(again) bug 116023 Parser recycling buffers. Protects all cases of

usage of mCurrentPosition without checking mSlidingBuffer. r=harishd,
sr=sfraser, a=asa

htmlparser/src/nsParserModule.cpp

@@ -53,6 +53,7 @@
 //#include "nsTextTokenizer.h"
 #include "nsElementTable.h"
 #include "nsParserService.h"
+#include "nsScanner.h"
 
 #ifdef NS_DEBUG
 #include "nsLoggingSink.h"
@@ -118,6 +119,8 @@ Shutdown(nsIModule* aSelf)
     DeleteElementTable();
     CNewlineToken::FreeNewline();
     gInitialized = PR_FALSE;
+    delete nsScanner::gAllocator;
+    nsScanner::gAllocator = nsnull;
   }
 }
 

htmlparser/src/nsScanner.cpp

@@ -46,9 +46,48 @@
 #include "nsFileSpec.h"
 #include "nsReadableUtils.h"
 
-nsScannerString::nsScannerString(PRUnichar* aStorageStart, 
+nsRecyclingAllocator* nsScanner::gAllocator = nsnull;
-                                 PRUnichar* aDataEnd, 
+
-                                 PRUnichar* aStorageEnd) : nsSlidingString(aStorageStart, aDataEnd, aStorageEnd)
+static void nsScannerRecycle(void *aPtr, void *aClientData)
+{
+  nsScanner::gAllocator->Free(aPtr);
+}
+
+static void *nsScannerAllocate(PRUint32 size)
+{
+  return nsScanner::gAllocator->Malloc(size);
+}
+
+/**
+ * Helper funciton to convert raw 8bit char * to unicode
+ *
+ * aStr : input 8bit string
+ * aLen : length of input string aStr
+ * aDest : Destination unicode buffer. Null terminated.
+ * aDestLength : size of destination buffer. Must be atleast aLen+1.
+ *
+ * return 0 if conversion succeeded
+ * returns -1, if there is not enough space in destination buffer, 
+ */
+static int RawToUnicode(const char *aStr, PRInt32 aLen, PRUnichar *aDest, PRUint32 aDestLength)
+{
+  // Alert if someone if passing null buffers to us
+  NS_ASSERTION(aStr && aDest, "Null buffers");
+
+  // Error checking
+  if (!aStr || !aDest || (PRInt32)aDestLength < aLen+1)
+    return -1;
+
+  while (*aStr)
+    *aDest++ = (PRUnichar) (unsigned char) *aStr++;
+  *aDest = 0;
+  return 0;
+}
+
+
+nsScannerString::nsScannerString(PRUnichar* aStorageStart, PRUnichar* aDataEnd,
+                                 PRUnichar* aStorageEnd, nsFreeProc *aFreeProc)
+    : nsSlidingString(aStorageStart, aDataEnd, aStorageEnd, aFreeProc)
 {
 }
 
