Query API: Introduces an OfflinePageModelQuery object.

components/offline_pages/offline_page_model_query.cc

Index: components/offline_pages/offline_page_model_query.cc
diff --git a/components/offline_pages/offline_page_model_query.cc b/components/offline_pages/offline_page_model_query.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3586aac33d675a103c322f35cdfc16b395ae8fd7
--- /dev/null
+++ b/components/offline_pages/offline_page_model_query.cc
@@ -0,0 +1,198 @@
+// 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.
+
+#include "components/offline_pages/offline_page_model_query.h"
+
+#include <algorithm>
+#include <unordered_set>
+
+#include "base/memory/ptr_util.h"
+
+namespace offline_pages {
+
+namespace {
+
+std::vector<std::string> InvertNamespaces(
+    ClientPolicyController* policy_controller,
+    const std::vector<std::string>& namespaces_to_remove) {
+  std::unordered_set<std::string> removal_set(namespaces_to_remove.begin(),
+                                              namespaces_to_remove.end());
+  std::vector<std::string> remaining_namespaces;
+  for (auto name_space : policy_controller->GetAllNamespaces()) {
+    if (removal_set.count(name_space) == 0)
+      remaining_namespaces.emplace_back(name_space);
+  }
+
+  return remaining_namespaces;
+}
+}
+
+OfflinePageModelQueryBuilder::OfflinePageModelQueryBuilder()
+    : query_(base::MakeUnique<OfflinePageModelQuery>()) {}
+
+OfflinePageModelQueryBuilder::~OfflinePageModelQueryBuilder() = default;
+
+OfflinePageModelQueryBuilder& OfflinePageModelQueryBuilder::SetOfflinePageIds(
+    const std::vector<int64_t>& ids) {
+  query_->offline_ids_ =
+      base::MakeUnique<std::set<int64_t>>(ids.begin(), ids.end());
+  return *this;
+}
+
+OfflinePageModelQueryBuilder& OfflinePageModelQueryBuilder::SetClientIds(
+    const std::vector<ClientId>& ids) {
+  query_->client_ids_ =
+      base::MakeUnique<std::set<ClientId>>(ids.begin(), ids.end());
+  return *this;
+}
+
+OfflinePageModelQueryBuilder& OfflinePageModelQueryBuilder::SetUrls(
+    const std::vector<GURL>& urls) {
+  query_->urls_ = base::MakeUnique<std::set<GURL>>(urls.begin(), urls.end());
+  return *this;
+}
+
+OfflinePageModelQueryBuilder&
+OfflinePageModelQueryBuilder::RequireSupportedByDownload(
+    Requirement supported_by_download) {
+  supported_by_download_ = supported_by_download;
+  return *this;
+}
+
+OfflinePageModelQueryBuilder&
+OfflinePageModelQueryBuilder::RequireShownAsRecentlyVisitedSite(
+    Requirement recently_visited) {
+  shown_as_recently_visited_site_ = recently_visited;
+  return *this;
+}
+
+OfflinePageModelQueryBuilder&
+OfflinePageModelQueryBuilder::RequireRestrictedToOriginalTab(
+    Requirement original_tab) {
+  restricted_to_original_tab_ = original_tab;
+  return *this;
+}
+
+OfflinePageModelQueryBuilder& OfflinePageModelQueryBuilder::AllowExpiredPages(
+    bool allow_expired) {
+  query_->allow_expired_ = allow_expired;
+  return *this;
+}
+
+void OfflinePageModelQueryBuilder::IntersectWithNamespaces(
+    ClientPolicyController* controller,
+    const std::vector<std::string>& namespaces,
+    bool invert) {
+  std::vector<std::string> desired_namespaces =
+      invert ? InvertNamespaces(controller, namespaces) : namespaces;
+  if (!query_->restricted_to_namespaces_) {
