threads / discuss / 9248

incremental fast-import

Subject: incremental fast-import

## tl;dr

3 messages between Jul 26, 2007 and Jul 27, 2007.

replies: 2people: 3as markdown or json

Julian Phillips· Jul 26, 2007, 21:47 UTC · lore

Sorry to be going on about fast-import again ...

I seem to be missing something though. I can't seem to get it to work when run in an incremental manner.

I have a saved stream of fast-import commands. Every time I run this through fast import I get the exact same marks file out. This is good.

However if I feed it in in two chunks, then nearly all of the SHA1s generated in the second run are different to those produced in a single pass. In addition I get a pair of "warning: Not updating refs/heads/BUG_101_BRANCH (new tip <some sha1> does not contain <other sha1>)" messages. This is not so good.

I'm using the --import-marks and --export-marks options. Is there something else I need to do to be able to run fast-import in an incremental manner?

-- 
Julian

  ---
A fool must now and then be right by chance.

Shawn O. Pearce· Jul 27, 2007, 00:51 UTC · re: Julian Phillips · lore

Re: incremental fast-import

Julian Phillips <julian@quantumfyre.co.uk> wrote:

Show 15 quoted lines

> I seem to be missing something though.  I can't seem to get it to work 
> when run in an incremental manner.
> 
> I have a saved stream of fast-import commands.  Every time I run this 
> through fast import I get the exact same marks file out.  This is good.
> 
> However if I feed it in in two chunks, then nearly all of the SHA1s 
> generated in the second run are different to those produced in a single 
> pass.  In addition I get a pair of "warning: Not updating 
> refs/heads/BUG_101_BRANCH (new tip <some sha1> does not contain <other 
> sha1>)" messages.  This is not so good.
> 
> I'm using the --import-marks and --export-marks options.  Is there 
> something else I need to do to be able to run fast-import in an 
> incremental manner?

I'm guessing you didn't restart the branches at the start of the second import. You need to do something like this to get the import going again:

  commit refs/heads/BUG_101_BRANCH
  from refs/heads/BUG_101_BRANCH^0
  ...

or because you imported the marks you can use a mark:

  commit refs/heads/BUG_101_BRANCH
  from :18981
  ...

where 18981 was the last revision on BUG_101_BRANCH that the frontend had imported during the last run.

fast-import doesn't assume the local branches already exist. It actually assumes its importing from scratch every time. The frontend tool needs to restart the branch if that is what it wants.

In other words, by splitting the file in half you actually also split the history in half, and got two root commits, one of which was in the middle of your history. :-(

-- 
Shawn.

Simon 'corecode' Schubert· Jul 27, 2007, 07:44 UTC · re: Shawn O. Pearce · lore

Re: incremental fast-import

Shawn O. Pearce wrote:

> fast-import doesn't assume the local branches already exist.
> It actually assumes its importing from scratch every time.  The
> frontend tool needs to restart the branch if that is what it wants.

Is there a compelling reason for this behavior?  Shouldn't be so complicated to get an overview on which branches already exist?

Right now I have to do this with a side channel to fast-import, asking the git repo directly, and then "recreating" the branch, etc.  Works, but could be nicer, I guess.

cheers
  simon

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