void
nsTextBoxFrame::UpdateAccessIndex()
{
    PRInt32 menuAccessKey;
    nsMenuBarListener::GetMenuAccessKey(&menuAccessKey);
    if (menuAccessKey) {
        if (mAccessKey.IsEmpty()) {
            if (mAccessKeyInfo) {
                delete mAccessKeyInfo;
                mAccessKeyInfo = nsnull;
            }
        } else {
            if (!mAccessKeyInfo) {
                mAccessKeyInfo = new nsAccessKeyInfo();
                if (!mAccessKeyInfo)
                    return;
            }

            nsAString::const_iterator start, end;
                
            mCroppedTitle.BeginReading(start);
            mCroppedTitle.EndReading(end);
            
            // remember the beginning of the string
            nsAString::const_iterator originalStart = start;

            PRBool found;
            if (!AlwaysAppendAccessKey()) {
                // not appending access key - do case-sensitive search
                // first
                found = FindInReadable(mAccessKey, start, end);
                if (!found) {
                    // didn't find it - perform a case-insensitive search
                    start = originalStart;
                    found = FindInReadable(mAccessKey, start, end,
                                           nsCaseInsensitiveStringComparator());
                }
            } else {
                found = RFindInReadable(mAccessKey, start, end,
                                        nsCaseInsensitiveStringComparator());
            }
            
            if (found)
                mAccessKeyInfo->mAccesskeyIndex = Distance(originalStart, start);
            else
                mAccessKeyInfo->mAccesskeyIndex = kNotFound;
        }
    }
}

bool IsVideoContentType(const nsCString& aContentType) {
  NS_NAMED_LITERAL_CSTRING(video, "video");
  if (FindInReadable(video, aContentType)) {
    return true;
  }
  return false;
}

// static
Modifiers
UIEvent::ComputeModifierState(const nsAString& aModifiersList)
{
  if (aModifiersList.IsEmpty()) {
    return 0;
  }

  // Be careful about the performance.  If aModifiersList is too long,
  // parsing it needs too long time.
  // XXX Should we abort if aModifiersList is too long?

  Modifiers modifiers = 0;

  nsAString::const_iterator listStart, listEnd;
  aModifiersList.BeginReading(listStart);
  aModifiersList.EndReading(listEnd);

  for (uint32_t i = 0; i < ArrayLength(kPairs); i++) {
    nsAString::const_iterator start(listStart), end(listEnd);
    if (!FindInReadable(NS_ConvertASCIItoUTF16(kPairs[i].name), start, end)) {
      continue;
    }

    if ((start != listStart && !NS_IsAsciiWhitespace(*(--start))) ||
        (end != listEnd && !NS_IsAsciiWhitespace(*(end)))) {
      continue;
    }
    modifiers |= kPairs[i].modifier;
  }

  return modifiers;
}

nsresult
nsAboutCache::ParseURI(nsIURI * uri, nsCString &deviceID)
{
    //
    // about:cache[?device=string]
    //
    nsresult rv;

    deviceID.Truncate();

    nsCAutoString path;
    rv = uri->GetPath(path);
    if (NS_FAILED(rv)) return rv;

    nsACString::const_iterator start, valueStart, end;
    path.BeginReading(start);
    path.EndReading(end);

    valueStart = end;
    if (!FindInReadable(NS_LITERAL_CSTRING("?device="), start, valueStart))
        return NS_OK;

    deviceID.Assign(Substring(valueStart, end));
    return NS_OK;
}

  // Reads over a boundary and sets start to the position after the end of the
  // boundary. Returns false if no boundary is found immediately.
  bool
  PushOverBoundary(const nsACString& aBoundaryString,
                   nsACString::const_iterator& aStart,
                   nsACString::const_iterator& aEnd)
  {
    // We copy the end iterator to keep the original pointing to the real end
    // of the string.
    nsACString::const_iterator end(aEnd);
    const char* beginning = aStart.get();
    if (FindInReadable(aBoundaryString, aStart, end)) {
      // We either should find the body immediately, or after 2 chars with the
      // 2 chars being '-', everything else is failure.
      if ((aStart.get() - beginning) == 0) {
        aStart.advance(aBoundaryString.Length());
        return true;
      }

      if ((aStart.get() - beginning) == 2) {
        if (*(--aStart) == '-' && *(--aStart) == '-') {
          aStart.advance(aBoundaryString.Length() + 2);
          return true;
        }
      }
    }

