Fetch incremental updates. Store new state in V4Store.

components/safe_browsing_db/v4_store.cc

Index: components/safe_browsing_db/v4_store.cc
diff --git a/components/safe_browsing_db/v4_store.cc b/components/safe_browsing_db/v4_store.cc
index 0262965bedc5daf2f2ceffbf96d1e5b171b815fd..a887185422590057e0163b2ed0f1eefeed2111fa 100644
--- a/components/safe_browsing_db/v4_store.cc
+++ b/components/safe_browsing_db/v4_store.cc
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/base64.h"
+#include "base/bind.h"
+#include "base/strings/stringprintf.h"
 #include "components/safe_browsing_db/v4_store.h"
 
 namespace safe_browsing {
@@ -16,11 +19,47 @@ V4Store::V4Store(const scoped_refptr<base::SequencedTaskRunner>& task_runner,
                  const base::FilePath& store_path)
     : task_runner_(task_runner), store_path_(store_path) {}
 
-V4Store::~V4Store() {}
+V4Store::V4Store(const V4Store& other)
+    : task_runner_(other.task_runner_), store_path_(other.store_path_) {}

[Nathan Parker, 2016/06/15 21:24:21]

Document what this constructor does or will do in the future, since (I expect)
it'll only copy some of the state.

[vakh (use Gerrit instead), 2016/06/16 01:07:35]

Done.

+
+V4Store::~V4Store() {
+  DVLOG(1) << "Destroying V4Store: " << *this;
+}
+
+std::string V4Store::DebugString() const {
+  std::string value;
+  base::SStringPrintf(&value, "path: %s; state: %s",
+                      store_path_.value().c_str(),
+                      GetHumanReadableState().c_str());
+  return value;
+}
 
 bool V4Store::Reset() {
   // TODO(vakh): Implement skeleton.
+  state_ = "";
   return true;
 }
 
+void V4Store::ApplyUpdate(
+    const ListUpdateResponse& response,
+    const scoped_refptr<base::SingleThreadTaskRunner>& callback_task_runner,
+    UpdatedStoreReadyCallback callback) {
+  std::unique_ptr<V4Store> new_store(new V4Store(*this));
+
+  // TODO(vakh): The new store currently only picks up the new state. Do more.
+  new_store->state_ = response.new_client_state();
+
+  DVLOG(1) << "Created V4Store: " << new_store->DebugString();
+
+  // new_store is done updataing, pass it to the callback.

[Nathan Parker, 2016/06/15 21:24:19]

nit: updating

[vakh (use Gerrit instead), 2016/06/16 01:07:35]

Done.

+  callback_task_runner->PostTask(
+      FROM_HERE, base::Bind(callback, base::Passed(&new_store)));
+}
+
+std::string V4Store::GetHumanReadableState() const {
+  std::string state_base64;
+  base::Base64Encode(state_, &state_base64);
+  return state_base64;
+}
+
 }  // namespace safe_browsing