@@ -107,14 +146,17 @@ MOZ_DECL_CTOR_COUNTER(nsScanner)
 nsScanner::nsScanner(const nsAString& anHTMLString, const nsString& aCharset, PRInt32 aSource)
 {
   MOZ_COUNT_CTOR(nsScanner);
-
+  InitAllocator();
-  PRUnichar* buffer = ToNewUnicode(anHTMLString);
-  mTotalRead = anHTMLString.Length();
   mSlidingBuffer = nsnull;
+  mTotalRead = anHTMLString.Length();
+  if (mTotalRead) {
+    // Append to buffer will take care of initializing mCurrentPosition
+    // and mMarkPosition. If we didnt get here, mCurrentPosition and
+    // mMarkPosition would be uninitialized and hence we protect using these
+    // variables with if (mSlidingBuffer) checks all over the code.
+    AppendToBuffer(anHTMLString);
+  }
   mCountRemaining = 0;
-  AppendToBuffer(buffer, buffer+mTotalRead, buffer+mTotalRead);
-  mSlidingBuffer->BeginReading(mCurrentPosition);
-  mMarkPosition = mCurrentPosition;
   mIncremental=PR_FALSE;
   mOwnsStream=PR_FALSE;
   mInputStream=0;
@@ -137,7 +179,7 @@ nsScanner::nsScanner(nsString& aFilename,PRBool aCreateStream, const nsString& a
     mFilename(aFilename)
 {
   MOZ_COUNT_CTOR(nsScanner);
-
+  InitAllocator();
   mSlidingBuffer = nsnull;
   mIncremental=PR_TRUE;
   mCountRemaining = 0;
@@ -166,7 +208,7 @@ nsScanner::nsScanner(const nsAString& aFilename,nsInputStream& aStream,const nsS
     mFilename(aFilename)
 {  
   MOZ_COUNT_CTOR(nsScanner);
-
+  InitAllocator();
   mSlidingBuffer = nsnull;
   mIncremental=PR_FALSE;
   mCountRemaining = 0;
@@ -262,8 +304,10 @@ nsScanner::~nsScanner() {
  *  @return  
  */
 void nsScanner::RewindToMark(void){
-  mCountRemaining += (Distance(mMarkPosition, mCurrentPosition));
+  if (mSlidingBuffer) {
-  mCurrentPosition = mMarkPosition;
+    mCountRemaining += (Distance(mMarkPosition, mCurrentPosition));
+    mCurrentPosition = mMarkPosition;
+  }
 }
 
 
@@ -293,9 +337,15 @@ void nsScanner::Mark() {
  */
 PRBool nsScanner::UngetReadable(const nsAReadableString& aBuffer) {
 
-  mSlidingBuffer->UngetReadable(aBuffer,mCurrentPosition);
+  if (!mSlidingBuffer) {
-  mSlidingBuffer->BeginReading(mCurrentPosition); // Insertion invalidated our iterators
+    // This happens to be the first buffer. Just append it.
-  mSlidingBuffer->EndReading(mEndPosition);
+    AppendToBuffer(aBuffer);
+  }
+  else {
+    mSlidingBuffer->UngetReadable(aBuffer,mCurrentPosition);
+    mSlidingBuffer->BeginReading(mCurrentPosition); // Insertion invalidated our iterators
+    mSlidingBuffer->EndReading(mEndPosition);
+  }
   mTotalRead += aBuffer.Length();
       
   return PR_TRUE;
@@ -309,12 +359,8 @@ PRBool nsScanner::UngetReadable(const nsAReadableString& aBuffer) {
  * @return  error code 
  */
 nsresult nsScanner::Append(const nsAReadableString& aBuffer) {
-  
+  AppendToBuffer(aBuffer);
-  PRUnichar* buffer = ToNewUnicode(aBuffer);
+  mTotalRead += aBuffer.Length();
-  PRUint32 bufLen = aBuffer.Length();
-  mTotalRead += bufLen;
-
-  AppendToBuffer(buffer, buffer+bufLen, buffer+bufLen);
 
   return NS_OK;
 }
@@ -332,8 +378,8 @@ nsresult nsScanner::Append(const char* aBuffer, PRUint32 aLen){
   if(mUnicodeDecoder) {
     PRInt32 unicharBufLen = 0;
     mUnicodeDecoder->GetMaxLength(aBuffer, aLen, &unicharBufLen);
-    start = unichars = (PRUnichar*)nsMemory::Alloc((unicharBufLen+1) * sizeof(PRUnichar));
+    start = unichars = (PRUnichar*) nsScannerAllocate((unicharBufLen+1) * sizeof(PRUnichar));
-    NS_ENSURE_TRUE(unichars,NS_ERROR_OUT_OF_MEMORY);
+    NS_ENSURE_TRUE(unichars, NS_ERROR_OUT_OF_MEMORY);
 	  
