trace2:gvfs:experiment: add data for check_updates() in unpack_trees()

Add data for the number of files created/overwritten and deleted during the checkout.

Give proper category name to all events in unpack-trees.c and eliminate "exp".

This is modified slightly from the original version due to interactions with 26f924d
(unpack-trees: exit check_updates() early if updates are not wanted, 2020-01-07).

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>

unpack-trees.c

@@ -427,8 +427,12 @@ static int check_updates(struct unpack_trees_options *o,
 	struct progress *progress;
 	struct checkout state = CHECKOUT_INIT;
 	int i, pc_workers, pc_threshold;
+	intmax_t sum_unlink = 0;
+	intmax_t sum_prefetch = 0;
+	intmax_t sum_checkout = 0;
 
 	trace_performance_enter();
+	trace2_region_enter("unpack_trees", "check_updates", NULL);
 	state.super_prefix = o->super_prefix;
 	state.force = 1;
 	state.quiet = 1;
@@ -438,8 +442,7 @@ static int check_updates(struct unpack_trees_options *o,
 
 	if (!o->update || o->dry_run) {
 		remove_marked_cache_entries(index, 0);
-		trace_performance_leave("check_updates");
-		return 0;
+		goto done;
 	}
 
 	if (o->clone)
@@ -461,6 +464,7 @@ static int check_updates(struct unpack_trees_options *o,
 		if (ce->ce_flags & CE_WT_REMOVE) {
 			display_progress(progress, ++cnt);
 			unlink_entry(ce, o->super_prefix);
+			sum_unlink++;
 		}
 	}
 
@@ -496,6 +500,7 @@ static int check_updates(struct unpack_trees_options *o,
 
 			if (last_pc_queue_size == pc_queue_size())
 				display_progress(progress, ++cnt);
+			sum_checkout++;
 		}
 	}
 	if (pc_workers > 1)
@@ -508,6 +513,15 @@ static int check_updates(struct unpack_trees_options *o,
 	if (o->clone)
 		report_collided_checkout(index);
 
+	if (sum_unlink > 0)
+		trace2_data_intmax("unpack_trees", NULL, "check_updates/nr_unlink", sum_unlink);
+	if (sum_prefetch > 0)
+		trace2_data_intmax("unpack_trees", NULL, "check_updates/nr_prefetch", sum_prefetch);
+	if (sum_checkout > 0)
+		trace2_data_intmax("unpack_trees", NULL, "check_updates/nr_write", sum_checkout);
+
+done:
+	trace2_region_leave("unpack_trees", "check_updates", NULL);
 	trace_performance_leave("check_updates");
 	return errs != 0;
 }
@@ -1778,10 +1792,9 @@ static int clear_ce_flags(struct index_state *istate,
 					_("Updating index flags"),
 					istate->cache_nr);
 
-	xsnprintf(label, sizeof(label), "clear_ce_flags(0x%08lx,0x%08lx)",
+	xsnprintf(label, sizeof(label), "clear_ce_flags/0x%08lx_0x%08lx",
 		  (unsigned long)select_mask, (unsigned long)clear_mask);
 	trace2_region_enter("unpack_trees", label, the_repository);
-
 	rval = clear_ce_flags_1(istate,
 				istate->cache,
 				istate->cache_nr,
@@ -1905,7 +1918,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	if (o->df_conflict_entry)
 		BUG("o->df_conflict_entry is an output only field");
 
-	trace2_region_enter("exp", "unpack_trees", NULL);
+	trace2_region_enter("unpack_trees", "unpack_trees", NULL);
 	nr_unpack_entry_at_start = get_nr_unpack_entry();
 
 	trace_performance_enter();
@@ -2114,7 +2127,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	trace_performance_leave("unpack_trees");
 	trace2_data_intmax("unpack_trees", NULL, "unpack_trees/nr_unpack_entries",
 			   (intmax_t)(get_nr_unpack_entry() - nr_unpack_entry_at_start));
-	trace2_region_leave("exp", "unpack_trees", NULL);
+	trace2_region_leave("unpack_trees", "unpack_trees", NULL);
 	return ret;
 
 return_failed: