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* clone: pass --progress decision to recursive submodulesjk/clone-recursive-progressJeff King2016-09-223-5/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When cloning with "--recursive", we'd generally expect submodules to show progress reports if the main clone did, too. In older versions of git, this mostly worked out of the box. Since we show progress by default when stderr is a tty, and since the child clones inherit the parent stderr, then both processes would come to the same decision by default. If the parent clone was asked for "--quiet", we passed down "--quiet" to the child. However, if stderr was not a tty and the user specified "--progress", we did not propagate this to the child. That's a minor bug, but things got much worse when we switched recently to submodule--helper's update_clone command. With that change, the stderr of the child clones are always connected to a pipe, and we never output progress at all. This patch teaches git-submodule and git-submodule--helper how to pass down an explicit "--progress" flag when cloning. The clone command then decides to propagate that flag based on the cloning decision made earlier (which takes into account isatty(2) of the parent process, existing --progress or --quiet flags, etc). Since the child processes always run without a tty on stderr, we don't have to worry about passing an explicit "--no-progress"; it's the default for them. This fixes the recent loss of progress during recursive clones. And as a bonus, it makes: git clone --recursive --progress ... 2>&1 | cat work by triggering progress explicitly in the children. Signed-off-by: Jeff King <peff@peff.net> Acked-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* Merge branch 'sb/submodule-clone-rr'Junio C Hamano2016-09-088-121/+379
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "git clone --resurse-submodules --reference $path $URL" is a way to reduce network transfer cost by borrowing objects in an existing $path repository when cloning the superproject from $URL; it learned to also peek into $path for presense of corresponding repositories of submodules and borrow objects from there when able. * sb/submodule-clone-rr: clone: recursive and reference option triggers submodule alternates clone: implement optional references clone: clarify option_reference as required clone: factor out checking for an alternate path submodule--helper update-clone: allow multiple references submodule--helper module-clone: allow multiple references t7408: merge short tests, factor out testing method t7408: modernize style
| * clone: recursive and reference option triggers submodule alternatessb/submodule-clone-rrStefan Beller2016-08-174-0/+176
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When `--recursive` and `--reference` is given, it is reasonable to expect that the submodules are created with references to the submodules of the given alternate for the superproject. An initial attempt to do this was presented to the mailing list, which used flags that are passed around ("--super-reference") that instructed the submodule clone to look for a reference in the submodules of the referenced superproject. This is not well thought out, as any further `submodule update` should also respect the initial setup. When a new submodule is added to the superproject and the alternate of the superproject does not know about that submodule yet, we rather error out informing the user instead of being unclear if we did or did not use a submodules alternate. To solve this problem introduce new options that store the configuration for what the user wanted originally. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * clone: implement optional referencesStefan Beller2016-08-152-11/+29
| | | | | | | | | | | | | | | | | | In a later patch we want to try to create alternates for submodules, but they might not exist in the referenced superproject. So add a way to skip the non existing references and report them. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * clone: clarify option_reference as requiredStefan Beller2016-08-151-4/+4
| | | | | | | | | | | | | | | | In the next patch we introduce optional references; To better distinguish between optional and required references we rename the variable. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * clone: factor out checking for an alternate pathStefan Beller2016-08-153-34/+86
| | | | | | | | | | | | | | | | | | | | In a later patch we want to determine if a path is suitable as an alternate from other commands than builtin/clone. Move the checking functionality of `add_one_reference` to `compute_alternate_path` that is defined in cache.h. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * submodule--helper update-clone: allow multiple referencesStefan Beller2016-08-122-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow the user to pass in multiple references to update_clone. Currently this is only internal API, but once the shell script is replaced by a C version, this is needed. This fixes an API bug between the shell script and the helper. Currently the helper accepts "--reference" "--reference=foo" as a OPT_STRING whose value happens to be "--reference=foo", and then uses if (suc->reference) argv_array_push(&child->args, suc->reference) where suc->reference _is_ "--reference=foo" when invoking the underlying "git clone", it cancels out. With this change we omit one of the "--reference" arguments when passing references from the shell script to the helper. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * submodule--helper module-clone: allow multiple referencesStefan Beller2016-08-121-8/+12
