# Overview

VSOA is the abbreviation of Vehicle SOA presented by ACOINFO, VSOA provides a reliable, Real-Time SOA (Service Oriented Architecture) framework, this framework has multi-language and multi-environment implementation, developers can use this framework to build a distributed service model.

VSOA includes the following features:

1. Support resource tagging of unified URL
2. Support URL matching subscribe and publish model
3. Support Real-Time Remote Procedure Call
4. Support parallel multiple command sequences
5. Support reliable and unreliable data publishing and datagram
6. Support multi-channel full-duplex high speed parallel data stream
7. Support network QoS control
8. Easily implement server fault-tolerant design
9. Supports multiple language bindings

VSOA is a dual-channel communication protocol, using both TCP and UDP, among which the API marked with quick uses the UDP channel. The quick channel is used for high-frequency data update channels. Due to the high data update frequency, the requirements for communication reliability are not strict. It should be noted that UDP channel cannot pass through NAT network, so please do not use quick channel in NAT network.

The total url and payload length of the VSOA data packet cannot exceed 256KBytes - 20Bytes and 65507Bytes - 20Bytes on quick channel, so if you need to send a large amount of data, you can use the VSOA data stream.

Downloadopen in new window this SDK to the src/ folder in GOPATH. Unzip go-vsoa@v1.0.4.zip to get go-vsoa@v1.0.4 folder. Create your work folder in GOPATH for example go-vsoa-example. Go into your work folder and save the following as go.mod.

module example.com/go-vsoa-example

go 1.20

require gitee.com/sylixos/go-vsoa v1.0.4
replace gitee.com/sylixos/go-vsoa v1.0.4 => ../go-vsoa@v1.0.4

User can use the following code to import the vsoa's sub modules.

Module Name should be like folder name or your online repo's URL

import (
    "gitee.com/sylixos/go-vsoa/client"
    "gitee.com/sylixos/go-vsoa/server"
    "gitee.com/sylixos/go-vsoa/position"
    "gitee.com/sylixos/go-vsoa/protocol"
)

# Support

The following shows vsoa package APIs available.

# VOSA Server package

NewServer(name string, so Option) *Server

• name {string} Server Name.
• opt {Option} Server option configuration.
• Returns: {*Server} VSOA Server struct instance.

To create a VSOA server, name should not be empty string, otherwise it will be set as default string "default GO-VSOA server name".

If the server requires a connection password, opt needs to contain the following member:

• Password {string} Connection password. Optional.

If the server requires TLS encryption to secure the communication connection, opt needs to contain the following member:

• TLSConfig {*tls.Config} Optional.

Example

s := server.NewServer("golang VSOA RPC server", server.Option{})

# VSOA Server Struct

• Name {string} Used for ServInfo.

The VSOA Server Struct is responsible for the entire lifecycle of go-vsoa. It's has On/OnDatagram/OnDatagramDefault/Publish/QuickPublish methods to add processing callbacks for different services.

Close() (err error)

• Returns: err {error} if err == nil means success.

Close VSOA server.

Count() (count int)

• Returns: count {int} Those without successful password verification will also be counted.

Get the number of connected clients.

Serve(address string) (err error)

• address {string} should be like "IP:Port".
• Returns: err {error} if err == nil means success.

Start the server to serve clients, if the startup fails, returns an error. In general, you can run the server asynchronously in the background using a goroutine.

Examples

// blocking process
s.Serve("127.0.0.1:3001")

// asynchronously
go func() {
    _ = s.Serve("127.0.0.1:3001")
}()

On(servicePath string, serviceMethod protocol.RpcMessageType,handler func(*protocol.Message, *protocol.Message)) (err error)

• servicePath {string} Request URL.
• serviceMethod {protocol.RpcMessageType} Operation method.
• handler {func(*protocol.Message, *protocol.Message)} callback handler.
• Returns: err {error} if err == nil means success.

When a remote client generates an RPC request, the server will receive the corresponding request event, usually the event name is the requested URL matched.

Possible values of serviceMethod include protocol.RpcMethodGet (0) and protocol.RpcMethodSet (1).

The server can reply to RPC calls through the handler function.

