C++ NS_UNLIKELY函数代码示例

PRInt32 CaseInsensitiveCompare(const char *aLeft,
                               const char *aRight,
                               PRUint32 aLeftBytes,
                               PRUint32 aRightBytes)
{
  const char *leftEnd = aLeft + aLeftBytes;
  const char *rightEnd = aRight + aRightBytes;

  while (aLeft < leftEnd && aRight < rightEnd) {
    PRUint32 leftChar = GetLowerUTF8Codepoint(aLeft, leftEnd, &aLeft);
    if (NS_UNLIKELY(leftChar == PRUint32(-1)))
      return -1;

    PRUint32 rightChar = GetLowerUTF8Codepoint(aRight, rightEnd, &aRight);
    if (NS_UNLIKELY(rightChar == PRUint32(-1)))
      return -1;

    // Now leftChar and rightChar are lower-case, so we can compare them.
    if (leftChar != rightChar) {
      if (leftChar > rightChar)
        return 1;
      return -1;
    }
  }

  // Make sure that if one string is longer than the other we return the
  // correct result.
  if (aLeft < leftEnd)
    return 1;
  if (aRight < rightEnd)
    return -1;

  return 0;
}

bool
CaseInsensitiveUTF8CharsEqual(const char* aLeft, const char* aRight,
                              const char* aLeftEnd, const char* aRightEnd,
                              const char** aLeftNext, const char** aRightNext,
                              bool* aErr)
{
  NS_ASSERTION(aLeftNext, "Out pointer shouldn't be null.");
  NS_ASSERTION(aRightNext, "Out pointer shouldn't be null.");
  NS_ASSERTION(aErr, "Out pointer shouldn't be null.");
  NS_ASSERTION(aLeft < aLeftEnd, "aLeft must be less than aLeftEnd.");
  NS_ASSERTION(aRight < aRightEnd, "aRight must be less than aRightEnd.");

  PRUint32 leftChar = GetLowerUTF8Codepoint(aLeft, aLeftEnd, aLeftNext);
  if (NS_UNLIKELY(leftChar == PRUint32(-1))) {
    *aErr = true;
    return false;
  }

  PRUint32 rightChar = GetLowerUTF8Codepoint(aRight, aRightEnd, aRightNext);
  if (NS_UNLIKELY(rightChar == PRUint32(-1))) {
    *aErr = true;
    return false;
  }

  // Can't have an error past this point.
  *aErr = false;

  return leftChar == rightChar;
}

/* void getInterfaces (out PRUint32 count, [array, size_is (count),
   retval] out nsIIDPtr array); */
NS_IMETHODIMP
WSPProxy::GetInterfaces(PRUint32 *count, nsIID * **array)
{
  if (!mIID) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  *count = 2;
  nsIID** iids = static_cast<nsIID**>(nsMemory::Alloc(2 * sizeof(nsIID*)));
  if (!iids) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  iids[0] = static_cast<nsIID *>(nsMemory::Clone(mIID, sizeof(nsIID)));
  if (NS_UNLIKELY(!iids[0])) {
    NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(0, iids);
    return NS_ERROR_OUT_OF_MEMORY;
  }
  const nsIID& wsiid = NS_GET_IID(nsIWebServiceProxy);
  iids[1] = static_cast<nsIID *>(nsMemory::Clone(&wsiid, sizeof(nsIID)));
  if (NS_UNLIKELY(!iids[1])) {
    NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(1, iids);
    return NS_ERROR_OUT_OF_MEMORY;
  }

  *array = iids;

  return NS_OK;
}

NS_IMETHODIMP
TelemetryImpl::GetHistogramById(const nsACString &name, JSContext *cx, jsval *ret)
{
  // Cache names
  // Note the histogram names are statically allocated
  if (!mHistogramMap.Count()) {
    for (PRUint32 i = 0; i < Telemetry::HistogramCount; i++) {
      CharPtrEntryType *entry = mHistogramMap.PutEntry(gHistograms[i].id);
      if (NS_UNLIKELY(!entry)) {
        mHistogramMap.Clear();
        return NS_ERROR_OUT_OF_MEMORY;
      }
      entry->mData = (Telemetry::ID) i;
    }
  }

