Adding dep files and dependencies.

vendor/github.com/samuel/go-zookeeper/LICENSE

@@ -0,0 +1,25 @@
+Copyright (c) 2013, Samuel Stauffer <samuel@descolada.com>
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright
+  notice, this list of conditions and the following disclaimer.
+* Redistributions in binary form must reproduce the above copyright
+  notice, this list of conditions and the following disclaimer in the
+  documentation and/or other materials provided with the distribution.
+* Neither the name of the author nor the
+  names of its contributors may be used to endorse or promote products
+  derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/samuel/go-zookeeper/zk/constants.go

@@ -0,0 +1,240 @@
+package zk
+
+import (
+	"errors"
+)
+
+const (
+	protocolVersion = 0
+
+	DefaultPort = 2181
+)
+
+const (
+	opNotify       = 0
+	opCreate       = 1
+	opDelete       = 2
+	opExists       = 3
+	opGetData      = 4
+	opSetData      = 5
+	opGetAcl       = 6
+	opSetAcl       = 7
+	opGetChildren  = 8
+	opSync         = 9
+	opPing         = 11
+	opGetChildren2 = 12
+	opCheck        = 13
+	opMulti        = 14
+	opClose        = -11
+	opSetAuth      = 100
+	opSetWatches   = 101
+	opError        = -1
+	// Not in protocol, used internally
+	opWatcherEvent = -2
+)
+
+const (
+	EventNodeCreated         EventType = 1
+	EventNodeDeleted         EventType = 2
+	EventNodeDataChanged     EventType = 3
+	EventNodeChildrenChanged EventType = 4
+
+	EventSession     EventType = -1
+	EventNotWatching EventType = -2
+)
+
+var (
+	eventNames = map[EventType]string{
+		EventNodeCreated:         "EventNodeCreated",
+		EventNodeDeleted:         "EventNodeDeleted",
+		EventNodeDataChanged:     "EventNodeDataChanged",
+		EventNodeChildrenChanged: "EventNodeChildrenChanged",
+		EventSession:             "EventSession",
+		EventNotWatching:         "EventNotWatching",
+	}
+)
+
+const (
+	StateUnknown           State = -1
+	StateDisconnected      State = 0
+	StateConnecting        State = 1
+	StateAuthFailed        State = 4
+	StateConnectedReadOnly State = 5
+	StateSaslAuthenticated State = 6
+	StateExpired           State = -112
+
+	StateConnected  = State(100)
+	StateHasSession = State(101)
+)
+
+const (
+	FlagEphemeral = 1
+	FlagSequence  = 2
+)
+
+var (
+	stateNames = map[State]string{
+		StateUnknown:           "StateUnknown",
+		StateDisconnected:      "StateDisconnected",
+		StateConnectedReadOnly: "StateConnectedReadOnly",
+		StateSaslAuthenticated: "StateSaslAuthenticated",
+		StateExpired:           "StateExpired",
+		StateAuthFailed:        "StateAuthFailed",
+		StateConnecting:        "StateConnecting",
+		StateConnected:         "StateConnected",
+		StateHasSession:        "StateHasSession",
+	}
+)
+
+type State int32
+
+func (s State) String() string {
+	if name := stateNames[s]; name != "" {
+		return name
+	}
+	return "Unknown"
+}
+
+type ErrCode int32
+
+var (
+	ErrConnectionClosed        = errors.New("zk: connection closed")
+	ErrUnknown                 = errors.New("zk: unknown error")
+	ErrAPIError                = errors.New("zk: api error")
+	ErrNoNode                  = errors.New("zk: node does not exist")
+	ErrNoAuth                  = errors.New("zk: not authenticated")
+	ErrBadVersion              = errors.New("zk: version conflict")
+	ErrNoChildrenForEphemerals = errors.New("zk: ephemeral nodes may not have children")
+	ErrNodeExists              = errors.New("zk: node already exists")
+	ErrNotEmpty                = errors.New("zk: node has children")
+	ErrSessionExpired          = errors.New("zk: session has been expired by the server")
+	ErrInvalidACL              = errors.New("zk: invalid ACL specified")