Example

s := server.NewServer("golang VSOA RPC server", server.Option{})

// Echo payload
s.On("/echo", protocol.RpcMethodGet, func(req, res *protocol.Message) {
    res.Param = req.Param
    res.Data = req.Data
})

// Strictly match '/a/b/c' path
s.On("/a/b/c", protocol.RpcMethodGet, func(req, res *protocol.Message) {
    res.Param = req.Param
    res.Data = req.Data
})

// Match '/a/b/c' and '/a/b/c/...'
s.On("/a/b/c/", protocol.RpcMethodGet, func(req, res *protocol.Message) {
    res.Param = req.Param
    res.Data = req.Data
})

// Default match
s.On("/", protocol.RpcMethodGet, func(req, res *protocol.Message) {
    res.Param = req.Param
    res.Data = req.Data
})

// Delay echo
s.On("/delayecho", protocol.RpcMethodGet, func(req, res *protocol.Message) {
    // This won't block the server main loop
    time.Sleep(1*time.Second)
    res.Param = req.Param
    res.Data = req.Data
})

RPC URL match rules

NOTICE: If both "/a/b/c" and "/a/b/c/" RPC handler are present, When the client makes a "/a/b/c" RPC call, "/a/b/c" handler is matched before "/a/b/c/".

OnDatagram(servicePath string, handler func(*protocol.Message, *protocol.Message)) (err error)

• servicePath {string} Request URL.
• handler {func(*protocol.Message, *protocol.Message)} callback handler.
• Returns: err {error} if err == nil means success.

The DATAGRAM is another transfer type, usually this type data is used to transmit some data that does not require confirmation, for example, VSOA's DATAGRAM data packets can be used to build a VPN network.

When a remote client generates an DATAGRAM request, the server will receive the corresponding request event, usually the event name is the requested URL matched.

The server can handle to DATAGRAM calls through the handler function.

warning：the second param in handler() means nothing here

Example

s := server.NewServer("golang VSOA DATAGRAM server", server.Option{})

// read datagram
s.OnDatagram("/datagram", func(req, _ *protocol.Message) {
    fmt.Println(req.Param)
    fmt.Println(req.Data)
})

OnDatagramDefault(handler func(*protocol.Message, *protocol.Message)) (err error)

• handler {func(*protocol.Message, *protocol.Message)} callback handler.
• Returns: err {error} if err == nil means success.

When a remote client generates an DATAGRAM request, the server will receive the corresponding request event, when no match URL found even if in wildcard match, do the default callback handler.

The server can handle to DATAGRAM calls dafault through the handler function.

warning：the second param in handler() means nothing here

Example

s := server.NewServer("golang VSOA DATAGRAM server", server.Option{})

// read datagram
s.OnDatagramDefault(func(req, _ *protocol.Message) {
    fmt.Println(req.Param)
    fmt.Println(req.Data)
})

Publish(servicePath string, timeDriction time.Duration, pubs func(*protocol.Message, *protocol.Message)) (err error)

Publish a message, all clients subscribed to this URL will receive this message. The arguments of this function are as follows:

• servicePath {string} publisging URL.
• timeDriction {time.Duration} pusblish interval.
• handler {func(*protocol.Message, *protocol.Message)} publish callback handler.
• Returns: err {error} if err == nil means success.

URL matching: URL uses '/' as a separator, for example: '/a/b/c', if the client subscribes to '/a/', the server publish '/a', '/a/b' or '/ a/b/c' message, the client will be received.

Example

s := server.NewServer("golang VSOA PUBLISH server", server.Option{})

s.Publish("/publisher", 1*time.Second, func(req, _ *protocol.Message) {
    req.Param, _ = json.RawMessage(`{"publish":"go-vsoa-Publishing"}`).MarshalJSON()
})

QuickPublish(servicePath string, timeDriction time.Duration, pubs func(*protocol.Message, *protocol.Message)) (err error)

QuickPublish is similar to Publish func, but in quick channel.

If a large number of high-frequency publish are required and delivery is not guaranteed, quick publish can be used. But the quick type publish cannot traverse a NAT network, so the quick publish interface is not allowed in a NAT network. quick publish uses a different channel than publish, quick publish does not guarantee the order of arrival.

• servicePath {string} publisging URL.
• timeDriction {time.Duration} pusblish interval.
• handler {func(*protocol.Message, *protocol.Message)} publish callback handler.
• Returns: err {error} if err == nil means success.

URL matching: URL uses '/' as a separator, for example: '/a/b/c', if the client subscribes to '/a/', the server publish '/a', '/a/b' or '/ a/b/c' message, the client will be received.

