Line data    Source code

       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 "BlobImpl.h"
       8             : #include "File.h"
       9             : #include "mozilla/CheckedInt.h"
      10             : 
      11             : namespace mozilla {
      12             : namespace dom {
      13             : 
      14             : // Makes sure that aStart and aEnd is less then or equal to aSize and greater
      15             : // than 0
      16             : static void
      17           0 : ParseSize(int64_t aSize, int64_t& aStart, int64_t& aEnd)
      18             : {
      19           0 :   CheckedInt64 newStartOffset = aStart;
      20           0 :   if (aStart < -aSize) {
      21           0 :     newStartOffset = 0;
      22             :   }
      23           0 :   else if (aStart < 0) {
      24           0 :     newStartOffset += aSize;
      25             :   }
      26           0 :   else if (aStart > aSize) {
      27           0 :     newStartOffset = aSize;
      28             :   }
      29             : 
      30           0 :   CheckedInt64 newEndOffset = aEnd;
      31           0 :   if (aEnd < -aSize) {
      32           0 :     newEndOffset = 0;
      33             :   }
      34           0 :   else if (aEnd < 0) {
      35           0 :     newEndOffset += aSize;
      36             :   }
      37           0 :   else if (aEnd > aSize) {
      38           0 :     newEndOffset = aSize;
      39             :   }
      40             : 
      41           0 :   if (!newStartOffset.isValid() || !newEndOffset.isValid() ||
      42           0 :       newStartOffset.value() >= newEndOffset.value()) {
      43           0 :     aStart = aEnd = 0;
      44             :   }
      45             :   else {
      46           0 :     aStart = newStartOffset.value();
      47           0 :     aEnd = newEndOffset.value();
      48             :   }
      49           0 : }
      50             : 
      51             : already_AddRefed<BlobImpl>
      52           0 : BlobImpl::Slice(const Optional<int64_t>& aStart,
      53             :                 const Optional<int64_t>& aEnd,
      54             :                 const nsAString& aContentType,
      55             :                 ErrorResult& aRv)
      56             : {
      57             :   // Truncate aStart and aEnd so that we stay within this file.
      58           0 :   uint64_t thisLength = GetSize(aRv);
      59           0 :   if (NS_WARN_IF(aRv.Failed())) {
      60           0 :     return nullptr;
      61             :   }
      62             : 
      63           0 :   int64_t start = aStart.WasPassed() ? aStart.Value() : 0;
      64           0 :   int64_t end = aEnd.WasPassed() ? aEnd.Value() : (int64_t)thisLength;
      65             : 
      66           0 :   ParseSize((int64_t)thisLength, start, end);
      67             : 
      68           0 :   nsAutoString type(aContentType);
      69           0 :   Blob::MakeValidBlobType(type);
      70           0 :   return CreateSlice((uint64_t)start, (uint64_t)(end - start), type, aRv);
      71             : }
      72             : 
      73           0 : NS_IMPL_ISUPPORTS(BlobImpl, BlobImpl)
      74             : 
      75             : } // namespace dom
      76             : } // namespace mozilla