unpack-trees: add performance tracing

We're going to optimize unpack_trees() a bit in the following
patches. Let's add some tracing to measure how long it takes before
and after. This is the baseline ("git checkout -" on webkit.git, 275k
files on worktree)

    performance: 0.056651714 s:  read cache .git/index
    performance: 0.183101080 s:  preload index
    performance: 0.008584433 s:  refresh index
    performance: 0.633767589 s:   traverse_trees
    performance: 0.340265448 s:   check_updates
    performance: 0.381884638 s:   cache_tree_update
    performance: 1.401562947 s:  unpack_trees
    performance: 0.338687914 s:  write index, changed mask = 2e
    performance: 0.411927922 s:    traverse_trees
    performance: 0.000023335 s:    check_updates
    performance: 0.423697246 s:   unpack_trees
    performance: 0.423708360 s:  diff-index
    performance: 2.559524127 s: git command: git checkout -

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/cache-tree.c b/cache-tree.c
index 181d5919f0fd4d8e838684cd14adafc8fa31ab71..caafbff2ff243bd65ee2def874c32cb75eada858 100644 (file)
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -433,7 +433,9 @@ int cache_tree_update(struct index_state *istate, int flags)
 
        if (i)
                return i;
+       trace_performance_enter();
        i = update_one(it, cache, entries, "", 0, &skip, flags);
+       trace_performance_leave("cache_tree_update");
        if (i < 0)
                return i;
        istate->cache_changed |= CACHE_TREE_CHANGED;

diff --git a/unpack-trees.c b/unpack-trees.c
index f9efee0836a20e7072477ae0f3de7c9e1a29ff78..6d9f692ea651dde9d408ea5196014e37872313b1 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -345,6 +345,7 @@ static int check_updates(struct unpack_trees_options *o)
        struct checkout state = CHECKOUT_INIT;
        int i;
 
+       trace_performance_enter();
        state.force = 1;
        state.quiet = 1;
        state.refresh_cache = 1;
@@ -414,6 +415,7 @@ static int check_updates(struct unpack_trees_options *o)
        errs |= finish_delayed_checkout(&state);
        if (o->update)
                git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
+       trace_performance_leave("check_updates");
        return errs != 0;
 }
 
@@ -1285,6 +1287,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
        if (len > MAX_UNPACK_TREES)
                die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
 
+       trace_performance_enter();
        memset(&el, 0, sizeof(el));
        if (!core_apply_sparse_checkout || !o->update)
                o->skip_sparse_checkout = 1;
@@ -1357,7 +1360,10 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
                        }
                }
 
-               if (traverse_trees(len, t, &info) < 0)
+               trace_performance_enter();
+               ret = traverse_trees(len, t, &info);
+               trace_performance_leave("traverse_trees");
+               if (ret < 0)
                        goto return_failed;
        }
 
@@ -1449,6 +1455,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
        o->src_index = NULL;
 
 done:
+       trace_performance_leave("unpack_trees");
        clear_exclude_list(&el);
        return ret;