Addressed review comments

- Removed first_buffer, finalizeImpl and logic to different buffer size from ForkWriteBuffer

src/IO/ForkWriteBuffer.cpp

@@ -16,46 +16,23 @@ ForkWriteBuffer::ForkWriteBuffer(WriteBufferPtrs && sources_)
 {
     if (sources.empty())
     {
-        first_buffer = nullptr;
         throw Exception("ForkWriteBuffer required WriteBuffer is not provided", ErrorCodes::CANNOT_CREATE_IO_BUFFER);
     }
-    else
+    set(sources.front()->buffer().begin(), sources.front()->buffer().size());
-    {
-        first_buffer = sources.begin()->get();
-        set(first_buffer->buffer().begin(), first_buffer->buffer().size());
-    }
 }
 
 
 void ForkWriteBuffer::nextImpl()
 {
-    if (!first_buffer)
+    sources.front()->position() = position();
-        return;
-
-    first_buffer->position() = position();
 
     try
     {
         for (const WriteBufferPtr & write_buffer : sources | std::views::reverse)
         {
-            if (write_buffer.get() != first_buffer)
+            if (write_buffer != sources.front())
             {
-                //if buffer size if not enough to write, then split the message with buffer length
+                write_buffer->write(sources.front()->buffer().begin(), sources.front()->offset());
-                if (write_buffer->available() < first_buffer->offset())
-                {
-                    size_t bytes_written = 0;
-                    auto to_be_written = first_buffer->offset();
-                    while (to_be_written != 0)
-                    {
-                        int bytes_to_copy = std::min(to_be_written, write_buffer->available());
-                        write_buffer->write(first_buffer->buffer().begin()+bytes_written, bytes_to_copy);
-                        write_buffer->next();
-                        bytes_written += bytes_to_copy;
-                        to_be_written -= bytes_to_copy;
-                    }
-                }
-                else
-                    write_buffer->write(first_buffer->buffer().begin(), first_buffer->offset());
             }
             write_buffer->next();
         }
@@ -68,12 +45,6 @@ void ForkWriteBuffer::nextImpl()
 
 }
 
-void ForkWriteBuffer::finalizeImpl()
-{
-    next();
-}
-
-
 ForkWriteBuffer::~ForkWriteBuffer()
 {
     finalize();

src/IO/ForkWriteBuffer.h

@@ -25,11 +25,9 @@ public:
 
 protected:
     void nextImpl() override;
-    void finalizeImpl() override;
 
 private:
     WriteBufferPtrs sources;
-    WriteBuffer *first_buffer;
 };
 
 }