><a href=#1236479389>08 Mar 2009 New Git for Windows version</a>
  24                         <li><a href=#1235092615>20 Feb 2009 Code reviews</a>
  25                         </ul></p>
  26                         <a href=dscho.git?a=blob_plain;hb=27b2c2e614f97056a75956e3e27c07cb2bffb1ea;f=index.html>Older posts</a>
  27                         </td></tr></table>
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  36                         <table width=400px bgcolor=#e0e0e0 border=0>
  37                         <tr><th>About this blog:</th></tr>
  38                         <tr><td>
  39                         <p>It is an active <a href=http://repo.or.cz/w/git/dscho.git?a=blob_plain;f=index.html;hb=5f002cab57a837125a8f901bcd1f3c1477bc3119>abuse</a> of <a href=http://repo.or.cz/>repo.or.cz</a>,
  40                         letting gitweb unpack the objects in the current tip of the branch <i>blog</i>,
  41                         including the images and the RSS feed.
  42                         </p><p>
  43                         Publishing means running a script that collects the posts, turns them into
  44                         HTML, makes sure all the images are checked in, and pushes the result.
  45                         </p><p>
  46                         This blog also serves to grace the world with Dscho's random thoughts on and
  47                         around Git.
  48                         </p>
  49                         </td></tr></table>
  50                         <br>
  51                         <table width=400px bgcolor=#e0e0e0 border=0>
  52                         <tr><th>Links:</th></tr>
  53                         <tr><td>
  54                         <ul>
  55                         <li> <a href=http://git-scm.com/>Git's homepage</a>
  56                         <li> <a href=http://gitster.livejournal.com/>Junio's blog</a>
  57                         <li> <a href=http://www.spearce.org/>Shawn's blog</a> seems to be sitting
  58                               idle ever since he started working for Google...
  59                         <li> <a href=http://torvalds-family.blogspot.com/>Linus' blog</a> does not
  60                               talk much about Git...
  61                         <li> Scott Chacon's <a href=http://whygitisbetterthanx.com/>Why Git is better
  62                              than X</a> site
  63                         <li> <a href=http://vilain.net/>The blog of mugwump</a>
  64                         <li> <a href=http://merlyn.vox.com/>Merlyn's blog</a>
  65                         <li> <a href=http://blogs.gnome.org/newren/>Elijah Newren</a> chose the
  66                               same path as Cogito, offering an alternative porcelain (an approach
  67                               that is doomed in my opinion)
  68                         <li> <a href=http://msysgit.googlecode.com/>The msysGit project</a>, a (mostly)
  69                               failed experiment to lure the many Windows developers out there to
  70                               contribute to Open Source for a change.
  71                         </ul>
  72                         </td></tr></table>
  73                         <br>
  74                         <table width=400px bgcolor=#e0e0e0 border=0>
  75                         <tr><th>Google Ads:</th></tr>
  76                         <tr><td>
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  88                         </td></tr></table>
  89                         </div>
  90                         <h6>Wednesday, 7th of October, Anno Domini MMIX, at the hour of the Rat</h6>
  91                         <a name=1254868748>
  92                         <h2>GitTogether in Berlin</h2>
  93
  94                         <p>
  95                         </p><p>
  96                         We had a GitTogether in Berlin, called "Alles wird Git" (past tense: "Alles
  97                         wurde Git").  It was great fun, we never had even a single boring minute,
  98                         and our special guest -- Gitzilla -- turned out to be quite some entertainer,
  99                         especially when he starting reciting a few of my most outrageous emails &#x263a;
 100                         </p><p>
 101                         There were a lot of good discussions, among other things about submodules (our
 102                         neglected child), Git Cheetah, and foreign VCS helpers (in particular Sverre's
 103                         plan to provide some Mercurial backend).
 104                         </p><p>
 105                         One of the most important outcomes for me was, though, to realize just how
 106                         detached we in the Git project are from our user base.  A few years back, we
 107                         could get away with saying "we have only developers as users, so they should
 108                         just sit down and scratch their own itch".
 109                         </p><p>
 110                         But today, we have a lot of users who never learnt to code (or who code in
 111                         some other language than C, or whose code we would not even want to review &#x263a;),
 112                         and we lose quite a few brownie points by keeping things complicated.
 113                         </p><p>
 114                         Now, in a lot of cases it cannot be helped.  For example, we have confusing
 115                         names for things, inconsistent namings even (as with "remote" vs "tracked"
 116                         branches), and we have some odd design decisions (like calling some program
 117                         almost nobody uses "git cherry", which makes tab-completion of the rather
 118                         often-used "git cherry-pick" pretty awkward).  The latter example also
 119                         illustrates that we have names for porcelains that are rather long, when
 120                         they should be rather short.
 121                         </p><p>
 122                         So, yes, we have a lot of things that do not work well, because we have
 123                         usability issues that need to be preserved for hysterical raisins.