| | | | | | | | | | | | | | | | Allow users to pass in multiple references, just as clone accepts multiple references as well. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * t7408: merge short tests, factor out testing methodStefan Beller2016-08-121-23/+25
| | | | | | | | | | | | | | | | | | | | | | Tests consisting of one line each can be consolidated to have fewer tests to run as well as fewer lines of code. When having just a few git commands, do not create a new shell but use the -C flag in Git to execute in the correct directory. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * t7408: modernize styleStefan Beller2016-08-121-69/+71
| | | | | | | | | | | | | | | | | | | | | | | | No functional change intended. This commit only changes formatting to the style we recently use, e.g. starting the body of a test with a single quote on the same line as the header, and then having the test indented in the following lines. Whenever we change directories, we do that in subshells. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | Merge branch 'jh/status-v2-porcelain'Junio C Hamano2016-09-087-112/+1306
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enhance "git status --porcelain" output by collecting more data on the state of the index and the working tree files, which may further be used to teach git-prompt (in contrib/) to make fewer calls to git. * jh/status-v2-porcelain: status: unit tests for --porcelain=v2 test-lib-functions.sh: add lf_to_nul helper git-status.txt: describe --porcelain=v2 format status: print branch info with --porcelain=v2 --branch status: print per-file porcelain v2 status data status: collect per-file data for --porcelain=v2 status: support --porcelain[=<version>] status: cleanup API to wt_status_print status: rename long-format print routines
| * | status: unit tests for --porcelain=v2jh/status-v2-porcelainJeff Hostetler2016-08-121-0/+593
| | | | | | | | | | | | | | | | | | | | | Test porcelain v2 status format. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | test-lib-functions.sh: add lf_to_nul helperJeff Hostetler2016-08-111-0/+4
| | | | | | | | | | | | | | | | | | | | | Add lf_to_nul helper function to test-lib-functions. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | git-status.txt: describe --porcelain=v2 formatJeff Hostetler2016-08-111-4/+122
| | | | | | | | | | | | | | | | | | | | | | | | Update status manpage to include information about porcelain v2 format. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | status: print branch info with --porcelain=v2 --branchJeff Hostetler2016-08-113-0/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | Expand porcelain v2 output to include branch and tracking branch information. This includes the commit id, the branch, the upstream branch, and the ahead and behind counts. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | status: print per-file porcelain v2 status dataJeff Hostetler2016-08-111-1/+284
| | | | | | | | | | | | | | | | | | | | | Print per-file information in porcelain v2 format. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | status: collect per-file data for --porcelain=v2Jeff Hostetler2016-08-113-2/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Collect extra per-file data for porcelain V2 format. The output of `git status --porcelain` leaves out many details about the current status that clients might like to have. This can force them to be less efficient as they may need to launch secondary commands (and try to match the logic within git) to accumulate this extra information. For example, a GUI IDE might want the file mode to display the correct icon for a changed item (without having to stat it afterwards). Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | status: support --porcelain[=<version>]Jeff Hostetler2016-08-053-5/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update --porcelain argument to take optional version parameter to allow multiple porcelain formats to be supported in the future. The token "v1" is the default value and indicates the traditional porcelain format. (The token "1" is an alias for that.) Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | status: cleanup API to wt_status_printJeff Hostetler2016-08-053-49/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Refactor the API between builtin/commit.c and wt-status.[ch]. Hide the details of the various wt_*status_print() routines inside wt-status.c behind a single (new) wt_status_print() routine. Eliminate the switch statements from builtin/commit.c. Allow details of new status formats to be isolated within wt-status.c Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | status: rename long-format print routinesJeff Hostetler2016-08-053-58/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename the various wt_status_print*() routines to be wt_longstatus_print*() to make it clear that these routines are only concerned with the normal/long status output and reduce developer confusion as other status formats are added in the future. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | Merge branch 'po/range-doc'Junio C Hamano2016-09-085-51/+88
