wsd: tile serializer now supports adding a suffix

Moves appending tokens into the serializer and
avoids making extra copies of itself.

Change-Id: I62d374e69d9c4a55643ea20cb5f8c2b9c75c88c5
Reviewed-on: https://gerrit.libreoffice.org/71022
Reviewed-by: Ashod Nakashian <ashnakash@gmail.com>
Tested-by: Ashod Nakashian <ashnakash@gmail.com>

3 files changed, 41 insertions, 36 deletions

diff --git a/kit/Kit.cpp b/kit/Kit.cpp
index 76dddab46..d098cd773 100644
--- a/kit/Kit.cpp
+++ b/kit/Kit.cpp
@@ -121,9 +121,9 @@ static std::string ObfuscatedFileId;
 #endif
 
 #if ENABLE_DEBUG
-#  define ADD_DEBUG_RENDERID(s) ((s)+ " renderid=" + Util::UniqueId())
+#  define ADD_DEBUG_RENDERID (" renderid=" + Util::UniqueId() + '\n')
 #else
-#  define ADD_DEBUG_RENDERID(s) (s)
+#  define ADD_DEBUG_RENDERID ("\n")
 #endif
 
 #if !MOBILEAPP
@@ -1098,9 +1098,9 @@ public:
 
         std::string tileMsg;
         if (combined)
-            tileMsg = ADD_DEBUG_RENDERID(tileCombined.serialize("tilecombine:")) + "\n";
+            tileMsg = tileCombined.serialize("tilecombine:", ADD_DEBUG_RENDERID);
         else
-            tileMsg = ADD_DEBUG_RENDERID(tiles[0].serialize("tile:")) + "\n";
+            tileMsg = tiles[0].serialize("tile:", ADD_DEBUG_RENDERID);
 
         LOG_TRC("Sending back painted tiles for " << tileMsg << " of size " << output.size() << " bytes) for: " << tileMsg);
 
diff --git a/wsd/DocumentBroker.cpp b/wsd/DocumentBroker.cpp
index 8524725ff..53d3e2dbe 100644
--- a/wsd/DocumentBroker.cpp
+++ b/wsd/DocumentBroker.cpp
@@ -48,6 +48,12 @@ using namespace LOOLProtocol;
 
 using Poco::JSON::Object;
 
+#if ENABLE_DEBUG
+#  define ADD_DEBUG_RENDERID (" renderid=cached\n")
+#else
+#  define ADD_DEBUG_RENDERID ("\n")
+#endif
+
 void ChildProcess::setDocumentBroker(const std::shared_ptr<DocumentBroker>& docBroker)
 {
     assert(docBroker && "Invalid DocumentBroker instance.");
@@ -1335,11 +1341,7 @@ void DocumentBroker::handleTileRequest(TileDesc& tile,
     TileCache::Tile cachedTile = _tileCache->lookupTile(tile);
     if (cachedTile)
     {
-#if ENABLE_DEBUG
-        const std::string response = tile.serialize("tile:") + " renderid=cached\n";
-#else
-        const std::string response = tile.serialize("tile:") + '\n';
-#endif
+        const std::string response = tile.serialize("tile:", ADD_DEBUG_RENDERID);
         session->sendTile(response, cachedTile);
         return;
     }
@@ -1452,7 +1454,6 @@ void DocumentBroker::sendRequestedTiles(const std::shared_ptr<ClientSession>& se
     float tilesOnFlyUpperLimit = 0;
     if (normalizedVisArea.hasSurface() && session->getTileWidthInTwips() != 0 && session->getTileHeightInTwips() != 0)
     {
-
         const int tilesFitOnWidth = std::ceil(normalizedVisArea.getRight() / session->getTileWidthInTwips()) -
                                     std::ceil(normalizedVisArea.getLeft() / session->getTileWidthInTwips()) + 1;
         const int tilesFitOnHeight = std::ceil(normalizedVisArea.getBottom() / session->getTileHeightInTwips()) -
@@ -1500,11 +1501,7 @@ void DocumentBroker::sendRequestedTiles(const std::shared_ptr<ClientSession>& se
             if (cachedTile)
             {
                 //TODO: Combine the response to reduce latency.
-#if ENABLE_DEBUG
-                const std::string response = tile.serialize("tile:") + " renderid=cached\n";
-#else
-                const std::string response = tile.serialize("tile:") + "\n";
-#endif
+                const std::string response = tile.serialize("tile:", ADD_DEBUG_RENDERID);
                 session->sendTile(response, cachedTile);
             }
             else
diff --git a/wsd/TileDesc.hpp b/wsd/TileDesc.hpp
index abb922b3f..77fb46b26 100644
--- a/wsd/TileDesc.hpp
+++ b/wsd/TileDesc.hpp
@@ -29,20 +29,21 @@ typedef uint64_t TileBinaryHash;
 class TileDesc
 {
 public:
-    TileDesc(int part, int width, int height, int tilePosX, int tilePosY, int tileWidth, int tileHeight, int ver, int imgSize, int id, bool broadcast) :
-        _part(part),
-        _width(width),
-        _height(height),
-        _tilePosX(tilePosX),
-        _tilePosY(tilePosY),
-        _tileWidth(tileWidth),
-        _tileHeight(tileHeight),
-        _ver(ver),
-        _imgSize(imgSize),
-        _id(id),
-        _broadcast(broadcast),
-        _oldWireId(0),
-        _wireId(0)
+    TileDesc(int part, int width, int height, int tilePosX, int tilePosY, int tileWidth,
+             int tileHeight, int ver, int imgSize, int id, bool broadcast)
+        : _part(part)
+        , _width(width)
+        , _height(height)
+        , _tilePosX(tilePosX)
+        , _tilePosY(tilePosY)
+        , _tileWidth(tileWidth)
+        , _tileHeight(tileHeight)
+        , _ver(ver)
+        , _imgSize(imgSize)
+        , _id(id)
+        , _broadcast(broadcast)
+        , _oldWireId(0)
+        , _wireId(0)
     {
         if (_part < 0 ||
             _width <= 0 ||
@@ -138,7 +139,8 @@ public:
 
     /// Serialize this instance into a string.
     /// Optionally prepend a prefix.
-    std::string serialize(const std::string& prefix = "") const
+    std::string serialize(const std::string& prefix = std::string(),
+                          const std::string& suffix = std::string()) const
     {
         std::ostringstream oss;
         oss << prefix
@@ -170,6 +172,7 @@ public:
             oss << " broadcast=yes";
         }
 
+        oss << suffix;
         return oss.str();
     }
 
@@ -351,7 +354,8 @@ public:
 
     /// Serialize this instance into a string.
     /// Optionally prepend a prefix.
-    std::string serialize(const std::string& prefix = "") const
+    std::string serialize(const std::string& prefix = std::string(),
+                          const std::string& suffix = std::string()) const
     {
         std::ostringstream oss;
         oss << prefix
@@ -397,15 +401,19 @@ public:
         oss.seekp(-1, std::ios_base::cur); // Ditto
 
         oss << " wid=";
+
+        bool comma = false;
         for (const auto& tile : _tiles)
         {
-            oss << tile.getWireId() << ',';
+            if (comma)
+                oss << ',';
+
+            oss << tile.getWireId();
+            comma = true;
         }
-        oss.seekp(-1, std::ios_base::cur); // See beow.
 
-        // Make sure we don't return a potential trailing comma that
-        // we have seeked back over but not overwritten after all.
-        return oss.str().substr(0, oss.tellp());
+        oss << suffix;
+        return oss.str();
     }
 
     /// Deserialize a TileDesc from a tokenized string.