SafeBrowising: Read and write V4Store from/to disk

components/safe_browsing_db/v4_store.proto

Index: components/safe_browsing_db/v4_store.proto
diff --git a/components/safe_browsing_db/v4_store.proto b/components/safe_browsing_db/v4_store.proto
new file mode 100644
index 0000000000000000000000000000000000000000..29e251ef275791877c88cc1d663b5be196e2a636
--- /dev/null
+++ b/components/safe_browsing_db/v4_store.proto
@@ -0,0 +1,27 @@
+// Copyright 2016 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.
+
+syntax = "proto2";
+
+import "safebrowsing.proto";
+
+option optimize_for = LITE_RUNTIME;
+
+package safe_browsing;
+
+// The message that's serialized to disk when a store update is processed.
+message V4StoreFileFormat {
+  // The magic bytes to identify this file as a SafeBrowsing hash-prefix file.
+  // https://en.wikipedia.org/wiki/Magic_number_(programming)

[Nathan Parker, 2016/06/16 00:07:50]

Is this to assert that your magic number hasn't been claimed?

[vakh (use Gerrit instead), 2016/06/16 08:25:19]

To assert that the file being read is a Store file.
Future versions of store may be very dissimilar in terms of the structure of the
proto, but the magic signature should be the same.

+  optional uint32 magic_number = 1;
+
+  // Identifies the version of the file we are reading.

[Nathan Parker, 2016/06/16 00:07:50]

// Identifies the version of the file format

[vakh (use Gerrit instead), 2016/06/16 08:25:18]

Done.

+  // Version 9 with PVer4 is very different from earlier versions.
+  optional uint32 version_number = 2;
+
+  // Contains the information about the store being written and the hash-prefix
+  // updates. For details about this message, see: safebrowsing.proto
+  optional FetchThreatListUpdatesResponse.ListUpdateResponse
+      list_update_response = 3;
+}