From ee5ebe05572bf83f3cb31ffd3ce79495ae698ba3 Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Sun, 29 Jan 2017 23:46:08 -0600
Subject: [PATCH] Fix O(n^2) behavior in name generation by remembering
previously successful counter
---
pytools/__init__.py | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/pytools/__init__.py b/pytools/__init__.py
index a02855c..0755496 100644
--- a/pytools/__init__.py
+++ b/pytools/__init__.py
@@ -1750,6 +1750,18 @@ def generate_unique_names(prefix):
try_num += 1
+def generate_numbered_unique_names(prefix, num=None):
+ orig_num = num
+ num = 0
+ if orig_num is None:
+ yield (num, prefix)
+
+ while True:
+ name = "%s_%d" % (prefix, num)
+ num += 1
+ yield (num, name)
+
+
generate_unique_possibilities = MovedFunctionDeprecationWrapper(
generate_unique_names)
@@ -1758,6 +1770,7 @@ class UniqueNameGenerator:
def __init__(self, existing_names=set(), forced_prefix=""):
self.existing_names = existing_names.copy()
self.forced_prefix = forced_prefix
+ self.prefix_to_counter = {}
def is_name_conflicting(self, name):
return name in self.existing_names
@@ -1777,10 +1790,14 @@ class UniqueNameGenerator:
def __call__(self, based_on="id"):
based_on = self.forced_prefix + based_on
- for var_name in generate_unique_names(based_on):
+ counter = self.prefix_to_counter.get(based_on, None)
+
+ for counter, var_name in generate_numbered_unique_names(based_on, counter):
if not self.is_name_conflicting(var_name):
break
+ self.prefix_to_counter[based_on] = counter
+
var_name = intern(var_name)
self.existing_names.add(var_name)
--
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