 124                         </p><p>
 125                         This is unfortunate enough, but it seems that we even fsck up with usability
 126                         issues we <u>can</u> solve.  Just think about "git checkout -b origin/master".  A
 127                         typo?  Yes, of course!  But a rather obvious one.
 128                         </p><p>
 129                         Another case which was discussed on the mailing list recently: "git checkout
 130                         next" when clearly "git checkout origin/next" was meant.
 131                         </p><p>
 132                         The biggest problem, though, is that almost all people on the Git mailing list
 133                         who are respected by the maintainer are obviously too detached from the user
 134                         base to realize just how difficult Git <u>still</u> is.  And refuse to do anything
 135                         about it, or even to allow others to do anything about it.
 136                         </p><p>
 137                         It almost seems as if the Git wizards do not want Git to become easier to
 138                         use, lest they lose their special status.
 139                         </p><p>
 140                         My biggest problem is that it seems that my input gets more and more ignored,
 141                         or perceived as some crazy ideas that will just go away (which is true, because
 142                         I am pretty happy about a day-job that keeps me more than just busy, so I do not
 143                         have time not fight windmills, let alone motiviation to do so).
 144                         </p><p>
 145                         Even when a real user comes along to chime in, he's just brushed off, by an
 146                         otherwise very polite maintainer.
 147                         </p><p>
 148                         I am not even sure if I want to continue sending my patches from my personal
 149                         tree upstream, because things get so frustrating, for little to show in return.
 150                         </p>
 151                         <h6>Sunday, 9th of August, Anno Domini MMIX, at the hour of the Rooster</h6>
 152                         <a name=1249835938>
 153                         <h2>The dilemma of being correct</h2>
 154
 155                         <p>
 156                         </p><p>
 157                         So I am opinionated.  No news there.  The problem of being opinionated, though,
 158                         is that people do not take you seriously even if you are correct.
 159                         </p><p>
 160                         For example, I vividly remember having had concerns about the Git wrapper
 161                         being linked to <a href=http://curl.haxx.se/>cURL</a>, and I vividly remember
 162                         that our maintainer did not have such concerns and took Daniel's patch.  I could
 163                         not find proof of my public comment quickly enough to add a link here, though.
 164                         </p><p>
 165                         Alas, there are serious problems with being correct:
 166                         </p><p>
 167                         <ol>
 168                         <li>If you're correct, you waste a lot of time trying to convince people (but
 169                         they ignore you nevertheless),
 170                         <li>Other people are regularly p*ssed off, especially when they find out
 171                         (or even worse, when it is pointed out to them) that they were wrong, and
 172                         <li>You can buy <u>nothing</u> for having been correct.
 173                         </ol>
 174                         </p><p>
 175                         It is a lose-lose situation.
 176                         </p><p>
 177                         In the current context, I am pretty certain that the rev cache and the pack
 178                         index are so similar in nature that we'll find quite a few issues that we had
 179                         with one repeated with the other.
 180                         </p><p>
 181                         As I <u>hate</u> losing time over a discussion others try to "win" -- which
 182                         invariably means that they refuse to be convinced of anything disagreeing with
 183                         their opinion &#x263a; -- I will just shut up, and probably have one or two odd
 184                         feelings when it turns out I was right.
 185                         </p>
 186                         <h6>Friday, 19th of June, Anno Domini MMIX, at the hour of the Monkey</h6>
 187                         <a name=1245419588>
 188                         <h2>The GraphGUI project</h2>
 189
 190                         <p>
 191                         </p><p>
 192                         After a few unfortunate delays (and some fortunate ones, just not for us), the
 193                         GraphGUI project finally takes off.  A quick first glance:
 194                         </p><p>
 195                         <center><img src=dscho.git?a=blob_plain;hb=c33212b23b2b3e45c14403efe82cabb1cd53f6e3;f=basic-gui.jpg basic-gui.jpg></center>
 196                         </p><p>
 197                         The delays were a bit unnerving, but the student is really bright and still
 198                         has the chance to pull the project off.
 199                         </p><p>
 200                         Next plans are to show text, too, to invent a rudimentary layout engine that
 201                         can be adjusted manually (this is in contrast to <i>gitk</i> or <i>log --graph</i>).
 202                         </p><p>
 203                         After that, integration into JGit (this probably triggered the eGit/JGit
 204                         split).
 205                         </p><p>
 206                         And then we'll go wild!
 207                         </p>
 208                         <h6>Friday, 15th of May, Anno Domini MMIX, at the hour of the Dog</h6>
 209                         <a name=1242408298>
 210                         <h2>Wasting way too much time on msysGit</h2>
 211
 212                         <p>
 213                         </p><p>
 214                         I recently got into the bad habit of spending a large amount of my waking
 215                         hours working on msysGit, more than is really healthy for me.
