Migrate cookies for the time epoch change.

chrome/common/net/cookie_monster_sqlite.cc

 // Copyright (c) 2006-2008 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/common/net/cookie_monster_sqlite.h"
 
 #include <list>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 253 matching lines @@
 
 SQLitePersistentCookieStore::~SQLitePersistentCookieStore() {
   if (backend_.get()) {
     backend_->Close();
     // Release our reference, it will probably still have a reference if the
     // background thread has not run Close() yet.
     backend_ = NULL;
   }
 }
 
-// Version number of the database.
-static const int kCurrentVersionNumber = 3;
+// Version number of the database. In version 4, we migrated the time epoch.
+// If you open the DB with an older version on Mac or Linux, the times will
+// look wonky, but the file will likely be usable. On Windows version 3 and 4
+// are the same.
+static const int kCurrentVersionNumber = 4;
 static const int kCompatibleVersionNumber = 3;

[Evan Martin, 2009/09/01 00:04:14]

Can you doc this too?  (I checked the code and it seems correct to leave it at
3, but it'd be nice if the comments made it so I didn't need to check.)

 
 namespace {
 
 // Initializes the cookies table, returning true on success.
 bool InitTable(sqlite3* db) {
   if (!DoesSqliteTableExist(db, "cookies")) {
     if (sqlite3_exec(db, "CREATE TABLE cookies ("
                          "creation_utc INTEGER NOT NULL UNIQUE PRIMARY KEY,"
                          "host_key TEXT NOT NULL,"
                          "name TEXT NOT NULL,"
@@ skipping 99 matching lines @@
       LOG(WARNING) << "Unable to update cookie database to version 3.";
       return false;
     }
     ++cur_version;
     meta_table_.SetVersionNumber(cur_version);
     meta_table_.SetCompatibleVersionNumber(
         std::min(cur_version, kCompatibleVersionNumber));
     transaction.Commit();
   }
 
+  if (cur_version == 3) {
+    // The time epoch changed for Mac & Linux in this version to match Windows.
+    // This patch came after the main epoch change happened, so some
+    // developers have "good" times for cookies added by the more recent
+    // versions. So we have to be careful to only update times that are under
+    // the old system (which will appear to be from before 1970 in the new
+    // system). The magic number used below is 1970 in our time units.
+    SQLTransaction transaction(db);
+    transaction.Begin();
+#if !defined(OS_WIN)
+    sqlite3_exec(db,
+        "UPDATE cookies "
+        "SET creation_utc = creation_utc + 11644473600000000 "
+        "WHERE rowid IN "
+        "(SELECT rowid FROM cookies WHERE "
+          "creation_utc > 0 AND creation_utc < 11644473600000000)",
+        NULL, NULL, NULL);
+    sqlite3_exec(db,
+        "UPDATE cookies "
+        "SET expires_utc = expires_utc + 11644473600000000 "
+        "WHERE rowid IN "
+        "(SELECT rowid FROM cookies WHERE "
+          "expires_utc > 0 AND expires_utc < 11644473600000000)",
+        NULL, NULL, NULL);
+    sqlite3_exec(db,
+        "UPDATE cookies "
+        "SET last_access_utc = last_access_utc + 11644473600000000 "
+        "WHERE rowid IN "
+        "(SELECT rowid FROM cookies WHERE "
+          "last_access_utc > 0 AND last_access_utc < 11644473600000000)",
+        NULL, NULL, NULL);
+#endif
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+    transaction.Commit();
+  }
+
   // Put future migration cases here.
 
   // When the version is too old, we just try to continue anyway, there should
   // not be a released product that makes a database too old for us to handle.
   LOG_IF(WARNING, cur_version < kCurrentVersionNumber) <<
       "Cookie database version " << cur_version << " is too old to handle.";
 
   return true;
 }
 
 void SQLitePersistentCookieStore::AddCookie(
     const std::string& key,
     const net::CookieMonster::CanonicalCookie& cc) {
   if (backend_.get())
     backend_->AddCookie(key, cc);
 }
 
 void SQLitePersistentCookieStore::UpdateCookieAccessTime(
     const net::CookieMonster::CanonicalCookie& cc) {
   if (backend_.get())
     backend_->UpdateCookieAccessTime(cc);
 }
 
 void SQLitePersistentCookieStore::DeleteCookie(
     const net::CookieMonster::CanonicalCookie& cc) {
   if (backend_.get())
     backend_->DeleteCookie(cc);
 }