feat: add support for Socket.IO v3

See also: - https://github.com/socketio/engine.io-protocol#difference-between-v3-and-v4 - https://github.com/socketio/socket.io-protocol#difference-between-v5-and-v4
2026-05-06 14:02:56 +00:00 · 2021-01-09 01:40:31 +01:00 · 2021-01-09 01:40:31 +01:00 · ec4d540ad5
commit ec4d540ad5
parent b1216ee428
10 changed files with 204 additions and 57 deletions
--- a/README.md
+++ b/README.md
@ -6,16 +6,24 @@ By virtue of being written in C++, this client works in several different platfo

 [![Clients with iPhone, QT, Console and web](https://cldup.com/ukvVVZmvYV.png)](https://github.com/socketio/socket.io-client-cpp/tree/master/examples)

+## Compatibility table
+
+| C++ Client version  | Socket.IO server version |
+| ------------------- | ------------------------ |
+| 2.x (`2.x` branch)  | 1.x / 2.x                |
+| 3.x (master branch) | 3.x                      |
+
 ## Features

 - 100% written in modern C++11
- Compatible with socket.io 1.0+ protocol
 - Binary support
 - Automatic JSON encoding
 - Multiplex support
 - Similar API to the Socket.IO JS client
 - Cross platform

+Note: Only the WebSocket transport is currently implemented (no fallback to HTTP long-polling)
+
 ## Installation alternatives

 * [With CMAKE](./INSTALL.md#with-cmake)
--- a/src/internal/sio_client_impl.cpp
+++ b/src/internal/sio_client_impl.cpp
@ -222,7 +222,7 @@ namespace sio
            } else {
                ss<<uo.get_host();
            }
-            ss<<":"<<uo.get_port()<<"/socket.io/?EIO=3&transport=websocket";
+            ss<<":"<<uo.get_port()<<"/socket.io/?EIO=4&transport=websocket";
            if(m_sid.size()>0){
                ss<<"&sid="<<m_sid;
            }
@ -295,12 +295,6 @@ namespace sio
            lib::error_code ec;
            this->m_client.send(this->m_con, *payload, frame::opcode::text, ec);
        });
-        if(m_ping_timer)
-        {
-            asio::error_code e_code;
-            m_ping_timer->expires_from_now(milliseconds(m_ping_interval), e_code);
-            m_ping_timer->async_wait(std::bind(&client_impl::ping,this, std::placeholders::_1));
-        }
        if(!m_ping_timeout_timer)
        {
            m_ping_timeout_timer.reset(new asio::steady_timer(m_client.get_io_service()));
@ -497,12 +491,6 @@ namespace sio
                m_ping_timeout = 60000;
            }

-            m_ping_timer.reset(new asio::steady_timer(m_client.get_io_service()));
-            asio::error_code ec;
-            m_ping_timer->expires_from_now(milliseconds(m_ping_interval), ec);
-            if(ec)LOG("ec:"<<ec.message()<<endl){};
-            m_ping_timer->async_wait(std::bind(&client_impl::ping,this, std::placeholders::_1));
-            LOG("On handshake,sid:"<<m_sid<<",ping interval:"<<m_ping_interval<<",ping timeout"<<m_ping_timeout<<endl);
            return;
        }
 failed:
@ -510,8 +498,14 @@ failed:
        m_client.get_io_service().dispatch(std::bind(&client_impl::close_impl, this,close::status::policy_violation,"Handshake error"));
    }

-    void client_impl::on_pong()
+    void client_impl::on_ping()
    {
+        packet p(packet::frame_pong);
+        m_packet_mgr.encode(p, [&](bool /*isBin*/,shared_ptr<const string> payload)
+        {
+            this->m_client.send(this->m_con, *payload, frame::opcode::text);
+        });
+
        if(m_ping_timeout_timer)
        {
            m_ping_timeout_timer->cancel();
@ -536,8 +530,8 @@ failed:
            //FIXME how to deal?
            this->close_impl(close::status::abnormal_close, "End by server");
            break;
-        case packet::frame_pong:
-            this->on_pong();
+        case packet::frame_ping:
+            this->on_ping();
            break;

