From 53800208bd762b1ecf14b60585cb906f22db7de8 Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Tue, 4 Aug 2020 16:21:37 +0200
Subject: [PATCH] rc: avoid stat calls for directory globbing

On Plan9, we can count on Readdir() onlydirs argument
to work, which allows us to avoid stating every single
file to see if it is a directory.
---
 sys/src/cmd/rc/glob.c  |  8 +++++++-
 sys/src/cmd/rc/plan9.c | 27 ++++++---------------------
 2 files changed, 13 insertions(+), 22 deletions(-)

diff --git a/sys/src/cmd/rc/glob.c b/sys/src/cmd/rc/glob.c
index e52b420ee..00c9f7504 100644
--- a/sys/src/cmd/rc/glob.c
+++ b/sys/src/cmd/rc/glob.c
@@ -60,9 +60,15 @@ globdir(word *list, char *p, char *name, char *namep)
 {
 	char *t, *newp;
 	int f;
-	/* scan the pattern looking for a component with a metacharacter in it */
+
+	/* append slashes, Readdir() already filtered directories */
+	while(*p=='/'){
+		*namep++=*p++;
+		*namep='\0';
+	}
 	if(*p=='\0')
 		return newword(name, list);
+	/* scan the pattern looking for a component with a metacharacter in it */
 	t = namep;
 	newp = p;
 	while(*newp){
diff --git a/sys/src/cmd/rc/plan9.c b/sys/src/cmd/rc/plan9.c
index fd12e666c..4ac9a0bf7 100644
--- a/sys/src/cmd/rc/plan9.c
+++ b/sys/src/cmd/rc/plan9.c
@@ -345,23 +345,15 @@ struct{
 int
 Opendir(char *name)
 {
-	Dir *db;
 	int f;
-	f = open(name, 0);
-	if(f==-1)
-		return f;
-	db = dirfstat(f);
-	if(db!=nil && (db->mode&DMDIR)){
-		if(f<NFD){
-			dir[f].i = 0;
-			dir[f].n = 0;
-		}
-		free(db);
+
+	if((f = open(name, 0)) < 0)
 		return f;
+	if(f<NFD){
+		dir[f].i = 0;
+		dir[f].n = 0;
 	}
-	free(db);
-	close(f);
-	return -1;
+	return f;
 }
 
 static int
@@ -375,13 +367,6 @@ trimdirs(Dir *d, int nd)
 	return w;
 }
 
-/*
- * onlydirs is advisory -- it means you only
- * need to return the directories.  it's okay to
- * return files too (e.g., on unix where you can't
- * tell during the readdir), but that just makes 
- * the globber work harder.
- */
 int
 Readdir(int f, void *p, int onlydirs)
 {