netwerk/ipc/RemoteOpenFileChild.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set sw=2 ts=8 et tw=80 : */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef _RemoteOpenFileChild_h
   8 #define _RemoteOpenFileChild_h
   9
  10 #include "mozilla/Attributes.h"
  11 #include "mozilla/dom/TabChild.h"
  12 #include "mozilla/net/PRemoteOpenFileChild.h"
  13 #include "nsICachedFileDescriptorListener.h"
  14 #include "nsILocalFile.h"
  15 #include "nsIRemoteOpenFileListener.h"
  16
  17 namespace mozilla {
  18
  19 namespace ipc {
  20 class FileDescriptor;
  21 }
  22
  23 namespace net {
  24
  25 /**
  26  * RemoteOpenFileChild: a thin wrapper around regular nsIFile classes that does
  27  * IPC to open a file handle on parent instead of child.  Used when we can't
  28  * open file handle on child (don't have permission), but we don't want the
  29  * overhead of shipping all I/O traffic across IPDL.  Example: JAR files.
  30  *
  31  * To open a file handle with this class, AsyncRemoteFileOpen() must be called
  32  * first.  After the listener's OnRemoteFileOpenComplete() is called, if the
  33  * result is NS_OK, nsIFile.OpenNSPRFileDesc() may be called--once--to get the
  34  * file handle.
  35  *
  36  * Note that calling Clone() on this class results in the filehandle ownership
  37  * being passed on to the new RemoteOpenFileChild. I.e. if
  38  * OnRemoteFileOpenComplete is called and then Clone(), OpenNSPRFileDesc() will
  39  * work in the cloned object, but not in the original.
  40  *
  41  * This class should only be instantiated in a child process.
  42  *
  43  */
  44 class RemoteOpenFileChild MOZ_FINAL
  45   : public PRemoteOpenFileChild
  46   , public nsIFile
  47   , public nsIHashable
  48   , public nsICachedFileDescriptorListener
  49 {
  50   typedef mozilla::dom::TabChild TabChild;
  51   typedef mozilla::ipc::FileDescriptor FileDescriptor;
  52
  53 public:
  54   RemoteOpenFileChild()
  55     : mNSPRFileDesc(nullptr)
  56     , mAsyncOpenCalled(false)
  57     , mNSPROpenCalled(false)
  58   {}
  59
  60   virtual ~RemoteOpenFileChild();
  61
  62   NS_DECL_ISUPPORTS
  63   NS_DECL_NSIFILE
  64   NS_DECL_NSIHASHABLE
  65
  66   // URI must be scheme 'remoteopenfile://': otherwise looks like a file:// uri.
  67   nsresult Init(nsIURI* aRemoteOpenUri);
  68
  69   // Send message to parent to tell it to open file handle for file.
  70   // TabChild is required, for IPC security.
  71   // Note: currently only PR_RDONLY is supported for 'flags'
  72   nsresult AsyncRemoteFileOpen(int32_t aFlags,
  73                                nsIRemoteOpenFileListener* aListener,
  74                                nsITabChild* aTabChild);
  75
  76   void ReleaseIPDLReference()
  77   {
  78     Release();
  79   }
  80
  81 private:
  82   RemoteOpenFileChild(const RemoteOpenFileChild& other);
  83
  84 protected:
  85   void AddIPDLReference()
  86   {
  87     AddRef();
  88   }
  89
  90   virtual bool Recv__delete__(const FileDescriptor&) MOZ_OVERRIDE;
  91
  92   virtual void OnCachedFileDescriptor(const nsAString& aPath,
  93                                       const FileDescriptor& aFD) MOZ_OVERRIDE;
  94
  95   void HandleFileDescriptorAndNotifyListener(const FileDescriptor&,
  96                                              bool aFromRecvDelete);
  97
  98   void NotifyListener(nsresult aResult);
  99
 100   // regular nsIFile object, that we forward most calls to.
 101   nsCOMPtr<nsIFile> mFile;
 102   nsCOMPtr<nsIURI> mURI;
 103   nsCOMPtr<nsIRemoteOpenFileListener> mListener;
 104   nsRefPtr<TabChild> mTabChild;
 105   PRFileDesc* mNSPRFileDesc;
 106   bool mAsyncOpenCalled;
 107   bool mNSPROpenCalled;
 108 };
 109
 110 } // namespace net
 111 } // namespace mozilla
 112
 113 #endif // _RemoteOpenFileChild_h