        default:
@ -560,11 +554,6 @@ failed:
            m_ping_timeout_timer->cancel(ec);
            m_ping_timeout_timer.reset();
        }
-        if(m_ping_timer)
-        {
-            m_ping_timer->cancel(ec);
-            m_ping_timer.reset();
-        }
    }
    
    void client_impl::reset_states()
--- a/src/internal/sio_client_impl.h
+++ b/src/internal/sio_client_impl.h
@ -170,7 +170,7 @@ namespace sio
        //socketio callbacks
        void on_handshake(message::ptr const& message);

-        void on_pong();
+        void on_ping();

        void reset_states();

@ -201,8 +201,6 @@ namespace sio
        
        packet_manager m_packet_mgr;
        
-        std::unique_ptr<asio::steady_timer> m_ping_timer;
-        
        std::unique_ptr<asio::steady_timer> m_ping_timeout_timer;

        std::unique_ptr<asio::steady_timer> m_reconn_timer;
--- a/src/internal/sio_packet.cpp
+++ b/src/internal/sio_packet.cpp
@ -53,13 +53,7 @@ namespace sio
        Value numVal;
        numVal.SetInt((int)buffers.size());
        val.AddMember("num", numVal, doc.GetAllocator());
-        //FIXME can not avoid binary copy here.
-        shared_ptr<string> write_buffer = make_shared<string>();
-        write_buffer->reserve(msg.get_binary()->size()+1);
-        char frame_char = packet::frame_message;
-        write_buffer->append(&frame_char,1);
-        write_buffer->append(*(msg.get_binary()));
-        buffers.push_back(write_buffer);
+        buffers.push_back(msg.get_binary());
    }

    void accept_array_message(array_message const& msg,Value& val,Document& doc,vector<shared_ptr<const string> >& buffers)
@ -253,7 +247,7 @@ namespace sio
    {
        if (_pending_buffers > 0) {
            assert(is_binary_message(buf_payload));//this is ensured by outside.
-            _buffers.push_back(std::make_shared<string>(buf_payload.data()+1,buf_payload.size()-1));
+            _buffers.push_back(std::make_shared<string>(buf_payload.data(),buf_payload.size()));
            _pending_buffers--;
            if (_pending_buffers == 0) {

--- a/src/sio_socket.cpp
+++ b/src/sio_socket.cpp
@ -269,10 +269,6 @@ namespace sio
    void socket::impl::send_connect()
    {
        NULL_GUARD(m_client);
-        if(m_nsp == "/")
-        {
-            return;
-        }
        packet p(packet::type_connect,m_nsp);
        m_client->send(p);
        m_connection_timer.reset(new asio::steady_timer(m_client->get_io_service()));
--- a/test/echo_server/index.js
+++ b/test/echo_server/index.js
@ -1,19 +1,17 @@
 var port = 3000;

-var io = require('socket.io').listen(port);
+var io = require('socket.io')().listen(port);
 console.log("Listening on port " + port);

 /* Socket.IO events */
 io.on("connection", function(socket){
    console.log("new connection");
-    socket.on('test_text',function()
-    {
-        console.log("test text event received.");
+    socket.on('test_text', (...args) => {
+        console.log("test text event received.", args);
    });

