Merge branch 'bp/refresh-index-using-preload'

The helper function to refresh the cached stat information in the
in-core index has learned to perform the lstat() part of the
operation in parallel on multi-core platforms.

* bp/refresh-index-using-preload:
  refresh_index: remove unnecessary calls to preload_index()
  speed up refresh_index() by utilizing preload_index()

Author: gitster

builtin/commit.c

@@ -1363,7 +1363,7 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 	if (status_format != STATUS_FORMAT_PORCELAIN &&
 	    status_format != STATUS_FORMAT_PORCELAIN_V2)
 		progress_flag = REFRESH_PROGRESS;
-	read_index_preload(&the_index, &s.pathspec, progress_flag);
+	read_index(&the_index);
 	refresh_index(&the_index,
 		      REFRESH_QUIET|REFRESH_UNMERGED|progress_flag,
 		      &s.pathspec, NULL, NULL);

builtin/describe.c

@@ -629,7 +629,7 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			struct argv_array args = ARGV_ARRAY_INIT;
 			int fd, result;
 
-			read_cache_preload(NULL);
+			read_cache();
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
 			fd = hold_locked_index(&index_lock, 0);

builtin/update-index.c

@@ -782,7 +782,7 @@ struct refresh_params {
 static int refresh(struct refresh_params *o, unsigned int flag)
 {
 	setup_work_tree();
-	read_cache_preload(NULL);
+	read_cache();
 	*o->has_errors |= refresh_cache(o->flags | flag);
 	return 0;
 }

cache.h

@@ -661,6 +661,9 @@ extern int daemonize(void);
 /* Initialize and use the cache information */
 struct lock_file;
 extern int read_index(struct index_state *);
+extern void preload_index(struct index_state *index,
+			  const struct pathspec *pathspec,
+			  unsigned int refresh_flags);
 extern int read_index_preload(struct index_state *,
 			      const struct pathspec *pathspec,
 			      unsigned int refresh_flags);

preload-index.c

@@ -9,7 +9,7 @@
 #include "progress.h"
 
 #ifdef NO_PTHREADS
-static void preload_index(struct index_state *index,
+void preload_index(struct index_state *index,
 			  const struct pathspec *pathspec,
 			  unsigned int refresh_flags)
 {
@@ -100,9 +100,9 @@ static void *preload_thread(void *_data)
 	return NULL;
 }
 
-static void preload_index(struct index_state *index,
-			  const struct pathspec *pathspec,
-			  unsigned int refresh_flags)
+void preload_index(struct index_state *index,
+		   const struct pathspec *pathspec,
+		   unsigned int refresh_flags)
 {
 	int threads, i, work, offset;
 	struct thread_data data[MAX_PARALLEL];

read-cache.c

@@ -1496,6 +1496,12 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 	typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n");
 	added_fmt = (in_porcelain ? "A\t%s\n" : "%s needs update\n");
 	unmerged_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
+	/*
+	 * Use the multi-threaded preload_index() to refresh most of the
+	 * cache entries quickly then in the single threaded loop below,
+	 * we only have to do the special cases that are left.
+	 */
+	preload_index(istate, pathspec, 0);
 	for (i = 0; i < istate->cache_nr; i++) {
 		struct cache_entry *ce, *new_entry;
 		int cache_errno = 0;

sequencer.c

@@ -1969,7 +1969,7 @@ static int read_and_refresh_cache(struct replay_opts *opts)
 {
 	struct lock_file index_lock = LOCK_INIT;
 	int index_fd = hold_locked_index(&index_lock, 0);
-	if (read_index_preload(&the_index, NULL, 0) < 0) {
+	if (read_index(&the_index) < 0) {
 		rollback_lock_file(&index_lock);
 		return error(_("git %s: failed to read the index"),
 			_(action_name(opts)));