Correct S3 PUT requests in WriteBufferFromS3.

dbms/src/IO/WriteBufferFromS3.cpp

@@ -18,11 +18,15 @@ WriteBufferFromS3::WriteBufferFromS3(
 
     LOG_TRACE((&Logger::get("WriteBufferFromS3")), "Sending request to " << uri.toString());
 
-    ostr = &session->sendRequest(request);
+    ostr = &temporary_stream;
 }
 
 void WriteBufferFromS3::finalize()
 {
+    const std::string & data = temporary_stream.str();
+    request.setContentLength(data.size());
+    ostr = &session->sendRequest(request);
+    *ostr << data;
     receiveResponse(*session, request, response);
     /// TODO: Response body is ignored.
 }

dbms/src/IO/WriteBufferFromS3.h

@@ -2,6 +2,7 @@
 
 #include <functional>
 #include <memory>
+#include <sstream>
 #include <Core/Types.h>
 #include <IO/ConnectionTimeouts.h>
 #include <IO/HTTPCommon.h>
@@ -34,6 +35,7 @@ private:
     HTTPSessionPtr session;
     Poco::Net::HTTPRequest request;
     Poco::Net::HTTPResponse response;
+    std::ostringstream temporary_stream; /// Maybe one shall use some DB:: buffer.
 
 public:
     explicit WriteBufferFromS3(const Poco::URI & uri,