    return false;
  }

 bool
 FindCRLF(nsACString::const_iterator& aStart,
          nsACString::const_iterator& aEnd)
 {
   nsACString::const_iterator end(aEnd);
   return FindInReadable(NS_LITERAL_CSTRING("\r\n"), aStart, end);
 }

static PRBool DoFindInReadable(const nsACString& str, const nsACString& value)
{
  nsACString::const_iterator start, end;
  str.BeginReading(start);
  str.EndReading(end);

  return FindInReadable(value, start, end);
}

nsresult
nsAboutCacheEntry::ParseURI(nsIURI *uri, nsCString &clientID,
                            bool &streamBased, nsCString &key)
{
    //
    // about:cache-entry?client=[string]&sb=[boolean]&key=[string]
    //
    nsresult rv;

    nsAutoCString path;
    rv = uri->GetPath(path);
    if (NS_FAILED(rv)) return rv;

    nsACString::const_iterator i1, i2, i3, end;
    path.BeginReading(i1);
    path.EndReading(end);

    i2 = end;
    if (!FindInReadable(NS_LITERAL_CSTRING("?client="), i1, i2))
        return NS_ERROR_FAILURE;
    // i2 points to the start of clientID

    i1 = i2;
    i3 = end;
    if (!FindInReadable(NS_LITERAL_CSTRING("&sb="), i1, i3))
        return NS_ERROR_FAILURE;
    // i1 points to the end of clientID
    // i3 points to the start of isStreamBased

    clientID.Assign(Substring(i2, i1));

    i1 = i3;
    i2 = end;
    if (!FindInReadable(NS_LITERAL_CSTRING("&key="), i1, i2))
        return NS_ERROR_FAILURE;
    // i1 points to the end of isStreamBased
    // i2 points to the start of key

    streamBased = FindCharInReadable('1', i3, i1);
    key.Assign(Substring(i2, end));

    return NS_OK;
}

static bool
AttrHasSubstring(Implementor* aElement, nsIAtom* aNS, nsIAtom* aName,
                 nsIAtom* aStr_)
{
  FakeRef<nsIAtom> aStr(aStr_);
  auto match = [aStr](const nsAttrValue* aValue) {
    nsAutoString str;
    aValue->ToString(str);
    return FindInReadable(str, nsDependentAtomString(aStr));
  };
  return DoMatch(aElement, aNS, aName, match);
}

// the following block is to append the accesskey to mTitle if there is an accesskey
// but the mTitle doesn't have the character
void
nsTextBoxFrame::UpdateAccessTitle()
{
    /*
     * Note that if you change appending access key label spec,
     * you need to maintain same logic in following methods. See bug 324159.
     * toolkit/content/commonDialog.js (setLabelForNode)
     * toolkit/content/widgets/text.xml (formatAccessKey)
     */
    PRInt32 menuAccessKey;
    nsMenuBarListener::GetMenuAccessKey(&menuAccessKey);
    if (!menuAccessKey || mAccessKey.IsEmpty())
        return;

    if (!AlwaysAppendAccessKey() &&
        FindInReadable(mAccessKey, mTitle, nsCaseInsensitiveStringComparator()))
        return;

    nsAutoString accessKeyLabel;
    accessKeyLabel += '(';
    accessKeyLabel += mAccessKey;
    ToUpperCase(accessKeyLabel);
    accessKeyLabel += ')';

    if (mTitle.IsEmpty()) {
        mTitle = accessKeyLabel;
        return;
    }

    const nsDependentString& kEllipsis = nsContentUtils::GetLocalizedEllipsis();
    PRUint32 offset = mTitle.Length();
    if (StringEndsWith(mTitle, kEllipsis)) {
        offset -= kEllipsis.Length();
    } else if (StringEndsWith(mTitle, OLD_ELLIPSIS)) {
        // Try to check with our old ellipsis (for old addons)
        offset -= OLD_ELLIPSIS.Length();
    } else {
        // Try to check with
        // our default ellipsis (for non-localized addons) or ':'
        const PRUnichar kLastChar = mTitle.Last();
        if (kLastChar == PRUnichar(0x2026) || kLastChar == PRUnichar(':'))
            offset--;
    }

    if (InsertSeparatorBeforeAccessKey() &&
        offset > 0 && !NS_IS_SPACE(mTitle[offset - 1])) {
        mTitle.Insert(' ', offset);
        offset++;
    }