     PRInt32 totalChars = 0;
     PRInt32 unicharLength = unicharBufLen;
@@ -375,9 +421,7 @@ nsresult nsScanner::Append(const char* aBuffer, PRUint32 aLen){
     res = NS_OK; 
   }
   else {
-    nsDependentCString str(aBuffer, aLen);
+    AppendToBuffer(aBuffer, aLen);
-    unichars = ToNewUnicode(str);
-    AppendToBuffer(unichars, unichars+aLen, unichars+aLen);
     mTotalRead+=aLen;
   }
 
@@ -411,23 +455,18 @@ nsresult nsScanner::FillBuffer(void) {
   }
   else {
     PRInt32 numread=0;
-    char* buf = new char[kBufsize+1];
+    char buf[kBufsize+1];
     buf[kBufsize]=0;
 
     if(mInputStream) {
     	numread = mInputStream->read(buf, kBufsize);
-      if (0 == numread) {
+      if (0 == numread)
-        delete [] buf;
         return kEOF;
-      }
     }
 
     if((0<numread) && (0==result)) {
-      nsDependentCString str(buf, numread);
+      AppendToBuffer(buf, numread);
-      PRUnichar* unichars = ToNewUnicode(str);
-      AppendToBuffer(unichars, unichars+numread, unichars+kBufsize+1);
     }
-    delete [] buf;
     mTotalRead+=numread;
   }
 
@@ -1359,11 +1398,13 @@ void nsScanner::BindSubstring(nsSlidingSubstring& aSubstring, const nsReadingIte
 
 void nsScanner::CurrentPosition(nsReadingIterator<PRUnichar>& aPosition)
 {
+  NS_ASSERTION(mSlidingBuffer, "No data yet. CurrentPosition in invalid");
   aPosition = mCurrentPosition;
 }
 
 void nsScanner::EndReading(nsReadingIterator<PRUnichar>& aPosition)
 {
+  NS_ASSERTION(mSlidingBuffer, "No data yet. EndPosition in invalid");
   aPosition = mEndPosition;
 }
  
@@ -1392,12 +1433,32 @@ void nsScanner::ReplaceCharacter(nsReadingIterator<PRUnichar>& aPosition,
   }
 }
 
+void nsScanner::AppendToBuffer(const nsAString &aData)
+{
+  PRUint32 len = aData.Length();
+  PRUnichar* buffer = (PRUnichar *) nsScannerAllocate(len * sizeof(PRUnichar));
+  if (buffer) {
+    CopyUnicodeTo(aData, 0, buffer, len);
+    AppendToBuffer(buffer, buffer+len, buffer+len);
+  }
+}
+
+void nsScanner::AppendToBuffer(const char *aData, PRUint32 aLen)
+{
+    PRUnichar *buffer = (PRUnichar*) nsScannerAllocate((aLen+1) * sizeof(PRUnichar));
+    if (buffer)
+    {
+      RawToUnicode(aData, aLen, buffer, aLen+1);
+      AppendToBuffer(buffer, buffer+aLen, buffer+aLen);
+    }
+}
+
 void nsScanner::AppendToBuffer(PRUnichar* aStorageStart, 
                                PRUnichar* aDataEnd, 
                                PRUnichar* aStorageEnd)
 {
   if (!mSlidingBuffer) {
-    mSlidingBuffer = new nsScannerString(aStorageStart, aDataEnd, aStorageEnd);
+    mSlidingBuffer = new nsScannerString(aStorageStart, aDataEnd, aStorageEnd, nsScannerRecycle);
     mSlidingBuffer->BeginReading(mCurrentPosition);
     mMarkPosition = mCurrentPosition;
     mSlidingBuffer->EndReading(mEndPosition);
@@ -1422,6 +1483,9 @@ void nsScanner::AppendToBuffer(PRUnichar* aStorageStart,
  *  @return  nada
  */
 void nsScanner::CopyUnusedData(nsString& aCopyBuffer) {
+  if (!mSlidingBuffer)
+    return;
+
   nsReadingIterator<PRUnichar> start, end;
   start = mCurrentPosition;
   end = mEndPosition;

