func createPath(path string, data []byte, client *zk.Conn) error {
exists, _, err := client.Exists(path)
if err != nil {
return err
}
if exists {
return nil
}
name := "/"
p := strings.Split(path, "/")
for _, v := range p[1 : len(p)-1] {
name += v
e, _, _ := client.Exists(name)
if !e {
_, err = client.Create(name, []byte{}, int32(0), zk.WorldACL(zk.PermAll))
if err != nil {
return err
}
}
name += "/"
}
_, err = client.Create(path, data, int32(0), zk.WorldACL(zk.PermAll))
return err
}
func ensurePathExists(conn *zk.Conn, path string) error {
pathExists, _, _ := conn.Exists(path)
if pathExists {
return nil
}
_, err := conn.Create(path, []byte{}, 0, defaultACL())
if err != nil {
return err
}
return nil
}
func zk_write(k string, v string, c *zk.Conn) {
e, stat, err := c.Exists(k)
check(err)
if e {
stat, err = c.Set(k, []byte(v), stat.Version)
check(err)
} else {
string, err := c.Create(k, []byte(v), int32(0), zk.WorldACL(zk.PermAll))
if string == "" {
check(err)
}
}
}
func createOrSet(zkConn *zk.Conn, path string, data []byte, flags int32, acl []zk.ACL) error {
exists, _, err := zkConn.Exists(path)
if err != nil {
return err
}
if exists {
_, err = zkConn.Set(path, data, -1)
} else {
err = createRecursively(zkConn, path, data, flags, acl)
}
return err
}
func ListenToConn(c *zk.Conn, path string, deb bool, repDelay time.Duration) (chan zk.Event, chan bool) {
exists, _, err := c.Exists(path)
if err != nil {
logger.Fatalf("Couldn't determine whether node %v exists in Zookeeper", path)
}
if !exists {
logger.Printf("Node '%v' does not exist in Zookeeper, creating...", path)
err := zkNodeCreateByPath(path, c)
if err != nil {
logger.Fatalf("Unable to create path '%v': %v", path, err)
}
}
quit := make(chan bool)
evts := make(chan zk.Event)
go pollZooKeeper(c, path, evts, quit)
if deb {
evts = debounce(evts, 100*time.Millisecond)
}
if repDelay > 0 {
evts = delay(evts, repDelay)
}
return evts, quit
}
// NewElection initializes a new instance of a Election that can later be used to request
// leadership for a specific resource.
//
// It accepts:
// zkConn - a connection to a running Zookeeper instance
// resource - the resource for which leadership is being requested
//
// It will return either a non-nil Election instance and a nil error, or a nil
// Election and a non-nil error.
//
func NewElection(zkConn *zk.Conn, electionNode string) (Election, error) {
//TODO: what should flags and acl be set to?
