Added keep-alive support to the http server.

include/server/connection.hpp

@@ -65,6 +65,9 @@ class Connection : public std::enable_shared_from_this<Connection>
     std::vector<char> compressed_output;
     // Header compression_header;
     std::vector<boost::asio::const_buffer> output_buffer;
+    //Keep alive support
+    bool keep_alive = false;
+    short processed_requests = 512;
 };
 }
 }

src/server/connection.cpp

@@ -4,12 +4,14 @@
 
 #include <boost/assert.hpp>
 #include <boost/bind.hpp>
+#include <boost/algorithm/string/predicate.hpp>
 #include <boost/iostreams/filter/gzip.hpp>
 #include <boost/iostreams/filtering_stream.hpp>
 
 #include <iterator>
 #include <string>
 #include <vector>
+#include <util/log.hpp>
 
 namespace osrm
 {
@@ -55,6 +57,14 @@ void Connection::handle_read(const boost::system::error_code &error, std::size_t
         current_request.endpoint = TCP_socket.remote_endpoint().address();
         request_handler.HandleRequest(current_request, current_reply);
 
+        if (boost::iequals(current_request.connection, "close")) {
+            current_reply.headers.emplace_back("Connection", "close");
+        } else {
+            keep_alive = true;
+            current_reply.headers.emplace_back("Connection", "keep-alive");
+            current_reply.headers.emplace_back("Keep-Alive", "timeout=5, max=512");
+        }
+
         // compress the result w/ gzip/deflate if requested
         switch (compression_type)
         {
@@ -116,10 +126,17 @@ void Connection::handle_write(const boost::system::error_code &error)
 {
     if (!error)
     {
+        if (keep_alive && processed_requests > 0) {
+            --processed_requests;
+            current_request = http::request();
+            request_parser = RequestParser();
+            this->start();
+        } else {
             // Initiate graceful connection closure.
             boost::system::error_code ignore_error;
             TCP_socket.shutdown(boost::asio::ip::tcp::socket::shutdown_both, ignore_error);
         }
+    }
 }
 
 std::vector<char> Connection::compress_buffers(const std::vector<char> &uncompressed_data,

src/server/http/reply.cpp

@@ -103,11 +103,7 @@ boost::asio::const_buffer reply::status_to_buffer(const reply::status_type statu
     return boost::asio::buffer(http_bad_request_string);
 }
 
-reply::reply() : status(ok)
-{
-    // We do not currently support keep alive. Always set 'Connection: close'.
-    headers.emplace_back("Connection", "close");
-}
+reply::reply() : status(ok) {}
 }
 }
 }