Bug 523646: make favicon optimization size and file limit configurable using a pref, r=mak

toolkit/components/places/src/nsFaviconService.cpp

@@ -69,6 +69,7 @@
 #include "mozIStorageStatementCallback.h"
 #include "mozIStorageError.h"
 #include "nsPlacesTables.h"
+#include "nsIPrefService.h"
 
 // For favicon optimization
 #include "imgITools.h"
@@ -81,10 +82,13 @@
 
 #define CONTENT_SNIFFING_SERVICES "content-sniffing-services"
 
-// If favicon is bigger than this size we will try to optimize it into a
-// 16x16 png. An uncompressed 16x16 RGBA image is 1024 bytes, and almost all
-// sensible 16x16 icons are under 1024 bytes.
-#define OPTIMIZED_FAVICON_SIZE 1024
+
+// Default value for mOptimizedIconDimension
+#define OPTIMIZED_FAVICON_DIMENSION 16
+
+// Most icons will be smaller than this rough estimate of the size of an
+// uncompressed 16x16 RGBA image of the same dimensions.
+#define MAX_ICON_FILESIZE(s) ((PRUint32) s*s*4)
 
 /**
  * The maximum time we will keep a favicon around.  We always ask the cache, if
@@ -143,6 +147,7 @@ NS_IMPL_ISUPPORTS1(
 // nsFaviconService::nsFaviconService
 
 nsFaviconService::nsFaviconService() : mExpirationRunning(false)
+                                     , mOptimizedIconDimension(OPTIMIZED_FAVICON_DIMENSION)
                                      , mFailedFaviconSerial(0)
 {
   NS_ASSERTION(! gFaviconService, "ATTEMPTING TO CREATE TWO FAVICON SERVICES!");
@@ -221,6 +226,10 @@ nsFaviconService::Init()
   if (! mFailedFavicons.Init(MAX_FAVICON_CACHE_SIZE))
     return NS_ERROR_OUT_OF_MEMORY;
 
+  nsCOMPtr<nsIPrefBranch> pb = do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (pb)
+    pb->GetIntPref("places.favicons.optimizeToDimension", &mOptimizedIconDimension);
+
   return NS_OK;
 }
 
@@ -697,7 +706,7 @@ nsFaviconService::SetFaviconData(nsIURI* aFaviconURI, const PRUint8* aData,
   // If the page provided a large image for the favicon (eg, a highres image
   // or a multiresolution .ico file), we don't want to store more data than
   // needed.
-  if (aDataLen > OPTIMIZED_FAVICON_SIZE) {
+  if (aDataLen > MAX_ICON_FILESIZE(mOptimizedIconDimension)) {
     rv = OptimizeFaviconImage(aData, aDataLen, aMimeType, newData, newMimeType);
     if (NS_SUCCEEDED(rv) && newData.Length() < aDataLen) {
       data = reinterpret_cast<PRUint8*>(const_cast<char*>(newData.get())),
@@ -1102,7 +1111,9 @@ nsFaviconService::OptimizeFaviconImage(const PRUint8* aData, PRUint32 aDataLen,
 
   // scale and recompress
   nsCOMPtr<nsIInputStream> iconStream;
-  rv = imgtool->EncodeScaledImage(container, aNewMimeType, 16, 16,
+  rv = imgtool->EncodeScaledImage(container, aNewMimeType,
+                                  mOptimizedIconDimension,
+                                  mOptimizedIconDimension,
                                   getter_AddRefs(iconStream));
   NS_ENSURE_SUCCESS(rv, rv);
 

toolkit/components/places/src/nsFaviconService.h

@@ -95,7 +95,7 @@ public:
   nsresult GetFaviconLinkForIconString(const nsCString& aIcon, nsIURI** aOutput);
   void GetFaviconSpecForIconString(const nsCString& aIcon, nsACString& aOutput);
 
-  static nsresult OptimizeFaviconImage(const PRUint8* aData, PRUint32 aDataLen,
+  nsresult OptimizeFaviconImage(const PRUint8* aData, PRUint32 aDataLen,
                                 const nsACString& aMimeType,
                                 nsACString& aNewData, nsACString& aNewMimeType);
 
@@ -146,6 +146,12 @@ private:
   // till expiration has finished.
   bool mExpirationRunning;
 
+  // The target dimension, in pixels, for favicons we optimize.
+  // If we find images that are as large or larger than an uncompressed RGBA
+  // image of this size (mOptimizedIconDimension*mOptimizedIconDimension*4),
+  // we will try to optimize it.
+  PRInt32 mOptimizedIconDimension;
+
   PRUint32 mFailedFaviconSerial;
   nsDataHashtable<nsCStringHashKey, PRUint32> mFailedFavicons;