Example

s := server.NewServer("golang VSOA PUBLISH server", server.Option{})

s.QuickPublish("/publisher/quick", 1*time.Second, func(req, _ *protocol.Message) {
    req.Param, _ = json.RawMessage(`{"publish":"go-vsoa-Publishing in quick channel"}`).MarshalJSON()
})

NewServerStream(res *protocol.Message) (ss *ServerStream, err error)

Create a stream to wait for the client stream to connect, this ServerStream struct is using when transfer streams.

• res {*protocol.Message} put an empty res for transfer tunnid automatic.
• Returns: ss {*ServerStream} ServerStream struct instance to start ss.ServeListener.
• Returns: err {error} if err == nil means success.

Example

// Create a new server instance
s := server.NewServer("golang VSOA stream server", server.Option{})

// Register URL and handler function
h := func(req, res *protocol.Message) {
    // Create a new server stream
    ss, _ := s.NewServerStream(res)

    // Prepare push and receive buffers
    pushBuf := bytes.NewBufferString("Golang VSOA stream server push Message")
    receiveBuf := bytes.NewBufferString("")

    // Start serving the server stream in a goroutine
    go func() {
      ss.ServeListener(pushBuf, receiveBuf)
      fmt.Println("stream server receiveBuf:", receiveBuf.String())
    }()
}
s.On("/read", protocol.RpcMethodGet, h)

# VOSA Client package

NewClient(option Option) *Client

• option {Option} Client option configuration.
• Returns: {*Client} VSOA Client struct instance.

If the server requires a connection password, opt needs to contain the following member:

• Password {string} Connection password. Optional.

option can also contain the following members:

• pingInterval {int} Ping interval time, must be greater than 2 (*time.Second). Optional.
• pingTimeout {int} Ping timeout, must be less than pingInterval default: half of pingInterval. Optional.
• pingLost {uint} How many consecutive ping timeouts will drop the connection. default: 3. Optional.
• ConnectTimeout {time.Duration} timeout for low level connection. default: 5*time.Second. Optional.

If the server requires TLS encryption to secure the communication connection, opt needs to contain the following member:

• TLSConfig {*tls.Config} Optional.

c := client.NewClient(client.Option{Password: "123456"})

# VSOA Client Struct

• Conn {net.Conn} Normal RPC/Datagram/Subs/UnSubs goes TCP.
• QConn {*net.UDPConn} Quick Datagram/Publish goes UDPs.
• SubscribeList {map[string]func(m *protocol.Message)} used for server publish.

The VSOA Client Struct is responsible for the entire lifecycle of go-vsoa. It's has Connect/Go/Call/Subscribe/UnSubscribe methods to processing connections or calls to VSOA server.

Connect(vsoa_or_VSOA_URL, address_or_URL string) (ServerInfo string, err error)

• vsoa_or_VSOA_URL {string} using VSOA_URL or not.
• address_or_URL {string} server URL or IP:PORT address.
• Returns: ServerInfo {string} server name.
• Returns: err {error} if err == nil means success.

Possible values of network include client.Type_URL (VSOA_URL) and other strings for IPV4 or IPV6 + port address.

Examples

// Connect to the VSOA server in IP:PORT mode
servInfo, err := c.Connect("vsoa", "127.0.0.1:3001")
if err != nil {
    fmt.Println(err)
} else {
    fmt.Println(servInfo)
}

var vsoa_test_server_url = "vsoa://vsoa_test_server"

err := c.SetPosition("127.0.0.1:6001")
if err != nil {
    fmt.Println(err)
    return
}
// Connect to the VSOA server in VSOA_URL mode
servInfo, err := c.Connect(client.Type_URL, vsoa_test_server_url)
if err != nil {
    fmt.Println(err)
} else {
    fmt.Println(servInfo)
}

Go(URL string, mt protocol.MessageType, flags any, req *protocol.Message, reply *protocol.Message, done chan *Call) *Call

Go method for client is call server asynchronously.

When go a RPC call all params is needed.

• URL {string} should be servicePath.
• mt {protocol.MessageType} should be protocol.TypeRPC.
• flags {any} should be protocal.RpcMethodGet or protocal.RpcMethodSet.
• req {*protocol.Message} should be whole request message.
• reply {*protocol.Message} should be init for save server reply's message.
• Returns: {*Call} for golang to select to finish this call.