  CharPtrEntryType *entry = mHistogramMap.GetEntry(PromiseFlatCString(name).get());
  if (!entry)
    return NS_ERROR_FAILURE;
  
  Histogram *h;

  nsresult rv = GetHistogramByEnumId(entry->mData, &h);
  if (NS_FAILED(rv))
    return rv;

  return WrapAndReturnHistogram(h, cx, ret);
}

void
TelemetryImpl::RecordSlowStatement(const nsACString &statement,
                                   const nsACString &dbName,
                                   PRUint32 delay)
{
  if (!sTelemetry) {
    // Make the service manager hold a long-lived reference to the service
    nsCOMPtr<nsITelemetry> telemetryService =
      do_GetService("@mozilla.org/base/telemetry;1");
    if (!telemetryService || !sTelemetry)
      return;
  }

  if (!sTelemetry->mCanRecord || !sTelemetry->mTrackedDBs.GetEntry(dbName))
    return;

  nsTHashtable<SlowSQLEntryType> *slowSQLMap = NULL;
  if (NS_IsMainThread())
    slowSQLMap = &(sTelemetry->mSlowSQLOnMainThread);
  else
    slowSQLMap = &(sTelemetry->mSlowSQLOnOtherThread);

  MutexAutoLock hashMutex(sTelemetry->mHashMutex);
  SlowSQLEntryType *entry = slowSQLMap->GetEntry(statement);
  if (!entry) {
    entry = slowSQLMap->PutEntry(statement);
    if (NS_UNLIKELY(!entry))
      return;
    entry->mData.hitCount = 0;
    entry->mData.totalTime = 0;
  }
  entry->mData.hitCount++;
  entry->mData.totalTime += delay;
}

const gfxFont::Metrics&
gfxFT2FontBase::GetMetrics()
{
    if (mHasMetrics)
        return mMetrics;

    if (NS_UNLIKELY(GetStyle()->size <= 0.0)) {
        new(&mMetrics) gfxFont::Metrics(); // zero initialize
        mSpaceGlyph = 0;
    } else {
        gfxFT2LockedFace(this).GetMetrics(&mMetrics, &mSpaceGlyph);
    }

    SanitizeMetrics(&mMetrics, PR_FALSE);

#if 0
    //    printf("font name: %s %f\n", NS_ConvertUTF16toUTF8(GetName()).get(), GetStyle()->size);
    //    printf ("pango font %s\n", pango_font_description_to_string (pango_font_describe (font)));

    fprintf (stderr, "Font: %s\n", NS_ConvertUTF16toUTF8(GetName()).get());
    fprintf (stderr, "    emHeight: %f emAscent: %f emDescent: %f\n", mMetrics.emHeight, mMetrics.emAscent, mMetrics.emDescent);
    fprintf (stderr, "    maxAscent: %f maxDescent: %f\n", mMetrics.maxAscent, mMetrics.maxDescent);
    fprintf (stderr, "    internalLeading: %f externalLeading: %f\n", mMetrics.externalLeading, mMetrics.internalLeading);
    fprintf (stderr, "    spaceWidth: %f aveCharWidth: %f xHeight: %f\n", mMetrics.spaceWidth, mMetrics.aveCharWidth, mMetrics.xHeight);
    fprintf (stderr, "    uOff: %f uSize: %f stOff: %f stSize: %f suOff: %f suSize: %f\n", mMetrics.underlineOffset, mMetrics.underlineSize, mMetrics.strikeoutOffset, mMetrics.strikeoutSize, mMetrics.superscriptOffset, mMetrics.subscriptOffset);
#endif

