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..346a7c0e024af009e3394f94c6b7530206029f36
--- /dev/null
+++ b/components/offline_pages/offline_page_model_query.cc
@@ -0,0 +1,257 @@
+// 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 {
+
+using Requirement = OfflinePageModelQuery::Requirement;
+
+namespace {
+
+void SubtractNamespaces(std::vector<std::string>* namespaces,
+                        const std::vector<std::string>& to_remove) {
+  std::set<std::string> remove_set(to_remove.begin(), to_remove.end());
+  auto found = [remove_set](const std::string& name_space) {
+    return remove_set.count(name_space) > 0;
+  };
+  namespaces->erase(
+      std::remove_if(namespaces->begin(), namespaces->end(), found),
+      namespaces->end());
+}
+
+void IntersectNamespaces(std::vector<std::string>* namespaces,
+                         const std::vector<std::string>& intersect_with) {
+  std::set<std::string> intersect_set(intersect_with.begin(),
+                                      intersect_with.end());
+  auto missing = [intersect_set](const std::string& name_space) {
+    return intersect_set.count(name_space) == 0;
+  };
+  namespaces->erase(
+      std::remove_if(namespaces->begin(), namespaces->end(), missing),
+      namespaces->end());
+}
+
+}  // namespace
+
+OfflinePageModelQueryBuilder::OfflinePageModelQueryBuilder()
+    : offline_ids_(std::make_pair(Requirement::UNSET, std::vector<int64_t>())) {
+}
+
+OfflinePageModelQueryBuilder::~OfflinePageModelQueryBuilder() = default;
+
+OfflinePageModelQueryBuilder& OfflinePageModelQueryBuilder::SetOfflinePageIds(
+    Requirement requirement,
+    const std::vector<int64_t>& ids) {
+  offline_ids_ = std::make_pair(requirement, ids);
+  return *this;
+}
+
+OfflinePageModelQueryBuilder& OfflinePageModelQueryBuilder::SetClientIds(
+    Requirement requirement,
+    const std::vector<ClientId>& ids) {
+  client_ids_ = std::make_pair(requirement, ids);
+  return *this;
+}
+
+OfflinePageModelQueryBuilder& OfflinePageModelQueryBuilder::SetUrls(
+    Requirement requirement,
+    const std::vector<GURL>& urls) {
+  urls_ = std::make_pair(requirement, urls);
+  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) {
+  allow_expired_ = allow_expired;
+  return *this;
+}
+
+std::unique_ptr<OfflinePageModelQuery> OfflinePageModelQueryBuilder::Build(
+    ClientPolicyController* controller) {
+  auto query = base::MakeUnique<OfflinePageModelQuery>();
+
+  query->allow_expired_ = allow_expired_;
+  query->urls_ = std::make_pair(
+      urls_.first, std::set<GURL>(urls_.second.begin(), urls_.second.end()));
+  urls_ = std::make_pair(Requirement::UNSET, std::vector<GURL>());
+  query->offline_ids_ = std::make_pair(
+      offline_ids_.first, std::set<int64_t>(offline_ids_.second.begin(),
+                                            offline_ids_.second.end()));
+  offline_ids_ = std::make_pair(Requirement::UNSET, std::vector<int64_t>());
+  query->client_ids_ = std::make_pair(
+      client_ids_.first,
+      std::set<ClientId>(client_ids_.second.begin(), client_ids_.second.end()));
+  client_ids_ = std::make_pair(Requirement::UNSET, std::vector<ClientId>());
+
+  std::vector<std::string> allowed_namespaces = controller->GetAllNamespaces();
+
+  std::vector<std::pair<Requirement, std::vector<std::string>>> op_list;
+  if (supported_by_download_ != Requirement::UNSET) {
+    op_list.emplace_back(
+        std::make_pair(supported_by_download_,
+                       controller->GetNamespacesSupportedByDownload()));
