| Message ID | 84511255d1f28e1bdcec3de6096d2d9ac2a9f483.1568904188.git.gitgitgadget@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | New sparse-checkout builtin and "cone" mode | expand |
On Thu, Sep 19, 2019 at 1:45 PM Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com> wrote: > > From: Derrick Stolee <dstolee@microsoft.com> > > The sparse-checkout feature can have quadratic performance as > the number of patterns and number of entries in the index grow. > If there are 1,000 patterns and 1,000,000 entries, this time can > be very significant. > > Create a new Boolean config option, core.sparseCheckoutCone, to > indicate that we expect the sparse-checkout file to contain a > more limited set of patterns. This is a separate config setting > from core.sparseCheckout to avoid breaking older clients by > introcuding a tri-state option. s/introcuding/introducing/ > The config option does nothing right now, but will be expanded > upon in a later commit. > > Signed-off-by: Derrick Stolee <dstolee@microsoft.com> > --- > Documentation/config/core.txt | 7 ++-- > Documentation/git-sparse-checkout.txt | 50 +++++++++++++++++++++++++++ > cache.h | 4 ++- > config.c | 5 +++ > environment.c | 1 + > t/t1091-sparse-checkout-builtin.sh | 14 ++++++++ > 6 files changed, 78 insertions(+), 3 deletions(-) > > diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt > index 75538d27e7..9b8ab2a6d4 100644 > --- a/Documentation/config/core.txt > +++ b/Documentation/config/core.txt > @@ -591,8 +591,11 @@ core.multiPackIndex:: > multi-pack-index design document]. > > core.sparseCheckout:: > - Enable "sparse checkout" feature. See section "Sparse checkout" in > - linkgit:git-read-tree[1] for more information. > + Enable "sparse checkout" feature. If "false", then sparse-checkout > + is disabled. If "true", then sparse-checkout is enabled with the full > + .gitignore pattern set. If "cone", then sparse-checkout is enabled with > + a restricted pattern set. See linkgit:git-sparse-checkout[1] for more > + information. This isn't consistent with the commit message that suggests it's a new option rather than a new possible value for an old option. > core.abbrev:: > Set the length object names are abbreviated to. If > diff --git a/Documentation/git-sparse-checkout.txt b/Documentation/git-sparse-checkout.txt > index da95b28b1c..757326618d 100644 > --- a/Documentation/git-sparse-checkout.txt > +++ b/Documentation/git-sparse-checkout.txt > @@ -87,6 +87,56 @@ using negative patterns. For example, to remove the file `unwanted`: > ---------------- > > > +## CONE PATTERN SET > + > +The full pattern set allows for arbitrary pattern matches and complicated > +inclusion/exclusion rules. These can result in O(N*M) pattern matches when > +updating the index, where N is the number of patterns and M is the number > +of paths in the index. To combat this performance issue, a more restricted > +pattern set is allowed when `core.spareCheckoutCone` is enabled. > + > +The accepted patterns in the cone pattern set are: > + > +1. *Recursive:* All paths inside a directory are included. > + > +2. *Parent:* All files immediately inside a directory are included. > + > +In addition to the above two patterns, we also expect that all files in the > +root directory are included. If a recursive pattern is added, then all > +leading directories are added as parent patterns. > + > +By default, when running `git sparse-checkout init`, the root directory is > +added as a parent pattern. At this point, the sparse-checkout file contains > +the following patterns: > + > +``` > +/* > +!/*/ > +``` > + > +This says "include everything in root, but nothing two levels below root." > +If we then add the folder `A/B/C` as a recursive pattern, the folders `A` and > +`A/B` are added as parent patterns. The resulting sparse-checkout file is > +now > + > +``` > +/* > +!