Changeset 54616 in webkit

Timestamp:

Feb 10, 2010 1:05:55 PM (14 years ago)

Author:

Adam Roben

Message:

Optimize ImageBuffer::toDataURL's CG implementation

There was some unused code that could have been removed in r31830 when
this function was changed not to flip the CG image anymore.

Fixes <​http://webkit.org/b/34808> ImageBuffer::toDataURL allocates
unnecessary memory under CoreGraphics

Reviewed by Sam Weinig.

• platform/graphics/cg/ImageBufferCG.cpp:

(WebCore::ImageBuffer::toDataURL): Don't allocate an unused CGImageRef
and buffer, and switch to the new overload of base64Encode that
doesn't require us to copy all the image data into a Vector first.

• platform/text/Base64.cpp:

(WebCore::base64Encode):

• platform/text/Base64.h:

Added an overload that takes a raw data pointer and length, just like
we have for base64Decode. The overload that takes a Vector as input
just calls through to the new overload.

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/cg/ImageBufferCG.cpp (modified) (1 diff)
• platform/text/Base64.cpp (modified) (2 diffs)
• platform/text/Base64.h (modified) (1 diff)

trunk/WebCore/ChangeLog

@@ +1 @@
+2010-02-10  Adam Roben  <aroben@apple.com>
+
+        Optimize ImageBuffer::toDataURL's CG implementation
+
+        There was some unused code that could have been removed in r31830 when
+        this function was changed not to flip the CG image anymore.
+
+        Fixes <http://webkit.org/b/34808> ImageBuffer::toDataURL allocates
+        unnecessary memory under CoreGraphics
+
+        Reviewed by Sam Weinig.
+
+        * platform/graphics/cg/ImageBufferCG.cpp:
+        (WebCore::ImageBuffer::toDataURL): Don't allocate an unused CGImageRef
+        and buffer, and switch to the new overload of base64Encode that
+        doesn't require us to copy all the image data into a Vector first.
+
+        * platform/text/Base64.cpp:
+        (WebCore::base64Encode):
+        * platform/text/Base64.h:
+        Added an overload that takes a raw data pointer and length, just like
+        we have for base64Decode. The overload that takes a Vector as input
+        just calls through to the new overload.
+
 2010-02-10  Dan Bernstein  <mitz@apple.com>
 

trunk/WebCore/platform/graphics/cg/ImageBufferCG.cpp

@@ -281 +281 @@
         return "data:,";
 
-    size_t width = CGImageGetWidth(image.get());
-    size_t height = CGImageGetHeight(image.get());
-
-    OwnArrayPtr<uint32_t> imageData(new uint32_t[width * height]);
-    if (!imageData)
+    RetainPtr<CFMutableDataRef> data(AdoptCF, CFDataCreateMutable(kCFAllocatorDefault, 0));
+    if (!data)
         return "data:,";
-    
-    RetainPtr<CGImageRef> transformedImage(AdoptCF, CGBitmapContextCreateImage(context()->platformContext()));
-    if (!transformedImage)
+
+    RetainPtr<CGImageDestinationRef> destination(AdoptCF, CGImageDestinationCreateWithData(data.get(), utiFromMIMEType(mimeType).get(), 1, 0));
+    if (!destination)
         return "data:,";
 
-    RetainPtr<CFMutableDataRef> transformedImageData(AdoptCF, CFDataCreateMutable(kCFAllocatorDefault, 0));
-    if (!transformedImageData)
-        return "data:,";
-
-    RetainPtr<CGImageDestinationRef> imageDestination(AdoptCF, CGImageDestinationCreateWithData(transformedImageData.get(),
-        utiFromMIMEType(mimeType).get(), 1, 0));
-    if (!imageDestination)
-        return "data:,";
-
-    CGImageDestinationAddImage(imageDestination.get(), transformedImage.get(), 0);
-    CGImageDestinationFinalize(imageDestination.get());
-
-    Vector<char> in;
-    in.append(CFDataGetBytePtr(transformedImageData.get()), CFDataGetLength(transformedImageData.get()));
+    CGImageDestinationAddImage(destination.get(), image.get(), 0);
+    CGImageDestinationFinalize(destination.get());
 
     Vector<char> out;
-    base64Encode(in, out);
+    base64Encode(reinterpret_cast<const char*>(CFDataGetBytePtr(data.get())), CFDataGetLength(data.get()), out);
     out.append('\0');
 

trunk/WebCore/platform/text/Base64.cpp

@@ -63 +63 @@
 void base64Encode(const Vector<char>& in, Vector<char>& out, bool insertLFs)
 {
+    base64Encode(in.data(), in.size(), out, insertLFs);
+}
+
+void base64Encode(const char* data, unsigned len, Vector<char>& out, bool insertLFs)
+{
     out.clear();
-    if (in.isEmpty())
+    if (!len)
         return;
 
@@ -71 +76 @@
     // Rather than being perfectly precise, this is a bit conservative.
     const unsigned maxInputBufferSize = UINT_MAX / 77 * 76 / 4 * 3 - 2;
-    if (in.size() > maxInputBufferSize)
+    if (len > maxInputBufferSize)
         return;
 
     unsigned sidx = 0;
     unsigned didx = 0;
-    const char* data = in.data();
-    const unsigned len = in.size();
 
     unsigned out_len = ((len + 2) / 3) * 4;

trunk/WebCore/platform/text/Base64.h

@@ -32 +32 @@
 
 void base64Encode(const Vector<char>&, Vector<char>&, bool insertLFs = false);
+void base64Encode(const char*, unsigned, Vector<char>&, bool insertLFs = false);
 
 // this decoder is not general purpose - it returns an error if it encounters a linefeed, as needed for window.atob