dom/quota/StreamUtils.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 file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "StreamUtils.h"
   8
   9 #include "mozilla/Result.h"
  10 #include "mozilla/dom/quota/Assertions.h"
  11 #include "mozilla/dom/quota/QuotaCommon.h"
  12 #include "mozilla/dom/quota/ResultExtensions.h"
  13 #include "nsCOMPtr.h"
  14 #include "nsIFile.h"
  15 #include "nsIObjectInputStream.h"
  16 #include "nsIObjectOutputStream.h"
  17 #include "nsIOutputStream.h"
  18 #include "nsIRandomAccessStream.h"
  19 #include "nsNetUtil.h"
  20
  21 namespace mozilla::dom::quota {
  22
  23 Result<nsCOMPtr<nsIOutputStream>, nsresult> GetOutputStream(
  24     nsIFile& aFile, FileFlag aFileFlag) {
  25   AssertIsOnIOThread();
  26
  27   switch (aFileFlag) {
  28     case FileFlag::Truncate:
  29       QM_TRY_RETURN(NS_NewLocalFileOutputStream(&aFile));
  30
  31     case FileFlag::Update: {
  32       QM_TRY_INSPECT(const bool& exists,
  33                      MOZ_TO_RESULT_INVOKE_MEMBER(&aFile, Exists));
  34
  35       if (!exists) {
  36         return nsCOMPtr<nsIOutputStream>();
  37       }
  38
  39       QM_TRY_INSPECT(const auto& stream,
  40                      NS_NewLocalFileRandomAccessStream(&aFile));
  41
  42       nsCOMPtr<nsIOutputStream> outputStream = do_QueryInterface(stream);
  43       QM_TRY(OkIf(outputStream), Err(NS_ERROR_FAILURE));
  44
  45       return outputStream;
  46     }
  47
  48     case FileFlag::Append:
  49       QM_TRY_RETURN(NS_NewLocalFileOutputStream(
  50           &aFile, PR_WRONLY | PR_CREATE_FILE | PR_APPEND));
  51
  52     default:
  53       MOZ_CRASH("Should never get here!");
  54   }
  55 }
  56
  57 Result<nsCOMPtr<nsIBinaryOutputStream>, nsresult> GetBinaryOutputStream(
  58     nsIFile& aFile, FileFlag aFileFlag) {
  59   QM_TRY_UNWRAP(auto outputStream, GetOutputStream(aFile, aFileFlag));
  60
  61   QM_TRY(OkIf(outputStream), Err(NS_ERROR_UNEXPECTED));
  62
  63   return nsCOMPtr<nsIBinaryOutputStream>(
  64       NS_NewObjectOutputStream(outputStream));
  65 }
  66
  67 Result<nsCOMPtr<nsIBinaryInputStream>, nsresult> GetBinaryInputStream(
  68     nsIFile& aDirectory, const nsAString& aFilename) {
  69   MOZ_ASSERT(!NS_IsMainThread());
  70
  71   QM_TRY_INSPECT(const auto& file, MOZ_TO_RESULT_INVOKE_MEMBER_TYPED(
  72                                        nsCOMPtr<nsIFile>, aDirectory, Clone));
  73
  74   QM_TRY(MOZ_TO_RESULT(file->Append(aFilename)));
  75
  76   QM_TRY_UNWRAP(auto stream, NS_NewLocalFileInputStream(file));
  77
  78   QM_TRY_INSPECT(const auto& bufferedStream,
  79                  NS_NewBufferedInputStream(stream.forget(), 512));
  80
  81   QM_TRY(OkIf(bufferedStream), Err(NS_ERROR_FAILURE));
  82
  83   return nsCOMPtr<nsIBinaryInputStream>(
  84       NS_NewObjectInputStream(bufferedStream));
  85 }
  86
  87 }  // namespace mozilla::dom::quota