Packet and socket optimisations

Sending/receiving data on a socket is roughly 5.5x faster, after removing data copies and buffer re-allocations.

.gitignore

@@ -1,2 +1,3 @@
 .idea
 cmake-build-debug
+cmake-build-release

include/frnetlib/Packet.h

@@ -12,11 +12,13 @@
 
 namespace fr
 {
+#define PACKET_HEADER_LENGTH sizeof(uint32_t)
     class Packet
     {
     public:
         Packet() noexcept
-        : buffer_offset(0)
+        : buffer_read_index(PACKET_HEADER_LENGTH),
+          buffer(PACKET_HEADER_LENGTH, '0')
         {
 
         }
@@ -41,17 +43,6 @@ namespace fr
             *this << part;
         }
 
-        /*!
-         * Gets the data added to the packet
-         *
-         * @return A string containing all of the data added to the packet
-         */
-        inline const std::string &get_buffer() const
-        {
-            return buffer;
-        }
-
-
         /*
          * Adds a vector to a packet
          */
@@ -108,8 +99,8 @@ namespace fr
         {
             assert_data_remaining(sizeof(var));
 
-            memcpy(&var, &buffer[buffer_offset], sizeof(var));
+            memcpy(&var, &buffer[buffer_read_index], sizeof(var));
-            buffer_offset += sizeof(var);
+            buffer_read_index += sizeof(var);
             return *this;
         }
 
@@ -131,8 +122,8 @@ namespace fr
         {
             assert_data_remaining(sizeof(var));
 
-            memcpy(&var, &buffer[buffer_offset], sizeof(var));
+            memcpy(&var, &buffer[buffer_read_index], sizeof(var));
-            buffer_offset += sizeof(var);
+            buffer_read_index += sizeof(var);
             var = ntohs(var);
             return *this;
         }
@@ -155,8 +146,8 @@ namespace fr
         {
             assert_data_remaining(sizeof(var));
 
-            memcpy(&var, &buffer[buffer_offset], sizeof(var));
+            memcpy(&var, &buffer[buffer_read_index], sizeof(var));
-            buffer_offset += sizeof(var);
+            buffer_read_index += sizeof(var);
             var = ntohl(var);
             return *this;
         }
@@ -179,8 +170,8 @@ namespace fr
         {
             assert_data_remaining(sizeof(var));
 
-            memcpy(&var, &buffer[buffer_offset], sizeof(var));
+            memcpy(&var, &buffer[buffer_read_index], sizeof(var));
-            buffer_offset += sizeof(var);
+            buffer_read_index += sizeof(var);
             var = ntohll(var);
             return *this;
         }
@@ -203,8 +194,8 @@ namespace fr
         {
             assert_data_remaining(sizeof(var));
 
-            memcpy(&var, &buffer[buffer_offset], sizeof(var));
+            memcpy(&var, &buffer[buffer_read_index], sizeof(var));
-            buffer_offset += sizeof(var);
+            buffer_read_index += sizeof(var);
             var = ntohs((uint16_t)var);
             return *this;
         }
@@ -227,8 +218,8 @@ namespace fr
         {
             assert_data_remaining(sizeof(var));
 
-            memcpy(&var, &buffer[buffer_offset], sizeof(var));
+            memcpy(&var, &buffer[buffer_read_index], sizeof(var));
-            buffer_offset += sizeof(var);
+            buffer_read_index += sizeof(var);
             var = ntohl((uint32_t)var);
             return *this;
         }
@@ -251,8 +242,8 @@ namespace fr
         {
             assert_data_remaining(sizeof(var));
 
-            memcpy(&var, &buffer[buffer_offset], sizeof(var));
+            memcpy(&var, &buffer[buffer_read_index], sizeof(var));
-            buffer_offset += sizeof(var);
+            buffer_read_index += sizeof(var);
             var = ntohll((uint64_t)var);
             return *this;
         }
@@ -275,8 +266,8 @@ namespace fr
         {
             assert_data_remaining(sizeof(var));
 
-            memcpy(&var, &buffer[buffer_offset], sizeof(var));
+            memcpy(&var, &buffer[buffer_read_index], sizeof(var));
-            buffer_offset += sizeof(var);
+            buffer_read_index += sizeof(var);
             var = ntohf(var);
             return *this;
         }
@@ -299,8 +290,8 @@ namespace fr
         {
             assert_data_remaining(sizeof(var));
 
-            memcpy(&var, &buffer[buffer_offset], sizeof(var));
+            memcpy(&var, &buffer[buffer_read_index], sizeof(var));
-            buffer_offset += sizeof(var);;
+            buffer_read_index += sizeof(var);;
             var = ntohd(var);
             return *this;
         }
@@ -333,8 +324,8 @@ namespace fr
             uint32_t length;
             *this >> length;
 
