chrome/browser/browsing_data/browsing_data_file_system_helper.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 CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_FILE_SYSTEM_HELPER_H_
   6 #define CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_FILE_SYSTEM_HELPER_H_
   7
   8 #include <list>
   9 #include <map>
  10 #include <string>
  11
  12 #include "base/callback.h"
  13 #include "base/compiler_specific.h"
  14 #include "base/files/file_path.h"
  15 #include "base/memory/ref_counted.h"
  16 #include "base/synchronization/lock.h"
  17 #include "chrome/common/url_constants.h"
  18 #include "storage/common/fileapi/file_system_types.h"
  19 #include "url/gurl.h"
  20
  21 namespace storage {
  22 class FileSystemContext;
  23 }
  24
  25 class Profile;
  26
  27 // Defines an interface for classes that deal with aggregating and deleting
  28 // browsing data stored in an origin's file systems.
  29 // BrowsingDataFileSystemHelper instances for a specific profile should be
  30 // created via the static Create method. Each instance will lazily fetch file
  31 // system data when a client calls StartFetching from the UI thread, and will
  32 // notify the client via a supplied callback when the data is available.
  33 // Only one StartFetching task can run at a time: executing StartFetching while
  34 // another StartFetching task is running will DCHECK.
  35 //
  36 // The client's callback is passed a list of FileSystemInfo objects containing
  37 // usage information for each origin's temporary and persistent file systems.
  38 //
  39 // Clients may remove an origin's file systems at any time (even before fetching
  40 // data) by calling DeleteFileSystemOrigin() on the UI thread. Calling
  41 // DeleteFileSystemOrigin() for an origin that doesn't have any is safe; it's
  42 // just an expensive NOOP.
  43 class BrowsingDataFileSystemHelper
  44     : public base::RefCountedThreadSafe<BrowsingDataFileSystemHelper> {
  45  public:
  46   // Detailed information about a file system, including it's origin GURL,
  47   // the amount of data (in bytes) for each sandboxed filesystem type.
  48   struct FileSystemInfo {
  49     explicit FileSystemInfo(const GURL& origin);
  50     ~FileSystemInfo();
  51
  52     // The origin for which the information is relevant.
  53     GURL origin;
  54     // FileSystemType to usage (in bytes) map.
  55     std::map<storage::FileSystemType, int64> usage_map;
  56   };
  57
  58   // Creates a BrowsingDataFileSystemHelper instance for the file systems
  59   // stored in |profile|'s user data directory. The BrowsingDataFileSystemHelper
  60   // object will hold a reference to the Profile that's passed in, but is not
  61   // responsible for destroying it.
  62   //
  63   // The BrowsingDataFileSystemHelper will not change the profile itself, but
  64   // can modify data it contains (by removing file systems).
  65   static BrowsingDataFileSystemHelper* Create(
  66       storage::FileSystemContext* file_system_context);
  67
  68   // Starts the process of fetching file system data, which will call |callback|
  69   // upon completion, passing it a constant list of FileSystemInfo objects.
  70   // StartFetching must be called only in the UI thread; the provided Callback1
  71   // will likewise be executed asynchronously on the UI thread.
  72   //
  73   // BrowsingDataFileSystemHelper takes ownership of the Callback1, and is
  74   // responsible for deleting it once it's no longer needed.
  75   virtual void StartFetching(const base::Callback<
  76       void(const std::list<FileSystemInfo>&)>& callback) = 0;
  77
  78   // Deletes any temporary or persistent file systems associated with |origin|
  79   // from the disk. Deletion will occur asynchronously on the FILE thread, but
  80   // this function must be called only on the UI thread.
  81   virtual void DeleteFileSystemOrigin(const GURL& origin) = 0;
  82
  83  protected:
  84   friend class base::RefCountedThreadSafe<BrowsingDataFileSystemHelper>;
  85
  86   BrowsingDataFileSystemHelper() {}
  87   virtual ~BrowsingDataFileSystemHelper() {}
  88 };
  89
  90 // An implementation of the BrowsingDataFileSystemHelper interface that can
  91 // be manually populated with data, rather than fetching data from the file
  92 // systems created in a particular Profile.
  93 class CannedBrowsingDataFileSystemHelper
  94     : public BrowsingDataFileSystemHelper {
  95  public:
  96   // |profile| is unused in this canned implementation, but it's the interface
  97   // we're writing to, so we'll accept it, but not store it.
  98   explicit CannedBrowsingDataFileSystemHelper(Profile* profile);
  99
 100   // Manually adds a filesystem to the set of canned file systems that this
 101   // helper returns via StartFetching. If an origin contains both a temporary
 102   // and a persistent filesystem, AddFileSystem must be called twice (once for
 103   // each file system type).
 104   void AddFileSystem(const GURL& origin,
 105                      storage::FileSystemType type,
 106                      int64 size);
 107
 108   // Clear this helper's list of canned filesystems.
 109   void Reset();
 110
 111   // True if no filesystems are currently stored.
 112   bool empty() const;
 113
 114   // Returns the number of currently stored filesystems.
 115   size_t GetFileSystemCount() const;
 116
 117   // Returns the current list of filesystems.
 118   const std::list<FileSystemInfo>& GetFileSystemInfo() {
 119     return file_system_info_;
 120   }
 121
 122   // BrowsingDataFileSystemHelper implementation.
 123   void StartFetching(
 124       const base::Callback<void(const std::list<FileSystemInfo>&)>& callback)
 125       override;
 126
 127   // Note that this doesn't actually have an implementation for this canned
 128   // class. It hasn't been necessary for anything that uses the canned
 129   // implementation, as the canned class is only used in tests, or in read-only
 130   // contexts (like the non-modal cookie dialog).
 131   void DeleteFileSystemOrigin(const GURL& origin) override {}
 132
 133  private:
 134   ~CannedBrowsingDataFileSystemHelper() override;
 135
 136   // Holds the current list of filesystems returned to the client.
 137   std::list<FileSystemInfo> file_system_info_;
 138
 139   // The callback passed in at the beginning of the StartFetching workflow so
 140   // that it can be triggered via NotifyOnUIThread.
 141   base::Callback<void(const std::list<FileSystemInfo>&)> completion_callback_;
 142
 143   DISALLOW_COPY_AND_ASSIGN(CannedBrowsingDataFileSystemHelper);
 144 };
 145
 146 #endif  // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_FILE_SYSTEM_HELPER_H_