    mTitle.Insert(accessKeyLabel, offset);
}

NS_IMETHODIMP nsMailboxService::NewURI(const nsACString &aSpec,
                                       const char *aOriginCharset,
                                       nsIURI *aBaseURI,
                                       nsIURI **_retval)
{
    nsresult rv = NS_OK;
    nsACString::const_iterator b, e;
    if (FindInReadable(NS_LITERAL_CSTRING("?uidl="), aSpec.BeginReading(b), aSpec.EndReading(e)) ||
        FindInReadable(NS_LITERAL_CSTRING("&uidl="), aSpec.BeginReading(b), aSpec.EndReading(e)))
  {
    nsCOMPtr<nsIProtocolHandler> handler = 
             do_GetService(kCPop3ServiceCID, &rv);
    if (NS_SUCCEEDED(rv))
        rv = handler->NewURI(aSpec, aOriginCharset, aBaseURI, _retval);
  }
  else
  {
    nsCOMPtr<nsIURI> aMsgUri = do_CreateInstance(kCMailboxUrl, &rv);
        
    if (NS_SUCCEEDED(rv))
    {
      if (aBaseURI) 
      {
        nsCAutoString newSpec;
        rv = aBaseURI->Resolve(aSpec, newSpec);
        if (NS_FAILED(rv))
          return rv;
        aMsgUri->SetSpec(newSpec);
      } 
      else 
      {
        aMsgUri->SetSpec(aSpec);
      }
      NS_ADDREF(*_retval = aMsgUri);
    }
  }

  return rv;
}

NS_IMETHODIMP
nsLocalFile::SetRelativeDescriptor(nsIFile* aFromFile,
                                   const nsACString& aRelativeDesc)
{
  NS_NAMED_LITERAL_CSTRING(kParentDirStr, "../");

  nsCOMPtr<nsIFile> targetFile;
  nsresult rv = aFromFile->Clone(getter_AddRefs(targetFile));
  if (NS_FAILED(rv)) {
    return rv;
  }

  //
  // aRelativeDesc is UTF-8 encoded
  //

  nsCString::const_iterator strBegin, strEnd;
  aRelativeDesc.BeginReading(strBegin);
  aRelativeDesc.EndReading(strEnd);

  nsCString::const_iterator nodeBegin(strBegin), nodeEnd(strEnd);
  nsCString::const_iterator pos(strBegin);

  nsCOMPtr<nsIFile> parentDir;
  while (FindInReadable(kParentDirStr, nodeBegin, nodeEnd)) {
    rv = targetFile->GetParent(getter_AddRefs(parentDir));
    if (NS_FAILED(rv)) {
      return rv;
    }
    if (!parentDir) {
      return NS_ERROR_FILE_UNRECOGNIZED_PATH;
    }
    targetFile = parentDir;

    nodeBegin = nodeEnd;
    pos = nodeEnd;
    nodeEnd = strEnd;
  }

  nodeBegin = nodeEnd = pos;
  while (nodeEnd != strEnd) {
    FindCharInReadable('/', nodeEnd, strEnd);
    targetFile->Append(NS_ConvertUTF8toUTF16(Substring(nodeBegin, nodeEnd)));
    if (nodeEnd != strEnd) { // If there's more left in the string, inc over the '/' nodeEnd is on.
      ++nodeEnd;
    }
    nodeBegin = nodeEnd;
  }

  return InitWithFile(targetFile);
}

nsresult
nsDASHWebMODParser::GetTime(nsAString& aTimeStr, double& aTime)
{
  NS_ENSURE_FALSE(aTimeStr.IsEmpty(), NS_ERROR_NOT_INITIALIZED);
  // Fail if time string is not of the format "PT<time>S".
  NS_NAMED_LITERAL_STRING(prefix, "PT");
  NS_NAMED_LITERAL_STRING(suffix, "S");
  nsAString::const_iterator start, end, prefixStart, prefixEnd,
                            suffixStart, suffixEnd;

  // Search for "PT" at the start.
  aTimeStr.BeginReading(start);
  aTimeStr.EndReading(end);
  prefixStart = start;
  prefixEnd = end;
  NS_ENSURE_TRUE(FindInReadable(prefix, prefixStart, prefixEnd),
                 NS_ERROR_ILLEGAL_VALUE);
  NS_ENSURE_TRUE(prefixStart == start, NS_ERROR_ILLEGAL_VALUE);

