package main import ( "bufio" "encoding/csv" "errors" "fmt" "log" "math/rand" "os" "path/filepath" "strconv" "strings" "sync" "time" "github.com/dirtbags/moth/pkg/award" "github.com/spf13/afero" ) // DistinguishableChars are visually unambiguous glyphs. // People with mediocre handwriting could write these down unambiguously, // and they can be entered without holding down shift. const DistinguishableChars = "34678abcdefhikmnpqrtwxy=" // RFC3339Space is a time layout which replaces 'T' with a space. // This is also a valid RFC3339 format. const RFC3339Space = "2006-01-02 15:04:05Z07:00" // ErrAlreadyRegistered means a team cannot be registered because it was registered previously. var ErrAlreadyRegistered = errors.New("team ID has already been registered") // State defines the current state of a MOTH instance. // We use the filesystem for synchronization between threads. // The only thing State methods need to know is the path to the state directory. type State struct { afero.Fs // Enabled tracks whether the current State system is processing updates Enabled bool refreshNow chan bool eventStream chan []string eventWriter *csv.Writer eventWriterFile afero.File // Caches, so we're not hammering NFS with metadata operations teamNames map[string]string pointsLog award.List messages string teamIDLock sync.RWMutex teamIDFileLock sync.RWMutex teamNameLock sync.RWMutex teamNameFileLock sync.RWMutex pointsLock sync.RWMutex pointsLogFileLock sync.RWMutex // Sometimes, we need to fiddle with the file, while leaving the internal state alone messageFileLock sync.RWMutex teamNamesLastChange time.Time } // NewState returns a new State struct backed by the given Fs func NewState(fs afero.Fs) *State { s := &State{ Fs: fs, Enabled: true, refreshNow: make(chan bool, 5), eventStream: make(chan []string, 80), teamNames: make(map[string]string), } if err := s.reopenEventLog(); err != nil { log.Fatal(err) } return s } // updateEnabled checks a few things to see if this state directory is "enabled". func (s *State) updateEnabled() { nextEnabled := true why := "`state/enabled` present, `state/hours.txt` missing" if untilFile, err := s.Open("hours.txt"); err == nil { defer untilFile.Close() why = "`state/hours.txt` present" scanner := bufio.NewScanner(untilFile) for scanner.Scan() { line := scanner.Text() if len(line) < 1 { continue } thisEnabled := true switch line[0] { case '+': thisEnabled = true line = line[1:] case '-': thisEnabled = false line = line[1:] case '#': continue default: log.Println("Misformatted line in hours.txt file") } line = strings.TrimSpace(line) until, err := time.Parse(time.RFC3339, line) if err != nil { until, err = time.Parse(RFC3339Space, line) } if err != nil { log.Println("Suspended: Unparseable until date:", line) continue } if until.Before(time.Now()) { nextEnabled = thisEnabled } } } if _, err := s.Stat("enabled"); os.IsNotExist(err) { nextEnabled = false why = "`state/enabled` missing" } if nextEnabled != s.Enabled { s.Enabled = nextEnabled log.Printf("Setting enabled=%v: %s", s.Enabled, why) if s.Enabled { s.LogEvent("enabled", "", "", "", 0, why) } else { s.LogEvent("disabled", "", "", "", 0, why) } } } /* ****************** Team ID functions ****************** */ func (s *State) TeamIDs() ([]string, error) { var teamIDs []string s.teamIDFileLock.RLock() defer s.teamIDFileLock.RUnlock() idsFile, err := s.Open("teamids.txt") if err != nil { return teamIDs, fmt.Errorf("team IDs file does not exist") } defer idsFile.Close() scanner := bufio.NewScanner(idsFile) for scanner.Scan() { teamIDs = append(teamIDs, scanner.Text()) } return teamIDs, nil } func (s *State) writeTeamIDs(teamIDs []string) error { s.teamIDFileLock.Lock() defer s.teamIDFileLock.Unlock() if f, err := s.OpenFile("teamids.txt", os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0644); err == nil { defer f.Close() for _, teamID := range teamIDs { fmt.Fprintln(f, string(teamID)) } } else { return err } return nil } func (s *State) SetTeamIDs(teamIDs []string) error { s.teamIDLock.Lock() defer s.teamIDLock.Unlock() return s.writeTeamIDs(teamIDs) } func (s *State) AddTeamID(newTeamID string) error { s.teamIDLock.Lock() defer s.teamIDLock.Unlock() teamIDs, err := s.TeamIDs() if err != nil { return err } for _, teamID := range teamIDs { if newTeamID == teamID { return fmt.Errorf("Team ID already exists") } } teamIDs = append(teamIDs, newTeamID) return s.writeTeamIDs(teamIDs) } func (s *State) RemoveTeamID(removeTeamID string) error { s.teamIDLock.Lock() defer s.teamIDLock.Unlock() teamIDs, err := s.TeamIDs() if err != nil { return err } for _, teamID := range teamIDs { if removeTeamID != teamID { teamIDs = append(teamIDs, teamID) } } return s.writeTeamIDs(teamIDs) } func (s *State) TeamIDExists(teamID string) (bool, error) { s.teamIDLock.RLock() defer s.teamIDLock.RUnlock() teamIDs, err := s.TeamIDs() if err != nil { return false, err } for _, candidateTeamID := range teamIDs { if teamID == candidateTeamID { return true, nil } } return false, nil } /* ********************* Team Name functions ********* */ // TeamName returns team name given a team ID. func (s *State) TeamName(teamID string) (string, error) { s.teamNameLock.RLock() defer s.teamNameLock.RUnlock() name, ok := s.teamNames[teamID] if !ok { return "", fmt.Errorf("unregistered team ID: %s", teamID) } return name, nil } func (s *State) TeamNames() map[string]string { s.teamNameLock.RLock() defer s.teamNameLock.RUnlock() return s.teamNames } // SetTeamName writes out team name. // This can only be done once per team. func (s *State) SetTeamName(teamID, teamName string) error { s.teamNameFileLock.Lock() defer s.teamNameFileLock.Unlock() teamIDs, err := s.TeamIDs() if err != nil { return err } found := false for _, validTeamID := range teamIDs { if validTeamID == teamID { found = true break } } if !found { return fmt.Errorf("team ID not found in list of valid team IDs") } s.teamNameLock.RLock() _, ok := s.teamNames[teamID] s.teamNameLock.RUnlock() if ok { return ErrAlreadyRegistered } teamFilename := filepath.Join("teams", teamID) teamFile, err := s.Fs.OpenFile(teamFilename, os.O_CREATE|os.O_WRONLY|os.O_EXCL, 0644) if os.IsExist(err) { // This shouldn't ever hit, since we just checked, but strange things happen return ErrAlreadyRegistered } else if err != nil { return err } defer teamFile.Close() log.Printf("Setting team name [%s] in file %s", teamName, teamFilename) fmt.Fprintln(teamFile, teamName) teamFile.Close() s.refreshNow <- true return nil } func (s *State) SetTeamNames(teams map[string]string) error { return s.writeTeamNames(teams) } func (s *State) TeamIDFromName(teamName string) (string, error) { for name, id := range s.TeamNames() { if name == teamName { return id, nil } } return "", fmt.Errorf("team name not found") } func (s *State) DeleteTeamName(teamID string) error { newTeams := s.TeamNames() _, ok := newTeams[teamID]; if ok { delete(newTeams, teamID) } else { return fmt.Errorf("team not found") } return s.writeTeamNames(newTeams) } func (s *State) writeTeamNames(teams map[string]string) error { s.teamNameFileLock.Lock() defer s.teamNameFileLock.Unlock() s.RemoveAll("teams") s.Mkdir("teams", 0755) // Write out all of the new team names for teamID, teamName := range teams { teamFilename := filepath.Join("teams", teamID) teamFile, err := s.Fs.OpenFile(teamFilename, os.O_CREATE|os.O_WRONLY|os.O_EXCL, 0644) if err != nil { return err } defer teamFile.Close() log.Printf("Setting team name [%s] in file %s", teamName, teamFilename) fmt.Fprintln(teamFile, teamName) teamFile.Close() } s.refreshNow <- true return nil } /* **************** Point log functions ************ */ // PointsLog retrieves the current points log. func (s *State) PointsLog() award.List { s.pointsLock.RLock() ret := make(award.List, len(s.pointsLog)) copy(ret, s.pointsLog) s.pointsLock.RUnlock() return ret } // AwardPoints gives points to teamID in category. // This doesn't attempt to ensure the teamID has been registered. // It first checks to make sure these are not duplicate points. // This