htmlparser/src/nsScanner.h

@@ -58,12 +58,17 @@
 #include "nsIUnicodeDecoder.h"
 #include "nsFileStream.h"
 #include "nsSlidingString.h"
+#include "nsRecyclingAllocator.h"
+
+// Recycling memory used by scanner
+#define NS_SCANNER_BUCKETS 10
 
 class nsScannerString : public nsSlidingString {
   public: 
     nsScannerString(PRUnichar* aStorageStart, 
                     PRUnichar* aDataEnd, 
-                    PRUnichar* aStorageEnd);
+                    PRUnichar* aStorageEnd,
+                    nsFreeProc* aFreeProc);
 
     virtual void UngetReadable(const nsAReadableString& aReadable, const nsReadingIterator<PRUnichar>& aCurrentPosition) { InsertReadable(aReadable,aCurrentPosition); }
     virtual void ReplaceCharacter(nsReadingIterator<PRUnichar>& aPosition,
@@ -382,6 +387,19 @@ class nsScanner {
                           PRUnichar* aDataEnd, 
                           PRUnichar* aStorageEnd);
 
+     /**
+      * These versions of AppendToBuffer allocate from the recyclingallocator,
+      * convert to unicode if necessary and then add the buffer into the sliding
+      * string
+      */
+      void AppendToBuffer(const nsAString &aData);
+      void AppendToBuffer(const char* aData, PRUint32 aLen);
+
+      static void InitAllocator() { 
+         if (!gAllocator)
+            gAllocator = new nsRecyclingAllocator(NS_SCANNER_BUCKETS, NS_DEFAULT_RECYCLE_TIMEOUT, "parser");
+      }
+
       nsInputStream*  mInputStream;
       nsScannerString*             mSlidingBuffer;
       nsReadingIterator<PRUnichar> mCurrentPosition; // The position we will next read from in the scanner buffer
@@ -397,6 +415,10 @@ class nsScanner {
       nsString        mCharset;
       nsIUnicodeDecoder *mUnicodeDecoder;
       PRInt32         mNewlinesSkipped;
+
+public:
+     // Allocator to recycle memory used by scanner
+     static nsRecyclingAllocator *gAllocator;
 };
 
 #endif

parser/htmlparser/src/nsParserModule.cpp

@@ -53,6 +53,7 @@
 //#include "nsTextTokenizer.h"
 #include "nsElementTable.h"
 #include "nsParserService.h"
+#include "nsScanner.h"
 
 #ifdef NS_DEBUG
 #include "nsLoggingSink.h"
@@ -118,6 +119,8 @@ Shutdown(nsIModule* aSelf)
     DeleteElementTable();
     CNewlineToken::FreeNewline();
     gInitialized = PR_FALSE;
+    delete nsScanner::gAllocator;
+    nsScanner::gAllocator = nsnull;
   }
 }
 

parser/htmlparser/src/nsScanner.cpp

@@ -46,9 +46,48 @@
 #include "nsFileSpec.h"
 #include "nsReadableUtils.h"
 
-nsScannerString::nsScannerString(PRUnichar* aStorageStart, 
+nsRecyclingAllocator* nsScanner::gAllocator = nsnull;
-                                 PRUnichar* aDataEnd, 
+
-                                 PRUnichar* aStorageEnd) : nsSlidingString(aStorageStart, aDataEnd, aStorageEnd)
+static void nsScannerRecycle(void *aPtr, void *aClientData)
+{
+  nsScanner::gAllocator->Free(aPtr);
+}
+
+static void *nsScannerAllocate(PRUint32 size)
+{
+  return nsScanner::gAllocator->Malloc(size);
+}
+
+/**
+ * Helper funciton to convert raw 8bit char * to unicode
+ *
+ * aStr : input 8bit string
+ * aLen : length of input string aStr
+ * aDest : Destination unicode buffer. Null terminated.
+ * aDestLength : size of destination buffer. Must be atleast aLen+1.
+ *
+ * return 0 if conversion succeeded
+ * returns -1, if there is not enough space in destination buffer, 
+ */
+static int RawToUnicode(const char *aStr, PRInt32 aLen, PRUnichar *aDest, PRUint32 aDestLength)
+{
+  // Alert if someone if passing null buffers to us
+  NS_ASSERTION(aStr && aDest, "Null buffers");
+
+  // Error checking
+  if (!aStr || !aDest || (PRInt32)aDestLength < aLen+1)
+    return -1;
+
+  while (*aStr)
+    *aDest++ = (PRUnichar) (unsigned char) *aStr++;
+  *aDest = 0;
+  return 0;
+}
+
+
+nsScannerString::nsScannerString(PRUnichar* aStorageStart, PRUnichar* aDataEnd,
+                                 PRUnichar* aStorageEnd, nsFreeProc *aFreeProc)
+    : nsSlidingString(aStorageStart, aDataEnd, aStorageEnd, aFreeProc)
 {
 }
 