    mHasMetrics = PR_TRUE;
    return mMetrics;
}

void
TelemetryImpl::StoreSlowSQL(const nsACString &sql, uint32_t delay,
                            bool isDynamicSql, bool isTrackedDB, bool isAggregate)
{
  AutoHashtable<SlowSQLEntryType> *slowSQLMap = NULL;
  if (NS_IsMainThread())
    slowSQLMap = &(sTelemetry->mSlowSQLOnMainThread);
  else
    slowSQLMap = &(sTelemetry->mSlowSQLOnOtherThread);

  MutexAutoLock hashMutex(sTelemetry->mHashMutex);

  SlowSQLEntryType *entry = slowSQLMap->GetEntry(sql);
  if (!entry) {
    entry = slowSQLMap->PutEntry(sql);
    if (NS_UNLIKELY(!entry))
      return;
    entry->mData.isDynamicSql = isDynamicSql;
    entry->mData.isTrackedDb = isTrackedDB;
    entry->mData.isAggregate = isAggregate;

    entry->mData.hitCount = 0;
    entry->mData.totalTime = 0;
  }

  entry->mData.hitCount++;
  entry->mData.totalTime += delay;
}

void
tableInterfaceInitCB(AtkTableIface* aIface)
{
  NS_ASSERTION(aIface, "no interface!");
  if (NS_UNLIKELY(!aIface))
    return;

  aIface->ref_at = refAtCB;
  aIface->get_index_at = getIndexAtCB;
  aIface->get_column_at_index = getColumnAtIndexCB;
  aIface->get_row_at_index = getRowAtIndexCB;
  aIface->get_n_columns = getColumnCountCB;
  aIface->get_n_rows = getRowCountCB;
  aIface->get_column_extent_at = getColumnExtentAtCB;
  aIface->get_row_extent_at = getRowExtentAtCB;
  aIface->get_caption = getCaptionCB;
  aIface->get_column_description = getColumnDescriptionCB;
  aIface->get_column_header = getColumnHeaderCB;
  aIface->get_row_description = getRowDescriptionCB;
  aIface->get_row_header = getRowHeaderCB;
  aIface->get_summary = getSummaryCB;
  aIface->get_selected_columns = getSelectedColumnsCB;
  aIface->get_selected_rows = getSelectedRowsCB;
  aIface->is_column_selected = isColumnSelectedCB;
  aIface->is_row_selected = isRowSelectedCB;
  aIface->is_selected = isCellSelectedCB;
}

NS_IMETHODIMP
nsMenuFrame::InsertFrames(nsIAtom*        aListName,
                          nsIFrame*       aPrevFrame,
                          nsFrameList&    aFrameList)
{
  if (!mPopupFrame && (!aListName || aListName == nsGkAtoms::popupList)) {
    SetPopupFrame(aFrameList);
    if (mPopupFrame) {
#ifdef DEBUG_LAYOUT
      nsBoxLayoutState state(PresContext());
      SetDebug(state, aFrameList, mState & NS_STATE_CURRENTLY_IN_DEBUG);
#endif

      PresContext()->PresShell()->
        FrameNeedsReflow(this, nsIPresShell::eTreeChange,
                         NS_FRAME_HAS_DIRTY_CHILDREN);
    }
  }

  if (aFrameList.IsEmpty())
    return NS_OK;

  if (NS_UNLIKELY(aPrevFrame == mPopupFrame)) {
    aPrevFrame = nsnull;
  }

  return nsBoxFrame::InsertFrames(aListName, aPrevFrame, aFrameList);
}

void
nsLineBox::DeleteLineList(nsPresContext* aPresContext, nsLineList& aLines,
                          nsIFrame* aDestructRoot, nsFrameList* aFrames)
{
  nsIPresShell* shell = aPresContext->PresShell();