 216                         </p><p>
 217                         For example, I spent the whole morning -- when I should have worked on a
 218                         very important day-job project -- on trying to fix issue 258, where
 219                         <i>git web--browse</i> does not work as expected because of quoting issues
 220                         with cmd.exe.
 221                         </p><p>
 222                         This is reducing my Git time budget to negative numbers, so much so that I
 223                         cannot even work on Git projects that I actually like, such as <i>jgit diff</i>
 224                         or <i>git rebase -i -p</i>, or at least projects I felt obliged to continue
 225                         to work on, such as <i>git notes</i>.
 226                         </p><p>
 227                         Now, some people who tried to teach me some time management strongly
 228                         criticized me for ignoring their lessons, and unfortunately, I have to agree.
 229                         </p><p>
 230                         The problem is that I would <u>hate</u> to see msysGit fall to the same state it
 231                         was after I stopped working on it last year.  I started it, and I would like
 232                         it to grow, but too few people took care of the issue tracker, too few tried
 233                         to debug their problems themselves, too few submitted fixes.
 234                         </p><p>
 235                         I note, though, that there is a positive trend.  But being the impatient person
 236                         I am ("2 seconds is my attention span") I tend to want the trend to be more
 237                         impressive.
 238                         </p><p>
 239                         Anyway, no work on msysGit for at least 4 days, that's what the doctor (me)
 240                         said...
 241                         </p>
 242                         <h6>Monday, 11th of May, Anno Domini MMIX, at the hour of the Rat</h6>
 243                         <a name=1241995759>
 244                         <h2>Working on jgit diff</h2>
 245
 246                         <p>
 247                         </p><p>
 248                         Shawn did so many useful things that I use on a daily basis that I felt really
 249                         awful when I realized just how <u>long</u> I had promised to clean up that diff
 250                         implementation I wrote for JGit.
 251                         </p><p>
 252                         Alas, it appears that the thing turned out to be almost a complete rewrite, as
 253                         the original implementation walked the edit graph in a rather inefficient way.
 254                         </p><p>
 255                         A little background: Myers' algorithm to generate "an edit script" works on
 256                         the <i>edit graph</i>: imagine you have all lines of file <i>A</i> as columns and
 257                         all lines of file <i>B</i> as rows, then the <i>edit graph</i> is a connection of
 258                         the upper left corner to the lower right corner, containing only horizontal,
 259                         vertical or diagonal elements, where diagonal elements are only allowed when
 260                         the lines of both files agree at that point:
 261                         </p><p>
 262 <pre>
 263  H E L L O , W O R L D
 264  ----
 265 L    \
 266       ---
 267 O        \
 268           ---
 269 W            \
 270               --------
 271 </pre>
 272                         </p><p>
 273                         The <i>shortest</i> edit path minimizes the number of non-diagonal elements.
 274                         </p><p>
 275                         Myers' idea is to develop forward and backward paths at the same time
 276                         (increasing the number of non-diagonal elements uniformly), storing
 277                         only the latest end points.  Once the paths meet, divide and conquer.
 278                         </p><p>
 279                         In theory, it would be quicker to store <u>all</u> end points and then just
 280                         reconstruct the shortest paths, alas, this takes way too much memory.
 281                         </p><p>
 282                         My first implementation did not remember start or end of the non-diagonal
 283                         parts, and had to recurse way more often than really necessary (in the end,
 284                         we will order the non-diagonal parts into horizontal and vertical parts
 285                         anyway, so start and end are sufficient).
 286                         </p><p>
 287                         The current progress can be seen <a href=http://repo.or.cz/w/egit/dscho.git/>
 288                         here</a>.
 289                         </p>
 290                         <h6>Friday, 17th of April, Anno Domini MMIX, at the hour of the Monkey</h6>
 291                         <a name=1239975597>
 292                         <h2>No time for Git</h2>
 293
 294                         <p>
 295                         </p><p>
 296                         It is a shame, but most of my Git time budget is taken by msysGit these
 297                         days.
 298                         </p><p>
 299                         But at least msysGit is moving again; I'll probably write a Herald about
 300                         it.
 301                         </p>
 302                         <h6>Monday, 6th of April, Anno Domini MMIX, at the hour of the Rat</h6>
 303                         <a name=1238970571>
 304                         <h2>How to recover from a hackathon</h2>
 305
 306                         <p>
 307                         </p><p>
 308                         Phew, 2 crazy and fantastic weeks are behind me.  But it takes its toll:
 309                         a weekend I was more offline than online.
 310                         </p><p>
 311                         Things that are important now: relax. sleep. take a walk. learn to sleep
 312                         more than 4 hours a night again. learn to watch a movie without thinking
 313                         about code. go for a run.
