components/drive/resource_metadata.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_RESOURCE_METADATA_H_
   6 #define COMPONENTS_DRIVE_RESOURCE_METADATA_H_
   7
   8 #include <set>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/files/file_path.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/threading/thread_checker.h"
  15 #include "components/drive/file_errors.h"
  16 #include "components/drive/resource_metadata_storage.h"
  17
  18 namespace base {
  19 class SequencedTaskRunner;
  20 }
  21
  22 namespace drive {
  23
  24 typedef std::vector<ResourceEntry> ResourceEntryVector;
  25
  26 namespace internal {
  27
  28 class FileCache;
  29
  30 // Storage for Drive Metadata.
  31 // All methods except the constructor and Destroy() function must be run with
  32 // |blocking_task_runner| unless otherwise noted.
  33 class ResourceMetadata {
  34  public:
  35   typedef ResourceMetadataStorage::Iterator Iterator;
  36
  37   ResourceMetadata(
  38       ResourceMetadataStorage* storage,
  39       FileCache* cache,
  40       scoped_refptr<base::SequencedTaskRunner> blocking_task_runner);
  41
  42   // Initializes this object.
  43   // This method should be called before any other methods.
  44   FileError Initialize() WARN_UNUSED_RESULT;
  45
  46   // Destroys this object.  This method posts a task to |blocking_task_runner_|
  47   // to safely delete this object.
  48   // Must be called on the UI thread.
  49   void Destroy();
  50
  51   // Resets this object.
  52   FileError Reset();
  53
  54   // Returns the largest changestamp.
  55   FileError GetLargestChangestamp(int64* out_value);
  56
  57   // Sets the largest changestamp.
  58   FileError SetLargestChangestamp(int64 value);
  59
  60   // Adds |entry| to the metadata tree based on its parent_local_id.
  61   FileError AddEntry(const ResourceEntry& entry, std::string* out_id);
  62
  63   // Removes entry with |id| from its parent.
  64   FileError RemoveEntry(const std::string& id);
  65
  66   // Finds an entry (a file or a directory) by |id|.
  67   FileError GetResourceEntryById(const std::string& id,
  68                                  ResourceEntry* out_entry);
  69
  70   // Synchronous version of GetResourceEntryByPathOnUIThread().
  71   FileError GetResourceEntryByPath(const base::FilePath& file_path,
  72                                    ResourceEntry* out_entry);
  73
  74   // Finds and reads a directory by |file_path|.
  75   FileError ReadDirectoryByPath(const base::FilePath& file_path,
  76                                 ResourceEntryVector* out_entries);
  77
  78   // Finds and reads a directory by |id|.
  79   FileError ReadDirectoryById(const std::string& id,
  80                               ResourceEntryVector* out_entries);
  81
  82   // Replaces an existing entry with the same local ID as |entry|.
  83   FileError RefreshEntry(const ResourceEntry& entry);
  84
  85   // Recursively gets directories under the entry pointed to by |id|.
  86   FileError GetSubDirectoriesRecursively(
  87       const std::string& id,
  88       std::set<base::FilePath>* sub_directories);
  89
  90   // Returns the id of the resource named |base_name| directly under
  91   // the directory with |parent_local_id|.
  92   // If not found, empty string will be returned.
  93   FileError GetChildId(const std::string& parent_local_id,
  94                        const std::string& base_name,
  95                        std::string* out_child_id);
  96
  97   // Returns an object to iterate over entries.
  98   scoped_ptr<Iterator> GetIterator();
  99
 100   // Returns virtual file path of the entry.
 101   FileError GetFilePath(const std::string& id, base::FilePath* out_file_path);
 102
 103   // Returns ID of the entry at the given path.
 104   FileError GetIdByPath(const base::FilePath& file_path, std::string* out_id);
 105
 106   // Returns the local ID associated with the given resource ID.
 107   FileError GetIdByResourceId(const std::string& resource_id,
 108                               std::string* out_local_id);
 109
 110  private:
 111   // Note: Use Destroy() to delete this object.
 112   ~ResourceMetadata();
 113
 114   // Sets up entries which should be present by default.
 115   FileError SetUpDefaultEntries();
 116
 117   // Used to implement Destroy().
 118   void DestroyOnBlockingPool();
 119
 120   // Puts an entry under its parent directory. Removes the child from the old
 121   // parent if there is. This method will also do name de-duplication to ensure
 122   // that the exposed presentation path does not have naming conflicts. Two
 123   // files with the same name "Foo" will be renamed to "Foo (1)" and "Foo (2)".
 124   FileError PutEntryUnderDirectory(const ResourceEntry& entry);
 125
 126   // Returns an unused base name for |entry|.
 127   FileError GetDeduplicatedBaseName(const ResourceEntry& entry,
 128                                     std::string* base_name);
 129
 130   // Removes the entry and its descendants.
 131   FileError RemoveEntryRecursively(const std::string& id);
 132
 133   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
 134
 135   ResourceMetadataStorage* storage_;
 136   FileCache* cache_;
 137
 138   base::ThreadChecker thread_checker_;
 139
 140   DISALLOW_COPY_AND_ASSIGN(ResourceMetadata);
 141 };
 142
 143 }  // namespace internal
 144 }  // namespace drive
 145
 146 #endif  // COMPONENTS_DRIVE_RESOURCE_METADATA_H_