Bug 1749935 - Make mSlidingBuffer a UniquePtr. r=hsivonen

Differential Revision: https://phabricator.services.mozilla.com/D135881
iaxat · Feb 14, 2022 · 6a184b6 · 6a184b6
1 parent bc2444e
commit 6a184b6
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Showing 2 changed files with 9 additions and 25 deletions.
diff --git a/parser/htmlparser/nsScanner.cpp b/parser/htmlparser/nsScanner.cpp
@@ -51,15 +51,8 @@ nsScanner::nsScanner(const nsAString& anHTMLString, bool aIncremental)
     : mIncremental(aIncremental) {
   MOZ_COUNT_CTOR(nsScanner);
 
-  mSlidingBuffer = nullptr;
-  if (AppendToBuffer(anHTMLString)) {
-    mSlidingBuffer->BeginReading(mCurrentPosition);
-  } else {
-    /* XXX see hack below, re: bug 182067 */
-    memset(&mCurrentPosition, 0, sizeof(mCurrentPosition));
-    mEndPosition = mCurrentPosition;
-  }
-  mMarkPosition = mCurrentPosition;
+  AppendToBuffer(anHTMLString);
+  MOZ_ASSERT(mMarkPosition == mCurrentPosition);
 }
 
 /**
@@ -69,7 +62,6 @@ nsScanner::nsScanner(const nsAString& anHTMLString, bool aIncremental)
  */
 nsScanner::nsScanner(nsIURI* aURI) : mURI(aURI), mIncremental(true) {
   MOZ_COUNT_CTOR(nsScanner);
-  mSlidingBuffer = nullptr;
 
   // XXX This is a big hack.  We need to initialize the iterators to something.
   // What matters is that mCurrentPosition == mEndPosition, so that our methods
@@ -112,11 +104,7 @@ nsresult nsScanner::SetDocumentCharset(NotNull<const Encoding*> aEncoding,
  *  @param
  *  @return
  */
-nsScanner::~nsScanner() {
-  delete mSlidingBuffer;
-
-  MOZ_COUNT_DTOR(nsScanner);
-}
+nsScanner::~nsScanner() { MOZ_COUNT_DTOR(nsScanner); }
 
 /**
  *  Resets current offset position of input stream to marked position.
@@ -238,7 +226,7 @@ nsresult nsScanner::Append(const char* aBuffer, uint32_t aLen) {
     // since it doesn't reflect on our success or failure
     // - Ref. bug 87110
     res = NS_OK;
-    if (!AppendToBuffer(buffer)) res = NS_ERROR_OUT_OF_MEMORY;
+    AppendToBuffer(buffer);
   } else {
     NS_WARNING("No decoder found.");
     res = NS_ERROR_FAILURE;
@@ -289,22 +277,18 @@ void nsScanner::SetPosition(nsScannerIterator& aPosition, bool aTerminate) {
   }
 }
 
-bool nsScanner::AppendToBuffer(nsScannerString::Buffer* aBuf) {
+void nsScanner::AppendToBuffer(nsScannerString::Buffer* aBuf) {
   if (!mSlidingBuffer) {
-    mSlidingBuffer = new nsScannerString(aBuf);
-    if (!mSlidingBuffer) return false;
+    mSlidingBuffer = MakeUnique<nsScannerString>(aBuf);
     mSlidingBuffer->BeginReading(mCurrentPosition);
     mMarkPosition = mCurrentPosition;
-    mSlidingBuffer->EndReading(mEndPosition);
   } else {
     mSlidingBuffer->AppendBuffer(aBuf);
     if (mCurrentPosition == mEndPosition) {
       mSlidingBuffer->BeginReading(mCurrentPosition);
     }
-    mSlidingBuffer->EndReading(mEndPosition);
   }
-
-  return true;
+  mSlidingBuffer->EndReading(mEndPosition);
 }
 
 /**

diff --git a/parser/htmlparser/nsScanner.h b/parser/htmlparser/nsScanner.h
@@ -161,15 +161,15 @@ class nsScanner final {
   void SetIncremental(bool anIncrValue) { mIncremental = anIncrValue; }
 
  protected:
-  bool AppendToBuffer(nsScannerString::Buffer* aBuffer);
+  void AppendToBuffer(nsScannerString::Buffer* aBuffer);
   bool AppendToBuffer(const nsAString& aStr) {
     nsScannerString::Buffer* buf = nsScannerString::AllocBufferFromString(aStr);
     if (!buf) return false;
     AppendToBuffer(buf);
     return true;
   }
 
-  nsScannerString* mSlidingBuffer;
+  mozilla::UniquePtr<nsScannerString> mSlidingBuffer;
   nsScannerIterator mCurrentPosition;  // The position we will next read from in
                                        // the scanner buffer
   nsScannerIterator