Move hg from storing files in data with base64 encoding to full

Move hg from storing files in data with base64 encoding to full
pathnames with .i and .d extensions. This means we naturally get good
FS layout, and cp and tar fix things up nicely rather than pessimizing
layout.

--- a/mercurial/hg.py	Fri May 20 17:22:02 2005 -0800
+++ b/mercurial/hg.py	Fri May 20 17:27:21 2005 -0800
@@ -5,7 +5,7 @@
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
-import sys, struct, sha, socket, os, time, base64, re, urllib2
+import sys, struct, sha, socket, os, time, re, urllib2
 import urllib
 from mercurial import byterange
 from mercurial.transaction import *
@@ -14,16 +14,7 @@
 
 class filelog(revlog):
     def __init__(self, opener, path):
-        s = self.encodepath(path)
-        revlog.__init__(self, opener, os.path.join("data", s + "i"),
-                        os.path.join("data", s))
-
-    def encodepath(self, path):
-        s = sha.sha(path).digest()
-        s = base64.encodestring(s)[:-3]
-        s = re.sub("\+", "%", s)
-        s = re.sub("/", "_", s)
-        return s
+        revlog.__init__(self, opener, path + ".i", path + ".d")
 
     def read(self, node):
         return self.revision(node)
@@ -210,11 +201,17 @@
 
         f = os.path.join(p, path)
 
-        if mode != "r" and os.path.isfile(f):
-            s = os.stat(f)
-            if s.st_nlink > 1:
-                file(f + ".tmp", "w").write(file(f).read())
-                os.rename(f+".tmp", f)
+        if mode != "r":
+            try:
+                s = os.stat(f)
+            except OSError:
+                d = os.path.dirname(f)
+                if not os.path.isdir(d):
+                    os.makedirs(d)
+            else:
+                if s.st_nlink > 1:
+                    file(f + ".tmp", "w").write(file(f).read())
+                    os.rename(f+".tmp", f)
 
         return file(f, mode)