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clarify various ways to specify the "revision ranges" in the documentation. * po/range-doc: doc: revisions: sort examples and fix alignment of the unchanged doc: revisions: show revision expansion in examples doc: revisions - clarify reachability examples doc: revisions - define `reachable` doc: gitrevisions - clarify 'latter case' is revision walk doc: gitrevisions - use 'reachable' in page description doc: revisions: single vs multi-parent notation comparison doc: revisions: extra clarification of <rev>^! notation effects doc: revisions: give headings for the two and three dot notations doc: show the actual left, right, and boundary marks doc: revisions - name the left and right sides doc: use 'symmetric difference' consistently
| * | | doc: revisions: sort examples and fix alignment of the unchangedpo/range-docPhilip Oakley2016-08-131-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous commit adjusted the column alignment for revision examples which show expansion. Fix the unchanged examples and sort those that show expansions to the end of the list. Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: revisions: show revision expansion in examplesPhilip Oakley2016-08-131-6/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The revisions examples show the revison arguments and the selected commits, but do not show the intermediate step of the expansion of the special 'range' notations. Extend the examples, including an all-parents multi-parent merge commit example. Sort the examples and fix the alignment for those unaffected in the next commit. Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: revisions - clarify reachability examplesPhilip Oakley2016-08-131-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For the r1..r2 case, the exclusion of r1, rather than inclusion of r2, would be the unexpected case in natural language for a simple linear development, i.e. start..end excludes start. Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: revisions - define `reachable`Philip Oakley2016-08-131-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do not self-define `reachable`, which can lead to misunderstanding. Instead define `reachability` explictly. Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: gitrevisions - clarify 'latter case' is revision walkPhilip Oakley2016-08-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The prior sentence has too many clauses for easy parsing. Replace 'the latter case' with a direct quote. Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: gitrevisions - use 'reachable' in page descriptionPhilip Oakley2016-08-131-2/+2
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: revisions: single vs multi-parent notation comparisonPhilip Oakley2016-08-131-0/+4
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: revisions: extra clarification of <rev>^! notation effectsPhilip Oakley2016-08-131-1/+2
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: revisions: give headings for the two and three dot notationsPhilip Oakley2016-08-121-22/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While there, also break out the other shorthand notations and add a title for the revision range summary (which also appears in git-rev-parse, so keep it mixed case). We do not quote the notation within the headings as the asciidoc -> docbook -> groff man viewer toolchain, particularly the docbook-groff step, does not cope with two font changes, failing to return the heading font to bold after the quotation of the notation. Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: show the actual left, right, and boundary marksPhilip Oakley2016-07-201-1/+1
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: revisions - name the left and right sidesPhilip Oakley2016-07-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The terms left and right side originate from the symmetric difference. Name them there. Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | doc: use 'symmetric difference' consistentlyPhilip Oakley2016-07-202-3/+3
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Philip Oakley <philipoakley@iee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | | Merge branch 'rt/help-unknown'Junio C Hamano2016-09-083-8/+89
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "git nosuchcommand --help" said "No manual entry for gitnosuchcommand", which was not intuitive, given that "git nosuchcommand" said "git: 'nosuchcommand' is not a git command". * rt/help-unknown: help: make option --help open man pages only for Git commands help: introduce option --exclude-guides