+    query_->restricted_to_namespaces_ = base::MakeUnique<std::set<std::string>>(
+        desired_namespaces.begin(), desired_namespaces.end());
+    return;
+  }
+
+  auto new_policy_set = base::MakeUnique<std::set<std::string>>();
+  for (auto& name_space : desired_namespaces) {
+    if (query_->restricted_to_namespaces_->count(name_space) > 0)
+      new_policy_set->insert(name_space);
+  }
+
+  query_->restricted_to_namespaces_.swap(new_policy_set);
+}
+
+std::unique_ptr<OfflinePageModelQuery> OfflinePageModelQueryBuilder::Build(
+    ClientPolicyController* controller) {
+  if (supported_by_download_ != Requirement::Unset) {
+    IntersectWithNamespaces(
+        controller, controller->GetNamespacesSupportedByDownload(),
+        supported_by_download_ == Requirement::OnlyNotMatching /* invert */);
+    supported_by_download_ = Requirement::Unset;
+  }
+  if (shown_as_recently_visited_site_ != Requirement::Unset) {
+    IntersectWithNamespaces(
+        controller, controller->GetNamespacesShownAsRecentlyVisitedSite(),
+        shown_as_recently_visited_site_ ==
+            Requirement::OnlyNotMatching /* invert */);
+    shown_as_recently_visited_site_ = Requirement::Unset;
+  }
+  if (restricted_to_original_tab_ != Requirement::Unset) {
+    IntersectWithNamespaces(controller,
+                            controller->GetNamespacesRestrictedToOriginalTab(),
+                            restricted_to_original_tab_ ==
+                                Requirement::OnlyNotMatching /* invert */);
+    restricted_to_original_tab_ = Requirement::Unset;
+  }
+
+  std::unique_ptr<OfflinePageModelQuery> returned_query;
+  // Swaps the current query with an uninitialized one.
+  query_.swap(returned_query);
+  query_ = base::MakeUnique<OfflinePageModelQuery>();
+  return returned_query;
+}
+
+OfflinePageModelQuery::OfflinePageModelQuery() = default;
+OfflinePageModelQuery::~OfflinePageModelQuery() = default;
+
+bool OfflinePageModelQuery::GetRestrictedToNamespaces(
+    std::set<std::string>* namespaces_out) {
+  if (!restricted_to_namespaces_)
+    return false;
+
+  *namespaces_out = *restricted_to_namespaces_;
+  return true;
+}
+
+bool OfflinePageModelQuery::GetRestrictedToOfflineIds(
+    std::set<int64_t>* ids_out) {
+  if (!offline_ids_)
+    return false;
+
+  *ids_out = *offline_ids_;
+  return true;
+}
+
+bool OfflinePageModelQuery::GetRestrictedToClientIds(
+    std::set<ClientId>* ids_out) {
+  if (!client_ids_)
+    return false;
+
+  *ids_out = *client_ids_;
+  return true;
+}
+
+bool OfflinePageModelQuery::GetRestrictedToUrls(std::set<GURL>* ids_out) {
+  if (!urls_)
+    return false;
+
+  *ids_out = *urls_;
+  return true;
+}
+
+bool OfflinePageModelQuery::GetAllowExpired() {
+  return allow_expired_;
+}
+
+bool OfflinePageModelQuery::Matches(const OfflinePageItem& item) {
+  if (!allow_expired_ && item.IsExpired())
+    return false;
+
+  if (offline_ids_ && offline_ids_->count(item.offline_id) == 0)
+    return false;
+
+  if (urls_ && urls_->count(item.url) == 0)
+    return false;
+
+  const ClientId& client_id = item.client_id;
+  if (restricted_to_namespaces_ &&
+      restricted_to_namespaces_->count(client_id.name_space) == 0) {
+    return false;
+  }
+
+  if (client_ids_ && client_ids_->count(client_id) == 0)
+    return false;
+
+  return true;
+}
+
+}  // namespace offline_pages