 314                         </p><p>
 315                         And after recovering, back to the rebase-i-p branch!
 316                         </p>
 317                         <h6>Monday, 9th of March, Anno Domini MMIX, at the hour of the Rat</h6>
 318                         <a name=1236554268>
 319                         <h2>So, what is missing from my <i>rebase-i-p</i> branch?</h2>
 320
 321                         <p>
 322                         </p><p>
 323                         I regularly use <i>rebase -i -p</i> these days, to update my personal Git
 324                         tree (which used to be <i>my-next</i>).
 325                         </p><p>
 326                         There are a few things missing before I can start assembling a patch
 327                         series for submission:
 328                         </p><p>
 329                         <ul>
 330                         <li>I need to handle the commit parents which are outside of the rebased
 331                         ones properly.  In other words, when a commit is picked whose parent is
 332                         not rebased, it needs to be rebased onto $ONTO.
 333                         <li>The patch which uses patch-id to generate DROPPED directly also tries to
 334                         consolidate the handling of DROPPED commits by putting them into REWRITTEN
 335                         instead of DROPPED, but that breaks the tests.  So, this patch needs to be
 336                         split.
 337                         <li>I want to introduce one more command, <i>rephrase</i>, which allows you to
 338                         modify the commit message, and nothing more, and <i>halt</i>, which does the
 339                         same as <i>edit</i> without <i>pick</i>.  Then there needs to be a new test script
 340                         for those commands, and this will be an early patch series.
 341                         <li>Time.  I need time, desperately.  If my day job was not as exciting as it
 342                         is, I would have more time for Git.  As it is, I have to budget my time so
 343                         that I get anything done at all.
 344                         </ul>
 345                         </p><p>
 346                         These issues have been postponed due to Steffen taking a well-deserved
 347                         vacation, which means that I have to act as msysGit maintainer again.
 348                         </p><p>
 349                         And this coming week, I will have other things to do in all likeliness, so
 350                         that I expect to be able to submit a <i>rebase -i -p</i> patch series only next
 351                         week.  If not then, due to a heavy workload, it will be postponed to early
 352                         April.
 353                         </p><p>
 354                         Oh well, the joys of being excited by several competing projects! &#x263a;
 355                         </p>
 356                         <h6>Sunday, 8th of March, Anno Domini MMIX, at the hour of the Tiger</h6>
 357                         <a name=1236479389>
 358                         <h2>New Git for Windows version</h2>
 359
 360                         <p>
 361                         </p><p>
 362                         Phew.  That was quite a day, almost exclusively spent on finishing that
 363                         installer.  The worst part: updating GCC seemed not to be such a good idea
 364                         after all...
 365                         </p><p>
 366                         For Windows, we need to use the printf format <i>%I64u</i> (which is
 367                         non-standard, in the common way of Microsoft) if you want to print 64-bit
 368                         wide unsigned numbers.  The rest of the world accepts the standard <i>%llu</i>.
 369                         </p><p>
 370                         After upgrading to the new GCC, a lot of warnings appeared, complaining
 371                         about <i>%I64u</i>.  The warnings went away when I replaced the format with
 372                         <i>%llu</i>.
 373                         </p><p>
 374                         Being the naive I am, I mistook that for a sign that we could finally go
 375                         more standards-compliant.
 376                         </p><p>
 377                         However, it only means that we have to live with the warnings for now, as
 378                         the C runtime provided on Windows still strongly disagrees with standards
 379                         (and it has to continue to do so, lest it break existing programs).
 380                         </p><p>
 381                         Sigh.
 382                         </p><p>
 383                         At least I have the feeling that I caught the most important bugs before
 384                         releasing.
 385                         </p>
 386                         <h6>Friday, 20th of February, Anno Domini MMIX, at the hour of the Buffalo</h6>
 387                         <a name=1235092615>
 388                         <h2>Code reviews</h2>
 389
 390                         <p>
 391                         </p><p>
 392                         It has been said that reviewing patches is a most thankless job.  As I really
 393                         like the elegance of Git's source code, and care a lot about it, I did not
 394                         think that it was thankless, just a little bit tedious (especially when the
 395                         patch authors mistake criticism for personal attacks).
 396                         </p><p>
 397                         Usually, I am pretty good at ignoring insults as responses to my comments;
 398                         after all, I have a lot more enjoyable things to do than to spend time talking
 399                         to a guy who shows how wise he is when he thinks that I criticize him
 400                         <u>personally</u> when I just try to enhance his work, by offering a little bit of
 401                         my knowledge.
 402                         </p><p>
 403                         However, in the last days, three people really seemed to want to insult me,
 404                         to make me go away, to stop the fun I have with Git.
 405                         </p><p>
 406                         And they almost succeeded.
 407                         </p><p>
 408                         So I guess it is time to reassess my priorities, and maybe stop reviewing
 409                         Git patches altogether.
 410                         </p>
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