gecko-dev/dom/file/TemporaryFileBlobImpl.cpp

143 строки
3.7 KiB
C++
Исходник Обычный вид История

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "TemporaryFileBlobImpl.h"
#include "IPCBlobInputStreamThread.h"
#include "nsFileStreams.h"
#include "nsIFile.h"
#include "nsIFileStreams.h"
#include "nsNetUtil.h"
#include "nsThreadUtils.h"
#include "nsXULAppAPI.h"
using namespace mozilla::ipc;
namespace mozilla {
namespace dom {
namespace {
// Here the flags needed in order to keep the temporary file opened.
// 1. REOPEN_ON_REWIND -> otherwise the stream is not serializable more than
// once.
// 2. no DEFER_OPEN -> the file must be kept open on windows in order to be
// deleted when used.
// 3. no CLOSE_ON_EOF -> the file will be closed by the DTOR. No needs. Also
// because the inputStream will not be read directly.
// 4. no SHARE_DELETE -> We don't want to allow this file to be deleted.
const uint32_t sTemporaryFileStreamFlags =
nsIFileInputStream::REOPEN_ON_REWIND;
class TemporaryFileInputStream final : public nsFileInputStream
{
public:
static nsresult
Create(nsIFile* aFile, nsIInputStream** aInputStream)
{
MOZ_ASSERT(aFile);
MOZ_ASSERT(aInputStream);
MOZ_ASSERT(XRE_IsParentProcess());
RefPtr<TemporaryFileInputStream> stream =
new TemporaryFileInputStream(aFile);
nsresult rv = stream->Init(aFile, -1, -1, sTemporaryFileStreamFlags);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
stream.forget(aInputStream);
return NS_OK;
}
void
Serialize(InputStreamParams& aParams,
FileDescriptorArray& aFileDescriptors) override
{
MOZ_CRASH("This inputStream cannot be serialized.");
}
bool
Deserialize(const InputStreamParams& aParams,
const FileDescriptorArray& aFileDescriptors) override
{
MOZ_CRASH("This inputStream cannot be deserialized.");
return false;
}
private:
explicit TemporaryFileInputStream(nsIFile* aFile)
: mFile(aFile)
{
MOZ_ASSERT(XRE_IsParentProcess());
}
~TemporaryFileInputStream()
{
// Let's delete the file on the IPCBlob Thread.
RefPtr<IPCBlobInputStreamThread> thread =
IPCBlobInputStreamThread::GetOrCreate();
if (NS_WARN_IF(!thread)) {
return;
}
nsCOMPtr<nsIFile> file = std::move(mFile);
thread->Dispatch(NS_NewRunnableFunction(
"TemporaryFileInputStream::Runnable",
[file]() {
file->Remove(false);
}
));
}
nsCOMPtr<nsIFile> mFile;
};
} // anonymous
TemporaryFileBlobImpl::TemporaryFileBlobImpl(nsIFile* aFile,
const nsAString& aContentType)
: FileBlobImpl(aFile, EmptyString(), aContentType)
#ifdef DEBUG
, mInputStreamCreated(false)
#endif
{
MOZ_ASSERT(XRE_IsParentProcess());
}
TemporaryFileBlobImpl::~TemporaryFileBlobImpl()
{
MOZ_ASSERT(mInputStreamCreated);
}
already_AddRefed<BlobImpl>
TemporaryFileBlobImpl::CreateSlice(uint64_t aStart, uint64_t aLength,
const nsAString& aContentType,
ErrorResult& aRv)
{
MOZ_CRASH("This BlobImpl is not meant to be sliced!");
return nullptr;
}
void
TemporaryFileBlobImpl::CreateInputStream(nsIInputStream** aStream, ErrorResult& aRv)
{
#ifdef DEBUG
MOZ_ASSERT(!mInputStreamCreated);
// CreateInputStream can be called only once.
mInputStreamCreated = true;
#endif
aRv = TemporaryFileInputStream::Create(mFile, aStream);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
}
} // namespace dom
} // namespace mozilla