Example

req1 := protocol.NewMessage()
req2 := protocol.NewMessage()
reply1 := protocol.NewMessage()
reply2 := protocol.NewMessage()

// Send the first RPC request ("/light") asynchronously and get the channel for waiting the response
Call1 := c.Go("/light", protocol.TypeRPC, protocol.RpcMethodGet, req1, reply1, nil).Done

// Send the second RPC request ("/light") asynchronously and get the channel for waiting the response
Call2 := c.Go("/light", protocol.TypeRPC, protocol.RpcMethodGet, req2, reply2, nil).Done

// Wait for the responses of both RPC calls and log the results using the logAsyncCall function
for i := 0; i < 2; i++ {
    select {
    case call := <-Call1:
        logAsyncCall(call)
    case call := <-Call2:
        logAsyncCall(call)
    }
}

func logAsyncCall(call *client.Call) {
    if call.Error != nil {
        fmt.Println("Error:", call.Error)
        return
    }
    reply := call.Reply
    fmt.Println("Seq:", reply.SeqNo())
}

When go a DATAGRAM call all params is needed.

• URL {string} should be servicePath.
• mt {protocol.MessageType} should be protocol.TypeDatagram.
• flags {any} should be protocal.ChannelQuick or protocal.ChannelNormal.
• req {*protocol.Message} should be whole request message.
• reply {*protocol.Message} should be init for save server reply's message.
• Returns: {*Call} for golang to select to finish this call.

Call(URL string, mt protocol.MessageType, flags any, req *protocol.Message) (*protocol.Message, error)

Call method for client is call server asynchronously.

When calling a RPC call all params is needed.

• URL {string} should be servicePath.
• mt {protocol.MessageType} should be protocol.TypeRPC.
• flags {any} should be protocal.RpcMethodGet or protocal.RpcMethodSet.
• req {*protocol.Message} should be whole request message.
• Returns: {*protocol.Message} for server save server reply's message.
• Returns: {error} if there is no error it should be nil.

Example

req := protocol.NewMessage()
req.Param, _ = json.RawMessage(`{"Test Num":123}`).MarshalJSON()
reply, err = c.Call("/a/b/c", protocol.TypeRPC, protocol.RpcMethodGet, req)
if err != nil {
    if err == strErr(protocol.StatusText(protocol.StatusInvalidUrl)) {
        fmt.Println("Pass: Invalid URL")
    } else {
        fmt.Println(err)
    }
} else {
    fmt.Println("Seq:", reply.SeqNo(), "Param:", reply.Param)
}

When calling a DATAGRAM call all params is needed.

• URL {string} should be servicePath.
• mt {protocol.MessageType} should be protocol.TypeDatagram.
• flags {any} should be protocal.ChannelQuick or protocal.ChannelNormal.
• req {*protocol.Message} should be whole request message.
• Returns: {*protocol.Message} is always empty .
• Returns: {error} if there is no error it should be nil.

Example

req := protocol.NewMessage()
req.Param, _ = json.RawMessage(`{"Test Num":123}`).MarshalJSON()
_, err = c.Call("/datagram", protocol.TypeDatagram, protocol.ChannelNormal, req)
if err != nil {
    fmt.Println(err)
} else {
    fmt.Println("Datagram send done")
}

Subscribe(URL string, onPublish func(m *protocol.Message)) error

• URL {string} should be publishPath.
• onPublish {func(*protocol.Message)} callback handler.
• Returns: {error} if there is no error it should be nil.

Subscribe to the specified event (URL), when the server sends the corresponding event, the Client can receive the event.

url indicates the event, VSOA event matching is prefix matching, for example, when the client subscribes to the '/a/b/' event, then the '/a/b' or '/a/b/c' event can be received.

Example

err = c.Subscribe("/light", func(pubs *protocol.Message) {
    fmt.Println(pubs.Param, pubs.Data)
})
if err != nil {
    fmt.Println(err)
}

Subscribe URL match rules

UnSubscribe(URL string) error

• URL {string} should be publishPath.
• Returns: {error} if there is no error it should be nil.

Unsubscribe the specified event. If Unsubscribe's URL ends with /, it will Unsubscribe all sub URLs.

This API calls UnSlot automatically

StartRegulator(interval time.Duration) error

• interval {time.Duration} should be greater than 1ms.
• Returns: {error} if there is no error it should be nil.

VSOA regulator provides the function of changing the speed of client subscription data. For example, the server publish period is 100ms, and the regulator can slow down the speed to receive once every 1000ms.

One client only allows have one regulator in lifetime. User can change interval by calling StopRegulator than StartRegulator with new interval.

