AppCache: Run a quick integrity check on the sqlite database when opening.

sql/connection.h

Index: sql/connection.h
diff --git a/sql/connection.h b/sql/connection.h
index ec76e3be89a133075f287cfb917cdd2c5ba91e30..402b75334e16e15ca9e532e34db7f639ddcfcb35 100644
--- a/sql/connection.h
+++ b/sql/connection.h
@@ -154,7 +154,13 @@ class SQL_EXPORT Connection {
   // |messages|.  Returns the success of running the statement - per
   // the SQLite documentation, if no errors are found the call should
   // succeed, and a single value "ok" should be in messages.
-  bool IntegrityCheck(std::vector<std::string>* messages);
+  bool FullIntegrityCheck(std::vector<std::string>* messages) {
+    return IntegrityCheck(messages, false);
+  }
+  bool QuickIntegrityCheck(std::vector<std::string>* messages) {
+    return IntegrityCheck(messages, true);
+  }
+  bool IntegrityCheck(std::vector<std::string>* messages, bool quick);

[Scott Hess - ex-Googler, 2013/12/06 00:44:00]

Move IntegrityCheck() to private, maybe call it "IntegrityCheckHelper(), and put
the in parameter before the out parameter.

I'm a little nervous about having these inline in the header.  There's no
performance reason for it (running the integrity check is like a billion times
more expensive than function-call overhead).  It maybe would make sense to move
them into the .cc and just have them pass in the pragma rather than passing a
bool which modifies the pragma.

It would be nice to have a unit test for both cases doing what they say.  I
_think_ that a quick check would probably succeed on the corruption helper which
messes up the index/table relationship, while a full check would not.

 
   // Initialization ------------------------------------------------------------