v0.1.0-alpha

Changes:
- Implement bootstrapping library for managing several concurrent internal services
- Refactor concurrency model for connections/logical clients and their associated I/O
- Refactor server context singleton
- Refactor error handling
    - Most errors are now gracefully sent to the FSD client directly encoded as an $ER packet,
      enhancing visibility and debugging
    - Most errors are now rightfully treated as non-fatal
- Refactor package/dependency graph
- Refactor calling conventions/interfaces for many packages
- Refactor database package
- Refactor post office

Features:
- Add VATSIM-esque HTTP/JSON "data feed"
- Add ephemeral in-memory database option
- Add user management REST API
- Add improved web interface
- Add MySQL support (drop SQLite support)

bootstrap/service/datafeed.go

@@ -0,0 +1,191 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"github.com/renorris/openfsd/postoffice"
+	"github.com/renorris/openfsd/protocol"
+	"github.com/renorris/openfsd/servercontext"
+	"log"
+	"time"
+)
+
+// DataFeedService polls the server post office every 15 seconds and
+// generates a JSON string representing the server state. Conventionally,
+// this file is obtained via the HTTP endpoint at /data/openfsd-data.json
+type DataFeedService struct{}
+
+type general struct {
+	Version          int       `json:"version"`           // Major version of the data feed
+	UpdateTimestamp  time.Time `json:"update_timestamp"`  // The last time the data feed was updated
+	ConnectedClients int       `json:"connected_clients"` // Number of clients connected
+	UniqueUsers      int       `json:"unique_users"`      // Number of unique users connected
+}
+
+type pilot struct {
+	Callsign    string               `json:"callsign"`
+	CID         int                  `json:"cid"`
+	Name        string               `json:"name"`
+	PilotRating protocol.PilotRating `json:"pilot_rating"`
+	Latitude    float64              `json:"latitude"`
+	Longitude   float64              `json:"longitude"`
+	Altitude    int                  `json:"altitude"`
+	Groundspeed int                  `json:"groundspeed"`
+	Transponder string               `json:"transponder"`
+	Heading     int                  `json:"heading"`      // Degrees magnetic
+	LastUpdated time.Time            `json:"last_updated"` // The time this pilot's information was last updated
+}
+
+type controllerRating struct {
+	ID        protocol.NetworkRating `json:"id"`         // Controller NetworkRating ID
+	ShortName string                 `json:"short_name"` // Short identifier
+	LongName  string                 `json:"long_name"`  // Human-readable long name
+}
+
+type pilotRating struct {
+	ID        protocol.PilotRating `json:"id"`         // pilot NetworkRating ID
+	ShortName string               `json:"short_name"` // Short identifier
+	LongName  string               `json:"long_name"`  // Human-readable long name
+}
+
+type schema struct {
+	General      general            `json:"general"`
+	Pilots       []pilot            `json:"pilots"`
+	Ratings      []controllerRating `json:"ratings"`
+	PilotRatings []pilotRating      `json:"pilot_ratings"`
+}
+
+func (s *DataFeedService) Start(ctx context.Context, doneErr chan<- error) (err error) {
+
+	readySig := make(chan struct{})
+
+	// boot data feed service on its own goroutine
+	go func() {
+		doneErr <- s.boot(ctx, readySig)
+	}()
+
+	// Wait for the ready signal
+	<-readySig
+	log.Println("Data feed service running.")
+
+	return nil
+}
+
+func (s *DataFeedService) boot(ctx context.Context, readySig chan struct{}) error {
+
+	// Run a tick first
+	if err := s.tick(); err != nil {
+		close(readySig)
+		return err
+	}
+
+	close(readySig)
+
+	ticker := time.NewTicker(15 * time.Second)
+	defer ticker.Stop()
+
+	// Loop until context close. On tick, update the feed.
+	for {
+		select {
+		case <-ctx.Done():
+			return nil
+		case <-ticker.C:
+			if err := s.tick(); err != nil {
+				return err
+			}
+		}
+	}
+}
+
+func (s *DataFeedService) tick() error {
+	// Load all pilot data from post office
+	numRegistered := servercontext.PostOffice().NumRegistered()
+	pilots := make([]pilot, 0, numRegistered+32)
+
+	uniqueCIDs := make(map[int]*interface{}, numRegistered+32)
+
+	servercontext.PostOffice().ForEachRegistered(func(name string, address postoffice.Address) bool {
+		state := address.State()
+
+		// Build pilot data
+		p := pilot{
+			Callsign:    name,
+			CID:         state.CID,
+			Name:        state.RealName,
+			PilotRating: state.PilotRating,
+			Latitude:    state.Latitude,
+			Longitude:   state.Longitude,
+			Altitude:    state.Altitude,
+			Groundspeed: state.Groundspeed,
+			Transponder: state.Transponder,
+			Heading:     state.Heading,
+			LastUpdated: state.LastUpdated.UTC(),
+		}
+
+		// Append it to the list
+		pilots = append(pilots, p)
+
+		// Add this CID to the unique CID list
+		uniqueCIDs[state.CID] = nil
+
+		return true
+	})
+
+	// Build the data feed
+	feed := schema{
+		General: general{
+			Version:          0,
+			UpdateTimestamp:  time.Now().UTC(),
+			ConnectedClients: len(pilots),
+			UniqueUsers:      len(uniqueCIDs),
+		},
+		Pilots:       pilots,
+		Ratings:      s.makeControllerRatingList(),
+		PilotRatings: s.makePilotRatingsList(),
+	}
+
+	return s.setFeed(feed)
+}
+
+func (s *DataFeedService) setFeed(feed schema) (err error) {
+
+	// Marshal result
+	var feedBytes []byte
+	if feedBytes, err = json.Marshal(feed); err != nil {
+		return err
+	}
+
+	// Set the new feed
+	d := servercontext.DataFeed()
+	d.SetFeed(string(feedBytes), feed.General.UpdateTimestamp)
+
+	return nil
+}
+
+func (s *DataFeedService) makeControllerRatingList() (ratings []controllerRating) {
+	ratings = make([]controllerRating, 0, 14)
+
+	protocol.ForEachNetworkRating(func(id protocol.NetworkRating, shortString string, longString string) {
+		ratings = append(ratings, controllerRating{
+			ID:        id,
+			ShortName: shortString,
+			LongName:  longString,
+		})
+	})
+
+	return ratings
+}
+
+func (s *DataFeedService) makePilotRatingsList() (ratings []pilotRating) {
+	ratings = make([]pilotRating, 0, 7)
+
+	protocol.ForEachPilotRating(func(id protocol.PilotRating, shortString string, longString string) {
+		ratings = append(ratings, pilotRating{
+			ID:        id,
+			ShortName: shortString,
+			LongName:  longString,
+		})
+	})
+
+	return ratings
+}