Bug 117119�BMP and ICO decoders should use ReadSegments, not Read

patch by cbiesinger@web.de r=pavlov sr=tor

modules/libpr0n/decoders/bmp/nsBMPDecoder.cpp

@@ -122,22 +122,19 @@ NS_IMETHODIMP nsBMPDecoder::Flush()
     return NS_OK;
 }
 
+NS_METHOD nsBMPDecoder::ReadSegCb(nsIInputStream* aIn, void* aClosure,
+                             const char* aFromRawSegment, PRUint32 aToOffset,
+                             PRUint32 aCount, PRUint32 *aWriteCount) {
+    nsBMPDecoder *decoder = NS_REINTERPRET_CAST(nsBMPDecoder*, aClosure);
+    *aWriteCount = aCount;
+    return decoder->ProcessData(aFromRawSegment, aCount);
+}
+
 NS_IMETHODIMP nsBMPDecoder::WriteFrom(nsIInputStream *aInStr, PRUint32 aCount, PRUint32 *aRetval)
 {
     PR_LOG(gBMPLog, PR_LOG_DEBUG, ("nsBMPDecoder::WriteFrom(%p, %lu, %p)\n", aInStr, aCount, aRetval));
 
-    char* buffer = new char[aCount];
+    return aInStr->ReadSegments(ReadSegCb, this, aCount, aRetval);
-    if (!buffer) {
-        return NS_ERROR_OUT_OF_MEMORY;
-    }
-    unsigned int realCount = aCount;
-    nsresult rv = aInStr->Read(buffer, aCount, &realCount);
-    NS_ENSURE_SUCCESS(rv, rv);
-    *aRetval = realCount;
-
-    rv = ProcessData(buffer, realCount);
-    delete []buffer;
-    return rv;
 }
 
 // ----------------------------------------

modules/libpr0n/decoders/bmp/nsBMPDecoder.h

@@ -125,6 +125,11 @@ public:
     virtual ~nsBMPDecoder();
 
 private:
+    /** Callback for ReadSegments to avoid copying the data */
+    static NS_METHOD ReadSegCb(nsIInputStream* aIn, void* aClosure,
+                               const char* aFromRawSegment, PRUint32 aToOffset,
+                               PRUint32 aCount, PRUint32 *aWriteCount);
+
     /** Processes the data.
      * @param aBuffer Data to process.
      * @oaram count Number of bytes in mBuffer */

modules/libpr0n/decoders/bmp/nsICODecoder.cpp

@@ -191,21 +191,18 @@ NS_IMETHODIMP nsICODecoder::Flush()
   return NS_OK;
 }
 
+
+NS_METHOD nsICODecoder::ReadSegCb(nsIInputStream* aIn, void* aClosure,
+                             const char* aFromRawSegment, PRUint32 aToOffset,
+                             PRUint32 aCount, PRUint32 *aWriteCount) {
+    nsICODecoder *decoder = NS_REINTERPRET_CAST(nsICODecoder*, aClosure);
+    *aWriteCount = aCount;
+    return decoder->ProcessData(aFromRawSegment, aCount);
+}
+
 NS_IMETHODIMP nsICODecoder::WriteFrom(nsIInputStream *aInStr, PRUint32 aCount, PRUint32 *aRetval)
 {
-  char* buffer = new char[aCount];
+    return aInStr->ReadSegments(ReadSegCb, this, aCount, aRetval);
-  if (!buffer)
-    return NS_ERROR_OUT_OF_MEMORY;
-  
-  unsigned int realCount = aCount;
-  nsresult rv = aInStr->Read(buffer, aCount, &realCount);
-  NS_ENSURE_SUCCESS(rv, rv);
-  
-  *aRetval = realCount;
-
-  rv = ProcessData(buffer, realCount);
-  delete []buffer;
-  return rv;
 }
 
 nsresult nsICODecoder::ProcessData(const char* aBuffer, PRUint32 aCount) {

modules/libpr0n/decoders/bmp/nsICODecoder.h

@@ -80,6 +80,11 @@ public:
   virtual ~nsICODecoder();
 
 private:
+  /** Callback for ReadSegments to avoid copying the data */
+  static NS_METHOD ReadSegCb(nsIInputStream* aIn, void* aClosure,
+                             const char* aFromRawSegment, PRUint32 aToOffset,
+                             PRUint32 aCount, PRUint32 *aWriteCount);
+
   // Private helper methods
   nsresult ProcessData(const char* aBuffer, PRUint32 aCount);
   void ProcessDirEntry();