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package main
import (
"encoding/json"
"log"
"net"
"sync"
)
func handleConnection(conn net.Conn) {
defer conn.Close()
// 1 мегабайт
var maxBodySize uint32 = 1048576
maxAuthAttempts := 5
authAttempts := 0
authenticated := false
buf := make([]byte, 4096)
for {
if authAttempts >= maxAuthAttempts {
resp, _ := json.Marshal(Response{
Status: FAILURE,
Data: "Превышено количество неавторизованных запросов",
})
_ = sendMessage(conn, resp)
break
}
_, err := conn.Read(buf)
if err != nil {
break
}
size := fromBytes(buf[:4])
if size > maxBodySize {
resp, _ := json.Marshal(Response{
Status: FAILURE,
Data: "Превышен максимальный размер запроса",
})
_ = sendMessage(conn, resp)
break
}
rawMessage := buf[4 : size+4]
message := parseMessage(rawMessage)
if message.Type == AUTHENTICATE {
// TODO(andrew): Добавить процесс аутентификации
if true {
authenticated = true
resp, _ := json.Marshal(Response{
Status: SUCCESS,
Data: "Аутентификация прошла успешно",
})
_ = sendMessage(conn, resp)
} else {
resp, _ := json.Marshal(Response{
Status: FAILURE,
Data: "При аутентификации произошла ошибка",
})
_ = sendMessage(conn, resp)
}
continue
}
if !authenticated {
resp, _ := json.Marshal(Response{
Status: FAILURE,
Data: "Для работы с сервером необходима аутентификация",
})
err = sendMessage(conn, resp)
if err != nil {
break
}
authAttempts += 1
continue
}
if message.Data == "exit" {
break
}
resp, _ := json.Marshal(Response{
Status: SUCCESS,
Data: "some data",
})
err = sendMessage(conn, resp)
if err != nil {
break
}
}
}
func reader(c chan Message) {
const maxMessages uint64 = 1024
var count uint64 = 0
for {
data := <-c
received.Lock()
if count >= maxMessages {
received.data = []Message{data}
received.messageShift += maxMessages
} else {
received.data = append(received.data, data)
count += 1
}
received.Unlock()
}
}
func handleSender(conn net.Conn) {
received.Lock()
lastIndex := received.messageShift
received.Unlock()
for {
var message Message
received.Lock()
idx := lastIndex - received.messageShift
if idx <= uint64(len(received.data)) {
message = received.data[idx]
}
received.Lock()
resp, _ := json.Marshal(Response{
Status: SUCCESS,
Data: message.serialize(),
})
_ = sendMessage(conn, resp)
}
}
var received struct {
sync.Mutex
data []Message
messageShift uint64
}
func main() {
var wg sync.WaitGroup
c := make(chan Message)
go reader(c)
sock, err := net.Listen("tcp", "localhost:8080")
handleError(err)
defer sock.Close()
wg.Add(1)
go func(sock net.Listener) {
for {
conn, err := sock.Accept()
if err == nil {
go handleConnection(conn)
} else {
break
}
}
wg.Done()
}(sock)
senderSock, err := net.Listen("tcp", "localhost:8081")
handleError(err)
defer senderSock.Close()
wg.Add(1)
go func(sock net.Listener) {
for {
conn, err := sock.Accept()
if err == nil {
go handleSender(conn)
} else {
break
}
}
wg.Done()
}(senderSock)
wg.Wait()
}
func handleError(err error) {
if err != nil {
log.Fatal(err)
}
}
|
