Bug 1380606 - Add an `IS_VALID_GUID()` SQL function to Places. r=mak

This exposes `IsValidGUID` to SQL, matching `GENERATE_GUID()` and
making it easier to SELECT rows with invalid GUIDs.

MozReview-Commit-ID: Dspm8A59P5L

--HG--
extra : rebase_source : 9bbc853ae3892314cc3bab7469c0f9c25706aea5

toolkit/components/places/Database.cpp

@@ -1330,6 +1330,8 @@ Database::InitFunctions()
   NS_ENSURE_SUCCESS(rv, rv);
   rv = GenerateGUIDFunction::create(mMainConn);
   NS_ENSURE_SUCCESS(rv, rv);
+  rv = IsValidGUIDFunction::create(mMainConn);
+  NS_ENSURE_SUCCESS(rv, rv);
   rv = FixupURLFunction::create(mMainConn);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = FrecencyNotificationFunction::create(mMainConn);

toolkit/components/places/SQLFunctions.cpp

@@ -771,6 +771,40 @@ namespace places {
     return NS_OK;
   }
 
+////////////////////////////////////////////////////////////////////////////////
+//// GUID Validation Function
+
+  /* static */
+  nsresult
+  IsValidGUIDFunction::create(mozIStorageConnection *aDBConn)
+  {
+    RefPtr<IsValidGUIDFunction> function = new IsValidGUIDFunction();
+    return aDBConn->CreateFunction(
+      NS_LITERAL_CSTRING("is_valid_guid"), 1, function
+    );
+  }
+
+  NS_IMPL_ISUPPORTS(
+    IsValidGUIDFunction,
+    mozIStorageFunction
+  )
+
+  NS_IMETHODIMP
+  IsValidGUIDFunction::OnFunctionCall(mozIStorageValueArray *aArguments,
+                                      nsIVariant **_result)
+  {
+    // Must have non-null function arguments.
+    MOZ_ASSERT(aArguments);
+
+    nsAutoCString guid;
+    aArguments->GetUTF8String(0, guid);
+
+    RefPtr<nsVariant> result = new nsVariant();
+    result->SetAsBool(IsValidGUID(guid));
+    result.forget(_result);
+    return NS_OK;
+  }
+
 ////////////////////////////////////////////////////////////////////////////////
 //// Get Unreversed Host Function
 

toolkit/components/places/SQLFunctions.h

@@ -241,6 +241,29 @@ private:
   ~GenerateGUIDFunction() {}
 };
 
+/**
+ * SQL function to check if a GUID is valid.  This is just a wrapper around
+ * IsValidGUID in Helpers.h.
+ *
+ * @return true if valid, false otherwise.
+ */
+class IsValidGUIDFunction final : public mozIStorageFunction
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_MOZISTORAGEFUNCTION
+
+  /**
+   * Registers the function with the specified database connection.
+   *
+   * @param aDBConn
+   *        The database connection to register with.
+   */
+  static nsresult create(mozIStorageConnection *aDBConn);
+private:
+  ~IsValidGUIDFunction() {}
+};
+
 /**
  * SQL function to unreverse the rev_host of a page.
  *