+	ErrAuthFailed              = errors.New("zk: client authentication failed")
+	ErrClosing                 = errors.New("zk: zookeeper is closing")
+	ErrNothing                 = errors.New("zk: no server responsees to process")
+	ErrSessionMoved            = errors.New("zk: session moved to another server, so operation is ignored")
+
+	// ErrInvalidCallback         = errors.New("zk: invalid callback specified")
+	errCodeToError = map[ErrCode]error{
+		0:                          nil,
+		errAPIError:                ErrAPIError,
+		errNoNode:                  ErrNoNode,
+		errNoAuth:                  ErrNoAuth,
+		errBadVersion:              ErrBadVersion,
+		errNoChildrenForEphemerals: ErrNoChildrenForEphemerals,
+		errNodeExists:              ErrNodeExists,
+		errNotEmpty:                ErrNotEmpty,
+		errSessionExpired:          ErrSessionExpired,
+		// errInvalidCallback:         ErrInvalidCallback,
+		errInvalidAcl:   ErrInvalidACL,
+		errAuthFailed:   ErrAuthFailed,
+		errClosing:      ErrClosing,
+		errNothing:      ErrNothing,
+		errSessionMoved: ErrSessionMoved,
+	}
+)
+
+func (e ErrCode) toError() error {
+	if err, ok := errCodeToError[e]; ok {
+		return err
+	}
+	return ErrUnknown
+}
+
+const (
+	errOk = 0
+	// System and server-side errors
+	errSystemError          = -1
+	errRuntimeInconsistency = -2
+	errDataInconsistency    = -3
+	errConnectionLoss       = -4
+	errMarshallingError     = -5
+	errUnimplemented        = -6
+	errOperationTimeout     = -7
+	errBadArguments         = -8
+	errInvalidState         = -9
+	// API errors
+	errAPIError                ErrCode = -100
+	errNoNode                  ErrCode = -101 // *
+	errNoAuth                  ErrCode = -102
+	errBadVersion              ErrCode = -103 // *
+	errNoChildrenForEphemerals ErrCode = -108
+	errNodeExists              ErrCode = -110 // *
+	errNotEmpty                ErrCode = -111
+	errSessionExpired          ErrCode = -112
+	errInvalidCallback         ErrCode = -113
+	errInvalidAcl              ErrCode = -114
+	errAuthFailed              ErrCode = -115
+	errClosing                 ErrCode = -116
+	errNothing                 ErrCode = -117
+	errSessionMoved            ErrCode = -118
+)
+
+// Constants for ACL permissions
+const (
+	PermRead = 1 << iota
+	PermWrite
+	PermCreate
+	PermDelete
+	PermAdmin
+	PermAll = 0x1f
+)
+
+var (
+	emptyPassword = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+	opNames       = map[int32]string{
+		opNotify:       "notify",
+		opCreate:       "create",
+		opDelete:       "delete",
+		opExists:       "exists",
+		opGetData:      "getData",
+		opSetData:      "setData",
+		opGetAcl:       "getACL",
+		opSetAcl:       "setACL",
+		opGetChildren:  "getChildren",
+		opSync:         "sync",
+		opPing:         "ping",
+		opGetChildren2: "getChildren2",
+		opCheck:        "check",
+		opMulti:        "multi",
+		opClose:        "close",
+		opSetAuth:      "setAuth",
+		opSetWatches:   "setWatches",
+
+		opWatcherEvent: "watcherEvent",
+	}
+)
+
+type EventType int32
+
+func (t EventType) String() string {
+	if name := eventNames[t]; name != "" {
+		return name
+	}
+	return "Unknown"
+}
+
+// Mode is used to build custom server modes (leader|follower|standalone).
+type Mode uint8
+
+func (m Mode) String() string {
+	if name := modeNames[m]; name != "" {
+		return name
+	}
+	return "unknown"
+}
+
+const (
+	ModeUnknown    Mode = iota
+	ModeLeader     Mode = iota
+	ModeFollower   Mode = iota
+	ModeStandalone Mode = iota
+)
+
+var (
+	modeNames = map[Mode]string{
+		ModeLeader:     "leader",
+		ModeFollower:   "follower",
+		ModeStandalone: "standalone",
+	}
+)

