bool
VLPrefixSet::GetSmallestPrefix(nsDependentCSubstring& aOutString) {
  PrefixString* pick = nullptr;
  for (auto iter = mMap.ConstIter(); !iter.Done(); iter.Next()) {
    PrefixString* str = iter.Data();

    if (!str->get()) {
      continue;
    }

    if (aOutString.IsEmpty()) {
      aOutString.Rebind(str->get(), iter.Key());
      pick = str;
      continue;
    }

    nsDependentCSubstring cur(str->get(), iter.Key());
    if (cur < aOutString) {
      aOutString.Rebind(str->get(), iter.Key());
      pick = str;
    }
  }

  if (pick) {
    pick->next();
  }

  return pick != nullptr;
}

void
VolumeManager::OnLineRead(int aFd, nsDependentCSubstring& aMessage)
{
  MOZ_ASSERT(aFd == mSocket.get());
  char* endPtr;
  int responseCode = strtol(aMessage.Data(), &endPtr, 10);
  if (*endPtr == ' ') {
    endPtr++;
  }

  // Now fish out the rest of the line after the response code
  nsDependentCString  responseLine(endPtr, aMessage.Length() - (endPtr - aMessage.Data()));
  DBG("Rcvd: %d '%s'", responseCode, responseLine.Data());

  if (responseCode >= ::ResponseCode::UnsolicitedInformational) {
    // These are unsolicited broadcasts. We intercept these and process
    // them ourselves
    HandleBroadcast(responseCode, responseLine);
  } else {
    // Everything else is considered to be part of the command response.
    if (mCommands.size() > 0) {
      VolumeCommand* cmd = mCommands.front();
      cmd->HandleResponse(responseCode, responseLine);
      if (responseCode >= ::ResponseCode::CommandOkay) {
        // That's a terminating response. We can remove the command.
        mCommands.pop();
        mCommandPending = false;
        // Start the next command, if there is one.
        WriteCommandData();
      }
    } else {
      ERR("Response with no command");
    }
  }
}

/* static */
nsresult
DataStorage::Reader::ParseLine(nsDependentCSubstring& aLine, nsCString& aKeyOut,
                               Entry& aEntryOut)
{
  // First find the indices to each part of the line.
  int32_t scoreIndex;
  scoreIndex = aLine.FindChar('\t', 0) + 1;
  if (scoreIndex <= 0) {
    return NS_ERROR_UNEXPECTED;
  }
  int32_t accessedIndex = aLine.FindChar('\t', scoreIndex) + 1;
  if (accessedIndex <= 0) {
    return NS_ERROR_UNEXPECTED;
  }
  int32_t valueIndex = aLine.FindChar('\t', accessedIndex) + 1;
  if (valueIndex <= 0) {
    return NS_ERROR_UNEXPECTED;
  }

  // Now make substrings based on where each part is.
  nsDependentCSubstring keyPart(aLine, 0, scoreIndex - 1);
  nsDependentCSubstring scorePart(aLine, scoreIndex,
                                  accessedIndex - scoreIndex - 1);
  nsDependentCSubstring accessedPart(aLine, accessedIndex,
                                     valueIndex - accessedIndex - 1);
  nsDependentCSubstring valuePart(aLine, valueIndex);

  nsresult rv;
  rv = DataStorage::ValidateKeyAndValue(nsCString(keyPart),
                                        nsCString(valuePart));
  if (NS_FAILED(rv)) {
    return NS_ERROR_UNEXPECTED;
  }

  // Now attempt to decode the score part as a uint32_t.
  // XXX nsDependentCSubstring doesn't support ToInteger
  int32_t integer = nsCString(scorePart).ToInteger(&rv);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  if (integer < 0) {
    return NS_ERROR_UNEXPECTED;
  }
  aEntryOut.mScore = (uint32_t)integer;

  integer = nsCString(accessedPart).ToInteger(&rv);
  if (NS_FAILED(rv)) {
    return rv;
  }
  if (integer < 0) {
    return NS_ERROR_UNEXPECTED;
  }
  aEntryOut.mLastAccessed = integer;

  // Now set the key and value.
  aKeyOut.Assign(keyPart);
  aEntryOut.mValue.Assign(valuePart);

  return NS_OK;
}

  /* static */
  bool
  MatchAutoCompleteFunction::findBeginning(const nsDependentCSubstring &aToken,
                                           const nsACString &aSourceString)
  {
    NS_PRECONDITION(!aToken.IsEmpty(), "Don't search for an empty token!");