/*/ > +/A/ > +!/A/*/ > +/A/B/ > +!/A/B/*/ > +/A/B/C/ > +``` > + > +Here, order matters, so the negative patterns are overridden by the positive > +patterns that appear lower in the file. > + > +If `core.sparseCheckoutCone=true`, then Git will parse the sparse-checkout file > +expecting patterns of these types. Git will warn if the patterns do not match. > +If the patterns do match the expected format, then Git will use faster hash- > +based algorithms to compute inclusion in the sparse-checkout. > + > SEE ALSO > -------- > > diff --git a/cache.h b/cache.h > index cf5d70c196..8e8ea67efa 100644 > --- a/cache.h > +++ b/cache.h > @@ -911,12 +911,14 @@ extern char *git_replace_ref_base; > > extern int fsync_object_files; > extern int core_preload_index; > -extern int core_apply_sparse_checkout; > extern int precomposed_unicode; > extern int protect_hfs; > extern int protect_ntfs; > extern const char *core_fsmonitor; > > +int core_apply_sparse_checkout; > +int core_sparse_checkout_cone; > + > /* > * Include broken refs in all ref iterations, which will > * generally choke dangerous operations rather than letting > diff --git a/config.c b/config.c > index 296a6d9cc4..f65c74f5b7 100644 > --- a/config.c > +++ b/config.c > @@ -1329,6 +1329,11 @@ static int git_default_core_config(const char *var, const char *value, void *cb) > return 0; > } > > + if (!strcmp(var, "core.sparsecheckoutcone")) { > + core_sparse_checkout_cone = git_config_bool(var, value); > + return 0; > + } > + > if (!strcmp(var, "core.precomposeunicode")) { > precomposed_unicode = git_config_bool(var, value); > return 0; > diff --git a/environment.c b/environment.c > index 89af47cb85..670d92bcc0 100644 > --- a/environment.c > +++ b/environment.c > @@ -69,6 +69,7 @@ enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE; > char *notes_ref_name; > int grafts_replace_parents = 1; > int core_apply_sparse_checkout; > +int core_sparse_checkout_cone; > int merge_log_config = -1; > int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */ > unsigned long pack_size_limit_cfg; > diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh > index 22fa032d6d..9b089c98c4 100755 > --- a/t/t1091-sparse-checkout-builtin.sh > +++ b/t/t1091-sparse-checkout-builtin.sh > @@ -140,6 +140,20 @@ test_expect_success 'set sparse-checkout using --stdin' ' > test_cmp expect dir > ' > > +test_expect_success 'cone mode: match patterns' ' > + git -C repo config --worktree core.sparseCheckoutCone true && > + rm -rf repo/a repo/folder1 repo/folder2 && > + git -C repo read-tree -mu HEAD && > + git -C repo reset --hard && > + ls repo >dir && > + cat >expect <<-EOF && > + a > + folder1 > + folder2 > + EOF > + test_cmp expect dir > +' > + > test_expect_success 'sparse-checkout disable' ' > git -C repo sparse-checkout disable && > test_path_is_missing repo/.git/info/sparse-checkout && > -- > gitgitgadget What if core.sparseCheckoutCone is true but core.sparseCheckout is false? Is that an error case we warn the user about, or do we make sense of it somehow?
On 10/6/2019 12:22 AM, Elijah Newren wrote: > On Thu, Sep 19, 2019 at 1:45 PM Derrick Stolee via GitGitGadget > <gitgitgadget@gmail.com> wrote: >> >> From: Derrick Stolee <dstolee@microsoft.com> >> >> The sparse-checkout feature can have quadratic performance as >> the number of patterns and number of entries in the index grow. >> If there are 1,000 patterns and 1,000,000 entries, this time can >> be very significant. >> >> Create a new Boolean config option, core.sparseCheckoutCone, to >> indicate that we expect the sparse-checkout file to contain a >> more limited set of patterns. This is a separate config setting >> from core.sparseCheckout to avoid breaking older clients by >> introcuding a tri-state option. > > s/introcuding/introducing/ > >> The config option does nothing right