dom/file/BlobImpl.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 "BlobImpl.h"
   8 #include "File.h"
   9 #include "mozilla/CheckedInt.h"
  10 #include "mozilla/ErrorResult.h"
  11 #include "nsIInputStream.h"
  12
  13 namespace mozilla::dom {
  14
  15 // Makes sure that aStart and aEnd is less then or equal to aSize and greater
  16 // than 0
  17 static void ParseSize(int64_t aSize, int64_t& aStart, int64_t& aEnd) {
  18   CheckedInt64 newStartOffset = aStart;
  19   if (aStart < -aSize) {
  20     newStartOffset = 0;
  21   } else if (aStart < 0) {
  22     newStartOffset += aSize;
  23   } else if (aStart > aSize) {
  24     newStartOffset = aSize;
  25   }
  26
  27   CheckedInt64 newEndOffset = aEnd;
  28   if (aEnd < -aSize) {
  29     newEndOffset = 0;
  30   } else if (aEnd < 0) {
  31     newEndOffset += aSize;
  32   } else if (aEnd > aSize) {
  33     newEndOffset = aSize;
  34   }
  35
  36   if (!newStartOffset.isValid() || !newEndOffset.isValid() ||
  37       newStartOffset.value() >= newEndOffset.value()) {
  38     aStart = aEnd = 0;
  39   } else {
  40     aStart = newStartOffset.value();
  41     aEnd = newEndOffset.value();
  42   }
  43 }
  44
  45 already_AddRefed<BlobImpl> BlobImpl::Slice(const Optional<int64_t>& aStart,
  46                                            const Optional<int64_t>& aEnd,
  47                                            const nsAString& aContentType,
  48                                            ErrorResult& aRv) {
  49   // Truncate aStart and aEnd so that we stay within this file.
  50   uint64_t thisLength = GetSize(aRv);
  51   if (NS_WARN_IF(aRv.Failed())) {
  52     return nullptr;
  53   }
  54
  55   int64_t start = aStart.WasPassed() ? aStart.Value() : 0;
  56   int64_t end = aEnd.WasPassed() ? aEnd.Value() : (int64_t)thisLength;
  57
  58   ParseSize((int64_t)thisLength, start, end);
  59
  60   nsAutoString type(aContentType);
  61   Blob::MakeValidBlobType(type);
  62   return CreateSlice((uint64_t)start, (uint64_t)(end - start), type, aRv);
  63 }
  64
  65 nsresult BlobImpl::GetSendInfo(nsIInputStream** aBody, uint64_t* aContentLength,
  66                                nsACString& aContentType, nsACString& aCharset) {
  67   MOZ_ASSERT(aContentLength);
  68
  69   ErrorResult rv;
  70
  71   nsCOMPtr<nsIInputStream> stream;
  72   CreateInputStream(getter_AddRefs(stream), rv);
  73   if (NS_WARN_IF(rv.Failed())) {
  74     return rv.StealNSResult();
  75   }
  76
  77   *aContentLength = GetSize(rv);
  78   if (NS_WARN_IF(rv.Failed())) {
  79     return rv.StealNSResult();
  80   }
  81
  82   nsAutoString contentType;
  83   GetType(contentType);
  84
  85   if (contentType.IsEmpty()) {
  86     aContentType.SetIsVoid(true);
  87   } else {
  88     CopyUTF16toUTF8(contentType, aContentType);
  89   }
  90
  91   aCharset.Truncate();
  92
  93   stream.forget(aBody);
  94   return NS_OK;
  95 }
  96
  97 NS_IMPL_ISUPPORTS(BlobImpl, BlobImpl)
  98
  99 }  // namespace mozilla::dom