@@ -107,14 +146,17 @@ MOZ_DECL_CTOR_COUNTER(nsScanner)
 nsScanner::nsScanner(const nsAString& anHTMLString, const nsString& aCharset, PRInt32 aSource)
 {
   MOZ_COUNT_CTOR(nsScanner);
-
+  InitAllocator();
-  PRUnichar* buffer = ToNewUnicode(anHTMLString);
-  mTotalRead = anHTMLString.Length();
   mSlidingBuffer = nsnull;
+  mTotalRead = anHTMLString.Length();
+  if (mTotalRead) {
+    // Append to buffer will take care of initializing mCurrentPosition
+    // and mMarkPosition. If we didnt get here, mCurrentPosition and
+    // mMarkPosition would be uninitialized and hence we protect using these
+    // variables with if (mSlidingBuffer) checks all over the code.
+    AppendToBuffer(anHTMLString);
+  }
   mCountRemaining = 0;
-  AppendToBuffer(buffer, buffer+mTotalRead, buffer+mTotalRead);
-  mSlidingBuffer->BeginReading(mCurrentPosition);
-  mMarkPosition = mCurrentPosition;
   mIncremental=PR_FALSE;
   mOwnsStream=PR_FALSE;
   mInputStream=0;
@@ -137,7 +179,7 @@ nsScanner::nsScanner(nsString& aFilename,PRBool aCreateStream, const nsString& a
     mFilename(aFilename)
 {
   MOZ_COUNT_CTOR(nsScanner);
-
+  InitAllocator();
   mSlidingBuffer = nsnull;
   mIncremental=PR_TRUE;
   mCountRemaining = 0;
@@ -166,7 +208,7 @@ nsScanner::nsScanner(const nsAString& aFilename,nsInputStream& aStream,const nsS
     mFilename(aFilename)
 {  
   MOZ_COUNT_CTOR(nsScanner);
-
+  InitAllocator();
   mSlidingBuffer = nsnull;
   mIncremental=PR_FALSE;
   mCountRemaining = 0;
@@ -262,8 +304,10 @@ nsScanner::~nsScanner() {
  *  @return  
  */
 void nsScanner::RewindToMark(void){
-  mCountRemaining += (Distance(mMarkPosition, mCurrentPosition));
+  if (mSlidingBuffer) {
-  mCurrentPosition = mMarkPosition;
+    mCountRemaining += (Distance(mMarkPosition, mCurrentPosition));
+    mCurrentPosition = mMarkPosition;
+  }
 }
 
 
@@ -293,9 +337,15 @@ void nsScanner::Mark() {
  */
 PRBool nsScanner::UngetReadable(const nsAReadableString& aBuffer) {
 