  // Search for "S" after "PT".
  suffixStart = prefixEnd;
  suffixEnd = end;
  NS_ENSURE_TRUE(FindInReadable(suffix, suffixStart, suffixEnd),
                 NS_ERROR_ILLEGAL_VALUE);
  NS_ENSURE_TRUE(suffixStart != prefixEnd, NS_ERROR_ILLEGAL_VALUE);
  NS_ENSURE_TRUE(suffixEnd == end, NS_ERROR_ILLEGAL_VALUE);

  // Parse inner substring for time.
  const nsAutoString timeSubString(Substring(prefixEnd, suffixStart));
  LOG("Parsing substring \"%s\" in \"%s\"",
      NS_ConvertUTF16toUTF8(timeSubString).get(),
      NS_ConvertUTF16toUTF8(aTimeStr).get());
  NS_ENSURE_FALSE(timeSubString.IsEmpty(), NS_ERROR_ILLEGAL_VALUE);
  nsresult rv;
  aTime = timeSubString.ToDouble(&rv);
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

static void ReplaceChar(nsCString& str, const nsACString& character,
                        const nsACString& replacement)
{
  nsCString::const_iterator start, end;

  str.BeginReading(start);
  str.EndReading(end);

  while (FindInReadable(character, start, end)) {
    PRInt32 pos = end.size_backward();
    str.Replace(pos - 1, 1, replacement);

    str.BeginReading(start);
    start.advance(pos + replacement.Length() - 1);
    str.EndReading(end);
  }
}

/**
 * Determines whether or not a string exists as the root element in an XML data
 * string buffer.
 * @param   dataString
 *          The data being sniffed
 * @param   substring
 *          The substring being tested for existence and root-ness.
 * @returns true if the substring exists and is the documentElement, false
 *          otherwise.
 */
static bool
ContainsTopLevelSubstring(nsACString& dataString, const char *substring) 
{
  nsACString::const_iterator start, end;
  dataString.BeginReading(start);
  dataString.EndReading(end);

  if (!FindInReadable(nsCString(substring), start, end)){
    return false;
  }

  auto offset = start.get() - dataString.Data();

  const char *begin = dataString.BeginReading();

  // Only do the validation when we find the substring.
  return IsDocumentElement(begin, begin + offset);
}

bool
nsPicoService::GetVoiceFileLanguage(const nsACString& aFileName, nsAString& aLang)
{
  nsACString::const_iterator start, end;
  aFileName.BeginReading(start);
  aFileName.EndReading(end);

  // The lingware filename syntax is language_(ta/sg).bin,
  // we extract the language prefix here.
  if (FindInReadable(NS_LITERAL_CSTRING("_"), start, end)) {
    end = start;
    aFileName.BeginReading(start);
    aLang.Assign(NS_ConvertUTF8toUTF16(Substring(start, end)));
    return true;
  }

  return false;
}

PRBool
nsCoreUtils::IsErrorPage(nsIDocument *aDocument)
{
  nsIURI *uri = aDocument->GetDocumentURI();
  PRBool isAboutScheme = PR_FALSE;
  uri->SchemeIs("about", &isAboutScheme);
  if (!isAboutScheme)
    return PR_FALSE;

  nsCAutoString path;
  uri->GetPath(path);

  nsCAutoString::const_iterator start, end;
  path.BeginReading(start);
  path.EndReading(end);

  NS_NAMED_LITERAL_CSTRING(neterror, "neterror");
  return FindInReadable(neterror, start, end);
}

/* static */ eMATHVARIANT
nsMathMLOperators::LookupInvariantChar(const nsAString& aChar)
{
  if (!gInitialized) {
    InitGlobals();
  }
  if (gInvariantCharArray) {
    for (PRInt32 i = gInvariantCharArray->Length()-1; i >= 0; --i) {
      const nsString& list = gInvariantCharArray->ElementAt(i);
      nsString::const_iterator start, end;
      list.BeginReading(start);
      list.EndReading(end);
      // Style-invariant characters are at offset 3*j + 1.
      if (FindInReadable(aChar, start, end) &&
          start.size_backward() % 3 == 1) {
        return eMATHVARIANT(i);
      }
    }
  }
  return eMATHVARIANT_NONE;
}

