From b4ef64817c0af7bf73e6828ce9ccaeb301394c04 Mon Sep 17 00:00:00 2001
From: Marcin Kuzminski <marcin@rhodecode.com>
Date: Mon, 24 Sep 2018 15:59:38 +0200
Subject: [PATCH] diffs: make validation of version, so we can change diffs and
 force re-cache if diffs are in old version.

---
 rhodecode/lib/diffs.py | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/rhodecode/lib/diffs.py b/rhodecode/lib/diffs.py
index 189a13be..4ac51356 100644
--- a/rhodecode/lib/diffs.py
+++ b/rhodecode/lib/diffs.py
@@ -1134,10 +1134,23 @@ class DiffLimitExceeded(Exception):
     pass
 
 
+# NOTE(marcink): if diffs.mako change, probably this
+# needs a bump to next version
+CURRENT_DIFF_VERSION = 'v1'
+
+
+def _cleanup_cache_file(cached_diff_file):
+    # cleanup file to not store it "damaged"
+    try:
+        os.remove(cached_diff_file)
+    except Exception:
+        log.exception('Failed to cleanup path %s', cached_diff_file)
+
+
 def cache_diff(cached_diff_file, diff, commits):
 
     struct = {
-        'version': 'v1',
+        'version': CURRENT_DIFF_VERSION,
         'diff': diff,
         'commits': commits
     }
@@ -1148,17 +1161,13 @@ def cache_diff(cached_diff_file, diff, commits):
         log.debug('Saved diff cache under %s', cached_diff_file)
     except Exception:
         log.warn('Failed to save cache', exc_info=True)
-        # cleanup file to not store it "damaged"
-        try:
-            os.remove(cached_diff_file)
-        except Exception:
-            log.exception('Failed to cleanup path %s', cached_diff_file)
+        _cleanup_cache_file(cached_diff_file)
 
 
 def load_cached_diff(cached_diff_file):
 
     default_struct = {
-        'version': 'v1',
+        'version': CURRENT_DIFF_VERSION,
         'diff': None,
         'commits': None
     }
@@ -1182,6 +1191,12 @@ def load_cached_diff(cached_diff_file):
         # old version of data ?
         data = default_struct
 
+    # check version
+    if data.get('version') != CURRENT_DIFF_VERSION:
+        # purge cache
+        _cleanup_cache_file(cached_diff_file)
+        return default_struct
+
     return data