-    socket.on('test_binary',function()
-    {
-       var args =Array.prototype.slice.call(arguments);
+    socket.on('test_binary', (...args) => {
+        console.log("test binary event received", args);
      if(args[0] instanceof Buffer)
      {
        console.log("test binary event received,binary length:"+ args[0].length);
--- a/test/echo_server/package-lock.json
+++ b/test/echo_server/package-lock.json
@ -0,0 +1,165 @@
+{
+    "name": "echo_server",
+    "version": "0.0.0",
+    "lockfileVersion": 1,
+    "requires": true,
+    "dependencies": {
+        "@types/component-emitter": {
+            "version": "1.2.10",
+            "resolved": "https://registry.npmjs.org/@types/component-emitter/-/component-emitter-1.2.10.tgz",
+            "integrity": "sha512-bsjleuRKWmGqajMerkzox19aGbscQX5rmmvvXl3wlIp5gMG1HgkiwPxsN5p070fBDKTNSPgojVbuY1+HWMbFhg=="
+        },
+        "@types/cookie": {
+            "version": "0.4.0",
+            "resolved": "https://registry.npmjs.org/@types/cookie/-/cookie-0.4.0.tgz",
+            "integrity": "sha512-y7mImlc/rNkvCRmg8gC3/lj87S7pTUIJ6QGjwHR9WQJcFs+ZMTOaoPrkdFA/YdbuqVEmEbb5RdhVxMkAcgOnpg=="
+        },
+        "@types/cors": {
+            "version": "2.8.9",
+            "resolved": "https://registry.npmjs.org/@types/cors/-/cors-2.8.9.tgz",
+            "integrity": "sha512-zurD1ibz21BRlAOIKP8yhrxlqKx6L9VCwkB5kMiP6nZAhoF5MvC7qS1qPA7nRcr1GJolfkQC7/EAL4hdYejLtg=="
+        },
+        "@types/node": {
+            "version": "14.14.20",
+            "resolved": "https://registry.npmjs.org/@types/node/-/node-14.14.20.tgz",
+            "integrity": "sha512-Y93R97Ouif9JEOWPIUyU+eyIdyRqQR0I8Ez1dzku4hDx34NWh4HbtIc3WNzwB1Y9ULvNGeu5B8h8bVL5cAk4/A=="
+        },
+        "accepts": {
+            "version": "1.3.7",
+            "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.7.tgz",
+            "integrity": "sha512-Il80Qs2WjYlJIBNzNkK6KYqlVMTbZLXgHx2oT0pU/fjRHyEp+PEfEPY0R3WCwAGVOtauxh1hOxNgIf5bv7dQpA==",
+            "requires": {
+                "mime-types": "~2.1.24",
+                "negotiator": "0.6.2"
+            }
+        },
+        "base64-arraybuffer": {
+            "version": "0.1.4",
+            "resolved": "https://registry.npmjs.org/base64-arraybuffer/-/base64-arraybuffer-0.1.4.tgz",
+            "integrity": "sha1-mBjHngWbE1X5fgQooBfIOOkLqBI="
+        },
+        "base64id": {
+            "version": "2.0.0",
+            "resolved": "https://registry.npmjs.org/base64id/-/base64id-2.0.0.tgz",
+            "integrity": "sha512-lGe34o6EHj9y3Kts9R4ZYs/Gr+6N7MCaMlIFA3F1R2O5/m7K06AxfSeO5530PEERE6/WyEg3lsuyw4GHlPZHog=="
+        },
+        "component-emitter": {
+            "version": "1.3.0",
+            "resolved": "https://registry.npmjs.org/component-emitter/-/component-emitter-1.3.0.tgz",
+            "integrity": "sha512-Rd3se6QB+sO1TwqZjscQrurpEPIfO0/yYnSin6Q/rD3mOutHvUrCAhJub3r90uNb+SESBuE0QYoB90YdfatsRg=="
+        },
+        "cookie": {
+            "version": "0.4.1",
+            "resolved": "https://registry.npmjs.org/cookie/-/cookie-0.4.1.tgz",
+            "integrity": "sha512-ZwrFkGJxUR3EIoXtO+yVE69Eb7KlixbaeAWfBQB9vVsNn/o+Yw69gBWSSDK825hQNdN+wF8zELf3dFNl/kxkUA=="
+        },
+        "cors": {
+            "version": "2.8.5",
+            "resolved": "https://registry.npmjs.org/cors/-/cors-2.8.5.tgz",