/* static */
already_AddRefed<MediaEncoder>
MediaEncoder::CreateEncoder(const nsAString& aMIMEType)
{
  nsAutoPtr<ContainerWriter> writer;
  nsAutoPtr<AudioTrackEncoder> audioEncoder;
  nsAutoPtr<VideoTrackEncoder> videoEncoder;
  nsRefPtr<MediaEncoder> encoder;

  if (aMIMEType.IsEmpty()) {
    // TODO: Should pick out a default container+codec base on the track
    //       coming from MediaStreamGraph. For now, just default to Ogg+Opus.
    const_cast<nsAString&>(aMIMEType) = NS_LITERAL_STRING("audio/ogg");
  }

  bool isAudioOnly = FindInReadable(NS_LITERAL_STRING("audio/"), aMIMEType);
#ifdef MOZ_OGG
  if (IsOggType(aMIMEType)) {
    writer = new OggWriter();
    if (!isAudioOnly) {
      // Initialize the videoEncoder.
    }
#ifdef MOZ_OPUS
    audioEncoder = new OpusTrackEncoder();
#endif
  }
#endif
  // If the given mime-type is video but fail to create the video encoder.
  if (!isAudioOnly) {
    NS_ENSURE_TRUE(videoEncoder, nullptr);
  }

  // Return null if we fail to create the audio encoder.
  NS_ENSURE_TRUE(audioEncoder, nullptr);

  encoder = new MediaEncoder(writer.forget(), audioEncoder.forget(),
                             videoEncoder.forget(), aMIMEType);


  return encoder.forget();
}

  // The end of a body is marked by a CRLF followed by the boundary. So the
  // CRLF is part of the boundary and not the body, but any prior CRLFs are
  // part of the body. This will position the iterator at the beginning of the
  // boundary (after the CRLF).
  bool
  ParseBody(const nsACString& aBoundaryString,
            nsACString::const_iterator& aStart,
            nsACString::const_iterator& aEnd)
  {
    const char* beginning = aStart.get();

    // Find the boundary marking the end of the body.
    nsACString::const_iterator end(aEnd);
    if (!FindInReadable(aBoundaryString, aStart, end)) {
      return false;
    }

    // We found a boundary, strip the just prior CRLF, and consider
    // everything else the body section.
    if (aStart.get() - beginning < 2) {
      // Only the first entry can have a boundary right at the beginning. Even
      // an empty body will have a CRLF before the boundary. So this is
      // a failure.
      return false;
    }

    // Check that there is a CRLF right before the boundary.
    aStart.advance(-2);

    // Skip optional hyphens.
    if (*aStart == '-' && *(aStart.get()+1) == '-') {
      if (aStart.get() - beginning < 2) {
        return false;
      }

      aStart.advance(-2);
    }

    if (*aStart != nsCRT::CR || *(aStart.get()+1) != nsCRT::LF) {
      return false;
    }

    nsAutoCString body(beginning, aStart.get() - beginning);

    // Restore iterator to after the \r\n as we promised.
    // We do not need to handle the extra hyphens case since our boundary
    // parser in PushOverBoundary()
    aStart.advance(2);

    if (!mFormData) {
      mFormData = new nsFormData();
    }

    NS_ConvertUTF8toUTF16 name(mName);

    if (mFilename.IsVoid()) {
      mFormData->Append(name, NS_ConvertUTF8toUTF16(body));
    } else {
      // Unfortunately we've to copy the data first since all our strings are
      // going to free it. We also need fallible alloc, so we can't just use
      // ToNewCString().
      char* copy = static_cast<char*>(moz_xmalloc(body.Length()));
      if (!copy) {
        NS_WARNING("Failed to copy File entry body.");
        return false;
      }
      nsCString::const_iterator bodyIter, bodyEnd;
      body.BeginReading(bodyIter);
      body.EndReading(bodyEnd);
      char *p = copy;
      while (bodyIter != bodyEnd) {
        *p++ = *bodyIter++;
      }
      p = nullptr;

      nsRefPtr<Blob> file =
        File::CreateMemoryFile(mParentObject,
                               reinterpret_cast<void *>(copy), body.Length(),
                               NS_ConvertUTF8toUTF16(mFilename),
                               NS_ConvertUTF8toUTF16(mContentType), /* aLastModifiedDate */ 0);
      Optional<nsAString> dummy;
      mFormData->Append(name, *file, dummy);
    }

    return true;
  }