@matheusbsbs / matheus-bagliano / commits / da8be8ced6

tree-walk: report recursion counts

The traverse_trees() method recursively walks through trees, but also prunes the tree-walk based on a callback. Some callers, such as unpack_trees(), are quite complicated and can have wildly different performance between two different commands. Create constants that count these values and then report the results at the end of a process. These counts are cumulative across multiple "root" instances of traverse_trees(), but they provide reproducible values for demonstrating improvements to the pruning algorithm when possible. This change is modeled after a similar statistics reporting in 42e50e78 (revision.c: add trace2 stats around Bloom filter usage, 2020-04-06). Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Derrick Stolee committed Jan 4, 2021 at 03:09 UTC da8be8ced672fc00d5dea8a95d04854b2e35d925

1 file changed +33

tree-walk.c

+33

index 0160294712..2d6226d5f1 100644 --- a/tree-walk.c +++ b/tree-walk.c @@ -4,6 +4,7 @@ #include "object-store.h" #include "tree.h" #include "pathspec.h" +#include "json-writer.h" static const char *get_mode(const char *str, unsigned int *modep) { @@ -167,6 +168,25 @@ int tree_entry_gently(struct tree_desc *desc, struct name_entry *entry) return 1; } +static int traverse_trees_atexit_registered; +static int traverse_trees_count; +static int traverse_trees_cur_depth; +static int traverse_trees_max_depth; + +static void trace2_traverse_trees_statistics_atexit(void) +{ + struct json_writer jw = JSON_WRITER_INIT; + + jw_object_begin(&jw, 0); + jw_object_intmax(&jw, "traverse_trees_count", traverse_trees_count); + jw_object_intmax(&jw, "traverse_trees_max_depth", traverse_trees_max_depth); + jw_end(&jw); + + trace2_data_json("traverse_trees", the_repository, "statistics", &jw); + + jw_release(&jw); +} + void setup_traverse_info(struct traverse_info *info, const char *base) { size_t pathlen = strlen(base); @@ -180,6 +200,11 @@ void setup_traverse_info(struct traverse_info *info, const char *base) info->namelen = pathlen; if (pathlen) info->prev = &dummy; + + if (trace2_is_enabled() && !traverse_trees_atexit_registered) { + atexit(trace2_traverse_trees_statistics_atexit); + traverse_trees_atexit_registered = 1; + } } char *make_traverse_path(char *path, size_t pathlen, @@ -416,6 +441,12 @@ int traverse_trees(struct index_state *istate, int interesting = 1; char *traverse_path; + traverse_trees_count++; + traverse_trees_cur_depth++; + + if (traverse_trees_cur_depth > traverse_trees_max_depth) + traverse_trees_max_depth = traverse_trees_cur_depth; + if (n >= ARRAY_SIZE(entry)) BUG("traverse_trees() called with too many trees (%d)", n); @@ -515,6 +546,8 @@ int traverse_trees(struct index_state *istate, free(traverse_path); info->traverse_path = NULL; strbuf_release(&base); + + traverse_trees_cur_depth--; return error; }