// PollDirectory will poll a git repo.
// It will look for changes to branches and tags including creation and
// deletion.
func PollDirectory(l log.Logger, dirName string, repo Repo, changes chan GitChange, period time.Duration) {
l.Info("Watching %s as %s\n", repo, dirName)
defer l.Info("Stopped watching %s as %s\n", repo, dirName)
prev := make(map[string]*GitChange) // last seen ref status
// Every poll period, get the list of branches.
// For those seen before, fill in previous and currect SHA in change. Remove
// from prev set.
// For those that are new, fill in data.
// For remaining entries in prev set, these are deleted. Send them with
// current as empty.
for firstAttempt := true; ; firstAttempt = false {
var (
next = make(map[string]*GitChange) // currently seen refs, becomes prev set
branches []*GitChange // working set of branches
err error
)
// run cmd every period, except on the first try
if !firstAttempt {
time.Sleep(period)
}
if branches, err = repo.Branches(); err != nil {
l.Critical("Cannot get branch list for %s: %s", repo, err)
continue
}
for _, branch := range branches {
if strings.HasPrefix(branch.RefName, "gitsync-") {
continue
}
var (
old, seenBefore = prev[branch.RefName]
existsAndChanged = seenBefore && (old.Current != branch.Current || old.CheckedOut != branch.CheckedOut)
)
branch.RepoName = path.Base(dirName)
next[branch.RefName] = branch
if existsAndChanged {
branch.Prev = old.Current
}
// share changes and new branches
if !seenBefore || existsAndChanged {
l.Info("sending local change for %s %+v", repo, branch)
changes <- *branch
}
// Cleanup any branch we have seen before, and handled above
if seenBefore {
delete(prev, branch.RefName)
}
}
// report remaining branches in prev as deleted
// Note: Use the prev set object since we have no current one to play with
for _, old := range prev {
old.Prev = old.Current
old.Current = ""
old.CheckedOut = false
l.Info("sending local delete for %s %+v", repo, old)
changes <- *old
}
prev = next
}
}
// NetIO shares GitChanges on toNet with the network via a multicast group. It
// will pass on GitChanges from the network via fromNet. It uniques the daemon
// instance by changing the .Name member to be name@<host IP>/<original .Name)
func NetIO(l log.Logger, repo Repo, addr *net.UDPAddr, fromNet, toNet chan GitChange) {
var (
err error
recvConn, sendConn *net.UDPConn // UDP connections to allow us to send and receive change updates
)
l.Info("Joining %v multicast(%t) group", addr, addr.IP.IsMulticast())
if recvConn, sendConn, err = establishConnPair(addr); err != nil {
l.Critical("Error joining listening: %s\n", addr, err)
return
}
l.Info("Successfully joined %v multicast(%t) group", addr, addr.IP.IsMulticast())
defer recvConn.Close()
defer sendConn.Close()
hostIp := sendConn.LocalAddr().(*net.UDPAddr).IP.String()
term := false
defer func() { term = true }()
rawFromNet := make(chan []byte, 128)
go func() {
for !term {
b := make([]byte, 1024)
if n, err := recvConn.Read(b); err != nil {
l.Critical("Cannot read socket: %s", err)
continue
} else {
rawFromNet <- b[:n]
}
}
}()
for {
select {
case req, ok := <-toNet:
if !ok {
return
}
req.User = repo.User()
req.HostIp = hostIp
l.Info("Sending %+v", req)
buf := &bytes.Buffer{}
enc := gob.NewEncoder(buf)
if err := enc.Encode(req); err != nil {
l.Critical("%s", err)
continue
}
l.Fine("Sending %+v", buf.Bytes())
if _, err := sendConn.Write(buf.Bytes()); err != nil {
l.Critical("%s", err)
continue
}
case resp := <-rawFromNet:
var change GitChange
dec := gob.NewDecoder(bytes.NewReader(resp))
if err := dec.Decode(&change); err != nil {
l.Critical("%s", err)
continue
} else {
l.Debug("received %+v", change)
}
if rootCommit, err := repo.RootCommit(); err != nil {
log.Critical("Error getting root commit")
} else {
if (repo.User() != change.User) && (rootCommit == change.RootCommit) {
fromNet <- change
}
}
}
}
}