StopRegulator() error

• Returns: {error} if there is no error it should be nil.

Stop VSOA regulator. The regulator can be restart by calling StartRegulator API again.

*Slot(URL string, onPublish func(m protocol.Message)) error

• URL {string} should be publishPath.
• onPublish {func(*protocol.Message)} callback handler.
• Returns: {error} if there is no error it should be nil.

Slot to the specified event (URL), when the server sends the corresponding event, the Client can receive the event in regulator sampling interval.

url indicates the event, VSOA event matching is prefix matching, for example, when the client subscribes to the '/a/b/' event, then the '/a/b' or '/a/b/c' event can be received.

UnSlot(URL string) error

• URL {string} should be publishPath.
• Returns: {error} if there is no error it should be nil.

UnSlot the specified event. If UnSlot's URL ends with /, it will UnSlot all slots' URLs.

NewClientStream(tunid uint16) (cs *ClientStream, err error)

Create a stream to wait to connet the server stream tunnel, this ClientStream struct is using when transfer streams.

• tunid {uint16} we need to get stream tunnel id form server.
• Returns: cs {*ClientStream} ClientStream struct instance to start ss.ServeListener.
• Returns: err {error} shoud be nil when its success.

Example

req := protocol.NewMessage()

// Send a request to the server using the "/read" method
reply, err := c.Call("/read", protocol.TypeRPC, protocol.RpcMethodGet, req)
if err != nil {
// Check if the error is due to an invalid URL
    if err == errors.New(protocol.StatusText(protocol.StatusInvalidUrl)) {
        fmt.Println("Pass: Invalid URL")
    } else {
        fmt.Println(err)
    }
    return
} else {
    StreamTunID = reply.TunID()
    fmt.Println("Seq:", reply.SeqNo(), "Stream TunID:", StreamTunID)
}

receiveBuf := bytes.NewBufferString("")

// Create a new client stream
cs, err := c.NewClientStream(StreamTunID)
if err != nil {
    fmt.Println(err)
    return
} else {
    go func() {
        buf := make([]byte, 32*1024)
        for {
            n, err := cs.Read(buf)
            if err != nil {
            // EOF means stream closed
            if err == io.EOF {
                break
            } else {
                fmt.Println(err)
            break
            }
        }
        receiveBuf.Write(buf[:n])
        fmt.Println("stream receiveBuf:", receiveBuf.String())

        // Add data to push back to server
        receiveBuf.WriteString(" received & push back to server")
        // Push data back to stream server
        cs.Write(receiveBuf.Bytes())

        // In this example, we just receive little data from server, so we just stop here
        goto STOP
}

STOP:
    cs.StopClientStream()
        streamDone <- 1
    }()
}
// Don't close the stream util the stream goroutine is done
<-streamDone

IsAuthed() bool

• Returns: {bool} when you call Connect methoud without error, it returns true otherwise false.

IsClosing() bool

• Returns: {bool} Check if client is during closing progress.

IsShutdown() bool

• Returns: {bool} Check if client is closed.

# VSOA position package

VSOA Position Server provides the function of querying VSOA server address by service name, similar to DNS server.

NewPositionList() *PositionList

• Returns: *{PositionList} to hold server url dns.

NewPosition(name string, domain int, ip string, port int, security bool) *Position

• name {string} VSOA server name. Must set! for position server to lookup.
• domain {int} Address domain. Refer to tcp or socket module.
• ip {string} Server IP Address.
• port {int} Server Port.
• Security {bool} Server using TLS or not. default: false

# VSOA PositionList struct

Add(p Position)

• p {Position} the server position you want to add to position server.

Add adds a Position to the PositionList. It updates the PositionList if the Position already exists. If Position.IP is not a valid IP address, it does nothing.

Remove(p Position)

• name {string} the name of the server position you want to remove from position server.

Remove removes an element from the PositionList based on the provided name.

ServePositionListener(address net.UDPAddr) (err error)

• address {net.UDPAddr} position address.
• Returns: err {error}* if err == nil means success.