-            var = buffer.substr(buffer_offset, length);
+            var = buffer.substr(buffer_read_index, length);
-            buffer_offset += length;
+            buffer_read_index += length;
 
             return *this;
         }
@@ -354,20 +345,50 @@ namespace fr
          */
         inline void clear()
         {
-            buffer.clear();
+            buffer.erase(PACKET_HEADER_LENGTH, buffer.size() - PACKET_HEADER_LENGTH);
-            buffer_offset = 0;
+            buffer_read_index = PACKET_HEADER_LENGTH;
         }
 
         /*!
-         * Resets the buffer read cursor back to the beginning
+         * Resets the read cursor back to 0, or a specified position.
-         * of the packet.
+         *
+         * @param pos The buffer index to continue reading from.
          */
-        inline void reset_read_cursor()
+        inline void reset_read_cursor(size_t pos = 0)
         {
-            buffer_offset = 0;
+            buffer_read_index = PACKET_HEADER_LENGTH + pos;
+        }
+
+        /*!
+         * Reserves space in the internal packet buffer,
+         * for if you know how much data you expect to receive
+         * or send.
+         *
+         * @param bytes The number of bytes to reserve
+         */
+        inline void reserve(size_t bytes)
+        {
+            buffer.reserve(PACKET_HEADER_LENGTH + bytes);
         }
 
     private:
+        friend class Socket;
+
+        /*!
+         * Gets the data added to the packet
+         *
+         * @return A string containing all of the data added to the packet
+         */
+        inline std::string &get_buffer()
+        {
+            //Update packet length first
+            uint32_t length = htonl((uint32_t)buffer.size() - PACKET_HEADER_LENGTH);
+            memcpy(&buffer[0], &length, sizeof(uint32_t));
+
+            //Then a reference to the buffer
+            return buffer;
+        }
+
         /*!
          * Checks that there's enough data in the buffer to extract
          * a given number of bytes to prevent buffer overflows.
@@ -377,12 +398,13 @@ namespace fr
          */
         inline void assert_data_remaining(size_t required_space)
         {
-            if(buffer_offset + required_space > buffer.size())
+            if(buffer_read_index + required_space > buffer.size())
                 throw std::out_of_range("Not enough bytes remaining in packet to extract requested");
         }
 
+
         std::string buffer; //Packet data buffer
-        size_t buffer_offset; //Current read position
+        size_t buffer_read_index; //Current read position
     };
 }
 

include/frnetlib/SSLSocket.h

@@ -98,17 +98,7 @@ namespace fr
             abort();
         }
 
-        /*!
-         * Checks to see if there's data still in the socket's
-         * recv buffer.
-         *
-         * @return True if there is data in the buffer, false otherwise.
-         */
-        virtual bool has_data() const override;
-
     private:
-        std::string unprocessed_buffer;
-        std::unique_ptr<char[]> recv_buffer;
         std::shared_ptr<SSLContext> ssl_context;
 
         std::unique_ptr<mbedtls_net_context> ssl_socket_descriptor;

include/frnetlib/Socket.h

@@ -5,7 +5,7 @@
 #ifndef FRNETLIB_SOCKET_H
 #define FRNETLIB_SOCKET_H
 
-
+#include <mutex>
 #include "NetworkEncoding.h"
 #include "Packet.h"
 
@@ -95,7 +95,8 @@ namespace fr
          * @param packet The packet to send
          * @return True on success, false on failure.
          */
-        Status send(const Packet &packet);
+        Status send(Packet &packet);
+        Status send(Packet &&packet);
 
         /*!
          * Receive a packet through the socket
@@ -146,13 +147,6 @@ namespace fr
          */
         void shutdown();
 
-        /*!
-         * Checks to see if there's data still in the socket's
-         * recv buffer.
-         *
-         * @return True if there is data in the buffer, false otherwise.
-         */
-        virtual bool has_data() const = 0;
 
     protected:
         /*!
@@ -164,6 +158,8 @@ namespace fr
         std::string remote_address;
         bool is_blocking;
         bool is_connected;
+        std::mutex outbound_mutex;
+        std::mutex inbound_mutex;
 
         #ifdef _WIN32
                 static WSADATA wsaData;

include/frnetlib/TcpListener.h

@@ -45,7 +45,6 @@ private:
     virtual fr::Socket::Status send_raw(const char*, size_t){return Socket::Error;}
     virtual fr::Socket::Status receive_raw(void*, size_t, size_t&){return Socket::Error;}
     virtual int32_t get_socket_descriptor() const {return socket_descriptor;}
-    virtual bool has_data() const override {return false;};
 };
 
