On June 23, 2021 4:02 PM, Ævar Arnfjörð Bjarmason wrote: >On Wed, Jun 23 2021, Randall S. Becker wrote: >> On June 23, 2021 1:48 PM, Ævar Arnfjörð Bjarmason wrote: >>>> On Mon, Jun 21, 2021 at 02:59:53AM +0200, Ævar Arnfjörð Bjarmason wrote: >>>>> >>>>> On Sun, Jun 20 2021, SZEDER Gábor wrote: >>>>> >>>>> > Splitting off from: >>>>> > >>>>> > >>>>> > https://public-inbox.org/git/cover-0.2-0000000000-20210607T144206 >>>>> > Z- >>>>> > avarab@xxxxxxxxx/T/#me5d3176914d4268fd9f2a96fc63f4e41beb26bd6 >>>>> > >>>>> > On Tue, Jun 08, 2021 at 06:14:42PM +0200, René Scharfe wrote: >>>>> >> I wonder (only in a semi-curious way, though) if we can detect >>>>> >> off-by-one errors by adding an assertion to display_progress() >>>>> >> that requires the first update to have the value 0, and in >>>>> >> stop_progress() one that requires the previous >>>>> >> display_progress() call to have a value equal to the total >>>>> >> number of work items. Not sure it'd be worth the hassle.. >>>>> > >>>>> > I fixed and reported a number of bogus progress lines in the >>>>> > past, the last one during v2.31.0-rc phase, so I've looked into >>>>> > whether progress counters could be automatically validated in our >>>>> > tests, and came up with these patches a few months ago. It >>>>> > turned out that progress counters can be checked easily and >>>>> > transparently in case of progress lines that are shown in the >>>>> > tests, i.e. that are shown even when stderr is not a terminal or >>>>> > are forced with '--progress'. (In other cases it's still fairly >>>>> > easy but not quite transparent, as I think we need changes to the >>>>> > progress API; more on that later in a separate >>>>> > series.) >>>>> >>>>> I've also been working on some progress.[ch] patches that are >>>>> mostly finished, and I'm some 20 patches in at the moment. I wasn't >>>>> sure about whether to send an alternate 20-patch "let's do this (mostly) instead?" >>>>> series, hence this message. >>>>> >>>>> Much of what you're doing here becomes easier after that series, e.g. >>>>> your global process struct in 2/7 is something I ended up >>>>> implementing as part of a general feature to allow progress to be >>>>> driven by either display_progress() *or* the signal handler itself. >>>> >>>> It's difficult to know who should rebase onto who without seeing one >>>> half of the patches. >>> >>>I was sort of hoping he'd take me word for it, but here it is. Don't >>>say I didn't warn you :) >>> >>>> I couldn't find a link to them anywhere (even if they are only >>>> available in your fork in a pre-polished state) despite looking, but >>>> my apologies if they are available and I'm just missing them. >>> >>>FWIW it's avar-szeder/progress-bar-assertions in >>>https://github.com/avar/git.git, that repo contains various functioning and not-so- functioning code. >>> >>>https://github.com/avar/git/tree/meta/ is my version of the crappy >>>scripts we probably all have some version of for building my own git, things that are uncommented in series.conf is what I build my own >git from. >>> >>>> In general, I think that these patches are clear and are helpful in >>>> pinning down issues with the progress API (which I have made a >>>> hadnful of times in the past), so I would be happy to see them picked up. >>> >>>Here's all 25 patches (well, around 20 before) that I had queued up locally and fixed up a bit. >>> >>>The 01/25 is something I submitted already as >>>https://lore.kernel.org/git/patch-1.1-cba5d88ca35-20210621T070114Z-ava >>>rab@xxxxxxxxx; >>>hoping to get this in incrementally. >>> >>>The 12/25 is my own version of that "global progress struct, 11/25 is >>>the first of many bugs SZEDER missed in his :) >>> >>>18/25 is the first step of the UI I was going for, the signal handler >>>can now drive the progress bar, so e.g. during "git gc" we show (at least for me, on git.git), a "stalled" message just before we start the >actual count of "Enumerating Objects". >>> >>>After that was in I was planning on adding config-driven support to >>>show a "spinner" when we stalled in that way, config-driven because >>>you could just scrape e.g. >>>https://github.com/sindresorhus/cli-spinners/blob/main/spinners.json >>>into your own config. See >>>https://jsfiddle.net/sindresorhus/2eLtsbey/embedded/result/ :) >>> >>>19-23/25 is my grabbing of SZEDER's patches that I'm comfortable >>>labeling as "PATCH", I think they work, but no BUG() assertions yet. I left out the GIT_TEST_CHECK_PROGRESS parts, since my earlier >works set things up to do any BUG() we trust by default. >>> >>>22/25 is what I think we should do instead of SZEDER's 6/7 >>>(http://lore.kernel.org/git/20210620200303.2328957-7-szeder.dev@gmail. >>>com) I don't think this "our total doesn't match at the end" is >>>something we should always BUG() on, for reasons explained there. >>> >>>I am sympathetic to doing it by default though, hence the >>>stop_progress_early() API, that's there to allow select callers to bypass his BUG(...) assertion. >>> >>>24/25 and 25/25 are "RFC" and a rebased+modified version of SZEDER's >>>BUG(...) assertions. >>> >>>His series passes the test suite, but actually severely break things >>>things. It'll make e.g. "git commit-graph write" BUG(...) out. The reason the tests don't catch it is because we have a blind spot in the >tests. >>> >>>Namely, that most things that use the progress bar API use isatty() to check if they should start_progress(). If you run the tests as e.g. >>>(better ways to do this, especially in parallel, most