| * | | | help: make option --help open man pages only for Git commandsrt/help-unknownRalf Thielow2016-08-302-1/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If option --help is passed to a Git command, we try to open the man page of that command. However, we do it for both commands and concepts. Make sure it is an actual command. This makes "git <concept> --help" not working anymore, while "git help <concept>" still works. Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | help: introduce option --exclude-guidesRalf Thielow2016-08-302-7/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce option --exclude-guides to the help command. With this option being passed, "git help" will open man pages only for actual commands. Since we know it is a command, we can use function help_unknown_command to give the user advice on typos. Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | Merge branch 'js/no-html-bypass-on-windows' into rt/help-unknownJunio C Hamano2016-08-263-52/+0
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | * js/no-html-bypass-on-windows: Revert "display HTML in default browser using Windows' shell API"
* | \ \ \ \ Merge branch 'cc/receive-pack-limit'Junio C Hamano2016-09-088-0/+93
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An incoming "git push" that attempts to push too many bytes can now be rejected by setting a new configuration variable at the receiving end. * cc/receive-pack-limit: receive-pack: allow a maximum input size to be specified unpack-objects: add --max-input-size=<size> option index-pack: add --max-input-size=<size> option
| * | | | | | receive-pack: allow a maximum input size to be specifiedcc/receive-pack-limitJeff King2016-08-244-0/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Receive-pack feeds its input to either index-pack or unpack-objects, which will happily accept as many bytes as a sender is willing to provide. Let's allow an arbitrary cutoff point where we will stop writing bytes to disk. Cleaning up what has already been written to disk is a related problem that is not addressed by this patch. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | | | unpack-objects: add --max-input-size=<size> optionChristian Couder2016-08-242-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When receiving a pack-file, it can be useful to abort the `git unpack-objects`, if the pack-file is too big. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | | | index-pack: add --max-input-size=<size> optionJeff King2016-08-242-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When receiving a pack-file, it can be useful to abort the `git index-pack`, if the pack-file is too big. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | | | | | Merge branch 'jk/format-patch-number-singleton-patch-with-cover'Junio C Hamano2016-09-082-4/+21
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "git format-patch --cover-letter HEAD^" to format a single patch with a separate cover letter now numbers the output as [PATCH 0/1] and [PATCH 1/1] by default. * jk/format-patch-number-singleton-patch-with-cover: format-patch: show 0/1 and 1/1 for singleton patch with cover letter
| * | | | | | | format-patch: show 0/1 and 1/1 for singleton patch with cover letterjk/format-patch-number-singleton-patch-with-coverJacob Keller2016-08-232-4/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the default behavior of git-format-patch to generate numbered sequence of 0/1 and 1/1 when generating both a cover-letter and a single patch. This standardizes the cover letter to have 0/N which helps distinguish the cover letter from the patch itself. Since the behavior is easily changed via configuration as well as the use of -n and -N this should be acceptable default behavior. Add tests for the new default behavior. Signed-off-by: Jacob Keller <jacob.keller@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | | | | | | Merge branch 'jk/delta-base-cache'Junio C Hamano2016-09-082-73/+111
|\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The delta-base-cache mechanism has been a key to the performance in a repository with a tightly packed packfile, but it did not scale well even with a larger value of core.deltaBaseCacheLimit. * jk/delta-base-cache: t/perf: add basic perf tests for delta base cache delta_base_cache: use hashmap.h delta_base_cache: drop special treatment of blobs delta_base_cache: use list.h for LRU release_delta_base_cache: reuse existing detach function clear_delta_base_cache_entry: use a more descriptive name cache_or_unpack_entry: drop keep_cache parameter
