Added diff scheme checker.

5 files changed, 188 insertions, 0 deletions

diff --git a/storage/CMakeLists.txt b/storage/CMakeLists.txt
index 1048cd0ff3..d8799ac5a0 100644
--- a/storage/CMakeLists.txt
+++ b/storage/CMakeLists.txt
@@ -15,6 +15,9 @@ set(
   country_name_getter.hpp
   country_polygon.hpp
   country_tree.hpp
+  diff_scheme_checker.cpp
+  diff_scheme_checker.hpp
+  diff_types.hpp
   downloader_search_params.hpp
   downloading_policy.cpp
   downloading_policy.hpp
diff --git a/storage/diff_scheme_checker.cpp b/storage/diff_scheme_checker.cpp
new file mode 100644
index 0000000000..d5b16ac909
--- /dev/null
+++ b/storage/diff_scheme_checker.cpp
@@ -0,0 +1,131 @@
+#include "storage/diff_scheme_checker.hpp"
+
+#include "platform/http_client.hpp"
+#include "platform/platform.hpp"
+
+#include "base/logging.hpp"
+#include "base/thread.hpp"
+
+#include <memory>
+#include <utility>
+
+#include "3party/jansson/myjansson.hpp"
+
+#include "private.h"
+
+using namespace std;
+
+namespace
+{
+using namespace diff_scheme;
+
+char const * const kMaxVersionKey = "max_version";
+char const * const kMwmsKey = "mwms";
+char const * const kNameKey = "name";
+char const * const kSizeKey = "size";
+char const * const kVersionKey = "version";
+
+string SerializeCheckerData(Checker::LocalMapsInfo const & info)
+{
+  auto mwmsArrayNode = my::NewJSONArray();
+  for (auto const & nameAndVersion : info.m_localMaps)
+  {
+    auto node = my::NewJSONObject();
+    ToJSONObject(*node, kNameKey, nameAndVersion.first);
+    ToJSONObject(*node, kVersionKey, nameAndVersion.second);
+    json_array_append_new(mwmsArrayNode.get(), node.release());
+  }
+
+  auto const root = my::NewJSONObject();
+  json_object_set_new(root.get(), kMwmsKey, mwmsArrayNode.release());
+  ToJSONObject(*root, kMaxVersionKey, info.m_currentDataVersion);
+  unique_ptr<char, JSONFreeDeleter> buffer(json_dumps(root.get(), JSON_COMPACT | JSON_ENSURE_ASCII));
+  return buffer.get();
+}
+
+NameFileMap DeserializeResponse(string const & response, Checker::NameVersionMap const & nameVersionMap)
+{
+  if (response.empty())
+  {
+    LOG(LERROR, ("Diff responce shouldn't be empty."));
+    return {};
+  }
+
+  my::Json const json(response.c_str());
+  if (json.get() == nullptr)
+    return {};
+
+  auto const root = json_object_get(json.get(), kMwmsKey);
+  if (root == nullptr || !json_is_array(root))
+    return {};
+
+  auto const size = json_array_size(root);
+  if (size == 0 || size != nameVersionMap.size())
+  {
+    LOG(LERROR, ("Diff list size in response must be equal to mwm list size in request."));
+    return {};
+  }
+
+  NameFileMap diffs;
+
+  for (size_t i = 0; i < size; ++i)
+  {
+    auto const node = json_array_get(root, i);
+
+    if (!node)
+    {
+      LOG(LERROR, ("Incorrect server response."));
+      return diffs;
+    }
+
+    string name;
+    FromJSONObject(node, kNameKey, name);
+    int64_t size;
+    FromJSONObject(node, kSizeKey, size);
+    // Invalid size. The diff is not available.
+    if (size == -1)
+      continue;
+
+    if (nameVersionMap.find(name) == nameVersionMap.end())
+    {
+      LOG(LERROR, ("Incorrect country name in response:", name));
+      return {};
+    }
+
+    FileInfo info(size, nameVersionMap.at(name));
+    diffs.emplace(move(name), move(info));
+  }
+
+  return diffs;
+}
+}  // namespace
+
+namespace diff_scheme
+{
+// static
+void Checker::Check(LocalMapsInfo const & info, Callback const & fn)
+{
+  // TODO(Vlad): Log falling back to old scheme.
+  if (info.m_localMaps.empty())
+  {
+    fn({});
+    return;
+  }
+
+  threads::SimpleThread thread([info, fn] {
+    platform::HttpClient request(DIFF_LIST_URL);
+    // TODO(Vlad): Check request's time.
+    string const body = SerializeCheckerData(info);
+    ASSERT(!body.empty(), ());
+    request.SetBodyData(body, "application/json");
+    NameFileMap diffs;
+    if (request.RunHttpRequest() && !request.WasRedirected() && request.ErrorCode() == 200)
+      diffs = DeserializeResponse(request.ServerResponse(), info.m_localMaps);
+
+    GetPlatform().RunOnGuiThread([fn, diffs] {
+      fn(diffs);
+    });
+  });
+  thread.detach();
+}
+}  // namespace diff_scheme
diff --git a/storage/diff_scheme_checker.hpp b/storage/diff_scheme_checker.hpp
new file mode 100644
index 0000000000..c338604769
--- /dev/null
+++ b/storage/diff_scheme_checker.hpp
@@ -0,0 +1,27 @@
+#pragma once
+
+#include "storage/diff_types.hpp"
+
+#include <cstdint>
+#include <functional>
+#include <string>
+#include <unordered_map>
+
+namespace diff_scheme
+{
+class Checker final
+{
+public:
+  using NameVersionMap = std::unordered_map<std::string, uint64_t>;
+
+  struct LocalMapsInfo final
+  {
+    uint64_t m_currentDataVersion = 0;
+    NameVersionMap m_localMaps;
+  };
+
+  using Callback = std::function<void(NameFileMap const & diffs)>;
+
+  static void Check(LocalMapsInfo const & info, Callback const & fn);
+};
+}  // namespace diff_scheme
diff --git a/storage/diff_types.hpp b/storage/diff_types.hpp
new file mode 100644
index 0000000000..9f01d8f079
--- /dev/null
+++ b/storage/diff_types.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <unordered_map>
+
+namespace diff_scheme
+{
+enum class Status
+{
+  Undefined,
+  NotAvailable,
+  Available
+};
+
+struct FileInfo final
+{
+  FileInfo(uint64_t size, uint64_t version) : m_size(size), m_version(version) {}
+  uint64_t m_size;
+  uint64_t m_version;
+};
+
+using NameFileMap = std::unordered_map<std::string, FileInfo>;
+}  // namespace diff_scheme
diff --git a/storage/storage.pro b/storage/storage.pro
index e0ac68c67f..818b511ab5 100644
--- a/storage/storage.pro
+++ b/storage/storage.pro
@@ -17,6 +17,8 @@ HEADERS += \
   country_name_getter.hpp \
   country_polygon.hpp \
   country_tree.hpp \
+  diff_scheme_checker.hpp \
+  diff_types.hpp \
   downloader_search_params.hpp \
   downloading_policy.hpp \
   http_map_files_downloader.hpp \
@@ -32,6 +34,7 @@ SOURCES += \
   country_decl.cpp \
   country_info_getter.cpp \
   country_name_getter.cpp \
+  diff_scheme_checker.cpp \
   downloading_policy.cpp \
   http_map_files_downloader.cpp \
   index.cpp \