git-p4 originally would fetch changes in one query. On large repos this
could fail because of the limits that Perforce imposes on the number of
items returned and the number of queries in the database.
To fix this, git-p4 learned to query changes in blocks of 512 changes,
However, this can be very slow - if you have a few million changes,
with each chunk taking about a second, it can be an hour or so.
Although it's possible to tune this value manually with the
"--changes-block-size" option, it's far from obvious to ordinary users
that this is what needs doing.
This change alters the block size dynamically by looking for the
specific error messages returned from the Perforce server, and reducing
the block size if the error is seen, either to the limit reported by the
server, or to half the current block size.
That means we can start out with a very large block size, and then let
it automatically drop down to a value that works without error, while
still failing correctly if some other error occurs.
Signed-off-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When fetching changes from a depot using a full client spec, there
is no need to perform as many queries as there are top-level paths
in the client spec. Instead we query all changes in chronological
order, also getting rid of the need to sort the results and remove
duplicates.
Signed-off-by: Sam Hocevar <sam@hocevar.net>
Signed-off-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
James Farwell reported that with multiple depots git-p4 would
skip changes.
http://article.gmane.org/gmane.comp.version-control.git/282297
Add a failing test case demonstrating the problem.
Signed-off-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The --changes-block-size handling was intended to help when
a user has a limited "maxscanrows" (see "p4 group"). It used
"p4 changes -m $maxchanges" to limit the number of results.
Unfortunately, it turns out that the "maxscanrows" and "maxresults"
limits are actually applied *before* the "-m maxchanges" parameter
is considered (experimentally).
Fix the block-size handling so that it gets blocks of changes
limited by revision number ($Start..$Start+$N, etc). This limits
the number of results early enough that both sets of tests pass.
Note that many other Perforce operations can fail for the same
reason (p4 print, p4 files, etc) and it's probably not possible
to workaround this. In the real world, this is probably not
usually a problem.
Signed-off-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the --changes-block-size git-p4 test to use an account with
limited "maxresults" and "maxscanrows" values.
These conditions are applied in the server *before* the "-m maxchanges"
parameter to "p4 changes" is applied, and so the strategy that git-p4
uses for limiting the number of changes does not work. As a result,
the tests all fail.
Note that "maxscanrows" is set quite high, as it appears to not only
limit results from "p4 changes", but *also* limits results from
"p4 print". Files that have more than "maxscanrows" changes seem
(experimentally) to be impossible to print. There's no good way to
work around this.
Signed-off-by: Luke Diamand <luke@diamand.org>
Acked-by: Lex Spoon <lex@lexspoon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add additional tests of some corner-cases of the
--changes-block-size git-p4 parameter.
Also reduce the number of p4 changes created during the
tests, so that they complete faster.
Signed-off-by: Luke Diamand <luke@diamand.org>
Acked-by: Lex Spoon <lex@lexspoon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Simply running "p4 changes" on a large branch can result in a "too
many rows scanned" error from the Perforce server. It is better to
use a sequence of smaller calls to "p4 changes", using the "-m"
option to limit the size of each call.
Signed-off-by: Lex Spoon <lex@lexspoon.org>
Acked-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
