dom/file/TemporaryFileBlobImpl.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 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 #include "TemporaryFileBlobImpl.h"
   8
   9 #include "RemoteLazyInputStreamThread.h"
  10 #include "mozilla/ErrorResult.h"
  11 #include "nsFileStreams.h"
  12 #include "nsIFile.h"
  13 #include "nsIFileStreams.h"
  14 #include "nsNetUtil.h"
  15 #include "nsThreadUtils.h"
  16 #include "nsXULAppAPI.h"
  17
  18 using namespace mozilla::ipc;
  19
  20 namespace mozilla::dom {
  21
  22 namespace {
  23
  24 // Here the flags needed in order to keep the temporary file opened.
  25 // 1. REOPEN_ON_REWIND -> otherwise the stream is not serializable more than
  26 //                        once.
  27 // 2. no DEFER_OPEN -> the file must be kept open on windows in order to be
  28 //                     deleted when used.
  29 // 3. no CLOSE_ON_EOF -> the file will be closed by the DTOR. No needs. Also
  30 //                       because the inputStream will not be read directly.
  31 // 4. no SHARE_DELETE -> We don't want to allow this file to be deleted.
  32 const uint32_t sTemporaryFileStreamFlags = nsIFileInputStream::REOPEN_ON_REWIND;
  33
  34 class TemporaryFileInputStream final : public nsFileInputStream {
  35  public:
  36   static nsresult Create(nsIFile* aFile, nsIInputStream** aInputStream) {
  37     MOZ_ASSERT(aFile);
  38     MOZ_ASSERT(aInputStream);
  39     MOZ_ASSERT(XRE_IsParentProcess());
  40
  41     RefPtr<TemporaryFileInputStream> stream =
  42         new TemporaryFileInputStream(aFile);
  43
  44     nsresult rv = stream->Init(aFile, -1, -1, sTemporaryFileStreamFlags);
  45     if (NS_WARN_IF(NS_FAILED(rv))) {
  46       return rv;
  47     }
  48
  49     stream.forget(aInputStream);
  50     return NS_OK;
  51   }
  52
  53   void Serialize(InputStreamParams& aParams,
  54                  FileDescriptorArray& aFileDescriptors, bool aDelayedStart,
  55                  uint32_t aMaxSize, uint32_t* aSizeUsed,
  56                  ParentToChildStreamActorManager* aManager) override {
  57     MOZ_CRASH("This inputStream cannot be serialized.");
  58   }
  59
  60   void Serialize(InputStreamParams& aParams,
  61                  FileDescriptorArray& aFileDescriptors, bool aDelayedStart,
  62                  uint32_t aMaxSize, uint32_t* aSizeUsed,
  63                  ChildToParentStreamActorManager* aManager) override {
  64     MOZ_CRASH("This inputStream cannot be serialized.");
  65   }
  66
  67   bool Deserialize(const InputStreamParams& aParams,
  68                    const FileDescriptorArray& aFileDescriptors) override {
  69     MOZ_CRASH("This inputStream cannot be deserialized.");
  70     return false;
  71   }
  72
  73  private:
  74   explicit TemporaryFileInputStream(nsIFile* aFile) : mFile(aFile) {
  75     MOZ_ASSERT(XRE_IsParentProcess());
  76   }
  77
  78   ~TemporaryFileInputStream() {
  79     // Let's delete the file on the RemoteLazyInputStream Thread.
  80     RefPtr<RemoteLazyInputStreamThread> thread =
  81         RemoteLazyInputStreamThread::GetOrCreate();
  82     if (NS_WARN_IF(!thread)) {
  83       return;
  84     }
  85
  86     nsCOMPtr<nsIFile> file = std::move(mFile);
  87     thread->Dispatch(
  88         NS_NewRunnableFunction("TemporaryFileInputStream::Runnable",
  89                                [file]() { file->Remove(false); }));
  90   }
  91
  92   nsCOMPtr<nsIFile> mFile;
  93 };
  94
  95 }  // namespace
  96
  97 TemporaryFileBlobImpl::TemporaryFileBlobImpl(nsIFile* aFile,
  98                                              const nsAString& aContentType)
  99     : FileBlobImpl(aFile, u""_ns, aContentType)
 100 #ifdef DEBUG
 101       ,
 102       mInputStreamCreated(false)
 103 #endif
 104 {
 105   MOZ_ASSERT(XRE_IsParentProcess());
 106
 107   // This must be considered a blob.
 108   mIsFile = false;
 109 }
 110
 111 TemporaryFileBlobImpl::~TemporaryFileBlobImpl() {
 112   MOZ_ASSERT(mInputStreamCreated);
 113 }
 114
 115 already_AddRefed<BlobImpl> TemporaryFileBlobImpl::CreateSlice(
 116     uint64_t aStart, uint64_t aLength, const nsAString& aContentType,
 117     ErrorResult& aRv) {
 118   MOZ_CRASH("This BlobImpl is not meant to be sliced!");
 119   return nullptr;
 120 }
 121
 122 void TemporaryFileBlobImpl::CreateInputStream(nsIInputStream** aStream,
 123                                               ErrorResult& aRv) {
 124 #ifdef DEBUG
 125   MOZ_ASSERT(!mInputStreamCreated);
 126   // CreateInputStream can be called only once.
 127   mInputStreamCreated = true;
 128 #endif
 129
 130   aRv = TemporaryFileInputStream::Create(mFile, aStream);
 131   if (NS_WARN_IF(aRv.Failed())) {
 132     return;
 133   }
 134 }
 135
 136 }  // namespace mozilla::dom