-  mSlidingBuffer->UngetReadable(aBuffer,mCurrentPosition);
+  if (!mSlidingBuffer) {
-  mSlidingBuffer->BeginReading(mCurrentPosition); // Insertion invalidated our iterators
+    // This happens to be the first buffer. Just append it.
-  mSlidingBuffer->EndReading(mEndPosition);
+    AppendToBuffer(aBuffer);
+  }
+  else {
+    mSlidingBuffer->UngetReadable(aBuffer,mCurrentPosition);
+    mSlidingBuffer->BeginReading(mCurrentPosition); // Insertion invalidated our iterators
+    mSlidingBuffer->EndReading(mEndPosition);
+  }
   mTotalRead += aBuffer.Length();
       
   return PR_TRUE;
@@ -309,12 +359,8 @@ PRBool nsScanner::UngetReadable(const nsAReadableString& aBuffer) {
  * @return  error code 
  */
 nsresult nsScanner::Append(const nsAReadableString& aBuffer) {
-  
+  AppendToBuffer(aBuffer);
-  PRUnichar* buffer = ToNewUnicode(aBuffer);
+  mTotalRead += aBuffer.Length();
-  PRUint32 bufLen = aBuffer.Length();
-  mTotalRead += bufLen;
-
-  AppendToBuffer(buffer, buffer+bufLen, buffer+bufLen);
 
   return NS_OK;
 }
@@ -332,8 +378,8 @@ nsresult nsScanner::Append(const char* aBuffer, PRUint32 aLen){
   if(mUnicodeDecoder) {
     PRInt32 unicharBufLen = 0;
     mUnicodeDecoder->GetMaxLength(aBuffer, aLen, &unicharBufLen);
-    start = unichars = (PRUnichar*)nsMemory::Alloc((unicharBufLen+1) * sizeof(PRUnichar));
+    start = unichars = (PRUnichar*) nsScannerAllocate((unicharBufLen+1) * sizeof(PRUnichar));
-    NS_ENSURE_TRUE(unichars,NS_ERROR_OUT_OF_MEMORY);
+    NS_ENSURE_TRUE(unichars, NS_ERROR_OUT_OF_MEMORY);
 	  
     PRInt32 totalChars = 0;
     PRInt32 unicharLength = unicharBufLen;
@@ -375,9 +421,7 @@ nsresult nsScanner::Append(const char* aBuffer, PRUint32 aLen){
     res = NS_OK; 
   }
   else {
-    nsDependentCString str(aBuffer, aLen);
+    AppendToBuffer(aBuffer, aLen);
-    unichars = ToNewUnicode(str);
-    AppendToBuffer(unichars, unichars+aLen, unichars+aLen);
     mTotalRead+=aLen;
   }
 
@@ -411,23 +455,18 @@ nsresult nsScanner::FillBuffer(void) {
   }
   else {
     PRInt32 numread=0;
-    char* buf = new char[kBufsize+1];
+    char buf[kBufsize+1];
     buf[kBufsize]=0;
 
     if(mInputStream) {
     	numread = mInputStream->read(buf, kBufsize);
-      if (0 == numread) {
+      if (0 == numread)
-        delete [] buf;
         return kEOF;
-      }
     }
 
     if((0<numread) && (0==result)) {
-      nsDependentCString str(buf, numread);
+      AppendToBuffer(buf, numread);
-      PRUnichar* unichars = ToNewUnicode(str);
-      AppendToBuffer(unichars, unichars+numread, unichars+kBufsize+1);
     }
-    delete [] buf;
     mTotalRead+=numread;
   }
 
@@ -1359,11 +1398,13 @@ void nsScanner::BindSubstring(nsSlidingSubstring& aSubstring, const nsReadingIte
 
 void nsScanner::CurrentPosition(nsReadingIterator<PRUnichar>& aPosition)
 {
+  NS_ASSERTION(mSlidingBuffer, "No data yet. CurrentPosition in invalid");
   aPosition = mCurrentPosition;
 }
 
 void nsScanner::EndReading(nsReadingIterator<PRUnichar>& aPosition)
 {
+  NS_ASSERTION(mSlidingBuffer, "No data yet. EndPosition in invalid");
   aPosition = mEndPosition;
 }
  
@@ -1392,12 +1433,32 @@ void nsScanner::ReplaceCharacter(nsReadingIterator<PRUnichar>& aPosition,
   }
 }
 
