storage/browser/fileapi/file_system_file_util.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_FILE_UTIL_H_
   6 #define STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_FILE_UTIL_H_
   7
   8 #include "base/files/file.h"
   9 #include "base/files/file_path.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "storage/browser/fileapi/file_system_operation.h"
  12 #include "storage/browser/storage_browser_export.h"
  13 #include "storage/common/blob/scoped_file.h"
  14
  15 namespace base {
  16 class Time;
  17 }
  18
  19 namespace storage {
  20
  21 class FileSystemOperationContext;
  22 class FileSystemURL;
  23
  24 // A file utility interface that provides basic file utility methods for
  25 // FileSystem API.
  26 //
  27 // Layering structure of the FileSystemFileUtil was split out.
  28 // See http://crbug.com/128136 if you need it.
  29 class STORAGE_EXPORT FileSystemFileUtil {
  30  public:
  31   typedef FileSystemOperation::CopyOrMoveOption CopyOrMoveOption;
  32
  33   // It will be implemented by each subclass such as FileSystemFileEnumerator.
  34   class STORAGE_EXPORT AbstractFileEnumerator {
  35    public:
  36     virtual ~AbstractFileEnumerator() {}
  37
  38     // Returns an empty string if there are no more results.
  39     virtual base::FilePath Next() = 0;
  40
  41     // These methods return metadata for the file most recently returned by
  42     // Next(). If Next() has never been called, or if Next() most recently
  43     // returned an empty string, then return the default values of 0,
  44     // "null time", and false, respectively.
  45     virtual int64 Size() = 0;
  46     virtual base::Time LastModifiedTime() = 0;
  47     virtual bool IsDirectory() = 0;
  48   };
  49
  50   class STORAGE_EXPORT EmptyFileEnumerator
  51       : public AbstractFileEnumerator {
  52     virtual base::FilePath Next() OVERRIDE;
  53     virtual int64 Size() OVERRIDE;
  54     virtual base::Time LastModifiedTime() OVERRIDE;
  55     virtual bool IsDirectory() OVERRIDE;
  56   };
  57
  58   virtual ~FileSystemFileUtil() {}
  59
  60   // Creates or opens a file with the given flags.
  61   // See header comments for AsyncFileUtil::CreateOrOpen() for more details.
  62   // This is used only by Pepper/NaCl File API.
  63   virtual base::File CreateOrOpen(
  64       FileSystemOperationContext* context,
  65       const FileSystemURL& url,
  66       int file_flags) = 0;
  67
  68   // Ensures that the given |url| exist.  This creates a empty new file
  69   // at |url| if the |url| does not exist.
  70   // See header comments for AsyncFileUtil::EnsureFileExists() for more details.
  71   virtual base::File::Error EnsureFileExists(
  72       FileSystemOperationContext* context,
  73       const FileSystemURL& url, bool* created) = 0;
  74
  75   // Creates directory at given url.
  76   // See header comments for AsyncFileUtil::CreateDirectory() for more details.
  77   virtual base::File::Error CreateDirectory(
  78       FileSystemOperationContext* context,
  79       const FileSystemURL& url,
  80       bool exclusive,
  81       bool recursive) = 0;
  82
  83   // Retrieves the information about a file.
  84   // See header comments for AsyncFileUtil::GetFileInfo() for more details.
  85   virtual base::File::Error GetFileInfo(
  86       FileSystemOperationContext* context,
  87       const FileSystemURL& url,
  88       base::File::Info* file_info,
  89       base::FilePath* platform_path) = 0;
  90
  91   // Returns a pointer to a new instance of AbstractFileEnumerator which is
  92   // implemented for each FileSystemFileUtil subclass. The instance needs to be
  93   // freed by the caller, and its lifetime should not extend past when the
  94   // current call returns to the main FILE message loop.
  95   //
  96   // The supplied context must remain valid at least lifetime of the enumerator
  97   // instance.
