// Announce generates and triggers a tracker announces request
func Announce(tracker TorrentTracker, user data.UserRecord, query url.Values) []byte {
// Store announce information in struct
announce := new(data.AnnounceLog)
err := announce.FromValues(query)
if err != nil {
return tracker.Error("Malformed announce")
}
// Request to store announce
go func(announce *data.AnnounceLog) {
if err := announce.Save(); err != nil {
log.Println(err.Error())
}
}(announce)
// Only report event when needed
event := ""
if announce.Event != "" {
event = announce.Event + " "
}
log.Printf("announce: [%s %s:%d] %s%s", tracker.Protocol(), announce.IP, announce.Port, event, announce.InfoHash)
// Check for a matching file via info_hash
file, err := new(data.FileRecord).Load(announce.InfoHash, "info_hash")
if err != nil {
log.Println(err.Error())
return tracker.Error(ErrAnnounceFailure.Error())
}
// Torrent is currently unregistered
if file == (data.FileRecord{}) {
log.Printf("tracker: detected new file, awaiting manual approval [hash: %s]", announce.InfoHash)
// Create an entry in file table for this hash, but mark it as unverified
file.InfoHash = announce.InfoHash
file.Verified = false
// Save file asynchronously
go func(file data.FileRecord) {
if err := file.Save(); err != nil {
log.Println(err.Error())
}
}(file)
// Report error
return tracker.Error("Unregistered torrent")
}
// Ensure file is verified, meaning we will permit tracking of it
if !file.Verified {
return tracker.Error("Unverified torrent")
}
// Launch peer reaper asynchronously to remove old peers from this file
go func(file data.FileRecord) {
// Start peer reaper
count, err := file.PeerReaper()
if err != nil {
log.Println(err.Error())
}
// Report peers reaped
if count > 0 {
log.Println("peerReaper: reaped %d peers on file ID: %d", count, file.ID)
}
}(file)
// If UDP tracker, we cannot reliably detect user, so we announce anonymously
if _, ok := tracker.(UDPTracker); ok {
return tracker.Announce(query, file)
}
// Check existing record for this user with this file and this IP
fileUser, err := new(data.FileUserRecord).Load(file.ID, user.ID, query.Get("ip"))
if err != nil {
log.Println(err.Error())
return tracker.Error(ErrAnnounceFailure.Error())
}
// New user, starting torrent
if fileUser == (data.FileUserRecord{}) {
// Create new relationship
fileUser.FileID = file.ID
fileUser.UserID = user.ID
fileUser.IP = query.Get("ip")
fileUser.Active = true
fileUser.Announced = 1
// If announce reports 0 left, but no existing record, user is probably the initial seeder
if announce.Left == 0 {
fileUser.Completed = true
} else {
fileUser.Completed = false
}
// Track the initial uploaded, download, and left values
// NOTE: clients report absolute values, so delta should NEVER be calculated for these
fileUser.Uploaded = announce.Uploaded
fileUser.Downloaded = announce.Downloaded
fileUser.Left = announce.Left
} else {
// Else, pre-existing record, so update
// Event "stopped", mark as inactive
// NOTE: likely only reported by clients which are actively seeding, NOT when stopped during leeching
if announce.Event == "stopped" {
fileUser.Active = false
} else {
// Else, "started", "completed", or no status, mark as active
fileUser.Active = true
}
// Check for completion
// Could be from a peer stating completed, or a seed reporting 0 left
if announce.Event == "completed" || announce.Left == 0 {
fileUser.Completed = true
} else {
fileUser.Completed = false
}
// Add an announce
fileUser.Announced = fileUser.Announced + 1
// Store latest statistics, but do so in a sane way (no removing upload/download, no adding left)
// NOTE: clients report absolute values, so delta should NEVER be calculated for these
// NOTE: It is also worth noting that if a client re-downloads a file they have previously downloaded,
// but the data.FileUserRecord relationship is not cleared, they will essentially get a "free" download, with
// no extra download penalty to their share ratio
// For the time being, this behavior will be expected and acceptable
if announce.Uploaded > fileUser.Uploaded {
fileUser.Uploaded = announce.Uploaded
}
if announce.Downloaded > fileUser.Downloaded {
fileUser.Downloaded = announce.Downloaded
}
if announce.Left < fileUser.Left {
fileUser.Left = announce.Left
}
}
// Update file/user relationship record asynchronously
go func(fileUser data.FileUserRecord) {
if err := fileUser.Save(); err != nil {
log.Println(err.Error())
}
}(fileUser)
// Create announce
return tracker.Announce(query, file)
}