Use zstd dict for packing/unpacking frame images.

This only affects run-time memory usage and needs an offline calculation of
the dictionary. Results vary depending on similarity of image blocks.

agora        34.96 MB ->  28.21 MB
agora2       40.75 MB ->  34.14 MB
android-vk   36.21 MB ->  18.44 MB
astar3       44.72 MB ->  43.38 MB
clipper1    134.36 MB ->  52.16 MB
fi           50.82 MB ->  40.79 MB
fi-big      537.74 MB -> 469.54 MB
test         23.26 MB ->   1.87 MB

server/TracyTextureCompression.cpp

@@ -11,6 +11,7 @@ TextureCompression::TextureCompression()
     , m_bufSize( 0 )
     , m_cctx( ZSTD_createCCtx() )
     , m_dctx( ZSTD_createDCtx() )
+    , m_dict( nullptr )
 {
 }
 
@@ -19,6 +20,7 @@ TextureCompression::~TextureCompression()
     delete[] m_buf;
     ZSTD_freeCCtx( m_cctx );
     ZSTD_freeDCtx( m_dctx );
+    ZSTD_freeDDict( m_dict );
 }
 
 uint32_t TextureCompression::Pack( struct ZSTD_CCtx_s* ctx, char*& buf, size_t& bufsz, const char* image, uint32_t inBytes )
@@ -67,7 +69,14 @@ const char* TextureCompression::Unpack( const FrameImage& image )
         m_buf = new char[outsz];
     }
     assert( m_dctx );
-    ZSTD_decompressDCtx( m_dctx, m_buf, outsz, image.ptr, image.csz );
+    if( m_dict )
+    {
+        ZSTD_decompress_usingDDict( m_dctx, m_buf, outsz, image.ptr, image.csz, m_dict );
+    }
+    else
+    {
+        ZSTD_decompressDCtx( m_dctx, m_buf, outsz, image.ptr, image.csz );
+    }
     return m_buf;
 }
 

server/TracyTextureCompression.hpp

@@ -11,6 +11,7 @@
 struct ZSTD_CCtx_s;
 struct ZSTD_DCtx_s;
 struct ZSTD_CDict_s;
+struct ZSTD_DDict_s;
 
 namespace tracy
 {
@@ -23,6 +24,8 @@ public:
     TextureCompression();
     ~TextureCompression();
 
+    void SetDict( struct ZSTD_DDict_s* dict ) { m_dict = dict; }
+
     uint32_t Pack( struct ZSTD_CCtx_s* ctx, char*& buf, size_t& bufsz, const char* image, uint32_t inBytes );
     uint32_t Pack( struct ZSTD_CCtx_s* ctx, const struct ZSTD_CDict_s* dict, char*& buf, size_t& bufsz, const char* image, uint32_t inBytes );
 
@@ -49,6 +52,7 @@ private:
     size_t m_bufSize;
     struct ZSTD_CCtx_s* m_cctx;
     struct ZSTD_DCtx_s* m_dctx;
+    struct ZSTD_DDict_s* m_dict;
 
     std::atomic<uint64_t> m_inputBytes { 0 };
     std::atomic<uint64_t> m_outputBytes { 0 };

server/TracyWorker.cpp

@@ -1291,6 +1291,18 @@ Worker::Worker( FileRead& f, EventType::Type eventMask, bool bgTasks )
 
     if( eventMask & EventType::FrameImages )
     {
+        ZSTD_CDict* cdict = nullptr;
+        if( fileVer >= FileVersion( 0, 7, 8 ) )
+        {
+            uint32_t dsz;
+            f.Read( dsz );
+            auto dict = new char[dsz];
+            f.Read( dict, dsz );
+            cdict = ZSTD_createCDict( dict, dsz, 3 );
+            m_texcomp.SetDict( ZSTD_createDDict( dict, dsz ) );
+            delete[] dict;
+        }
+
         f.Read( sz );
         m_data.frameImage.reserve_exact( sz, m_slab );
         s_loadProgress.subTotal.store( sz, std::memory_order_relaxed );
@@ -1353,9 +1365,16 @@ Worker::Worker( FileRead& f, EventType::Type eventMask, bool bgTasks )
                 data[idx].fi = fi;
 
                 data[idx].state.store( JobData::InProgress, std::memory_order_release );
-                td->Queue( [this, &data, idx, fi, fileVer] {
+                td->Queue( [this, &data, idx, fi, fileVer, cdict] {
                     if( fileVer <= FileVersion( 0, 6, 9 ) ) m_texcomp.Rdo( data[idx].buf, fi->w * fi->h / 16 );
-                    fi->csz = m_texcomp.Pack( data[idx].ctx, data[idx].outbuf, data[idx].outsz, data[idx].buf, fi->w * fi->h / 2 );
+                    if( cdict )
+                    {
+                        fi->csz = m_texcomp.Pack( data[idx].ctx, cdict, data[idx].outbuf, data[idx].outsz, data[idx].buf, fi->w * fi->h / 2 );
+                    }
+                    else
+                    {
+                        fi->csz = m_texcomp.Pack( data[idx].ctx, data[idx].outbuf, data[idx].outsz, data[idx].buf, fi->w * fi->h / 2 );
+                    }
                     data[idx].state.store( JobData::DataReady, std::memory_order_release );
                 } );
 
@@ -1387,9 +1406,17 @@ Worker::Worker( FileRead& f, EventType::Type eventMask, bool bgTasks )
                 }
             }
         }
+
+        ZSTD_freeCDict( cdict );
     }
     else
     {
+        if( fileVer >= FileVersion( 0, 7, 8 ) )
+        {
+            uint32_t dsz;
+            f.Read( dsz );
+            f.Skip( dsz );
+        }
         f.Read( sz );
         s_loadProgress.subTotal.store( sz, std::memory_order_relaxed );
         for( uint64_t i=0; i<sz; i++ )