is not a perfect check, you can trigger a race condition here. // It's just a courtesy to the user. // The update task makes sure we never have duplicate points in the log. func (s *State) AwardPoints(teamID, category string, points int) error { return s.awardPointsAtTime(time.Now().Unix(), teamID, category, points) } func (s *State) AwardPointsAtTime(teamID, category string, points int, when int64) error { return s.awardPointsAtTime(when, teamID, category, points) } func (s *State) awardPointsAtTime(when int64, teamID string, category string, points int) error { a := award.T{ When: when, TeamID: teamID, Category: category, Points: points, } for _, e := range s.PointsLog() { if a.Equal(e) { return fmt.Errorf("points already awarded to this team in this category") } } //fn := fmt.Sprintf("%s-%s-%d", a.TeamID, a.Category, a.Points) fn := a.Filename() tmpfn := filepath.Join("points.tmp", fn) newfn := filepath.Join("points.new", fn) if err := afero.WriteFile(s, tmpfn, []byte(a.String()), 0644); err != nil { return err } if err := s.Rename(tmpfn, newfn); err != nil { return err } // State should be updated immediately s.refreshNow <- true return nil } func (s *State) PointExists(teamID string, cat string, points int) bool { s.pointsLock.RLock() defer s.pointsLock.RUnlock() for _, pointEntry := range s.pointsLog { if (pointEntry.TeamID == teamID) && (pointEntry.Category == cat) && (pointEntry.Points == points) { return true } } return false } func (s *State) PointExistsAtTime(teamID string, cat string, points int, when int64) bool { s.pointsLock.RLock() defer s.pointsLock.RUnlock() for _, pointEntry := range s.pointsLog { if (pointEntry.TeamID == teamID) && (pointEntry.Category == cat) && (pointEntry.Points == points) && (pointEntry.When == when) { return true } if (pointEntry.When > when) { // Since the points log is sorted, we can bail out earlier, if we see that current points are from later than our event return false } } return false } func (s *State) flushPointsLog(newPoints award.List) error { s.pointsLogFileLock.Lock() defer s.pointsLogFileLock.Unlock() logf, err := s.OpenFile("points.log", os.O_CREATE|os.O_WRONLY, 0644) defer logf.Close() if err != nil { return fmt.Errorf("Can't write to points log: %s", err) } for _, pointEntry := range newPoints { fmt.Fprintln(logf, pointEntry.String()) } return nil } func (s *State) RemovePoints(teamID string, cat string, points int) error { s.pointsLock.Lock() defer s.pointsLock.Unlock() var newPoints award.List removed := false for _, pointEntry := range s.pointsLog { if (pointEntry.TeamID == teamID) && (pointEntry.Category == cat) && (pointEntry.Points == points) { removed = true } else { newPoints = append(newPoints, pointEntry) } } if (! removed) { return fmt.Errorf("Unable to find matching point entry") } err := s.flushPointsLog(newPoints) if err != nil { return err } s.refreshNow <- true return nil } func (s *State) RemovePointsAtTime(teamID string, cat string, points int, when int64) error { s.pointsLock.Lock() defer s.pointsLock.Unlock() var newPoints award.List removed := false for _, pointEntry := range s.pointsLog { if (pointEntry.TeamID == teamID) && (pointEntry.Category == cat) && (pointEntry.Points == points) && (pointEntry.When == when) { removed = true } else { newPoints = append(newPoints, pointEntry) } } if (! removed) { return fmt.Errorf("Unable to find matching point entry") } err := s.flushPointsLog(newPoints) if err != nil { return err } s.refreshNow <- true return nil } func (s *State) SetPoints(newPoints award.List) error { err := s.flushPointsLog(newPoints) if err != nil { return err } s.refreshNow <- true return nil } // collectPoints gathers up files in points.new/ and appends their contents to points.log, // removing each points.new/ file as it goes. func (s *State) collectPoints() { files, err := afero.ReadDir(s, "points.new") if err != nil { log.Print(err) return } for _, f := range files { filename := filepath.Join("points.new", f.Name()) awardstr, err := afero.ReadFile(s, filename) if