util: create bytecount array just once

This avoids tons of gettext calls on workloads that call bytecount a lot.

mercurial/util.py

@@ -1167,10 +1167,7 b' def ellipsis(text, maxlength=400):'
     except (UnicodeDecodeError, UnicodeEncodeError):
         return _ellipsis(text, maxlength)[0]
 
-def bytecount(nbytes):
-    '''return byte count formatted as readable string, with units'''
-
-    units = (
+_byteunits = (
         (100, 1 << 30, _('%.0f GB')),
         (10, 1 << 30, _('%.1f GB')),
         (1, 1 << 30, _('%.2f GB')),
@@ -1183,7 +1180,10 b' def bytecount(nbytes):'
         (1, 1, _('%.0f bytes')),
         )
 
-    for multiplier, divisor, format in units:
+def bytecount(nbytes):
+    '''return byte count formatted as readable string, with units'''
+
+    for multiplier, divisor, format in _byteunits:
         if nbytes >= divisor * multiplier:
             return format % (nbytes / float(divisor))
     return units[-1][2] % nbytes