| * | | | | | | | t/perf: add basic perf tests for delta base cacheJeff King2016-08-231-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This just shows off the improvements done by the last few patches, and gives us a baseline for noticing regressions in the future. Here are the results with linux.git as the perf "large repo": Test origin HEAD ------------------------------------------------------------------- 0003.1: log --raw 43.41(40.36+2.69) 33.86(30.96+2.41) -22.0% 0003.2: log -S 313.61(309.74+3.78) 298.75(295.58+3.00) -4.7% (for a large repo, the "log -S" improvements are greater if you bump the delta base cache limit, but I think it makes sense to test the "stock" behavior, since that is what most people will see). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | | | | | delta_base_cache: use hashmap.hJeff King2016-08-231-34/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The fundamental data structure of the delta base cache is a hash table mapping pairs of "(packfile, offset)" into structs containing the actual object data. The hash table implementation dates back to e5e0161 (Implement a simple delta_base cache, 2007-03-17), and uses a fixed-size table. The current size is a hard-coded 256 entries. Because we need to be able to remove objects from the hash table, entry lookup does not do any kind of probing to handle collisions. Colliding items simply replace whatever is in their slot. As a result, we have fewer usable slots than even the 256 we allocate. At half full, each new item has a 50% chance of displacing another one. Or another way to think about it: every item has a 1/256 chance of being ejected due to hash collision, without regard to our LRU strategy. So it would be interesting to see the effect of increasing the cache size on the runtime for some common operations. As with the previous patch, we'll measure "git log --raw" for tree-only operations, and "git log -Sfoo --raw" for operations that touch trees and blobs. All times are wall-clock best-of-3, done against fully packed repos with --depth=50, and the default core.deltaBaseCacheLimit of 96MB. Here are timings for various values of MAX_DELTA_CACHE against git.git (the asterisk marks the minimum time for each operation): MAX_DELTA_CACHE log-raw log-S --------------- --------- --------- 256 0m02.227s 0m12.821s 512 0m02.143s 0m10.602s 1024 0m02.127s 0m08.642s 2048 0m02.148s 0m07.123s 4096 0m02.194s 0m06.448s* 8192 0m02.239s 0m06.504s 16384 0m02.144s* 0m06.502s 32768 0m02.202s 0m06.622s 65536 0m02.230s 0m06.677s The log-raw case isn't changed much at all here (probably because our trees just aren't that big in the first place, or possibly because we have so _few_ trees in git.git that the 256-entry cache is enough). But once we start putting blobs in the cache, too, we see a big improvement (almost 50%). The curve levels off around 4096, which means that we can hold about that many entries before hitting the 96MB memory limit (or possibly that the workload is small enough that there is simply no more work to be optimized out by caching more). (As a side note, I initially timed my existing git.git pack, which was a base of --aggressive combined with some pulls on top. So it had quite a few deeper delta chains. The 256-cache case was more like 15s, and it still dropped to ~6.5s in the same way). Here are the timings for linux.git: MAX_DELTA_CACHE log-raw log-S --------------- --------- --------- 256 0m41.661s 5m12.410s 512 0m39.547s 5m07.920s 1024 0m37.054s 4m54.666s 2048 0m35.871s 4m41.194s* 4096 0m34.646s 4m51.648s 8192 0m33.881s 4m55.342s 16384 0m35.190s 5m00.122s 32768 0m35.060s 4m58.851s 65536 0m33.311s* 4m51.420s As we grow we see a nice 20% speedup in the tree traversal, and more modest 10% in the log-S. This is probably an indication that we are bound less by the number of entries, and more by the memory limit (more on that below). What is interesting is that the numbers bounce around a bit; increasing the number of entries isn't always a strict improvement. Partially this is due to noise in the measurement. But it may also be an indication that our LRU ejection scheme is not optimal. The smaller cache sizes introduce some randomness into the ejection (due to collisions), which may sometimes work in our favor (and sometimes not!). So what is the optimal setting of MAX_DELTA_CACHE? The "bouncing" in the linux.git log-S numbers notwithstanding, it mostly seems like bigger is better. And even if we were to try to find a "sweet spot", these are just two repositories, that are not necessarily representative. The shape of history, the size of trees and blobs, the memory limit configuration, etc, all will affect the outcome. Rather than trying to find the "right" number, another strategy is to just switch to a hash table that can actually store collisions: namely our hashmap.h implementation. Here are numbers for that compared to the "best" we saw from adjusting MAX_DELTA_CACHE: | log-raw | log-S | best hashmap | best hashmap | --------- --------- | --------- --------- git | 0m02.144s 0m02.144s | 0m06.448s 0m06.688s linux | 0m33.311s 0m33.092s | 4m41.194s 4m57.172s We can see the results are similar in most cases, which is what we'd expect. We're not ejecting due to collisions at all, so this is purely representing the LRU. So really, we'd expect this to model most closely the larger values of the static MAX_DELTA_CACHE limit. And that does seem to be what's happening, including the "bounce" in the linux log-S case. So while the value for that case _isn't_ as good as the optimal one measured above (which was 2048 entries), given the bouncing I'm hesitant to suggest that 2048 is