file_system_operation_context.h revision bb1529ce867d8845a77ec7cdf3e3003ef1771a40 
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 WEBKIT_BROWSER_FILEAPI_FILE_SYSTEM_OPERATION_CONTEXT_H_
6#define WEBKIT_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 "webkit/browser/fileapi/task_runner_bound_observer_list.h"
12#include "webkit/browser/webkit_storage_browser_export.h"
13#include "webkit/common/quota/quota_types.h"
14
15namespace base {
16class SequencedTaskRunner;
17}
18
19namespace fileapi {
20
21class 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.
29class WEBKIT_STORAGE_BROWSER_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  virtual ~FileSystemOperationContext();
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  quota::QuotaLimitType quota_limit_type() const { return quota_limit_type_; }
54  base::SequencedTaskRunner* task_runner() const { return task_runner_.get(); }
55  const base::FilePath& root_path() const { return root_path_; }
56
57  ChangeObserverList* change_observers() { return &change_observers_; }
58  UpdateObserverList* update_observers() { return &update_observers_; }
59
60  // Following setters should be called only on the same thread as the
61  // FileSystemOperationContext is created (i.e. are not supposed be updated
62  // after the context's passed onto other task runners).
63  void set_change_observers(const ChangeObserverList& list) {
64    DCHECK(setter_thread_checker_.CalledOnValidThread());
65    change_observers_ = list;
66  }
67  void set_update_observers(const UpdateObserverList& list) {
68    DCHECK(setter_thread_checker_.CalledOnValidThread());
69    update_observers_ = list;
70  }
71  void set_quota_limit_type(quota::QuotaLimitType limit_type) {
72    DCHECK(setter_thread_checker_.CalledOnValidThread());
73    quota_limit_type_ = limit_type;
74  }
75  void set_root_path(const base::FilePath& root_path) {
76    DCHECK(setter_thread_checker_.CalledOnValidThread());
77    root_path_ = root_path;
78  }
79
80 private:
81  scoped_refptr<FileSystemContext> file_system_context_;
82  scoped_refptr<base::SequencedTaskRunner> task_runner_;
83
84  // The current remaining quota, used by ObfuscatedFileUtil.
85  int64 allowed_bytes_growth_;
86
87  // The current quota limit type, used by ObfuscatedFileUtil.
88  quota::QuotaLimitType quota_limit_type_;
89
90  // Observers attached to this context.
91  ChangeObserverList change_observers_;
92  UpdateObserverList update_observers_;
93
94  // Root path for the operation, used by LocalFileUtil.
95  base::FilePath root_path_;
96
97  // Used to check its setters are not called on arbitrary thread.
98  base::ThreadChecker setter_thread_checker_;
99
100  DISALLOW_COPY_AND_ASSIGN(FileSystemOperationContext);
101};
102
103}  // namespace fileapi
104
105#endif  // WEBKIT_BROWSER_FILEAPI_FILE_SYSTEM_OPERATION_CONTEXT_H_
106