+void nsScanner::AppendToBuffer(const nsAString &aData)
+{
+  PRUint32 len = aData.Length();
+  PRUnichar* buffer = (PRUnichar *) nsScannerAllocate(len * sizeof(PRUnichar));
+  if (buffer) {
+    CopyUnicodeTo(aData, 0, buffer, len);
+    AppendToBuffer(buffer, buffer+len, buffer+len);
+  }
+}
+
+void nsScanner::AppendToBuffer(const char *aData, PRUint32 aLen)
+{
+    PRUnichar *buffer = (PRUnichar*) nsScannerAllocate((aLen+1) * sizeof(PRUnichar));
+    if (buffer)
+    {
+      RawToUnicode(aData, aLen, buffer, aLen+1);
+      AppendToBuffer(buffer, buffer+aLen, buffer+aLen);
+    }
+}
+
 void nsScanner::AppendToBuffer(PRUnichar* aStorageStart, 
                                PRUnichar* aDataEnd, 
                                PRUnichar* aStorageEnd)
 {
   if (!mSlidingBuffer) {
-    mSlidingBuffer = new nsScannerString(aStorageStart, aDataEnd, aStorageEnd);
+    mSlidingBuffer = new nsScannerString(aStorageStart, aDataEnd, aStorageEnd, nsScannerRecycle);
     mSlidingBuffer->BeginReading(mCurrentPosition);
     mMarkPosition = mCurrentPosition;
     mSlidingBuffer->EndReading(mEndPosition);
@@ -1422,6 +1483,9 @@ void nsScanner::AppendToBuffer(PRUnichar* aStorageStart,
  *  @return  nada
  */
 void nsScanner::CopyUnusedData(nsString& aCopyBuffer) {
+  if (!mSlidingBuffer)
+    return;
+
   nsReadingIterator<PRUnichar> start, end;
   start = mCurrentPosition;
   end = mEndPosition;

parser/htmlparser/src/nsScanner.h

@@ -58,12 +58,17 @@
 #include "nsIUnicodeDecoder.h"
 #include "nsFileStream.h"
 #include "nsSlidingString.h"
+#include "nsRecyclingAllocator.h"
+
+// Recycling memory used by scanner
+#define NS_SCANNER_BUCKETS 10
 
 class nsScannerString : public nsSlidingString {
   public: 
     nsScannerString(PRUnichar* aStorageStart, 
                     PRUnichar* aDataEnd, 
-                    PRUnichar* aStorageEnd);
+                    PRUnichar* aStorageEnd,
+                    nsFreeProc* aFreeProc);
 
     virtual void UngetReadable(const nsAReadableString& aReadable, const nsReadingIterator<PRUnichar>& aCurrentPosition) { InsertReadable(aReadable,aCurrentPosition); }
     virtual void ReplaceCharacter(nsReadingIterator<PRUnichar>& aPosition,
@@ -382,6 +387,19 @@ class nsScanner {
                           PRUnichar* aDataEnd, 
                           PRUnichar* aStorageEnd);
 
+     /**
+      * These versions of AppendToBuffer allocate from the recyclingallocator,
+      * convert to unicode if necessary and then add the buffer into the sliding
+      * string
+      */
+      void AppendToBuffer(const nsAString &aData);
+      void AppendToBuffer(const char* aData, PRUint32 aLen);
+
+      static void InitAllocator() { 
+         if (!gAllocator)
+            gAllocator = new nsRecyclingAllocator(NS_SCANNER_BUCKETS, NS_DEFAULT_RECYCLE_TIMEOUT, "parser");
+      }
+
       nsInputStream*  mInputStream;
       nsScannerString*             mSlidingBuffer;
       nsReadingIterator<PRUnichar> mCurrentPosition; // The position we will next read from in the scanner buffer
@@ -397,6 +415,10 @@ class nsScanner {
       nsString        mCharset;
       nsIUnicodeDecoder *mUnicodeDecoder;
       PRInt32         mNewlinesSkipped;
+
+public:
+     // Allocator to recycle memory used by scanner
+     static nsRecyclingAllocator *gAllocator;
 };
 
 #endif