components/dom_distiller/core/dom_distiller_model.h

   1 // Copyright 2013 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_DOM_DISTILLER_CORE_DOM_DISTILLER_MODEL_H_
   6 #define COMPONENTS_DOM_DISTILLER_CORE_DOM_DISTILLER_MODEL_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/containers/hash_tables.h"
  12 #include "base/id_map.h"
  13 #include "components/dom_distiller/core/article_entry.h"
  14 #include "sync/api/sync_change.h"
  15 #include "sync/api/sync_change_processor.h"  // syncer::SyncChangeList
  16 #include "sync/api/sync_data.h"
  17 #include "url/gurl.h"
  18
  19 namespace dom_distiller {
  20
  21 // This stores the in-memory model of the DOM distiller list. Entries can be
  22 // looked up by URL or by entry_id.
  23 // The model assumes that an URL corresponds to at most a single entry. If this
  24 // assumption is broken, lookup by URL may return unexpected results.
  25 class DomDistillerModel {
  26  public:
  27   DomDistillerModel();
  28   explicit DomDistillerModel(const std::vector<ArticleEntry>& initial_data);
  29
  30   ~DomDistillerModel();
  31
  32   // Lookup an ArticleEntry by ID or URL. Returns whether a corresponding entry
  33   // was found. On success, if |entry| is not null, it will contain the entry.
  34   bool GetEntryById(const std::string& entry_id, ArticleEntry* entry) const;
  35   bool GetEntryByUrl(const GURL& url, ArticleEntry* entry) const;
  36
  37   std::vector<ArticleEntry> GetEntries() const;
  38   size_t GetNumEntries() const;
  39
  40   syncer::SyncDataList GetAllSyncData() const;
  41
  42   // Convert a SyncDataList to a SyncChangeList of add or update changes based
  43   // on the state of the model. Also calculate the entries missing from the
  44   // SyncDataList.
  45   void CalculateChangesForMerge(const syncer::SyncDataList& data,
  46                                 syncer::SyncChangeList* changes_to_apply,
  47                                 syncer::SyncChangeList* changes_missing);
  48
  49   // Applies the change list to the model, appending the actual changes made to
  50   // the model to |changes_applied|. If conflict resolution does not apply the
  51   // requested change, then adds the "diff" between what was requested and what
  52   // was actually applied to |changes_missing|.
  53   // Note: Currently conflicts are resolved by just applying the requested
  54   // change. This means nothing will be added to |changes_missing|.
  55   void ApplyChangesToModel(const syncer::SyncChangeList& change_list,
  56                            syncer::SyncChangeList* changes_applied,
  57                            syncer::SyncChangeList* changes_missing);
  58
  59  private:
  60   typedef int32 KeyType;
  61   typedef base::hash_map<KeyType, ArticleEntry> EntryMap;
  62   typedef base::hash_map<std::string, KeyType> StringToKeyMap;
  63
  64   void AddEntry(const ArticleEntry& entry);
  65   void RemoveEntry(const ArticleEntry& entry);
  66
  67   // Lookup an entry's key by ID or URL. Returns whether a corresponding key was
  68   // found. On success, if |key| is not null, it will contain the entry.
  69   bool GetKeyById(const std::string& entry_id, KeyType* key) const;
  70   bool GetKeyByUrl(const GURL& url, KeyType* key) const;
  71
  72   // If |entry| is not null, assigns the entry for |key| to it. |key| must map
  73   // to an entry in |entries_|.
  74   void GetEntryByKey(KeyType key, ArticleEntry* entry) const;
  75
  76   void ApplyChangeToModel(const syncer::SyncChange& change,
  77                           syncer::SyncChangeList* changes_applied,
  78                           syncer::SyncChangeList* changes_missing);
  79
  80   KeyType next_key_;
  81   EntryMap entries_;
  82   StringToKeyMap url_to_key_map_;
  83   StringToKeyMap entry_id_to_key_map_;
  84
  85   DISALLOW_COPY_AND_ASSIGN(DomDistillerModel);
  86 };
  87
  88 }  // namespace dom_distiller
  89
  90 #endif  // COMPONENTS_DOM_DISTILLER_CORE_DOM_DISTILLER_MODEL_H_