Add probability of culling if sync is enabled to https://chromiumcodereview.appspot.com/9585020/ In…

chrome/browser/webdata/autofill_entry.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "chrome/browser/webdata/autofill_entry.h"
+
 #include <algorithm>
 #include <set>
 
 #include "base/logging.h"
-#include "chrome/browser/webdata/autofill_entry.h"
 #include "base/utf_string_conversions.h"
 
+namespace {
+
+// The period after which Autofill entries should expire in days.
+const int64 kExpirationPeriodInDays = 60;
+
+}  // namespace
+
 AutofillKey::AutofillKey() {}
 
 AutofillKey::AutofillKey(const string16& name, const string16& value)
     : name_(name),
       value_(value) {
 }
 
 AutofillKey::AutofillKey(const char* name, const char* value)
     : name_(UTF8ToUTF16(name)),
       value_(UTF8ToUTF16(value)) {
@@ skipping 43 matching lines @@
       return false;
   }
 
   return true;
 }
 
 bool AutofillEntry::operator<(const AutofillEntry& entry) const {
   return key_ < entry.key();
 }
 
-// Culls the list of timestamps to the most recent |kMaxAutofillTimeStamps|.
+bool AutofillEntry::IsExpired() const {
+  base::Time time = ExpirationTime();
+  // TODO(georgey): add DCHECK(!timestamps_.empty()) after conversion of the db
+  // is complete.
+  return (timestamps_.empty() || timestamps_.back() < time);
+}
+
+// static
+base::Time AutofillEntry::ExpirationTime() {
+  return base::Time::Now() - base::TimeDelta::FromDays(kExpirationPeriodInDays);
+}
+
+// Culls the list of timestamps to the first and last used.
 // If sync is enabled, at every browser restart, sync will do a match up of all
 // autofill items on the server with all items on the web db. When webdb loads
 // all the items in memory(for sync to process. The method is
 // |GetAllAutofillEntries|) they will pass through this method for culling. If
 // sync finds any of these items were culled it will updates the server AND the
 // web db with these new timestamps. However after restart if an autofill item
 // exceeds the |kMaxAutofillTimeStamps| it will NOT be written to web db until
 // restart. But sync when uploading to the server will only upload this culled
 // list. Meaning until restart there will be mis-match in timestamps but
 // it should correct itself at startup.
-// Also if sync is not enabled this culling would never take place.
 bool AutofillEntry::CullTimeStamps(const std::vector<base::Time>& source,
-                                       std::vector<base::Time>* result) {
+                                   std::vector<base::Time>* result) {
   DCHECK(result);
   DCHECK(&source != result);
 
   // First copy the source to result.
   result->clear();
-  result->insert(result->begin(), source.begin(), source.end());
 
-  if (source.size() <= kMaxAutofillTimeStamps)
+  if (source.size() <= 2) {
+    result->insert(result->begin(), source.begin(), source.end());
     return false;
+  }
 
-  VLOG(1) << "Culling timestamps. Current count is : " << source.size();
+  result->push_back(source.front());
+  result->push_back(source.back());
 
-  // Regular sort does ascending order. So we pass in a comparator function.
-  partial_sort(result->begin(), result->begin() + kMaxAutofillTimeStamps,
-               result->end(), std::greater<base::Time>());
-
-  result->erase(result->begin() + kMaxAutofillTimeStamps, result->end());
+  DVLOG(1) << "Culling timestamps. Current count is : " << source.size();
 
   return true;
 }