flags := int32(0)
acl := zk.WorldACL(zk.PermAll)
exists, _, _ := zkConn.Exists(electionNode)
var (
path string
err error
)
if !exists {
path, err = zkConn.Create(electionNode, []byte("data"), flags, acl)
must(err)
fmt.Printf("created: %+v\n", path)
}
return Election{electionNode, Candidate{}, false, zkConn, nil}, nil
}
func checkPath(conn *zk.Conn, path string) {
exists, _, err := conn.Exists(path)
if exists {
if path == "/" {
path = os.Getenv("ZK_BASE")
if path == "" {
path = zkBase
}
_, err := conn.Create(path, []byte{}, flags, acl)
check(err)
}
return
}
checkPath(conn, filepath.Dir(path))
_, err = conn.Create(path, []byte{}, flags, acl)
check(err)
return
}
func mkdirs(conn *zk.Conn, path string) (err error) {
if path == "" {
return errors.New("path should not been empty")
}
if path == "/" {
return nil
}
if path[0] != '/' {
return errors.New("path must start with /")
}
//check whether this path exists
exist, _, err := conn.Exists(path)
if exist {
return nil
}
flags := int32(0)
acl := zk.WorldACL(zk.PermAll)
_, err = conn.Create(path, []byte(""), flags, acl)
if err == nil { //created successfully
return
}
//create parent
paths := strings.Split(path[1:], "/")
createdPath := ""
for _, p := range paths {
createdPath = createdPath + "/" + p
exist, _, _ = conn.Exists(createdPath)
if !exist {
_, err = conn.Create(createdPath, []byte(""), flags, acl)
if err != nil {
return
}
}
}
return nil
}
// Tries to create the configuration path, if it doesn't exist
// It tries multiple times in case there's a race with another quotaservice node coming up
func createPath(conn *zk.Conn, path string) (err error) {
for i := 0; i < createRetries; i++ {
exists, _, err := conn.Exists(path)
if exists && err == nil {
return nil
}
_, err = conn.Create(path, []byte{}, 0, zk.WorldACL(zk.PermAll))
if err == nil {
return nil
}
logging.Printf("Could not create zk path, sleeping for 100ms")
time.Sleep(100 * time.Millisecond)
}
if err == nil {
err = errors.New("could not create and get path " + path)
}
return err
}
func zkCreateNodes(path string, nodes []string, c *zk.Conn) error {
if len(nodes) > 0 {
// strings.Split will return empty-strings for leading split chars, lets skip over these.
if len(nodes[0]) == 0 {
return zkCreateNodes(path, nodes[1:], c)
}
fqPath := path + "/" + nodes[0]
log.Printf("Creating path: %v", fqPath)
exists, _, err := c.Exists(fqPath)
if err != nil {
return err
}
if !exists {
_, err := c.Create(fqPath, []byte{}, 0, zk.WorldACL(zk.PermAll))
if err != nil {
return err
}
}
return zkCreateNodes(fqPath, nodes[1:], c)
}
return nil
}
func resolveRecursive(zconn zookeeper.Conn, parts []string, toplevel bool) ([]string, error) {
for i, part := range parts {
if HasWildcard(part) {
var children []string
zkParentPath := strings.Join(parts[:i], "/")
var err error
children, _, err = zconn.Children(zkParentPath)
if err != nil {
// we asked for something like
// /zk/cell/aaa/* and
// /zk/cell/aaa doesn't exist
// -> return empty list, no error
// (note we check both a regular zk
// error and the error the test
// produces)
if ZkErrorEqual(err, zookeeper.ErrNoNode) {
return nil, nil
}
// otherwise we return the error
return nil, err
}
sort.Strings(children)
results := make([][]string, len(children))
wg := &sync.WaitGroup{}
mu := &sync.Mutex{}
var firstError error
for j, child := range children {
matched, err := path.Match(part, child)
if err != nil {
return nil, err
}
if matched {
// we have a match!
wg.Add(1)
newParts := make([]string, len(parts))
copy(newParts, parts)
newParts[i] = child
go func(j int) {
defer wg.Done()
subResult, err := resolveRecursive(zconn, newParts, false)
if err != nil {
mu.Lock()
if firstError != nil {
log.Infof("Multiple error: %v", err)
} else {
firstError = err
}
mu.Unlock()
} else {
results[j] = subResult
}
}(j)
}
}
wg.Wait()
if firstError != nil {
return nil, firstError
}
result := make([]string, 0, 32)
for j := 0; j < len(children); j++ {
subResult := results[j]
if subResult != nil {
result = append(result, subResult...)
}
}
// we found a part that is a wildcard, we
// added the children already, we're done
return result, nil
}
}
// no part contains a wildcard, add the path if it exists, and done
path := strings.Join(parts, "/")
if toplevel {
// for whatever the user typed at the toplevel, we don't
// check it exists or not, we just return it
return []string{path}, nil
}
// this is an expanded path, we need to check if it exists
_, stat, err := zconn.Exists(path)
if err != nil {
return nil, err
}
if stat != nil {
return []string{path}, nil
}
return nil, nil
}