err != nil { log.Print("Opening new points: ", err) continue } awd, err := award.Parse(string(awardstr)) if err != nil { log.Print("Can't parse award file ", filename, ": ", err) continue } duplicate := false s.pointsLock.RLock() for _, e := range s.pointsLog { if awd.Equal(e) { duplicate = true break } } s.pointsLock.RUnlock() if duplicate { log.Print("Skipping duplicate points: ", awd.String()) } else { log.Print("Award: ", awd.String()) { s.pointsLogFileLock.Lock() logf, err := s.OpenFile("points.log", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644) if err != nil { log.Print("Can't append to points log: ", err) s.pointsLogFileLock.Unlock() return } fmt.Fprintln(logf, awd.String()) logf.Close() s.pointsLogFileLock.Unlock() } // Stick this on the cache too s.pointsLock.Lock() s.pointsLog = append(s.pointsLog, awd) s.pointsLock.Unlock() } if err := s.Remove(filename); err != nil { log.Print("Unable to remove new points file: ", err) } } } /* ******************* Message functions *********** */ // Messages retrieves the current messages. func (s *State) Messages() string { return s.messages } // SetMessages sets the current message func (s *State) SetMessages(message string) error { s.messageFileLock.Lock() defer s.messageFileLock.Unlock() err := afero.WriteFile(s, "messages.html", []byte(message), 0600) s.refreshNow <- true return err } /* ***************** Other utilitity functions ******* */ func (s *State) maybeInitialize() { // Are we supposed to re-initialize? if _, err := s.Stat("initialized"); !os.IsNotExist(err) { return } now := time.Now().UTC().Format(time.RFC3339) log.Print("initialized file missing, re-initializing") // Remove any extant control and state files s.Remove("enabled") s.Remove("hours.txt") s.pointsLogFileLock.Lock() s.Remove("points.log") s.pointsLogFileLock.Unlock() s.Remove("events.csv") s.messageFileLock.Lock() s.Remove("messages.html") s.messageFileLock.Unlock() s.Remove("mothd.log") s.RemoveAll("points.tmp") s.RemoveAll("points.new") s.teamNameFileLock.Lock() s.RemoveAll("teams") s.Mkdir("teams", 0755) s.teamNameFileLock.Unlock() // Open log file if err := s.reopenEventLog(); err != nil { log.Fatal(err) } s.LogEvent("init", "", "", "", 0) // Make sure various subdirectories exist s.Mkdir("points.tmp", 0755) s.Mkdir("points.new", 0755) // Preseed available team ids if file doesn't exist var teamIDs []string id := make([]byte, 8) for i := 0; i < 100; i++ { for i := range id { char := rand.Intn(len(DistinguishableChars)) id[i] = DistinguishableChars[char] } teamIDs = append(teamIDs, string(id)) } s.SetTeamIDs(teamIDs) // Create some files if f, err := s.Create("initialized"); err == nil { fmt.Fprintln(f, "initialized: remove to re-initialize the contest.") fmt.Fprintln(f) fmt.Fprintln(f, "This instance was initialized at", now) f.Close() } if f, err := s.Create("enabled"); err == nil { fmt.Fprintln(f, "enabled: remove or rename to suspend the contest.") f.Close() } if f, err := s.Create("hours.txt"); err == nil { fmt.Fprintln(f, "# hours.txt: when the contest is enabled") fmt.Fprintln(f, "#") fmt.Fprintln(f, "# Enable: + timestamp") fmt.Fprintln(f, "# Disable: - timestamp") fmt.Fprintln(f, "#") fmt.Fprintln(f, "# You can have multiple start/stop times.") fmt.Fprintln(f, "# Whatever time is the most recent, wins.") fmt.Fprintln(f, "# Times in the future are ignored.") fmt.Fprintln(f) fmt.Fprintln(f, "+", now) fmt.Fprintln(f, "- 2519-10-31T00:00:00Z") f.Close() } s.messageFileLock.Lock() if f, err := s.Create("messages.html"); err == nil { fmt.Fprintln(f, "") f.Close() } s.messageFileLock.Unlock() if f, err := s.Create("points.log"); err == nil { f.Close() } } // LogEvent writes to the event log func (s *State) LogEvent(event, participantID, teamID, cat string, points int, extra ...string) { s.eventStream <- append( []string{ strconv.FormatInt(time.Now().Unix(), 10), event, participantID, teamID, cat, strconv.Itoa(points), }, extra..., ) } func (s *State) reopenEventLog() error { if s.eventWriter != nil { s.eventWriter.Flush() } if s.eventWriterFile != nil { if err := s.eventWriterFile.Close(); err != nil { // We're going to soldier on if Close returns error log.Print(err) } } eventWriterFile, err := s.OpenFile("events.csv", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644) if err != nil { return err } s.eventWriterFile = eventWriterFile s.eventWriter = csv.NewWriter(s.eventWriterFile) return nil } func (s *State) updateCaches() { // Re-read the points log { s.pointsLogFileLock.RLock() defer s.pointsLogFileLock.RUnlock() if f, err := s.Open("points.log"); err != nil { log.Println(err) } else { defer f.Close() pointsLog := make(award.List, 0, 200) scanner := bufio.NewScanner(f) for scanner.Scan() { line := scanner.Text() cur, err := award.Parse(line) if err != nil { log.Printf("Skipping malformed award line %s: %s", line, err) continue } pointsLog = append(pointsLog, cur) } s.pointsLock.Lock() s.pointsLog = pointsLog s.pointsLock.Unlock() } } // Only do this if the teams directory has a newer mtime; directories with // hundreds of team names can cause NFS I/O storms { s.teamNameLock.Lock() defer s.teamNameLock.Unlock() s.teamNameFileLock.RLock() defer s.teamNameFileLock.RUnlock() _, ismmfs := s.Fs.(*afero.MemMapFs) // Tests run so quickly that the time check isn't precise enough if fi, err := s.Fs.Stat("teams"); err != nil { log.Printf("Getting modification time of teams directory: %v", err) } else if ismmfs || s.teamNamesLastChange.Before(fi.ModTime()) { s.teamNamesLastChange = fi.ModTime() // The compiler recognizes this as an optimization case for k := range s.teamNames { delete(s.teamNames, k) } teamsFs := afero.NewBasePathFs(s.Fs, "teams") if dirents, err := afero.ReadDir(teamsFs, "."); err != nil { log.Printf("Reading team ids: %v", err) } else { for _, dirent := range dirents { teamID := dirent.Name() if teamNameBytes, err := afero.ReadFile(teamsFs, teamID); err != nil { log.Printf("Reading team %s: %v", teamID, err) } else { teamName := strings.TrimSpace(string(teamNameBytes)) s.teamNames[teamID] = teamName } } } } } // Re-read the messages file { s.messageFileLock.RLock() defer s.messageFileLock.RUnlock() if bMessages, err := afero.ReadFile(s, "messages.html"); err == nil { s.messages = string(bMessages) } } } func (s *State) refresh() { s.maybeInitialize() s.updateEnabled() if s.Enabled { s.collectPoints() } s.updateCaches() } // Maintain performs housekeeping on a State struct. func (s *State) Maintain(updateInterval time.Duration) { ticker := time.NewTicker(updateInterval) s.refresh() for { select { case msg := <-s.eventStream: s.eventWriter.Write(msg) s.eventWriter.Flush() s.eventWriterFile.Sync() case <-ticker.C: s.refresh() case <-s.refreshNow: s.refresh() } } } // DevelState is a StateProvider for use by development servers type DevelState struct { StateProvider } // NewDevelState returns a new state object that can be used by the development server. // // The main thing this provides is the ability to register a team with any team ID. // If a team ID is provided that wasn't recognized by the underlying StateProvider, // it is associated with a team named "". // // This makes it possible to use the server without having to register a team. func NewDevelState(sp StateProvider) *DevelState { return &DevelState{sp} } // TeamName returns a valid team name for any teamID // // If one's registered, it will use it. // Otherwise, it returns "" func (ds *DevelState) TeamName(teamID string) (string, error) { if name, err := ds.StateProvider.TeamName(teamID); err == nil { return name, nil } return fmt.Sprintf("«devel:%s»", teamID), nil } // SetTeamName associates a team name with any teamID // // If the underlying StateProvider returns any sort of error, // this returns ErrAlreadyRegistered, // so the user can join a pre-existing team for whatever ID the provide. func (ds *DevelState) SetTeamName(teamID, teamName string) error { if err := ds.StateProvider.SetTeamName(teamID, teamName); err != nil { return ErrAlreadyRegistered } return nil }