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[PATCH v2 12/14] git-p4: simplify regex pattern generation for parsing diff-tree

From
Yang Zhao <yang.zhao@skyboxlabs.com>
Date
Dec 13, 2019, 23:52 UTC
Message-ID
<20191213235247.23660-14-yang.zhao@skyboxlabs.com>
In-Reply-To
<20191213235247.23660-1-yang.zhao@skyboxlabs.com>

It is not clear why a generator was used to create the regex used to parse git-diff-tree output; I assume an early implementation required it, but is not part of the mainline change.

Simply use a lazily initialized global instead.
Signed-off-by: Yang Zhao <yang.zhao@skyboxlabs.com>
Reviewed-by: Ben Keene <seraphire@gmail.com>
---
 git-p4.py | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/git-p4.py b/git-p4.py
index b7e31d4738..3af8df9f83 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -544,12 +544,7 @@ def getGitTags():
         gitTags.add(tag)
     return gitTags
 
-def diffTreePattern():
-    # This is a simple generator for the diff tree regex pattern. This could be
-    # a class variable if this and parseDiffTreeEntry were a part of a class.
-    pattern = re.compile(':(\d+) (\d+) (\w+) (\w+) ([A-Z])(\d+)?\t(.*?)((\t(.*))|$)')
-    while True:
-        yield pattern
+_diff_tree_pattern = None
 
 def parseDiffTreeEntry(entry):
     """Parses a single diff tree entry into its component elements.
@@ -570,7 +565,11 @@ def parseDiffTreeEntry(entry):
 
     If the pattern is not matched, None is returned."""
 
-    match = diffTreePattern().next().match(entry)
+    global _diff_tree_pattern
+    if not _diff_tree_pattern:
+        _diff_tree_pattern = re.compile(':(\d+) (\d+) (\w+) (\w+) ([A-Z])(\d+)?\t(.*?)((\t(.*))|$)')
+
+    match = _diff_tree_pattern.match(entry)
     if match:
         return {
             'src_mode': match.group(1),
-- 
2.21.0.windows.1
Previous: Yang ZhaoNext: Yang Zhao
Message 19 of 22 in “git-p4: python3 compatibility”
  1. 00/14 git-p4: python3 compatibilityYang Zhao, Dec 13, 2019
  2. Yang ZhaoJan 17, 2020
  3. Luke DiamandJan 24, 2020
  4. Luke DiamandJan 30, 2020
  5. Luke DiamandFeb 3, 2020
  6. Yang ZhaoFeb 3, 2020
  7. Yang ZhaoFeb 4, 2020
  8. 01/14 git-p4: make python2.7 the oldest supported versionYang Zhao, Dec 13, 2019
  9. 02/14 git-p4: change the expansion test from basestring to listYang Zhao, Dec 13, 2019
  10. 05/14 git-p4: encode/decode communication with git for python3Yang Zhao, Dec 13, 2019
  11. 03/14 git-p4: remove string type aliasingYang Zhao, Dec 13, 2019
  12. 04/14 git-p4: encode/decode communication with p4 for python3Yang Zhao, Dec 13, 2019
  13. Junio C HamanoDec 17, 2019
  14. 08/14 git-p4: use marshal format version 2 when sending to p4Yang Zhao, Dec 13, 2019
  15. 07/14 git-p4: open .gitp4-usercache.txt in text modeYang Zhao, Dec 13, 2019
  16. 06/14 git-p4: convert path to unicode before processing themYang Zhao, Dec 13, 2019
  17. 09/14 git-p4: fix freezing while waiting for fast-import progressYang Zhao, Dec 13, 2019
  18. 10/14 git-p4: use functools.reduce instead of reduceYang Zhao, Dec 13, 2019
  19. 12/14 git-p4: simplify regex pattern generation for parsing diff-treeYang Zhao, Dec 13, 2019
  20. 11/14 git-p4: use dict.items() iteration for python3 compatibilityYang Zhao, Dec 13, 2019
  21. 14/14 ci: also run linux-gcc pipeline with python3.5 environmentYang Zhao, Dec 13, 2019
  22. 13/14 git-p4: use python3's input() everywhereYang Zhao, Dec 13, 2019

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