now, but will be expanded >> upon in a later commit. >> >> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> >> --- >> Documentation/config/core.txt | 7 ++-- >> Documentation/git-sparse-checkout.txt | 50 +++++++++++++++++++++++++++ >> cache.h | 4 ++- >> config.c | 5 +++ >> environment.c | 1 + >> t/t1091-sparse-checkout-builtin.sh | 14 ++++++++ >> 6 files changed, 78 insertions(+), 3 deletions(-) >> >> diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt >> index 75538d27e7..9b8ab2a6d4 100644 >> --- a/Documentation/config/core.txt >> +++ b/Documentation/config/core.txt >> @@ -591,8 +591,11 @@ core.multiPackIndex:: >> multi-pack-index design document]. >> >> core.sparseCheckout:: >> - Enable "sparse checkout" feature. See section "Sparse checkout" in >> - linkgit:git-read-tree[1] for more information. >> + Enable "sparse checkout" feature. If "false", then sparse-checkout >> + is disabled. If "true", then sparse-checkout is enabled with the full >> + .gitignore pattern set. If "cone", then sparse-checkout is enabled with >> + a restricted pattern set. See linkgit:git-sparse-checkout[1] for more >> + information. > > This isn't consistent with the commit message that suggests it's a new > option rather than a new possible value for an old option. Thanks for the catch. I forgot to update the docs. Fixed for v3. >> core.abbrev:: >> Set the length object names are abbreviated to. If >> diff --git a/Documentation/git-sparse-checkout.txt b/Documentation/git-sparse-checkout.txt >> index da95b28b1c..757326618d 100644 >> --- a/Documentation/git-sparse-checkout.txt >> +++ b/Documentation/git-sparse-checkout.txt >> @@ -87,6 +87,56 @@ using negative patterns. For example, to remove the file `unwanted`: >> ---------------- >> >> >> +## CONE PATTERN SET >> + >> +The full pattern set allows for arbitrary pattern matches and complicated >> +inclusion/exclusion rules. These can result in O(N*M) pattern matches when >> +updating the index, where N is the number of patterns and M is the number >> +of paths in the index. To combat this performance issue, a more restricted >> +pattern set is allowed when `core.spareCheckoutCone` is enabled. >> + >> +The accepted patterns in the cone pattern set are: >> + >> +1. *Recursive:* All paths inside a directory are included. >> + >> +2. *Parent:* All files immediately inside a directory are included. >> + >> +In addition to the above two patterns, we also expect that all files in the >> +root directory are included. If a recursive pattern is added, then all >> +leading directories are added as parent patterns. >> + >> +By default, when running `git sparse-checkout init`, the root directory is >> +added as a parent pattern. At this point, the sparse-checkout file contains >> +the following patterns: >> + >> +``` >> +/* >> +!/*/ >> +``` >> + >> +This says "include everything in root, but nothing two levels below root." >> +If we then add the folder `A/B/C` as a recursive pattern, the folders `A` and >> +`A/B` are added as parent patterns. The resulting sparse-checkout file is >> +now >> + >> +``` >> +/* >> +!/*/ >> +/A/ >> +!/A/*/ >> +/A/B/ >> +!/A/B/*/ >> +/A/B/C/ >> +``` >> + >> +Here, order matters, so the negative patterns are overridden by the positive >> +patterns that appear lower in the file. >> + >> +If `core.sparseCheckoutCone=true`, then Git will parse the sparse-checkout file >> +expecting patterns of these types. Git will warn if the patterns do not match. >> +If the patterns do match the expected format, then Git will use faster hash- >> +based algorithms to compute inclusion in the sparse-checkout. >> + >> SEE ALSO >> -------- >> >> diff --git a/cache.h b/cache.h >> index cf5d70c196..8e8ea67efa 100644 >> --- a/cache.h >> +++ b/cache.h >> @@ -911,12 +911,14 @@ extern char *git_replace_ref_base; >> >> extern int fsync_object_files; >> extern