ppapi/cpp/file_ref.h

   1 // Copyright (c) 2011 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 PPAPI_CPP_FILE_REF_H_
   6 #define PPAPI_CPP_FILE_REF_H_
   7
   8 #include "ppapi/c/pp_file_info.h"
   9 #include "ppapi/c/pp_stdint.h"
  10 #include "ppapi/c/ppb_file_ref.h"
  11 #include "ppapi/cpp/resource.h"
  12 #include "ppapi/cpp/var.h"
  13
  14 /// @file
  15 /// This file defines the API to create a file reference or "weak pointer" to a
  16 /// file in a file system.
  17
  18 namespace pp {
  19
  20 class DirectoryEntry;
  21 class FileSystem;
  22 class CompletionCallback;
  23 template <typename T> class CompletionCallbackWithOutput;
  24
  25 /// The <code>FileRef</code> class represents a "weak pointer" to a file in
  26 /// a file system.
  27 class FileRef : public Resource {
  28  public:
  29   /// Default constructor for creating an is_null() <code>FileRef</code>
  30   /// object.
  31   FileRef() {}
  32
  33   /// A constructor used when you have an existing PP_Resource for a FileRef
  34   /// and which to create a C++ object that takes an additional reference to
  35   /// the resource.
  36   ///
  37   /// @param[in] resource A PP_Resource corresponding to file reference.
  38   explicit FileRef(PP_Resource resource);
  39
  40   /// A constructor used when you have received a PP_Resource as a return
  41   /// value that has already been reference counted.
  42   ///
  43   /// @param[in] resource A PP_Resource corresponding to file reference.
  44   FileRef(PassRef, PP_Resource resource);
  45
  46   /// A constructor that creates a weak pointer to a file in the given file
  47   /// system. File paths are POSIX style.
  48   ///
  49   /// @param[in] file_system A <code>FileSystem</code> corresponding to a file
  50   /// system type.
  51   /// @param[in] path A path to the file.
  52   FileRef(const FileSystem& file_system, const char* path);
  53
  54   /// The copy constructor for <code>FileRef</code>.
  55   ///
  56   /// @param[in] other A pointer to a <code>FileRef</code>.
  57   FileRef(const FileRef& other);
  58
  59   /// GetFileSystemType() returns the type of the file system.
  60   ///
  61   /// @return A <code>PP_FileSystemType</code> with the file system type if
  62   /// valid or <code>PP_FILESYSTEMTYPE_INVALID</code> if the provided resource
  63   /// is not a valid file reference.
  64   PP_FileSystemType GetFileSystemType() const;
  65
  66   /// GetName() returns the name of the file.
  67   ///
  68   /// @return A <code>Var</code> containing the name of the file.  The value
  69   /// returned by this function does not include any path components (such as
  70   /// the name of the parent directory, for example). It is just the name of the
  71   /// file. Use GetPath() to get the full file path.
  72   Var GetName() const;
  73
  74   /// GetPath() returns the absolute path of the file.
  75   ///
  76   /// @return A <code>Var</code> containing the absolute path of the file.
  77   /// This function fails if the file system type is
  78   /// <code>PP_FileSystemType_External</code>.
  79   Var GetPath() const;
  80
  81   /// GetParent() returns the parent directory of this file.  If
  82   /// <code>file_ref</code> points to the root of the filesystem, then the root
  83   /// is returned.
  84   ///
  85   /// @return A <code>FileRef</code> containing the parent directory of the
  86   /// file. This function fails if the file system type is
  87   /// <code>PP_FileSystemType_External</code>.
  88   FileRef GetParent() const;
  89
  90   /// MakeDirectory() makes a new directory in the file system.  It is not
  91   /// valid to make a directory in the external file system.
  92   /// <strong>Note:</strong> Use MakeDirectoryIncludingAncestors() to create
  93   /// parent directories.
  94   ///
  95   /// @param[in] cc A <code>CompletionCallback</code> to be called upon
  96   /// completion of MakeDirectory().