+            "integrity": "sha512-KIHbLJqu73RGr/hnbrO9uBeixNGuvSQjul/jdFvS/KFSIH1hWVd1ng7zOHx+YrEfInLG7q4n6GHQ9cDtxv/P6g==",
+            "requires": {
+                "object-assign": "^4",
+                "vary": "^1"
+            }
+        },
+        "debug": {
+            "version": "4.3.1",
+            "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.1.tgz",
+            "integrity": "sha512-doEwdvm4PCeK4K3RQN2ZC2BYUBaxwLARCqZmMjtF8a51J2Rb0xpVloFRnCODwqjpwnAoao4pelN8l3RJdv3gRQ==",
+            "requires": {
+                "ms": "2.1.2"
+            }
+        },
+        "engine.io": {
+            "version": "4.0.6",
+            "resolved": "https://registry.npmjs.org/engine.io/-/engine.io-4.0.6.tgz",
+            "integrity": "sha512-rf7HAVZpcRrcKEKddgIzYUnwg0g5HE1RvJaTLwkcfJmce4g+po8aMuE6vxzp6JwlK8FEq/vi0KWN6tA585DjaA==",
+            "requires": {
+                "accepts": "~1.3.4",
+                "base64id": "2.0.0",
+                "cookie": "~0.4.1",
+                "cors": "~2.8.5",
+                "debug": "~4.3.1",
+                "engine.io-parser": "~4.0.0",
+                "ws": "~7.4.2"
+            }
+        },
+        "engine.io-parser": {
+            "version": "4.0.2",
+            "resolved": "https://registry.npmjs.org/engine.io-parser/-/engine.io-parser-4.0.2.tgz",
+            "integrity": "sha512-sHfEQv6nmtJrq6TKuIz5kyEKH/qSdK56H/A+7DnAuUPWosnIZAS2NHNcPLmyjtY3cGS/MqJdZbUjW97JU72iYg==",
+            "requires": {
+                "base64-arraybuffer": "0.1.4"
+            }
+        },
+        "mime-db": {
+            "version": "1.45.0",
+            "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.45.0.tgz",
+            "integrity": "sha512-CkqLUxUk15hofLoLyljJSrukZi8mAtgd+yE5uO4tqRZsdsAJKv0O+rFMhVDRJgozy+yG6md5KwuXhD4ocIoP+w=="
+        },
+        "mime-types": {
+            "version": "2.1.28",
+            "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.28.tgz",
+            "integrity": "sha512-0TO2yJ5YHYr7M2zzT7gDU1tbwHxEUWBCLt0lscSNpcdAfFyJOVEpRYNS7EXVcTLNj/25QO8gulHC5JtTzSE2UQ==",
+            "requires": {
+                "mime-db": "1.45.0"
+            }
+        },
+        "ms": {
+            "version": "2.1.2",
+            "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+            "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
+        },
+        "negotiator": {
+            "version": "0.6.2",
+            "resolved": "https://registry.npmjs.org/negotiator/-/negotiator-0.6.2.tgz",
+            "integrity": "sha512-hZXc7K2e+PgeI1eDBe/10Ard4ekbfrrqG8Ep+8Jmf4JID2bNg7NvCPOZN+kfF574pFQI7mum2AUqDidoKqcTOw=="
+        },
+        "object-assign": {
+            "version": "4.1.1",
+            "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.1.tgz",
+            "integrity": "sha1-IQmtx5ZYh8/AXLvUQsrIv7s2CGM="
+        },
+        "socket.io": {
+            "version": "3.0.5",
+            "resolved": "https://registry.npmjs.org/socket.io/-/socket.io-3.0.5.tgz",
+            "integrity": "sha512-5yWQ43P/4IttmPCGKDQ3CVocBiJWGpibyhYJxgUhf69EHMzmK8XW0DkmHIoYdLmZaVZJyiEkUqpeC7rSCIqekw==",
+            "requires": {
+                "@types/cookie": "^0.4.0",
+                "@types/cors": "^2.8.8",
+                "@types/node": "^14.14.10",
