From 4f525d2eb71175fb540106152c17145d5a506d60 Mon Sep 17 00:00:00 2001
From: Zac Medico <zmedico@gentoo.org>
Date: Thu, 27 Jun 2013 14:31:49 -0700
Subject: [PATCH] util.listir: simplify and optimize

Use zip() to simplify, and fix "list = list + foo" usage to use
list.extend() or equivalent.
---
 pym/portage/util/listdir.py | 87 ++++++++++++++++++-------------------
 1 file changed, 43 insertions(+), 44 deletions(-)

diff --git a/pym/portage/util/listdir.py b/pym/portage/util/listdir.py
index 61a025ae7..2012e145f 100644
--- a/pym/portage/util/listdir.py
+++ b/pym/portage/util/listdir.py
@@ -5,6 +5,10 @@ __all__ = ['cacheddir', 'listdir']
 
 import errno
 import stat
+import sys
+
+if sys.hexversion < 0x3000000:
+	from itertools import izip as zip
 
 from portage import os
 from portage.const import VCS_DIRS
@@ -21,7 +25,6 @@ dircache = {}
 
 def cacheddir(my_original_path, ignorecvs, ignorelist, EmptyOnError, followSymlinks=True):
 	mypath = normalize_path(my_original_path)
-	cached_mtime, list, ftype = -1, [], []
 	try:
 		pathstat = os.stat(mypath)
 		if not stat.S_ISDIR(pathstat.st_mode):
@@ -35,14 +38,14 @@ def cacheddir(my_original_path, ignorecvs, ignorelist, EmptyOnError, followSymli
 		return [], []
 	else:
 		try:
-			list = os.listdir(mypath)
+			fpaths = os.listdir(mypath)
 		except EnvironmentError as e:
 			if e.errno != errno.EACCES:
 				raise
 			del e
 			raise PermissionDenied(mypath)
 		ftype = []
-		for x in list:
+		for x in fpaths:
 			try:
 				if followSymlinks:
 					pathstat = os.stat(mypath+"/"+x)
@@ -60,19 +63,20 @@ def cacheddir(my_original_path, ignorecvs, ignorelist, EmptyOnError, followSymli
 			except (IOError, OSError):
 				ftype.append(3)
 
-	ret_list = []
-	ret_ftype = []
-	for x in range(0, len(list)):
-		if list[x] in ignorelist:
-			pass
-		elif ignorecvs:
-			if list[x][:2] != ".#" and \
-				not (ftype[x] == 1 and list[x] in VCS_DIRS):
-				ret_list.append(list[x])
-				ret_ftype.append(ftype[x])
-		else:
-			ret_list.append(list[x])
-			ret_ftype.append(ftype[x])
+	if ignorelist or ignorecvs:
+		ret_list = []
+		ret_ftype = []
+		for file_path, file_type in zip(fpaths, ftype):
+			if file_path in ignorelist:
+				pass
+			elif ignorecvs:
+				if file_path[:2] != ".#" and \
+					not (file_type == 1 and file_path in VCS_DIRS):
+					ret_list.append(file_path)
+					ret_ftype.append(file_type)
+	else:
+		ret_list = fpaths
+		ret_ftype = ftype
 
 	return ret_list, ret_ftype
 
@@ -101,40 +105,35 @@ def listdir(mypath, recursive=False, filesonly=False, ignorecvs=False, ignorelis
 	@return: A list of files and directories (or just files or just directories) or an empty list.
 	"""
 
-	list, ftype = cacheddir(mypath, ignorecvs, ignorelist, EmptyOnError, followSymlinks)
+	fpaths, ftype = cacheddir(mypath, ignorecvs, ignorelist, EmptyOnError, followSymlinks)
 
-	if list is None:
-		list=[]
+	if fpaths is None:
+		fpaths = []
 	if ftype is None:
-		ftype=[]
+		ftype = []
 
 	if not (filesonly or dirsonly or recursive):
-		return list
+		return fpaths
 
 	if recursive:
-		x=0
-		while x<len(ftype):
-			if ftype[x] == 1:
-				l,f = cacheddir(mypath+"/"+list[x], ignorecvs, ignorelist, EmptyOnError,
-					followSymlinks)
-
-				l=l[:]
-				for y in range(0,len(l)):
-					l[y]=list[x]+"/"+l[y]
-				list=list+l
-				ftype=ftype+f
-			x+=1
+		stack = list(zip(fpaths, ftype))
+		fpaths = []
+		ftype = []
+		while stack:
+			file_path, file_type = stack.pop()
+			fpaths.append(file_path)
+			ftype.append(file_type)
+			if file_type == 1:
+				subdir_list, subdir_types = cacheddir(
+					os.path.join(mypath, file_path), ignorecvs,
+					ignorelist, EmptyOnError, followSymlinks)
+				stack.extend((os.path.join(file_path, x), x_type)
+					for x, x_type in zip(subdir_list, subdir_types))
+
 	if filesonly:
-		rlist=[]
-		for x in range(0,len(ftype)):
-			if ftype[x]==0:
-				rlist=rlist+[list[x]]
+		fpaths = [x for x, x_type in zip(fpaths, ftype) if x_type == 0]
+
 	elif dirsonly:
-		rlist = []
-		for x in range(0, len(ftype)):
-			if ftype[x] == 1:
-				rlist = rlist + [list[x]]	
-	else:
-		rlist=list
+		fpaths = [x for x, x_type in zip(fpaths, ftype) if x_type == 1]
 
-	return rlist
+	return fpaths
-- 
2.26.2