  98   virtual scoped_ptr<AbstractFileEnumerator> CreateFileEnumerator(
  99       FileSystemOperationContext* context,
 100       const FileSystemURL& root_url) = 0;
 101
 102   // Maps |file_system_url| given |context| into |local_file_path|
 103   // which represents physical file location on the host OS.
 104   // This may not always make sense for all subclasses.
 105   virtual base::File::Error GetLocalFilePath(
 106       FileSystemOperationContext* context,
 107       const FileSystemURL& file_system_url,
 108       base::FilePath* local_file_path) = 0;
 109
 110   // Updates the file metadata information.
 111   // See header comments for AsyncFileUtil::Touch() for more details.
 112   virtual base::File::Error Touch(
 113       FileSystemOperationContext* context,
 114       const FileSystemURL& url,
 115       const base::Time& last_access_time,
 116       const base::Time& last_modified_time) = 0;
 117
 118   // Truncates a file to the given length.
 119   // See header comments for AsyncFileUtil::Truncate() for more details.
 120   virtual base::File::Error Truncate(
 121       FileSystemOperationContext* context,
 122       const FileSystemURL& url,
 123       int64 length) = 0;
 124
 125   // Copies or moves a single file from |src_url| to |dest_url|.
 126   // The filesystem type of |src_url| and |dest_url| MUST be same.
 127   // For |option|, please see file_system_operation.h
 128   //
 129   // This returns:
 130   // - File::FILE_ERROR_NOT_FOUND if |src_url|
 131   //   or the parent directory of |dest_url| does not exist.
 132   // - File::FILE_ERROR_NOT_A_FILE if |src_url| exists but is not a file.
 133   // - File::FILE_ERROR_INVALID_OPERATION if |dest_url| exists and
 134   //   is not a file.
 135   // - File::FILE_ERROR_FAILED if |dest_url| does not exist and
 136   //   its parent path is a file.
 137   //
 138   virtual base::File::Error CopyOrMoveFile(
 139       FileSystemOperationContext* context,
 140       const FileSystemURL& src_url,
 141       const FileSystemURL& dest_url,
 142       CopyOrMoveOption option,
 143       bool copy) = 0;
 144
 145   // Copies in a single file from a different filesystem.
 146   // See header comments for AsyncFileUtil::CopyInForeignFile() for
 147   // more details.
 148   virtual base::File::Error CopyInForeignFile(
 149         FileSystemOperationContext* context,
 150         const base::FilePath& src_file_path,
 151         const FileSystemURL& dest_url) = 0;
 152
 153   // Deletes a single file.
 154   // See header comments for AsyncFileUtil::DeleteFile() for more details.
 155   virtual base::File::Error DeleteFile(
 156       FileSystemOperationContext* context,
 157       const FileSystemURL& url) = 0;
 158
 159   // Deletes a single empty directory.
 160   // See header comments for AsyncFileUtil::DeleteDirectory() for more details.
 161   virtual base::File::Error DeleteDirectory(
 162       FileSystemOperationContext* context,
 163       const FileSystemURL& url) = 0;
 164
 165   // Creates a local snapshot file for a given |url| and returns the
 166   // metadata and platform path of the snapshot file via |callback|.
 167   //
 168   // See header comments for AsyncFileUtil::CreateSnapshotFile() for
 169   // more details.
 170   virtual storage::ScopedFile CreateSnapshotFile(
 171       FileSystemOperationContext* context,
 172       const FileSystemURL& url,
 173       base::File::Error* error,
 174       base::File::Info* file_info,
 175       base::FilePath* platform_path) = 0;
 176
 177  protected:
 178   FileSystemFileUtil() {}
 179
 180  private:
 181   DISALLOW_COPY_AND_ASSIGN(FileSystemFileUtil);
 182 };
 183
 184 }  // namespace storage
 185
 186 #endif  // STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_FILE_UTIL_H_