+                "accepts": "~1.3.4",
+                "base64id": "~2.0.0",
+                "debug": "~4.3.1",
+                "engine.io": "~4.0.6",
+                "socket.io-adapter": "~2.0.3",
+                "socket.io-parser": "~4.0.3"
+            }
+        },
+        "socket.io-adapter": {
+            "version": "2.0.3",
+            "resolved": "https://registry.npmjs.org/socket.io-adapter/-/socket.io-adapter-2.0.3.tgz",
+            "integrity": "sha512-2wo4EXgxOGSFueqvHAdnmi5JLZzWqMArjuP4nqC26AtLh5PoCPsaRbRdah2xhcwTAMooZfjYiNVNkkmmSMaxOQ=="
+        },
+        "socket.io-parser": {
+            "version": "4.0.3",
+            "resolved": "https://registry.npmjs.org/socket.io-parser/-/socket.io-parser-4.0.3.tgz",
+            "integrity": "sha512-m4ybFiP4UYVORRt7jcdqf8UWx+ywVdAqqsJyruXxAdD3Sv6MDemijWij34mOWdMJ55bEdIb9jACBhxUgNK6sxw==",
+            "requires": {
+                "@types/component-emitter": "^1.2.10",
+                "component-emitter": "~1.3.0",
+                "debug": "~4.3.1"
+            }
+        },
+        "vary": {
+            "version": "1.1.2",
+            "resolved": "https://registry.npmjs.org/vary/-/vary-1.1.2.tgz",
+            "integrity": "sha1-IpnwLG3tMNSllhsLn3RSShj2NPw="
+        },
+        "ws": {
+            "version": "7.4.2",
+            "resolved": "https://registry.npmjs.org/ws/-/ws-7.4.2.tgz",
+            "integrity": "sha512-T4tewALS3+qsrpGI/8dqNMLIVdq/g/85U98HPMa6F0m6xTbvhXU6RCQLqPH3+SlomNV/LdY6RXEbBpMH6EOJnA=="
+        }
+    }
+}
--- a/test/echo_server/package.json
+++ b/test/echo_server/package.json
@ -1,8 +1,8 @@
 {
    "name": "echo_server",
-    "author":"Melo Yao",
-    "version":"0.0.0",
+    "author": "Melo Yao",
+    "version": "0.0.0",
    "dependencies": {
-        "socket.io": "1.*"
-  }
+        "socket.io": "^3.0.5"
+    }
 }
--- a/test/sio_test
+++ b/test/sio_test
--- a/test/sio_test.cpp
+++ b/test/sio_test.cpp
@ -118,16 +118,16 @@ TEST_CASE( "test_packet_accept_4" )
    int bin1Num = j["bin1"]["num"].get<int>();
    char numchar[] = {0,0};
    numchar[0] = bin1Num+'0';
-    CHECK(buffers[bin1Num]->length()==101);
+    CHECK(buffers[bin1Num]->length()==100);
    INFO("outputing payload bin1 num:" << numchar)
    CHECK(buffers[bin1Num]->at(50)==0);
-    CHECK(buffers[bin1Num]->at(0) == packet::frame_message);
+    CHECK(buffers[bin1Num]->at(0) == 0);
    int bin2Num = j["bin2"]["num"].get<int>();
    numchar[0] = bin2Num+'0';
-    CHECK(buffers[bin2Num]->length()==51);
+    CHECK(buffers[bin2Num]->length()==50);
    INFO("outputing payload bin2 num:" << numchar)
    CHECK(buffers[bin2Num]->at(25)==1);
-    CHECK(buffers[bin2Num]->at(0) == packet::frame_message);
+    CHECK(buffers[bin2Num]->at(0) == 1);
 }
 #endif

@ -209,12 +209,11 @@ TEST_CASE( "test_packet_parse_4" )
    packet p;
    bool hasbin = p.parse("452-/nsp,101[\"bin_event\",[{\"_placeholder\":true,\"num\":1},{\"_placeholder\":true,\"num\":0},\"text\"]]");
    CHECK(hasbin);
-    char buf[101];
-    buf[0] = packet::frame_message;
-    memset(buf+1,0,100);
+    char buf[100];
+    memset(buf,0,100);

-    std::string bufstr(buf,101);
-    std::string bufstr2(buf,51);
+    std::string bufstr(buf,100);
+    std::string bufstr2(buf,50);
    CHECK(p.parse_buffer(bufstr));
    CHECK(!p.parse_buffer(bufstr2));