[Libreoffice-commits] online.git: common/Png.hpp kit/Kit.cpp

[Ashod Nakashian]

 common/Png.hpp |    6 ++++++
 kit/Kit.cpp    |   28 ++++++++++++++++++----------
 2 files changed, 24 insertions(+), 10 deletions(-)

New commits:
commit b35725ab709864ad8680cc84986d27048687c5d3
Author: Ashod Nakashian <ashod.nakashian at collabora.co.uk>
Date:   Sun Nov 27 11:55:19 2016 -0500

    loolwsd: support more efficient full-buffer hashing
    
    Change-Id: Ie30929ad4665b51e280c1126adde645742814dad
    Reviewed-on: https://gerrit.libreoffice.org/31294
    Reviewed-by: Ashod Nakashian <ashnakash at gmail.com>
    Tested-by: Ashod Nakashian <ashnakash at gmail.com>

diff --git a/common/Png.hpp b/common/Png.hpp
index 96fa165..b4ff059 100644
--- a/common/Png.hpp
+++ b/common/Png.hpp
@@ -160,6 +160,12 @@ bool encodeBufferToPNG(unsigned char* pixmap, int width, int height,
 }
 
 inline
+uint64_t hashBuffer(unsigned char* pixmap, int width, int height)
+{
+    return SpookyHash::Hash64(pixmap, width * height * 4, 1073741789);
+}
+
+inline
 uint64_t hashSubBuffer(unsigned char* pixmap, size_t startX, size_t startY,
                        int width, int height, int bufferWidth, int bufferHeight)
 {
diff --git a/kit/Kit.cpp b/kit/Kit.cpp
index f070b3a..28df0d8 100644
--- a/kit/Kit.cpp
+++ b/kit/Kit.cpp
@@ -348,15 +348,9 @@ class PngCache
     bool cacheEncodeSubBufferToPNG(unsigned char* pixmap, size_t startX, size_t startY,
                                    int width, int height,
                                    int bufferWidth, int bufferHeight,
-                                   std::vector<char>& output, LibreOfficeKitTileMode mode)
+                                   std::vector<char>& output, LibreOfficeKitTileMode mode,
+                                   const uint64_t hash)
     {
-        uint64_t hash = png::hashSubBuffer(pixmap, startX, startY, width, height,
-                                           bufferWidth, bufferHeight);
-        if (cacheTest(hash, output))
-        {
-            return true;
-        }
-
         LOG_DBG("PNG cache with hash " << hash << " missed.");
         CacheEntry newEntry(bufferWidth * bufferHeight * 1);
         if (png::encodeSubBufferToPNG(pixmap, startX, startY, width, height,
@@ -390,16 +384,30 @@ public:
     bool encodeBufferToPNG(unsigned char* pixmap, int width, int height,
                            std::vector<char>& output, LibreOfficeKitTileMode mode)
     {
+        const uint64_t hash = png::hashBuffer(pixmap, width, height);
+        if (cacheTest(hash, output))
+        {
+            return true;
+        }
+
         return cacheEncodeSubBufferToPNG(pixmap, 0, 0, width, height,
-                                         width, height, output, mode);
+                                         width, height, output, mode, hash);
     }
+
     bool encodeSubBufferToPNG(unsigned char* pixmap, size_t startX, size_t startY,
                               int width, int height,
                               int bufferWidth, int bufferHeight,
                               std::vector<char>& output, LibreOfficeKitTileMode mode)
     {
+        const uint64_t hash = png::hashSubBuffer(pixmap, startX, startY, width, height,
+                                                 bufferWidth, bufferHeight);
+        if (cacheTest(hash, output))
+        {
+            return true;
+        }
+
         return cacheEncodeSubBufferToPNG(pixmap, startX, startY, width, height,
-                                         bufferWidth, bufferHeight, output, mode);
+                                         bufferWidth, bufferHeight, output, mode, hash);
     }
 };