any kind of optimum (not even for linux.git, let alone as a general rule). The generic hashmap has the appeal that it drops the number of tweakable numbers by one, which means we can focus on tuning other elements, like the LRU strategy or the core.deltaBaseCacheLimit setting. And indeed, if we bump the cache limit to 1G (which is probably silly for general use, but maybe something people with big workstations would want to do), the linux.git log-S time drops to 3m32s. That's something you really _can't_ do easily with the static hash table, because the number of entries needs to grow in proportion to the memory limit (so 2048 is almost certainly not going to be the right value there). This patch takes that direction, and drops the static hash table entirely in favor of using the hashmap.h API. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | | | | | delta_base_cache: drop special treatment of blobsJeff King2016-08-231-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the delta base cache runs out of allowed memory, it has to drop entries. It does so by walking an LRU list, dropping objects until we are under the memory limit. But we actually walk the list twice: once to drop blobs, and then again to drop other objects (which are generally trees). This comes from 18bdec1 (Limit the size of the new delta_base_cache, 2007-03-19). This performs poorly as the number of entries grows, because any time dropping blobs does not satisfy the limit, we have to walk the _entire_ list, trees included, looking for blobs to drop, before starting to drop any trees. It's not generally a problem now, as the cache is limited to only 256 entries. But as we could benefit from increasing that in a future patch, it's worth looking at how it performs as the cache size grows. And the answer is "not well". The table below shows times for various operations with different values of MAX_DELTA_CACHE (which is not a run-time knob; I recompiled with -DMAX_DELTA_CACHE=$n for each). I chose "git log --raw" ("log-raw" in the table) because it will access all of the trees, but no blobs at all (so in a sense it is a worst case for this problem, because we will always walk over the entire list of trees once before realizing there are no blobs to drop). This is also representative of other tree-only operations like "rev-list --objects" and "git log -- <path>". I also timed "git log -Sfoo --raw" ("log-S" in the table). It similarly accesses all of the trees, but also the blobs for each commit. It's representative of "git log -p", though it emphasizes the cost of blob access more, as "-S" is cheaper than computing an actual blob diff. All timings are best-of-3 wall-clock times (though they all were CPU bound, so the user CPU times are similar). The repositories were fully packed with --depth=50, and the default core.deltaBaseCacheLimit of 96M was in effect. The current value of MAX_DELTA_CACHE is 256, so I started there and worked up by factors of 2. First, here are values for git.git (the asterisk signals the fastest run for each operation): MAX_DELTA_CACHE log-raw log-S --------------- --------- --------- 256 0m02.212s 0m12.634s 512 0m02.136s* 0m10.614s 1024 0m02.156s 0m08.614s 2048 0m02.208s 0m07.062s 4096 0m02.190s 0m06.484s* 8192 0m02.176s 0m07.635s 16384 0m02.913s 0m19.845s 32768 0m03.617s 1m05.507s 65536 0m04.031s 1m18.488s You can see that for the tree-only log-raw case, we don't actually benefit that much as the cache grows (all the differences up through 8192 are basically just noise; this is probably because we don't actually have that many distinct trees in git.git). But for log-S, we get a definite speed improvement as the cache grows, but the improvements are lost as cache size grows and the linear LRU management starts to dominate. Here's the same thing run against linux.git: MAX_DELTA_CACHE log-raw log-S --------------- --------- ---------- 256 0m40.987s 5m13.216s 512 0m37.949s 5m03.243s 1024 0m35.977s 4m50.580s 2048 0m33.855s 4m39.818s 4096 0m32.913s 4m47.299s* 8192 0m32.176s* 5m14.650s 16384 0m32.185s 6m31.625s 32768 0m38.056s 9m31.136s 65536 1m30.518s 17m38.549s The pattern is similar, though the effect in log-raw is more pronounced here. The times dip down in the middle, and then go back up as we keep growing. So we know there's a problem. What's the solution? The obvious one is to improve the data structure to avoid walking over tree entries during the looking-for-blobs traversal. We can do this by keeping _two_ LRU lists: one for blobs, and one for other objects. We drop items from the blob LRU first, and then from the tree LRU (if necessary). Here's git.git using that strategy: MAX_DELTA_CACHE log-raw log-S --------------- --------- ---------- 256 0m02.264s 0m12.830s 512 0m02.201s 0m10.771s 1024 0m02.181s 0m08.593s 2048 0m02.205s 0m07.116s 4096 0m02.158s 0m06.537s* 8192 0m02.213s 0m07.246s 16384 0m02.155s* 0m10.975s 32768 0m02.159s 0m16.047s 65536 0m02.181s 0m16.992s The upswing on log-raw is gone completely. But log-S still has it (albeit much better than without this strategy). Let's see what linux.git shows: MAX_DELTA_CACHE log-raw log-S --------------- --------- --------- 