Example

// startPosition initializes a new position list and adds a new position to it.
// It then starts a position listener in a separate goroutine.
func startPosition() {
    // Create a new position list
    pl := position.NewPositionList()

    // Add a new position to the list
    pl.Add(*position.NewPosition("vsoa_test_server", 1, "127.0.0.1", 3001, false))

    // Start a position listener in a separate goroutine
    go pl.ServePositionListener(net.UDPAddr{
        IP:   net.ParseIP("127.0.0.1"),
        Port: 6001,
    })
}

LookUp(name string, position_addr string, timeout time.Duration) (err error)

• name {string} the name to look up.
• position_addr {string} the address of the position server.
• timeout {time.Duration} the duration to wait for the lookup operation to complete or timeout.
• Returns: err {error}* if err == nil means success.

When you call Connect in the Client, it will automatically invoke the LookUp method here. Of course, you can also call it manually for other purposes, such as checking if the IP of a known server name has changed.

Example

p := new(position.Position)
err := p.LookUp(address_or_URL, client.position, 500*time.Millisecond)
if err != nil {
    fmt.Println(err)
} else {
    fmt.Println(p)
}

# VSOA protocol package

This package has all methods you need about VSOA protocol.

NewMessage() *Message

NewMessage returns a new instance of the Message struct.

• Returns: {*Message} new instance of the Message struct.

Example

req := protocol.NewMessage()

TypeText(code MessageType) string

• code {MessageType} should be like above.
• Returns: {string} code in string like TYPE_SERVINFO.

StatusText(code StatusType) string

• code {StatusType} should be like above.
• Returns: {string} code in string like Password error.

You can also define your own status code. The user-defined failure value is recommended to be 128 ~ 254.

# VSOA Header Struct

MessageType() MessageType

• Returns: {MessageType} this Header's MessageType.

MessageTypeText() string

• Returns: {string} the text representation of the message type.

Version() byte

• Returns: {byte} version of the message.

MessageRpcMethod() RpcMessageTyp

• Returns: {RpcMessageTyp} the RPC method, returns 0xEE if it's not an RPC message of VSOA.

MessageRpcMethodText() string

• Returns: {string} the text representation of the RPC method.

StatusType() StatusType

• Returns: {StatusType} the status type of the message.

You can also define your own status code. The user-defined failure value is recommended to be 128 ~ 254.

StatusTypeText() string

• Returns: {string} the text representation of the status type.

SeqNo() uint32

• Returns: {uint32} the sequence number of the message.

For each RPC, this is a very important information to ensure the integrity of RPC transaction, because the RPC can be invoked in parallel asynchronously.

TunID() uint16

• Returns: {uint16} port number.

the tunnel ID of the active stream tunnel port or Client quick channel port.

IsOneway() bool

• Returns: {bool} whether the message is a one-way(DATAGRAM/PUBLISH) message.

IsRPC() bool

• Returns: {bool} whether the message is an RPC message.

IsReply() bool

• Returns: {bool} whether the message is a reply message.

IsPingEcho() bool

• Returns: {bool} whether the message is a Ping Echo message.

IsServInfo() bool

• Returns: {bool} whether the message is a service info message.

User will not using it.

IsSubscribe() bool

• Returns: {bool} whether the message is a subscribe message.

IsUnSubscribe() bool

• Returns: {bool} whether the message is an unsubscribe message.

IsValidTunid() bool

• Returns: {bool} whether the Header is a valid Tunid.

SetMessageType(mt MessageType)

• mt {MessageType} the VSOA message type of the message.

SetMessageRpcMethod(t RpcMessageType)

• t {RpcMessageType} the VSOA RPC method of the message.

SetReply(r bool)

• r {bool} sets the reply flag.

User will not using it.

SetSeqNo(seq uint32)

• seq {uint32} sets the sequence number.

User will not using it.

SetTunId(ti uint16)

• ti {uint16} sets the tunnel ID of the VSOA client.

User will not using it.

SetValidTunid()

sets a valid Tunid.

User will not using it.

SetPingEcho()

sets the type flag to PingEcho.

User will not using it.

# VSOA Message Struct

• _ {*Header} To have Header struct methods.
• URL {[]byte} We call it URL but it more likely to be the server PATH for rpcx users.
• Param {json.RawMessage} It's []byte but have Marshal & UnMarshal method.
• Data {[]byte} Raw data in VSOA message.

The VSOA Message Struct is holding Header's method & has all information like URL, Param, Data.

Param should be a Marshaled json.

Clone() *Message

Clone clones from an message.

• Returns: {*Message} new instance of the Message struct cloned the origin one.

Example

req := protocol.NewMessage()
reqClone := req.Clone()

Reset()

Reset clean data of this message but keep allocated data.

Example

req := protocol.NewMessage()
req.Reset()