storage/browser/fileapi/file_system_operation_context.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 STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_OPERATION_CONTEXT_H_
   6 #define STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_OPERATION_CONTEXT_H_
   7
   8 #include "base/files/file_path.h"
   9 #include "base/supports_user_data.h"
  10 #include "base/threading/thread_checker.h"
  11 #include "storage/browser/fileapi/task_runner_bound_observer_list.h"
  12 #include "storage/browser/storage_browser_export.h"
  13 #include "storage/common/quota/quota_types.h"
  14
  15 namespace base {
  16 class SequencedTaskRunner;
  17 }
  18
  19 namespace storage {
  20
  21 class FileSystemContext;
  22
  23 // A context class which is carried around by FileSystemOperation and
  24 // its delegated tasks. It is valid to reuse one context instance across
  25 // multiple operations as far as those operations are supposed to share
  26 // the same context (e.g. use the same task runner, share the quota etc).
  27 // Note that the remaining quota bytes (allowed_bytes_growth) may be
  28 // updated during the execution of write operations.
  29 class STORAGE_EXPORT_PRIVATE FileSystemOperationContext
  30     : public base::SupportsUserData {
  31  public:
  32   explicit FileSystemOperationContext(FileSystemContext* context);
  33
  34   // Specifies |task_runner| which the operation is performed on.
  35   // The backend of |task_runner| must outlive the IO thread.
  36   FileSystemOperationContext(FileSystemContext* context,
  37                              base::SequencedTaskRunner* task_runner);
  38
  39   ~FileSystemOperationContext() override;
  40
  41   FileSystemContext* file_system_context() const {
  42     return file_system_context_.get();
  43   }
  44
  45   // Updates the current remaining quota.
  46   // This can be called to update the remaining quota during the operation.
  47   void set_allowed_bytes_growth(const int64& allowed_bytes_growth) {
  48     allowed_bytes_growth_ = allowed_bytes_growth;
  49   }
  50
  51   // Returns the current remaining quota.
  52   int64 allowed_bytes_growth() const { return allowed_bytes_growth_; }
  53   storage::QuotaLimitType quota_limit_type() const { return quota_limit_type_; }
  54   base::SequencedTaskRunner* task_runner() const { return task_runner_.get(); }
  55
  56   ChangeObserverList* change_observers() { return &change_observers_; }
  57   UpdateObserverList* update_observers() { return &update_observers_; }
  58
  59   // Following setters should be called only on the same thread as the
  60   // FileSystemOperationContext is created (i.e. are not supposed be updated
  61   // after the context's passed onto other task runners).
  62   void set_change_observers(const ChangeObserverList& list) {
  63     DCHECK(setter_thread_checker_.CalledOnValidThread());
  64     change_observers_ = list;
  65   }
  66   void set_update_observers(const UpdateObserverList& list) {
  67     DCHECK(setter_thread_checker_.CalledOnValidThread());
  68     update_observers_ = list;
  69   }
  70   void set_quota_limit_type(storage::QuotaLimitType limit_type) {
  71     DCHECK(setter_thread_checker_.CalledOnValidThread());
  72     quota_limit_type_ = limit_type;
  73   }
  74
  75  private:
  76   scoped_refptr<FileSystemContext> file_system_context_;
  77   scoped_refptr<base::SequencedTaskRunner> task_runner_;
  78
  79   // The current remaining quota, used by ObfuscatedFileUtil.
  80   int64 allowed_bytes_growth_;
  81
  82   // The current quota limit type, used by ObfuscatedFileUtil.
  83   storage::QuotaLimitType quota_limit_type_;
  84
  85   // Observers attached to this context.
  86   ChangeObserverList change_observers_;
  87   UpdateObserverList update_observers_;
  88
  89   // Used to check its setters are not called on arbitrary thread.
  90   base::ThreadChecker setter_thread_checker_;
  91
  92   DISALLOW_COPY_AND_ASSIGN(FileSystemOperationContext);
  93 };
  94
  95 }  // namespace storage
  96
  97 #endif  // STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_OPERATION_CONTEXT_H_