256 0m42.519s 5m14.654s 512 0m39.106s 5m04.708s 1024 0m36.802s 4m51.454s 2048 0m34.685s 4m39.378s* 4096 0m33.663s 4m44.047s 8192 0m33.157s 4m50.644s 16384 0m33.090s* 4m49.648s 32768 0m33.458s 4m53.371s 65536 0m33.563s 5m04.580s The results are similar. The tree-only case again performs well (not surprising; we're literally just dropping the one useless walk, and not otherwise changing the cache eviction strategy at all). But the log-S case again does a bit worse as the cache grows (though possibly that's within the noise, which is much larger for this case). Perhaps this is an indication that the "remove blobs first" strategy is not actually optimal. The intent of it is to avoid blowing out the tree cache when we see large blobs, but it also means we'll throw away useful, recent blobs in favor of older trees. Let's run the same numbers without caring about object type at all (i.e., one LRU list, and always evicting whatever is at the head, regardless of type). Here's git.git: MAX_DELTA_CACHE log-raw log-S --------------- --------- --------- 256 0m02.227s 0m12.821s 512 0m02.143s 0m10.602s 1024 0m02.127s 0m08.642s 2048 0m02.148s 0m07.123s 4096 0m02.194s 0m06.448s* 8192 0m02.239s 0m06.504s 16384 0m02.144s* 0m06.502s 32768 0m02.202s 0m06.622s 65536 0m02.230s 0m06.677s Much smoother; there's no dramatic upswing as we increase the cache size (some remains, though it's small enough that it's mostly run-to-run noise. E.g., in the log-raw case, note how 8192 is 50-100ms higher than its neighbors). Note also that we stop getting any real benefit for log-S after about 4096 entries; that number will depend on the size of the repository, the size of the blob entries, and the memory limit of the cache. Let's see what linux.git shows for the same strategy: MAX_DELTA_CACHE log-raw log-S --------------- --------- --------- 256 0m41.661s 5m12.410s 512 0m39.547s 5m07.920s 1024 0m37.054s 4m54.666s 2048 0m35.871s 4m41.194s* 4096 0m34.646s 4m51.648s 8192 0m33.881s 4m55.342s 16384 0m35.190s 5m00.122s 32768 0m35.060s 4m58.851s 65536 0m33.311s* 4m51.420s It's similarly good. As with the "separate blob LRU" strategy, there's a lot of noise on the log-S run here. But it's certainly not any worse, is possibly a bit better, and the improvement over "separate blob LRU" on the git.git case is dramatic. So it seems like a clear winner, and that's what this patch implements. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | | | | | delta_base_cache: use list.h for LRUJeff King2016-08-231-22/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We keep an LRU list of entries for when we need to drop something from an over-full cache. The list is implemented as a circular doubly-linked list, which is exactly what list.h provides. We can save a few lines by using the list.h macros and functions. More importantly, this makes the code easier to follow, as the reader sees explicit concepts like "list_add_tail()" instead of pointer manipulation. As a bonus, the list_entry() macro lets us place the lru pointers anywhere inside the delta_base_cache_entry struct (as opposed to just casting the pointer, which requires it at the front of the struct). This will be useful in later patches when we need to place other items at the front of the struct (e.g., our hashmap implementation requires this). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | | | | | release_delta_base_cache: reuse existing detach functionJeff King2016-08-231-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This function drops an entry entirely from the cache, meaning that aside from the freeing of the buffer, it is exactly equivalent to detach_delta_base_cache_entry(). Let's build on top of the detach function, which shortens the code and will make it simpler when we change out the underlying storage in future patches. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | | | | | clear_delta_base_cache_entry: use a more descriptive nameJeff King2016-08-231-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The delta base cache entries are stored in a fixed-length hash table. So the way to remove an entry is to "clear" the slot in the table, and that is what this function does. However, the name is a leaky abstraction. If we were to change the hash table implementation, it would no longer be about "clearing". We should name it after _what_ it does, not _how_ it does it. I.e., something like "remove" instead of "clear". But that does not tell the whole story, either. The subtle thing about this function is that it removes the entry, but does not free the entry data. So a more descriptive name is "detach"; we give ownership of the data buffer to the caller, and remove any other resources. This patch uses the name detach_delta_base_cache_entry(). We could further model this after functions like strbuf_detach(), which pass back all of the detached information. However, since there are so many bits of information in the struct (the data, the size, the type), and so few callers (only one), it's not worth that awkwardness. The name change and a comment can make the intent clear. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>