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author | Derrick Stolee <dstolee@microsoft.com> | 2019-11-21 23:04:41 +0100 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2019-11-22 08:11:44 +0100 |
commit | 96cc8ab5318cd57c8bc203b8f064b35883b2386f (patch) | |
tree | 34c7c46a9525f853ba710fe070fd191060ac2cdd /dir.h | |
parent | sparse-checkout: add 'cone' mode (diff) | |
download | git-96cc8ab5318cd57c8bc203b8f064b35883b2386f.tar.xz git-96cc8ab5318cd57c8bc203b8f064b35883b2386f.zip |
sparse-checkout: use hashmaps for cone patterns
The parent and recursive patterns allowed by the "cone mode"
option in sparse-checkout are restrictive enough that we
can avoid using the regex parsing. Everything is based on
prefix matches, so we can use hashsets to store the prefixes
from the sparse-checkout file. When checking a path, we can
strip path entries from the path and check the hashset for
an exact match.
As a test, I created a cone-mode sparse-checkout file for the
Linux repository that actually includes every file. This was
constructed by taking every folder in the Linux repo and creating
the pattern pairs here:
/$folder/
!/$folder/*/
This resulted in a sparse-checkout file sith 8,296 patterns.
Running 'git read-tree -mu HEAD' on this file had the following
performance:
core.sparseCheckout=false: 0.21 s (0.00 s)
core.sparseCheckout=true: 3.75 s (3.50 s)
core.sparseCheckoutCone=true: 0.23 s (0.01 s)
The times in parentheses above correspond to the time spent
in the first clear_ce_flags() call, according to the trace2
performance traces.
While this example is contrived, it demonstrates how these
patterns can slow the sparse-checkout feature.
Helped-by: Eric Wong <e@80x24.org>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'dir.h')
-rw-r--r-- | dir.h | 31 |
1 files changed, 31 insertions, 0 deletions
@@ -4,6 +4,7 @@ /* See Documentation/technical/api-directory-listing.txt */ #include "cache.h" +#include "hashmap.h" #include "strbuf.h" struct dir_entry { @@ -37,6 +38,13 @@ struct path_pattern { int srcpos; }; +/* used for hashmaps for cone patterns */ +struct pattern_entry { + struct hashmap_entry ent; + char *pattern; + size_t patternlen; +}; + /* * Each excludes file will be parsed into a fresh exclude_list which * is appended to the relevant exclude_list_group (either EXC_DIRS or @@ -55,6 +63,26 @@ struct pattern_list { const char *src; struct path_pattern **patterns; + + /* + * While scanning the excludes, we attempt to match the patterns + * with a more restricted set that allows us to use hashsets for + * matching logic, which is faster than the linear lookup in the + * excludes array above. If non-zero, that check succeeded. + */ + unsigned use_cone_patterns; + unsigned full_cone; + + /* + * Stores paths where everything starting with those paths + * is included. + */ + struct hashmap recursive_hashmap; + + /* + * Used to check single-level parents of blobs. + */ + struct hashmap parent_hashmap; }; /* @@ -271,6 +299,9 @@ int is_excluded(struct dir_struct *dir, struct index_state *istate, const char *name, int *dtype); +int hashmap_contains_parent(struct hashmap *map, + const char *path, + struct strbuf *buffer); struct pattern_list *add_pattern_list(struct dir_struct *dir, int group_type, const char *src); int add_patterns_from_file_to_list(const char *fname, const char *base, int baselen, |