+  }
+  if (shown_as_recently_visited_site_ != Requirement::UNSET) {
+    op_list.emplace_back(
+        std::make_pair(shown_as_recently_visited_site_,
+                       controller->GetNamespacesShownAsRecentlyVisitedSite()));
+  }
+  if (restricted_to_original_tab_ != Requirement::UNSET) {
+    op_list.emplace_back(
+        std::make_pair(restricted_to_original_tab_,
+                       controller->GetNamespacesRestrictedToOriginalTab()));
+  }
+
+  for (auto& requirement_namespace_pair : op_list) {
+    Requirement r = requirement_namespace_pair.first;
+    const std::vector<std::string>& namespaces =
+        requirement_namespace_pair.second;
+
+    switch (r) {
+      case Requirement::UNSET:
+        break;
+      case Requirement::MATCH:
+        IntersectNamespaces(&allowed_namespaces, namespaces);
+        break;
+      case Requirement::EXCLUDE:
+        SubtractNamespaces(&allowed_namespaces, namespaces);
+        break;
+    }
+  }
+
+  supported_by_download_ = Requirement::UNSET;
+  shown_as_recently_visited_site_ = Requirement::UNSET;
+  restricted_to_original_tab_ = Requirement::UNSET;
+
+  if (op_list.size() > 0) {
+    query->restricted_to_namespaces_ = base::MakeUnique<std::set<std::string>>(
+        allowed_namespaces.begin(), allowed_namespaces.end());
+  }
+
+  return 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;
+}
+
+Requirement OfflinePageModelQuery::GetRestrictedToOfflineIds(
+    std::set<int64_t>* ids_out) {
+  if (offline_ids_.first == Requirement::UNSET)
+    return Requirement::UNSET;
+
+  *ids_out = offline_ids_.second;
+  return offline_ids_.first;
+}
+
+Requirement OfflinePageModelQuery::GetRestrictedToClientIds(
+    std::set<ClientId>* ids_out) {
+  if (client_ids_.first == Requirement::UNSET)
+    return Requirement::UNSET;
+
+  *ids_out = client_ids_.second;
+  return client_ids_.first;
+}
+
+Requirement OfflinePageModelQuery::GetRestrictedToUrls(
+    std::set<GURL>* urls_out) {
+  if (urls_.first == Requirement::UNSET)
+    return Requirement::UNSET;
+
+  *urls_out = urls_.second;
+  return urls_.first;
+}
+
+bool OfflinePageModelQuery::GetAllowExpired() {
+  return allow_expired_;
+}
+
+bool OfflinePageModelQuery::Matches(const OfflinePageItem& item) {
+  if (!allow_expired_ && item.IsExpired())
+    return false;
+
+  switch (offline_ids_.first) {
+    case Requirement::UNSET:
+      break;
+    case Requirement::MATCH:
+      if (offline_ids_.second.count(item.offline_id) == 0)
+        return false;
+      break;
+    case Requirement::EXCLUDE:
+      if (offline_ids_.second.count(item.offline_id) > 0)
+        return false;
+      break;
+  }
+
+  switch (urls_.first) {
+    case Requirement::UNSET:
+      break;
+    case Requirement::MATCH:
+      if (urls_.second.count(item.url) == 0)
+        return false;
+      break;
+    case Requirement::EXCLUDE:
+      if (urls_.second.count(item.url) > 0)
+        return false;
+      break;
+  }
+
+  const ClientId& client_id = item.client_id;
+  if (restricted_to_namespaces_ &&
+      restricted_to_namespaces_->count(client_id.name_space) == 0) {
+    return false;
+  }
+
+  switch (client_ids_.first) {
+    case Requirement::UNSET:
+      break;
+    case Requirement::MATCH:
+      if (client_ids_.second.count(client_id) == 0)
+        return false;
+      break;
+    case Requirement::EXCLUDE:
+      if (client_ids_.second.count(client_id) > 0)
+        return false;
+      break;
+  }
+
+  return true;
+}
+
+}  // namespace offline_pages