components/drive/change_list_processor.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_DRIVE_CHANGE_LIST_PROCESSOR_H_
   6 #define COMPONENTS_DRIVE_CHANGE_LIST_PROCESSOR_H_
   7
   8 #include <map>
   9 #include <set>
  10 #include <string>
  11
  12 #include "base/files/file_path.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/memory/scoped_vector.h"
  15 #include "components/drive/file_errors.h"
  16 #include "components/drive/file_errors.h"
  17 #include "url/gurl.h"
  18
  19 namespace base {
  20 class CancellationFlag;
  21 }  // namespace base
  22
  23 namespace google_apis {
  24 class AboutResource;
  25 class ChangeList;
  26 class FileList;
  27 }  // namespace google_apis
  28
  29 namespace drive {
  30
  31 class FileChange;
  32 class ResourceEntry;
  33
  34 namespace internal {
  35
  36 class ResourceMetadata;
  37
  38 // Holds information needed to fetch contents of a directory.
  39 // This object is copyable.
  40 class DirectoryFetchInfo {
  41  public:
  42   DirectoryFetchInfo() : changestamp_(0) {}
  43   DirectoryFetchInfo(const std::string& local_id,
  44                      const std::string& resource_id,
  45                      int64 changestamp)
  46       : local_id_(local_id),
  47         resource_id_(resource_id),
  48         changestamp_(changestamp) {
  49   }
  50
  51   // Returns true if the object is empty.
  52   bool empty() const { return local_id_.empty(); }
  53
  54   // Local ID of the directory.
  55   const std::string& local_id() const { return local_id_; }
  56
  57   // Resource ID of the directory.
  58   const std::string& resource_id() const { return resource_id_; }
  59
  60   // Changestamp of the directory. The changestamp is used to determine if
  61   // the directory contents should be fetched.
  62   int64 changestamp() const { return changestamp_; }
  63
  64   // Returns a string representation of this object.
  65   std::string ToString() const;
  66
  67  private:
  68   const std::string local_id_;
  69   const std::string resource_id_;
  70   const int64 changestamp_;
  71 };
  72
  73 // Class to represent a change list.
  74 class ChangeList {
  75  public:
  76   ChangeList();  // For tests.
  77   explicit ChangeList(const google_apis::ChangeList& change_list);
  78   explicit ChangeList(const google_apis::FileList& file_list);
  79   ~ChangeList();
  80
  81   const std::vector<ResourceEntry>& entries() const { return entries_; }
  82   std::vector<ResourceEntry>* mutable_entries() { return &entries_; }
  83   const std::vector<std::string>& parent_resource_ids() const {
  84     return parent_resource_ids_;
  85   }
  86   std::vector<std::string>* mutable_parent_resource_ids() {
  87     return &parent_resource_ids_;
  88   }
  89   const GURL& next_url() const { return next_url_; }
  90   int64 largest_changestamp() const { return largest_changestamp_; }
  91
  92   void set_largest_changestamp(int64 largest_changestamp) {
  93     largest_changestamp_ = largest_changestamp;
  94   }
  95
  96  private:
  97   std::vector<ResourceEntry> entries_;
  98   std::vector<std::string> parent_resource_ids_;
  99   GURL next_url_;
 100   int64 largest_changestamp_;
 101
 102   DISALLOW_COPY_AND_ASSIGN(ChangeList);
 103 };
 104
 105 // ChangeListProcessor is used to process change lists, or full resource
 106 // lists from WAPI (codename for Documents List API) or Google Drive API, and
 107 // updates the resource metadata stored locally.
 108 class ChangeListProcessor {
 109  public:
 110   ChangeListProcessor(ResourceMetadata* resource_metadata,
 111                       base::CancellationFlag* in_shutdown);
 112   ~ChangeListProcessor();
 113
 114   // Applies change lists or full resource lists to |resource_metadata_|.
 115   //
 116   // |is_delta_update| determines the type of input data to process, whether
 117   // it is full resource lists (false) or change lists (true).
 118   //
 119   // Must be run on the same task runner as |resource_metadata_| uses.
 120   FileError Apply(scoped_ptr<google_apis::AboutResource> about_resource,
 121                   ScopedVector<ChangeList> change_lists,
 122                   bool is_delta_update);
 123
 124   // The set of changed files as a result of change list processing.
 125   const FileChange& changed_files() const { return *changed_files_; }
 126
 127   // Adds or refreshes the child entries from |change_list| to the directory.
 128   static FileError RefreshDirectory(
 129       ResourceMetadata* resource_metadata,
 130       const DirectoryFetchInfo& directory_fetch_info,
 131       scoped_ptr<ChangeList> change_list,
 132       std::vector<ResourceEntry>* out_refreshed_entries);
 133
 134   // Sets |entry|'s parent_local_id.
 135   static FileError SetParentLocalIdOfEntry(
 136       ResourceMetadata* resource_metadata,
 137       ResourceEntry* entry,
 138       const std::string& parent_resource_id);
 139
 140  private:
 141   typedef std::map<std::string /* resource_id */, ResourceEntry>
 142       ResourceEntryMap;
 143   typedef std::map<std::string /* resource_id */,
 144                    std::string /* parent_resource_id*/> ParentResourceIdMap;
 145
 146   // Applies the pre-processed metadata from entry_map_ onto the resource
 147   // metadata. |about_resource| must not be null.
 148   FileError ApplyEntryMap(
 149       int64 changestamp,
 150       scoped_ptr<google_apis::AboutResource> about_resource);
 151
 152   // Apply |entry| to resource_metadata_.
 153   FileError ApplyEntry(const ResourceEntry& entry);
 154
 155   // Adds the directories changed by the update on |entry| to |changed_dirs_|.
 156   void UpdateChangedDirs(const ResourceEntry& entry);
 157
 158   ResourceMetadata* resource_metadata_;  // Not owned.
 159   base::CancellationFlag* in_shutdown_;  // Not owned.
 160
 161   ResourceEntryMap entry_map_;
 162   ParentResourceIdMap parent_resource_id_map_;
 163   scoped_ptr<FileChange> changed_files_;
 164
 165   DISALLOW_COPY_AND_ASSIGN(ChangeListProcessor);
 166 };
 167
 168 }  // namespace internal
 169 }  // namespace drive
 170
 171 #endif  // COMPONENTS_DRIVE_CHANGE_LIST_PROCESSOR_H_