welcome): >>> >>> for t in t[0-9]*.sh; do if ! ./$t -vixd; then echo $t bad; break; >>> fi; done >>> >>>You can discover various things that his series BUG()'s on, I fixed a couple of those myself, it's an early part of this series. >>> >>>But we'll still have various untested for BUG()'s even then, this is because you *also* have to have the test actually emit a "naked" >>>progress bar on stderr, if the test itself e.g. pipes fd 2 to a file it won't work. >>> >>>I created a shitty-and-mostly-broken throwaway change to >>>search-replace all the guards of "start_progress(...)" to run >>>unconditionally, and convert all the "delayed" to the non-delayed version. That'll find even more BUG()'s where SZEDER's series still >needs to be fixed (and also some unrelated segfaults, I gave up on it soon after). >>> >>>Even if we fix that I wouldn't trust it, because a lot of the progress >>>bars we have depend on the size and shape of the data we're >>>processing, e.g. the bug I fixed in 11/25. If people find this BUG() approach worth pursuing I think it would be better to make it an opt-in >flag we convert one caller at a time to. >>> >>>For some it's really clear that we could assert it, for others such as >>>the commit-graph it's much more subtle, we're in some callback after setting a "total", that callback does a "break", "continue" etc. in >various places, all depending on repository data. >>> >>>It's not easy to reason about that and be certain that we can hold to >>>the estimate. If we get it wrong someone's repo in the wild won't fully GC because of the overly eager BUG(). >>> >>>If SZEDER wants to pursue it I think it'll be easier on top of this series, but personally I really don't see the point of spending effort on it. >>> >>>We should really be going in the other direction, of having more fuzzy ETAs, not less. >>> >>>E.g. we often have enough data at the start of "Enumerating Objects" >>>to give a good-enough target value, that it's 5-10% off isn't really >>>the point, but that the user looking at it sees something better than >>>a dumb count-up, and can instead see that they'll probably be looking at it for about a minute. Now our API is to give no ETA/target if >we're not 100% sure, it's not good UX. >>> >>>So trying to get the current exact count/exact percentage right seems >>>like a distraction to me in the longer term. If anything we should just be rounding those numbers, showing fuzzy ETAs instead of >percentages if we can etc. >>> >>>SZEDER Gábor (4): >>> commit-graph: fix bogus counter in "Scanning merged commits" progress >>> line >>> entry: show finer-grained counter in "Filtering content" progress >>>line >>> progress: assert last update in stop_progress() >>> progress: assert counting upwards in display() >>> >>>Ævar Arnfjörð Bjarmason (21): >>> progress.c tests: fix breakage with COLUMNS != 80 >>> progress.c tests: make start/stop verbs on stdin >>> progress.c tests: test some invalid usage >>> progress.c tests: add a "signal" verb >>> progress.c: move signal handler functions lower >>> progress.c: call progress_interval() from >>>progress_test_force_update() >>> progress.c: stop eagerly fflush(stderr) when not a terminal >>> progress.c: add temporary variable from progress struct >>> midx perf: add a perf test for multi-pack-index >>> progress.c: remove the "sparse" mode nano-optimization >>> pack-bitmap-write.c: add a missing stop_progress() >>> progress.c: add & assert a "global_progress" variable >>> progress.[ch]: move the "struct progress" to the header >>> progress.[ch]: move test-only code away from "extern" variables >>> progress.c: pass "is done?" (again) to display() >>> progress.[ch]: convert "title" to "struct strbuf" >>> progress.c: refactor display() for less confusion, and fix bug >>> progress.c: emit progress on first signal, show "stalled" >>> midx: don't provide a total for QSORT() progress >>> progress.c: add a stop_progress_early() function >>> entry: deal with unexpected "Filtering content" total >>> >>> cache.h | 1 - >>> commit-graph.c | 2 +- >>> csum-file.h | 2 - >>> entry.c | 12 +- >>> midx.c | 25 +- >>> pack-bitmap-write.c | 1 + >>> pack.h | 1 - >>> parallel-checkout.h | 1 - >>> progress.c | 391 ++++++++++++++++++------------- >>> progress.h | 50 +++- >>> reachable.h | 1 - >>> t/helper/test-progress.c | 54 +++-- >>> t/perf/p5319-multi-pack-index.sh | 21 ++ >>> t/t0500-progress-display.sh | 247 ++++++++++++++----- >>> 14 files changed, 537 insertions(+), 272 deletions(-) create mode >>> 100755 t/perf/p5319-multi-pack-index.sh >> >> Is there provision for disabling progress on a per-command basis? My >> use case is specifically in a CI/CD script, being able to suppress >> progress handling. The current Jenkins plugin does not appear to have >> provision for hooking into a mechanism, which makes things get a bit >> wonky when a job runs with a pseudo-tty (as provided by Jenkins >> through SSH/RMI). >> -Randall > >There isn't, some commands support --no-progress, but it's hit and miss. > >You can then set the undocumented GIT_PROGRESS_DELAY=99999999 (or some really big number) to suppress more of them. > >We could just add it as a top-level "git --no-progress" option I suppose... > >Probably better would be to detect such not-a-terminals somehow, I think at some point our own gc.log was a victim of this. I think a global not-a-terminal would be best here. It does not make a lot of sense to dump progress on a device that does not handle Control-M. I think I recall someone recently saying that we should be detecting this.
