Swift-SocketServer端粘包处理

仅提供示例，因为每个项目对应的socket消息通讯协议几乎都是不同的，我这里每条消息的消息头占3个字节，其中第2、3字节是消息体长度(不包含消息头，大端模式)

import UIKit
import CocoaAsyncSocket

private class WSClientDataProt {
    
    var ip = ""
    
    private let queue = OperationQueue()
    private var operation: BlockOperation?
    private var tcpCacheData = Data()
    
    func unpackMsg(data: Data){
        let operation = BlockOperation { [weak self] in
            guard let strongSelf = self else { return }
            strongSelf.tcpCacheData.append(data)
            while !strongSelf.tcpCacheData.isEmpty {
                var lc: UInt16 = 0
                guard strongSelf.tcpCacheData.count >= 3 else { break }
                (strongSelf.tcpCacheData as NSData).getBytes(&lc, range: NSMakeRange(1, 2))
                let len = Int(UInt16(bigEndian: lc)) + 3
                guard let body = strongSelf.tcpCacheData.getSubData(start: 0, count: len) else { break }
                if currntAppMode == .microPhone{
                    WSMicroManager.shared.dealMicroData(data: body)
                }else{
                    WSCameraManager.shared.dealCameraData(data: body)
//                    print("摄像机端收到数据：\(body.hexString())")
                }
                strongSelf.removeCacheData(start: 0, num: len)
            }
        }
        if let op = self.operation {
            operation.addDependency(op)
        }
        queue.addOperation(operation)
        self.operation = operation
    }
    
    private func removeCacheData(start: Int, num: Int){
        guard start >= 0 && num >= 0 else { return }
        guard tcpCacheData.count >= start + num else { return }
        let startIndex = tcpCacheData.index(tcpCacheData.startIndex, offsetBy: start)
        let endIndex = tcpCacheData.index(tcpCacheData.startIndex, offsetBy: start + num)
        let range = startIndex..<endIndex
        tcpCacheData.removeSubrange(range)
    }
}

class WSSocketDataManager: NSObject {
    
    static let shared = WSSocketDataManager()
    private override init() { }
    
    private var clientDataDic = [String:WSClientDataProt]()
    
    func didReceiveData(data: Data, TCPSock: GCDAsyncSocket? = nil){
        //tcp
        if let sock = TCPSock {
            guard let add = sock.connectedHost else { return }
            if let client = clientDataDic[add] {
                client.unpackMsg(data: data)
            }else{
                let clientData = WSClientDataProt()
                clientData.ip = add
                clientDataDic[add] = clientData
                clientData.unpackMsg(data: data)
            }
        }
        //udp
        else{
            if currntAppMode == .microPhone{
                WSMicroManager.shared.dealMicroData(data: data)
            }else{
                WSCameraManager.shared.dealCameraData(data: data)
            }
        }
    }
    //socket断开时调用
    func removeSocketData(sock: GCDAsyncSocket){
        guard let add = sock.connectedHost else { return }
        clientDataDic.removeValue(forKey: add)
    }
    
}