  // Keep our line list and frame list up to date as we
  // remove frames, in case something wants to traverse the
  // frame tree while we're destroying.
  while (!aLines.empty()) {
    nsLineBox* line = aLines.front();
    if (NS_UNLIKELY(line->mFlags.mHasHashedFrames)) {
      line->SwitchToCounter();  // Avoid expensive has table removals.
    }
    while (line->GetChildCount() > 0) {
      nsIFrame* child = aFrames->RemoveFirstChild();
      MOZ_ASSERT(child == line->mFirstChild, "Lines out of sync");
      line->mFirstChild = aFrames->FirstChild();
      line->NoteFrameRemoved(child);
      child->DestroyFrom(aDestructRoot);
    }

    aLines.pop_front();
    line->Destroy(shell);
  }
}

nsresult
TelemetryImpl::GetHistogramEnumId(const char *name, Telemetry::ID *id)
{
  if (!sTelemetry) {
    return NS_ERROR_FAILURE;
  }

  // Cache names
  // Note the histogram names are statically allocated
  TelemetryImpl::HistogramMapType *map = &sTelemetry->mHistogramMap;
  if (!map->Count()) {
    for (uint32_t i = 0; i < Telemetry::HistogramCount; i++) {
      CharPtrEntryType *entry = map->PutEntry(gHistograms[i].id);
      if (NS_UNLIKELY(!entry)) {
        map->Clear();
        return NS_ERROR_OUT_OF_MEMORY;
      }
      entry->mData = (Telemetry::ID) i;
    }
  }

  CharPtrEntryType *entry = map->GetEntry(name);
  if (!entry) {
    return NS_ERROR_INVALID_ARG;
  }
  *id = entry->mData;
  return NS_OK;
}

bool
nsLineBox::RFindLineContaining(nsIFrame* aFrame,
                               const nsLineList::iterator& aBegin,
                               nsLineList::iterator& aEnd,
                               nsIFrame* aLastFrameBeforeEnd,
                               PRInt32* aFrameIndexInLine)
{
  NS_PRECONDITION(aFrame, "null ptr");

  nsIFrame* curFrame = aLastFrameBeforeEnd;
  while (aBegin != aEnd) {
    --aEnd;
    NS_ASSERTION(aEnd->LastChild() == curFrame, "Unexpected curFrame");
    if (NS_UNLIKELY(aEnd->mFlags.mHasHashedFrames) &&
        !aEnd->Contains(aFrame)) {
      if (aEnd->mFirstChild) {
        curFrame = aEnd->mFirstChild->GetPrevSibling();
      }
      continue;
    }
    // i is the index of curFrame in aEnd
    PRInt32 i = aEnd->GetChildCount() - 1;
    while (i >= 0) {
      if (curFrame == aFrame) {
        *aFrameIndexInLine = i;
        return true;
      }
      --i;
      curFrame = curFrame->GetPrevSibling();
    }
    MOZ_ASSERT(!aEnd->mFlags.mHasHashedFrames, "Contains lied to us!");
  }
  *aFrameIndexInLine = -1;
  return false;
}

nsLineBox::~nsLineBox()
{
  MOZ_COUNT_DTOR(nsLineBox);
  if (NS_UNLIKELY(mFlags.mHasHashedFrames)) {
    delete mFrames;
  }  
  Cleanup();
}

void
hyperlinkImplInterfaceInitCB(AtkHyperlinkImplIface *aIface)
{
  NS_ASSERTION(aIface, "no interface!");
  if (NS_UNLIKELY(!aIface))
    return;

  aIface->get_hyperlink = getHyperlinkCB;
}

void
mai_atk_component_iface_init(AtkComponentIface* aIface)
{
  NS_ASSERTION(aIface, "Invalid Interface");
  if (NS_UNLIKELY(!aIface))
    return;

  aIface->ref_accessible_at_point = RefAccessibleAtPoint;
  aIface->get_extents = GetExtents;
}