Re: henrik: memory pool stuff

On Thu, 5 Feb 2004, Robert Collins wrote:

> Henrik,
> How did you go with the use of arch to get the memory pool code?
>
> Was it easy/hard? Do you have any feedback..

arch does seem to have excellent branching and changeset tracking
capabilities, and the ability to have distributed repositories linking to
each other is great.

but all is not yet excellent:

* quite long commands due to the verbose naming scheme. Some of this could
be optimized to not have to specify all details of a revision when inside
a working directory and similar obvious things.

* due to design it is quite slow to work with remote repositories unless
the repository is carefully maintained with suitable cached revision
snapshots.

* is is also quite slow on local operations such as "tla changes". Seems
to always be comparing whole trees including TLA metadata, not even trying
to ignore what have obviously not been modified. And due to the the way
this is done it will totally kill performance if the working directory is
on NFS or on another syncronous filesystem. (tons of
create/write/close/unlink operations, one per file in the whole tree)

* local disk usage is significantly higher compared to using CVS due to
the requirements of having a complete copy of the original sources for
reasonable operation and rather verbose metadata. This can be optimized
somewhat by linking the sources to the library but when using linked
sources there is a great risk the library gets corrupted by overwriting a
linked file.

* The very verbose meta data kept in the working directory will over time
probably grow larger than the actual source size bringing an issue about
scaleability over time.

* In addition the tla-1.2 betas seem to be somewhat wasteful with
diskspace, not reusing the library as pristine source even if the same
revision exists. You always seem to get a pristine tree even if the
library has the exact same revision and in addition the pristine tree is
always a copy even if it could have been linked to the library files.
tla-1.1 seems to work slightly better in this aspect but I had the 1.2
beta installed to look into GPG signing.

* The tla command naming is not very consistent.

Another unrelated note: Your squid--HEAD--3.0 branch is not up to date. Is
missing some minor changes from beginning of January.

Regards
Henrik
Received on Sat Feb 07 2004 - 09:13:02 MST