  97   ///
  98   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
  99   /// Succeeds if the directory already exists. Fails if ancestor
 100   /// directortories do not exist (see MakeDirectoryIncludingAncestors for the
 101   /// alternative).
 102   int32_t MakeDirectory(const CompletionCallback& cc);
 103
 104   /// MakeDirectoryIncludingAncestors() makes a new directory in the file
 105   /// system as well as any parent directories. It is not valid to make a
 106   /// directory in the external file system.
 107   ///
 108   /// @param[in] cc A <code>CompletionCallback</code> to be called upon
 109   /// completion of MakeDirectoryIncludingAncestors().
 110   ///
 111   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
 112   /// Succeeds if the directory already exists.
 113   int32_t MakeDirectoryIncludingAncestors(const CompletionCallback& cc);
 114
 115   /// Touch() Updates time stamps for a file.  You must have write access to the
 116   /// file if it exists in the external filesystem.
 117   ///
 118   /// @param[in] last_access_time The last time the file was accessed.
 119   /// @param[in] last_modified_time The last time the file was modified.
 120   /// @param[in] cc A <code>CompletionCallback</code> to be called upon
 121   /// completion of Touch().
 122   ///
 123   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
 124   int32_t Touch(PP_Time last_access_time,
 125                 PP_Time last_modified_time,
 126                 const CompletionCallback& cc);
 127
 128   /// Delete() deletes a file or directory. If <code>file_ref</code> refers to
 129   /// a directory, then the directory must be empty. It is an error to delete a
 130   /// file or directory that is in use.  It is not valid to delete a file in
 131   /// the external file system.
 132   ///
 133   /// @param[in] cc A <code>CompletionCallback</code> to be called upon
 134   /// completion of Delete().
 135   ///
 136   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
 137   int32_t Delete(const CompletionCallback& cc);
 138
 139   /// Rename() renames a file or directory. Argument <code>new_file_ref</code>
 140   /// must refer to files in the same file system as in this object. It is an
 141   /// error to rename a file or directory that is in use.  It is not valid to
 142   /// rename a file in the external file system.
 143   ///
 144   /// @param[in] new_file_ref A <code>FileRef</code> corresponding to a new
 145   /// file reference.
 146   /// @param[in] cc A <code>CompletionCallback</code> to be called upon
 147   /// completion of Rename().
 148   ///
 149   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
 150   int32_t Rename(const FileRef& new_file_ref, const CompletionCallback& cc);
 151
 152   /// Query() queries info about a file or directory. You must have access to
 153   /// read this file or directory if it exists in the external filesystem.
 154   ///
 155   /// @param[in] callback A <code>CompletionCallbackWithOutput</code>
 156   /// to be called upon completion of Query().
 157   ///
 158   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
 159   int32_t Query(const CompletionCallbackWithOutput<PP_FileInfo>& callback);
 160
 161   /// ReadDirectoryEntries() Reads all entries in the directory.
 162   ///
 163   /// @param[in] cc A <code>CompletionCallbackWithOutput</code> to be called
 164   /// upon completion of ReadDirectoryEntries(). On success, the
 165   /// directory entries will be passed to the given function.
 166   ///
 167   /// Normally you would use a CompletionCallbackFactory to allow callbacks to
 168   /// be bound to your class. See completion_callback_factory.h for more
 169   /// discussion on how to use this. Your callback will generally look like:
 170   ///
 171   /// @code
 172   ///   void OnReadDirectoryEntries(
 173   ///       int32_t result,
 174   ///       const std::vector<DirectoryEntry>& entries) {
 175   ///     if (result == PP_OK)
 176   ///       // use entries...
 177   ///   }
 178   /// @endcode
 179   ///
 180   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
 181   int32_t ReadDirectoryEntries(
 182       const CompletionCallbackWithOutput< std::vector<DirectoryEntry> >&
 183           callback);
 184 };
 185
 186 }  // namespace pp
 187
 188 #endif  // PPAPI_CPP_FILE_REF_H_