int core_preload_index; >> -extern int core_apply_sparse_checkout; >> extern int precomposed_unicode; >> extern int protect_hfs; >> extern int protect_ntfs; >> extern const char *core_fsmonitor; >> >> +int core_apply_sparse_checkout; >> +int core_sparse_checkout_cone; >> + >> /* >> * Include broken refs in all ref iterations, which will >> * generally choke dangerous operations rather than letting >> diff --git a/config.c b/config.c >> index 296a6d9cc4..f65c74f5b7 100644 >> --- a/config.c >> +++ b/config.c >> @@ -1329,6 +1329,11 @@ static int git_default_core_config(const char *var, const char *value, void *cb) >> return 0; >> } >> >> + if (!strcmp(var, "core.sparsecheckoutcone")) { >> + core_sparse_checkout_cone = git_config_bool(var, value); >> + return 0; >> + } >> + >> if (!strcmp(var, "core.precomposeunicode")) { >> precomposed_unicode = git_config_bool(var, value); >> return 0; >> diff --git a/environment.c b/environment.c >> index 89af47cb85..670d92bcc0 100644 >> --- a/environment.c >> +++ b/environment.c >> @@ -69,6 +69,7 @@ enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE; >> char *notes_ref_name; >> int grafts_replace_parents = 1; >> int core_apply_sparse_checkout; >> +int core_sparse_checkout_cone; >> int merge_log_config = -1; >> int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */ >> unsigned long pack_size_limit_cfg; >> diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh >> index 22fa032d6d..9b089c98c4 100755 >> --- a/t/t1091-sparse-checkout-builtin.sh >> +++ b/t/t1091-sparse-checkout-builtin.sh >> @@ -140,6 +140,20 @@ test_expect_success 'set sparse-checkout using --stdin' ' >> test_cmp expect dir >> ' >> >> +test_expect_success 'cone mode: match patterns' ' >> + git -C repo config --worktree core.sparseCheckoutCone true && >> + rm -rf repo/a repo/folder1 repo/folder2 && >> + git -C repo read-tree -mu HEAD && >> + git -C repo reset --hard && >> + ls repo >dir && >> + cat >expect <<-EOF && >> + a >> + folder1 >> + folder2 >> + EOF >> + test_cmp expect dir >> +' >> + >> test_expect_success 'sparse-checkout disable' ' >> git -C repo sparse-checkout disable && >> test_path_is_missing repo/.git/info/sparse-checkout && >> -- >> gitgitgadget > > What if core.sparseCheckoutCone is true but core.sparseCheckout is > false? Is that an error case we warn the user about, or do we make > sense of it somehow? `core.sparseCheckoutCone` means "when you are doing sparse-checkout things, try to use the fast logic assuming you have the cone patterns." It does not enable the sparse-checkout on its own. It only changes run-time performance. This is important for compatibility with other clients that will only look at `core.sparseCheckout`. Thanks, -Stolee
diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt index 75538d27e7..9b8ab2a6d4 100644 --- a/Documentation/config/core.txt +++ b/Documentation/config/core.txt @@ -591,8 +591,11 @@ core.multiPackIndex:: multi-pack-index design document]. core.sparseCheckout:: - Enable "sparse checkout" feature. See section "Sparse checkout" in - linkgit:git-read-tree[1] for more information. + Enable "sparse checkout" feature. If "false", then sparse-checkout + is disabled. If "true", then sparse-checkout is enabled with the full + .gitignore pattern set. If "cone", then sparse-checkout is enabled with + a restricted pattern set. See linkgit:git-sparse-checkout[1] for more + information. core.abbrev:: Set the length object names are abbreviated to. If diff --git a/Documentation/git-sparse-checkout.txt b/Documentation/git-sparse-checkout.txt index da95b28b1c..757326618d 100644 --- a/Documentation/git-sparse-checkout.txt +++ b/Documentation/git-sparse-checkout.txt @@ -87,6 +87,56 @@ using negative patterns. For example, to remove the file `unwanted`: ---------------- +## CONE PATTERN SET + +The full pattern set allows for