DMAC/working_server/coordinator.go

package server

import (
    "fmt"
    "sync"
    "log"
)

// this package creates coordinators responsible for keeping track of active clients and invoking managers

type Coordinator struct {
    Type string // ["reactor","tui"]
    IncomingClients <-chan *Client
    *Managers
    Err chan error
}

type Managers struct {
    Directory map[uint32](chan<- bool)
    sync.Mutex
}

func NewCoordinator(t string,ch chan *Client, err chan error) *Coordinator {
    d := make(map[uint32](chan<- bool))
    m := &Managers{Directory:d}
    c := &Coordinator{Type: t,IncomingClients: ch,Err:err}
    c.Managers = m
    return c
}

func FindNewManager(c *Client,ch chan bool, err chan error) {
    switch c.Type {
    case "reactor":
        NewReactorManager(c,ch,err)
    case "tui":
        NewTUIManager(c,ch,err)
    default:
        log.Fatal(fmt.Sprintf("ERROR %v NOT FOUND",c.Type))
    }
}

func (c *Coordinator) Start() {
    // on start we need to create channel listener
    // on each new connection we want to check its id against our mapping
    go c.Listen()
}

func (c *Coordinator) Listen() {
    for {
        cl := <-c.IncomingClients
        go c.ClientHandler(cl)
    }
}

func (c *Coordinator) ClientHandler(cl *Client) {
    // (creates and) notifies manager of client connection
    c.Managers.Lock()
    defer c.Managers.Unlock()
    if m, exists := c.Managers.Directory[cl.Id]; exists {
        // manager in memory
        m <-true
    } else {
        // create channel and manager
        ch := make(chan bool)
        FindNewManager(cl, ch,c.Err)
        c.Managers.Directory[cl.Id] = ch
        // will block until manager is ready
        ch <-true
    }
}