Archive for January, 2015

Explicit rename/copy tracking vs. detection after the fact

One of the main differences in how mercurial and git track files is that mercurial does rename and copy tracking and git doesn’t. So in the case of mercurial, users are expected to explicitly rename or copy the files through the mercurial command line so that mercurial knows what happened. Git simply doesn’t care, and will try to detect after the fact when you ask it to.

The consequence is that my git-remote-hg, being currently a limited prototype, doesn’t make the effort to inform mercurial of renames or copies.

This week, Ehsan, as a user of that tool, pushed some file moves, and subsequently opened an issue, because some people didn’t like it.

It was a conscious choice on my part to make git-remote-hg public without rename/copies detection, because file renames/copies are not happening often, and can just as much not be registered by mercurial users.

In fact, they haven’t all been registered for as long as Mozilla has been using mercurial (see below, I didn’t actually know I was so spot on when I wrote this sentence), and people haven’t been pointed at for using broken tools (and I’ll skip the actual language that was used when talking about Ehsan’s push).

And since I’d rather not make unsubstantiated claims, I dug in all of mozilla-central and related repositories (inbound, b2g-inbound, fx-team, aurora, beta, release, esr*) and here is what I found, only accounting files that have been copied or renamed without being further modified (so, using git diff-tree -r -C100%, and eliminating empty files), and correlating with the mercurial rename/copy metadata:

  • There have been 45069 file renames or copies in 1546 changesets.
  • Mercurial doesn’t know 5482 (12.1%) of them, from 419 (27.1%) changesets.
  • 72 of those changesets were backouts.
  • 19 of those backouts were of changesets that didn’t have rename/copy information, so 53 of those backouts didn’t actually undo what mercurial knew of those backed out changesets.
  • Those 419 changesets were from 144 distinct authors (assuming I didn’t miss some duplicates from people who changed email).
  • Fun fact, the person with colorful language, and that doesn’t like git-remote-hg, is part of them. I am too, and that was with mercurial.
  • The most recent occurrence of renames/copies unknown to mercurial is already not Ehsan’s anymore.
  • The oldest occurrence is in the 19th (!) mercurial changeset.

And that’s not counting all the copies and renames with additional modifications.

Fun fact, this is what I found in the Mercurial mercurial repository:

  • There have been 255 file renames or copies in 41 changesets.
  • Mercurial doesn’t know about 38 (14.9%) of them, from 4 (9.7%) changesets.
  • One of those changesets was from Matt Mackall himself (creator and lead developer of mercurial).

There are 1061 files in mercurial, versus 115845 in mozilla-central, so there is less occasion for renames/copies there, still, even they forget to use “hg move” and break their history as a result.

I think this shows how requiring explicit user input simply doesn’t pan out.

Meanwhile, I have prototype copy/rename detection for git-remote-hg working, but I need to tweak it a little bit more before publishing.

2015-01-24 12:48:58+0900

cinnabar, p.m.o | 6 Comments »

Fx0を購入

Two weeks ago, I went to a local au shop to get a hand on the Fx0, KDDI’s LG-manufactured Firefox OS phone that was released in Japan for Christmas in a few flagship shops and on the web, and on January 6 everywhere else in Japan.

They had it on display, like any other phone.

But they didn’t have any stock, so I couldn’t bring one home, but ordered one.

Fast forward two days ago, the shop called to say they received it, and I went yesterday to get it.

Unboxing

Since the phone is not sold without a carrier subscription, the shop staff does the unboxing for you, to place the SIM card in the phone. But let’s pretend that didn’t happen.

The Fx0 comes in a gold box with a gold Firefox logo, wrapped in a white box with the characters “Fx0” embossed.

Opening the gold box, unsurprisingly, reveals the gold transparent phone.

Reading articles about this phone, opinions are divided about its look. I’m on the side that thinks it looks awesome, especially in the back. I does look bulky, probably because of its rather sharp edges, but it’s not much larger than a Nexus 4. Nor is it much thicker.

One side has “au” embossed, and the other has “Fx0”.

One downside of the transparent theme is that it limited the types of materials that could be used, so it sadly feels plastic to the touch. At least that’s why I think it is this way.

At the bottom of its front, a single “home” button, showing the Firefox logo.

Turning it on

Well, it was already on when I first got my hands on it, but in our pretense of unboxing, let’s say it was not, and that I turned it on for the first time (which, in some sense, is true). This is what it looks like when it boots:

After unlocking, the home screen appears.

I’ll be trying to use it as my main (smart)phone, and see how that goes. I’ll also test some of its KDDI specific features. Blog posts will come along. Stay tuned.

2015-01-22 00:25:45+0900

p.m.o | 8 Comments »