arbitrary pattern matches and complicated +inclusion/exclusion rules. These can result in O(N*M) pattern matches when +updating the index, where N is the number of patterns and M is the number +of paths in the index. To combat this performance issue, a more restricted +pattern set is allowed when `core.spareCheckoutCone` is enabled. + +The accepted patterns in the cone pattern set are: + +1. *Recursive:* All paths inside a directory are included. + +2. *Parent:* All files immediately inside a directory are included. + +In addition to the above two patterns, we also expect that all files in the +root directory are included. If a recursive pattern is added, then all +leading directories are added as parent patterns. + +By default, when running `git sparse-checkout init`, the root directory is +added as a parent pattern. At this point, the sparse-checkout file contains +the following patterns: + +``` +/* +!/*/ +``` + +This says "include everything in root, but nothing two levels below root." +If we then add the folder `A/B/C` as a recursive pattern, the folders `A` and +`A/B` are added as parent patterns. The resulting sparse-checkout file is +now + +``` +/* +!/*/ +/A/ +!/A/*/ +/A/B/ +!/A/B/*/ +/A/B/C/ +``` + +Here, order matters, so the negative patterns are overridden by the positive +patterns that appear lower in the file. + +If `core.sparseCheckoutCone=true`, then Git will parse the sparse-checkout file +expecting patterns of these types. Git will warn if the patterns do not match. +If the patterns do match the expected format, then Git will use faster hash- +based algorithms to compute inclusion in the sparse-checkout. + SEE ALSO -------- diff --git a/cache.h b/cache.h index cf5d70c196..8e8ea67efa 100644 --- a/cache.h +++ b/cache.h @@ -911,12 +911,14 @@ extern char *git_replace_ref_base; extern int fsync_object_files; extern int core_preload_index; -extern int core_apply_sparse_checkout; extern int precomposed_unicode; extern int protect_hfs; extern int protect_ntfs; extern const char *core_fsmonitor; +int core_apply_sparse_checkout; +int core_sparse_checkout_cone; + /* * Include broken refs in all ref iterations, which will * generally choke dangerous operations rather than letting diff --git a/config.c b/config.c index 296a6d9cc4..f65c74f5b7 100644 --- a/config.c +++ b/config.c @@ -1329,6 +1329,11 @@ static int git_default_core_config(const char *var, const char *value, void *cb) return 0; } + if (!strcmp(var, "core.sparsecheckoutcone")) { + core_sparse_checkout_cone = git_config_bool(var, value); + return 0; + } + if (!strcmp(var, "core.precomposeunicode")) { precomposed_unicode = git_config_bool(var, value); return 0; diff --git a/environment.c b/environment.c index 89af47cb85..670d92bcc0 100644 --- a/environment.c +++ b/environment.c @@ -69,6 +69,7 @@ enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE; char *notes_ref_name; int grafts_replace_parents = 1; int core_apply_sparse_checkout; +int core_sparse_checkout_cone; int merge_log_config = -1; int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */ unsigned long pack_size_limit_cfg; diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh index 22fa032d6d..9b089c98c4 100755 --- a/t/t1091-sparse-checkout-builtin.sh +++ b/t/t1091-sparse-checkout-builtin.sh @@ -140,6 +140,20 @@ test_expect_success 'set sparse-checkout using --stdin' ' test_cmp expect dir ' +test_expect_success 'cone mode: match patterns' ' + git -C repo config --worktree core.sparseCheckoutCone true && + rm -rf repo/a repo/folder1 repo/folder2 && + git -C repo read-tree -mu HEAD && + git -C repo reset --hard && + ls repo >dir && + cat >expect <<-EOF && + a + folder1 + folder2 + EOF + test_cmp expect dir +' + test_expect_success 'sparse-checkout disable' ' git -C repo sparse-checkout disable && test_path_is_missing repo/.git/info/sparse-checkout &&