    // We can't use StringBeginsWith here, unfortunately.  Although it will
    // happily take a case-insensitive UTF8 comparator, it eventually calls
    // nsACString::Equals, which checks that the two strings contain the same
    // number of bytes before calling the comparator.  This is clearly not what
    // we want.

    const_char_iterator tokenStart(aToken.BeginReading()),
                        tokenEnd(aToken.EndReading()),
                        sourceStart(aSourceString.BeginReading()),
                        sourceEnd(aSourceString.EndReading());

    PRBool dummy;
    while (sourceStart < sourceEnd &&
           CaseInsensitiveUTF8CharsEqual(sourceStart, tokenStart,
                                         sourceEnd, tokenEnd,
                                         &sourceStart, &tokenStart, &dummy)) {

      // We found the token!
      if (tokenStart >= tokenEnd) {
        return true;
      }
    }

    // We don't need to check CaseInsensitiveUTF8CharsEqual's error condition
    // (stored in |dummy|), since the function will return false if it
    // encounters an error.

    return false;
  }

static void
AppendPrefixToMap(PrefixStringMap& prefixes, nsDependentCSubstring& prefix)
{
  if (!prefix.Length()) {
    return;
  }

  nsCString* prefixString = prefixes.LookupOrAdd(prefix.Length());
  prefixString->Append(prefix.BeginReading(), prefix.Length());
}

void
Tokenizer::Claim(nsDependentCSubstring& aResult, ClaimInclusion aInclusion)
{
  nsACString::const_char_iterator close = aInclusion == EXCLUDE_LAST
    ? mRollback
    : mCursor;
  aResult.Rebind(mRecord, close - mRecord);
}

  /* static */
  bool
  MatchAutoCompleteFunction::findBeginningCaseSensitive(
    const nsDependentCSubstring &aToken,
    const nsACString &aSourceString)
  {
    NS_PRECONDITION(!aToken.IsEmpty(), "Don't search for an empty token!");

    return StringBeginsWith(aSourceString, aToken);
  }

void NetdClient::OnLineRead(int aFd, nsDependentCSubstring& aMessage)
{
  // Set errno to 0 first. For preventing to use the stale version of errno.
  errno = 0;
  // We found a line terminator. Each line is formatted as an
  // integer response code followed by the rest of the line.
  // Fish out the response code.
  int responseCode = strtol(aMessage.Data(), nullptr, 10);
  if (!errno) {
    NetdCommand* response = new NetdCommand();
    // Passing all the response message, including the line terminator.
    response->mSize = aMessage.Length();
    memcpy(response->mData, aMessage.Data(), aMessage.Length());
    gNetdConsumer->MessageReceived(response);
  }

  if (!responseCode) {
    LOG("Can't parse netd's response");
  }
}

nsresult
nsNetscapeProfileMigratorBase::ImportNetscapeCookies(nsIFile* aCookiesFile)
{
  nsresult rv;
  nsCOMPtr<nsIInputStream> cookiesStream;
  rv = NS_NewLocalFileInputStream(getter_AddRefs(cookiesStream), aCookiesFile);
  if (NS_FAILED(rv)) return rv;

  nsCOMPtr<nsILineInputStream> lineInputStream(do_QueryInterface(cookiesStream));

  // This code is copied from mozilla/netwerk/cookie/src/nsCookieManager.cpp
  static NS_NAMED_LITERAL_CSTRING(kTrue, "TRUE");

  nsCAutoString buffer;
  PRBool isMore = PR_TRUE;
  PRInt32 hostIndex = 0, isDomainIndex, pathIndex, secureIndex, expiresIndex, nameIndex, cookieIndex;
  PRInt32 numInts;
  PRInt64 expires;
  PRBool isDomain;
  PRInt64 currentTime = PR_Now() / PR_USEC_PER_SEC;

  nsCOMPtr<nsICookieManager2> cookieManager(do_GetService(NS_COOKIEMANAGER_CONTRACTID, &rv));
  if (NS_FAILED(rv)) return rv;