 }

include/frnetlib/TcpSocket.h

@@ -19,9 +19,7 @@ public:
     TcpSocket() noexcept;
     virtual ~TcpSocket() noexcept;
     TcpSocket(TcpSocket &&other) noexcept
-    : unprocessed_buffer(std::move(other.unprocessed_buffer)),
+    : socket_descriptor(other.socket_descriptor){}
-      recv_buffer(std::move(other.recv_buffer)),
-      socket_descriptor(other.socket_descriptor){}
     void operator=(const TcpSocket &other)=delete;
 
     /*!
@@ -95,20 +93,8 @@ public:
      */
     int32_t get_socket_descriptor() const override;
 
-    /*!
-     * Checks to see if there's data still in the socket's
-     * recv buffer.
-     *
-     * @return True if there is data in the buffer, false otherwise.
-     */
-    virtual bool has_data() const override;
-
 protected:
-    std::string unprocessed_buffer;
-    std::unique_ptr<char[]> recv_buffer;
     int32_t socket_descriptor;
-    std::mutex outbound_mutex;
-    std::mutex inbound_mutex;
 };
 
 }

main.cpp

@@ -3,6 +3,7 @@
 #include <thread>
 #include <atomic>
 #include <mutex>
+#include <chrono>
 #include "frnetlib/Packet.h"
 #include "frnetlib/TcpSocket.h"
 #include "frnetlib/TcpListener.h"
@@ -17,65 +18,50 @@
 void server()
 {
     fr::TcpListener listener;
-    fr::TcpSocket client;
+    listener.listen("9092");
 
-    listener.listen("8081");
+    fr::TcpSocket socket;
-    listener.accept(client);
+    listener.accept(socket);
-
-    uint32_t packet_no = 0;
 
+    uint64_t packet_count = 0;
+    auto last_print_time = std::chrono::system_clock::now();
     while(true)
     {
         fr::Packet packet;
-        client.receive(packet);
+        if(socket.receive(packet) != fr::Socket::Success)
+            break;
 
 
-        uint32_t num = 0;
+        std::string s1;
-        packet >> num;
+        packet >> s1;
 
-        if(num != ++packet_no)
+        packet_count++;
+        if(last_print_time + std::chrono::seconds(1) < std::chrono::system_clock::now())
         {
-            std::cout << "Packet mismatch. Expected " << packet_no + 1 << ". Got " << num << std::endl;
+            std::cout << "Packets per second: " << packet_count << std::endl;
-            return;
+            packet_count = 0;
+            last_print_time = std::chrono::system_clock::now();
         }
     }
-}
 
-void client()
-{
-    fr::TcpSocket server;
-    server.connect("127.0.0.1", "8081");
-
-    uint32_t packet_no = 0;
-    std::mutex m1;
-
-    auto lam = [&]()
-    {
-        while(true)
-        {
-            m1.lock();
-            fr::Packet packet;
-            packet << ++packet_no;
-            m1.unlock();
-
-            server.send(packet);
-        }
-    };
-
-    std::thread t1(lam);
-    std::thread t2(lam);
-    std::thread t3(lam);
-    std::thread t4(lam);
-    t1.join();
 }
 
 int main()
 {
-    std::thread s1(server);
+    std::thread server_thread(server);
     std::this_thread::sleep_for(std::chrono::milliseconds(100));
-    std::thread c1(client);
 
-    s1.join();
+    fr::TcpSocket socket;
-    c1.join();
+    socket.connect("127.0.0.1", "9092");
-    return 0;
+
+    std::string a(32384, 'c');
+    fr::Packet packet;
+    while(true)
+    {
+        packet << a;
+        if(socket.send(packet) != fr::Socket::Success)
+            break;
+        packet.clear();
+    }
+    server_thread.join();
 }

src/SSLSocket.cpp

@@ -9,8 +9,7 @@
 namespace fr
 {
     SSLSocket::SSLSocket(std::shared_ptr<SSLContext> ssl_context_) noexcept
-    : recv_buffer(new char[RECV_CHUNK_SIZE]),
+    :  ssl_context(ssl_context_)
-      ssl_context(ssl_context_)
     {
         //Initialise mbedtls structures
         mbedtls_ssl_config_init(&conf);
@@ -55,15 +54,12 @@ namespace fr
 
