sparse-read: skip gaps too small to be worth splitting
Splitting at too small gaps might not be worthwhile. With this changeset,
we stop considering splitting on too small gaps. The threshold is configurable.
We arbitrarily pick 256K as a default value because it seems "okay".
Further testing on various repositories and setups will be needed to tune it.
The option name is 'experimental.sparse-read.min-gap-size`, and replaces
`experimental.sparse-read.min-block-size` which is not used any more.
Create a repo, set the username to something more than 255 bytes, then run hg amend on it.
$ unset HGUSER
$ cat >> $HGRCPATH << EOF
> [ui]
> username = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <very.long.name@example.com>
> [extensions]
> amend =
> [experimental]
> evolution.createmarkers=True
> evolution.exchange=True
> EOF
$ hg init tmpa
$ cd tmpa
$ echo a > a
$ hg add
adding a
$ hg commit -m "Initial commit"
$ echo a >> a
$ hg amend 2>&1 | egrep -v '^(\*\*| )'
transaction abort!
rollback completed
Traceback (most recent call last):
*ProgrammingError: obsstore metadata value cannot be longer than 255 bytes (value "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <very.long.name@example.com>" for key "user" is 285 bytes) (glob)