  /* file format is:
   *
   * host \t isDomain \t path \t secure \t expires \t name \t cookie
   *
   * if this format isn't respected we move onto the next line in the file.
   * isDomain is "TRUE" or "FALSE" (default to "FALSE")
   * isSecure is "TRUE" or "FALSE" (default to "TRUE")
   * expires is a PRInt64 integer
   * note 1: cookie can contain tabs.
   * note 2: cookies are written in order of lastAccessed time:
   *         most-recently used come first; least-recently-used come last.
   */

  while (isMore && NS_SUCCEEDED(lineInputStream->ReadLine(buffer, &isMore))) {
    if (buffer.IsEmpty() || buffer.First() == '#')
      continue;

    // this is a cheap, cheesy way of parsing a tab-delimited line into
    // string indexes, which can be lopped off into substrings. just for
    // purposes of obfuscation, it also checks that each token was found.
    // todo: use iterators?
    if ((isDomainIndex = buffer.FindChar('\t', hostIndex)     + 1) == 0 ||
        (pathIndex     = buffer.FindChar('\t', isDomainIndex) + 1) == 0 ||
        (secureIndex   = buffer.FindChar('\t', pathIndex)     + 1) == 0 ||
        (expiresIndex  = buffer.FindChar('\t', secureIndex)   + 1) == 0 ||
        (nameIndex     = buffer.FindChar('\t', expiresIndex)  + 1) == 0 ||
        (cookieIndex   = buffer.FindChar('\t', nameIndex)     + 1) == 0)
      continue;

    // check the expirytime first - if it's expired, ignore
    // nullstomp the trailing tab, to avoid copying the string
    char *iter = buffer.BeginWriting();
    *(iter += nameIndex - 1) = char(0);
    numInts = PR_sscanf(buffer.get() + expiresIndex, "%lld", &expires);
    if (numInts != 1 || expires < currentTime)
      continue;

    isDomain = Substring(buffer, isDomainIndex, pathIndex - isDomainIndex - 1).Equals(kTrue);
    const nsDependentCSubstring host =
      Substring(buffer, hostIndex, isDomainIndex - hostIndex - 1);
    // check for bad legacy cookies (domain not starting with a dot, or containing a port),
    // and discard
    if (isDomain && !host.IsEmpty() && host.First() != '.' ||
        host.FindChar(':') != -1)
      continue;

    // create a new nsCookie and assign the data.
    rv = cookieManager->Add(host,
                            Substring(buffer, pathIndex, secureIndex - pathIndex - 1),
                            Substring(buffer, nameIndex, cookieIndex - nameIndex - 1),
                            Substring(buffer, cookieIndex, buffer.Length() - cookieIndex),
                            Substring(buffer, secureIndex, expiresIndex - secureIndex - 1).Equals(kTrue),
                            PR_FALSE, // isHttpOnly
                            PR_FALSE, // isSession
                            expires);
  }

  return rv;
}

NS_IMETHODIMP
nsStringInputStream::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
                                  uint32_t aCount, uint32_t* aResult)
{
  NS_ASSERTION(aResult, "null ptr");
  NS_ASSERTION(Length() >= mOffset, "bad stream state");

  if (Closed()) {
    return NS_BASE_STREAM_CLOSED;
  }

  // We may be at end-of-file
  uint32_t maxCount = LengthRemaining();
  if (maxCount == 0) {
    *aResult = 0;
    return NS_OK;
  }

  if (aCount > maxCount) {
    aCount = maxCount;
  }
  nsresult rv = aWriter(this, aClosure, mData.BeginReading() + mOffset, 0,
                        aCount, aResult);
  if (NS_SUCCEEDED(rv)) {
    NS_ASSERTION(*aResult <= aCount,
                 "writer should not write more than we asked it to write");
    mOffset += *aResult;
  }

  // errors returned from the writer end here!
  return NS_OK;
}

NS_IMETHODIMP
nsStringInputStream::SetData(const nsACString& aData)
{
  mData.Assign(aData);
  mOffset = 0;
  return NS_OK;
}

NS_IMETHODIMP
nsStringInputStream::SetData(const nsACString& aData)
{
  if (NS_WARN_IF(!mData.Assign(aData, fallible))) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  mOffset = 0;
  return NS_OK;
}

NS_IMETHODIMP
nsStringInputStream::ShareData(const char* aData, int32_t aDataLen)
{
  if (NS_WARN_IF(!aData)) {
    return NS_ERROR_INVALID_ARG;
  }

  if (aDataLen < 0) {
    aDataLen = strlen(aData);
  }

  mData.Rebind(aData, aDataLen);
  mOffset = 0;
  return NS_OK;
}