     Socket::Status SSLSocket::receive_raw(void *data, size_t data_size, size_t &received)
     {
-        std::lock_guard<std::mutex> guard(inbound_mutex);
-
         int read = MBEDTLS_ERR_SSL_WANT_READ;
         received = 0;
-        if(unprocessed_buffer.size() < data_size)
+
-        {
         while(read == MBEDTLS_ERR_SSL_WANT_READ || read == MBEDTLS_ERR_SSL_WANT_WRITE)
         {
-                read = mbedtls_ssl_read(ssl.get(), (unsigned char *)recv_buffer.get(), RECV_CHUNK_SIZE);
+            read = mbedtls_ssl_read(ssl.get(), (unsigned char *)data, data_size);
         }
 
         if(read == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY)
@@ -78,19 +74,6 @@ namespace fr
         }
 
         received += read;
-            unprocessed_buffer += {recv_buffer.get(), (size_t)read};
-
-            if(received > data_size)
-                received = data_size;
-        }
-        else
-        {
-            received = data_size;
-        }
-
-        //Copy data to where it needs to go
-        memcpy(data, &unprocessed_buffer[0], received);
-        unprocessed_buffer.erase(0, received);
         return Socket::Status::Success;
 
     }
@@ -171,11 +154,6 @@ namespace fr
         ssl_socket_descriptor = std::move(context);
         reconfigure_socket();
     }
-
-    bool SSLSocket::has_data() const
-    {
-        return !unprocessed_buffer.empty();
-    }
 }
 
 #endif

src/Socket.cpp

@@ -2,6 +2,7 @@
 // Created by fred on 06/12/16.
 //
 
+#include <mutex>
 #include "frnetlib/NetworkEncoding.h"
 #include "frnetlib/Socket.h"
 
@@ -30,20 +31,21 @@ namespace fr
         #endif // _WIN32
     }
 
-    Socket::Status Socket::send(const Packet &packet)
+    Socket::Status Socket::send(Packet &packet)
     {
         if(!is_connected)
             return Socket::Disconnected;
 
-        //Get packet data
+        std::string &data = packet.get_buffer();
-        std::string data = packet.get_buffer();
+        return send_raw(data.c_str(), data.size());
+    }
 
-        //Prepend packet length
+    Socket::Status Socket::send(Packet &&packet)
-        uint32_t length = htonl((uint32_t)data.size());
+    {
-        data.insert(0, "1234");
+        if(!is_connected)
-        memcpy(&data[0], &length, sizeof(uint32_t));
+            return Socket::Disconnected;
 
-        //Send it
+        std::string &data = packet.get_buffer();
         return send_raw(data.c_str(), data.size());
     }
 
@@ -53,6 +55,7 @@ namespace fr
             return Socket::Disconnected;
 
         Socket::Status status;
+        std::lock_guard<std::mutex> guard(inbound_mutex);
 
         //Try to read packet length
         uint32_t packet_length = 0;
@@ -62,13 +65,11 @@ namespace fr
         packet_length = ntohl(packet_length);
 
         //Now we've got the length, read the rest of the data in
-        std::string data(packet_length, 'c');
+        packet.buffer.resize(packet_length + PACKET_HEADER_LENGTH);
-        status = receive_all(&data[0], packet_length);
+        status = receive_all(&packet.buffer[PACKET_HEADER_LENGTH], packet_length);
         if(status != Socket::Status::Success)
             return status;
 
-        //Set the packet to what we've read
-        packet.set_buffer(std::move(data));
 
         return Socket::Status::Success;
     }

src/SocketSelector.cpp

@@ -3,6 +3,7 @@
 //
 
 #include <thread>
+#include <mutex>
 #include "frnetlib/SocketSelector.h"
 
 namespace fr

src/TcpSocket.cpp

@@ -9,7 +9,6 @@ namespace fr
 {
 
     TcpSocket::TcpSocket() noexcept
-    : recv_buffer(new char[RECV_CHUNK_SIZE])
     {
 
     }
@@ -56,16 +55,13 @@ namespace fr
 
     Socket::Status TcpSocket::receive_raw(void *data, size_t buffer_size, size_t &received)
     {
-        std::lock_guard<std::mutex> guard(inbound_mutex);
         received = 0;
-        if(unprocessed_buffer.size() < buffer_size)
+
-        {
         //Read RECV_CHUNK_SIZE bytes into the recv buffer
-            ssize_t status = ::recv(socket_descriptor, recv_buffer.get(), RECV_CHUNK_SIZE, 0);
+        ssize_t status = ::recv(socket_descriptor, data, buffer_size, 0);
 
         if(status > 0)
         {
-                unprocessed_buffer += {recv_buffer.get(), (size_t)status};
             received += status;
         }
         else
@@ -85,15 +81,7 @@ namespace fr
 
         if(received > buffer_size)
             received = buffer_size;
-        }
-        else
-        {
-            received = buffer_size;
-        }
 
-        //Copy data to where it needs to go
-        memcpy(data, &unprocessed_buffer[0], received);
-        unprocessed_buffer.erase(0, received);
         return Socket::Status::Success;
     }
 
@@ -162,9 +150,4 @@ namespace fr
     {
         return socket_descriptor;
     }
-
-    bool TcpSocket::has_data() const
-    {
-        return !unprocessed_buffer.empty();
-    }
 }