vendor/github.com/samuel/go-zookeeper/zk/dnshostprovider.go

@@ -0,0 +1,88 @@
+package zk
+
+import (
+	"fmt"
+	"net"
+	"sync"
+)
+
+// DNSHostProvider is the default HostProvider. It currently matches
+// the Java StaticHostProvider, resolving hosts from DNS once during
+// the call to Init.  It could be easily extended to re-query DNS
+// periodically or if there is trouble connecting.
+type DNSHostProvider struct {
+	mu         sync.Mutex // Protects everything, so we can add asynchronous updates later.
+	servers    []string
+	curr       int
+	last       int
+	lookupHost func(string) ([]string, error) // Override of net.LookupHost, for testing.
+}
+
+// Init is called first, with the servers specified in the connection
+// string. It uses DNS to look up addresses for each server, then
+// shuffles them all together.
+func (hp *DNSHostProvider) Init(servers []string) error {
+	hp.mu.Lock()
+	defer hp.mu.Unlock()
+
+	lookupHost := hp.lookupHost
+	if lookupHost == nil {
+		lookupHost = net.LookupHost
+	}
+
+	found := []string{}
+	for _, server := range servers {
+		host, port, err := net.SplitHostPort(server)
+		if err != nil {
+			return err
+		}
+		addrs, err := lookupHost(host)
+		if err != nil {
+			return err
+		}
+		for _, addr := range addrs {
+			found = append(found, net.JoinHostPort(addr, port))
+		}
+	}
+
+	if len(found) == 0 {
+		return fmt.Errorf("No hosts found for addresses %q", servers)
+	}
+
+	// Randomize the order of the servers to avoid creating hotspots
+	stringShuffle(found)
+
+	hp.servers = found
+	hp.curr = -1
+	hp.last = -1
+
+	return nil
+}
+
+// Len returns the number of servers available
+func (hp *DNSHostProvider) Len() int {
+	hp.mu.Lock()
+	defer hp.mu.Unlock()
+	return len(hp.servers)
+}
+
+// Next returns the next server to connect to. retryStart will be true
+// if we've looped through all known servers without Connected() being
+// called.
+func (hp *DNSHostProvider) Next() (server string, retryStart bool) {
+	hp.mu.Lock()
+	defer hp.mu.Unlock()
+	hp.curr = (hp.curr + 1) % len(hp.servers)
+	retryStart = hp.curr == hp.last
+	if hp.last == -1 {
+		hp.last = 0
+	}
+	return hp.servers[hp.curr], retryStart
+}
+
+// Connected notifies the HostProvider of a successful connection.
+func (hp *DNSHostProvider) Connected() {
+	hp.mu.Lock()
+	defer hp.mu.Unlock()
+	hp.last = hp.curr
+}

vendor/github.com/samuel/go-zookeeper/zk/flw.go

@@ -0,0 +1,266 @@
+package zk
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// FLWSrvr is a FourLetterWord helper function. In particular, this function pulls the srvr output
+// from the zookeeper instances and parses the output. A slice of *ServerStats structs are returned
+// as well as a boolean value to indicate whether this function processed successfully.
+//
+// If the boolean value is false there was a problem. If the *ServerStats slice is empty or nil,
+// then the error happened before we started to obtain 'srvr' values. Otherwise, one of the
+// servers had an issue and the "Error" value in the struct should be inspected to determine
+// which server had the issue.
+func FLWSrvr(servers []string, timeout time.Duration) ([]*ServerStats, bool) {
+	// different parts of the regular expression that are required to parse the srvr output
+	const (
+		zrVer   = `^Zookeeper version: ([A-Za-z0-9\.\-]+), built on (\d\d/\d\d/\d\d\d\d \d\d:\d\d [A-Za-z0-9:\+\-]+)`
+		zrLat   = `^Latency min/avg/max: (\d+)/(\d+)/(\d+)`
+		zrNet   = `^Received: (\d+).*\n^Sent: (\d+).*\n^Connections: (\d+).*\n^Outstanding: (\d+)`
+		zrState = `^Zxid: (0x[A-Za-z0-9]+).*\n^Mode: (\w+).*\n^Node count: (\d+)`
+	)
+
+	// build the regex from the pieces above
+	re, err := regexp.Compile(fmt.Sprintf(`(?m:\A%v.*\n%v.*\n%v.*\n%v)`, zrVer, zrLat, zrNet, zrState))
+	if err != nil {
+		return nil, false
+	}
+
+	imOk := true
+	servers = FormatServers(servers)
+	ss := make([]*ServerStats, len(servers))
+
+	for i := range ss {
+		response, err := fourLetterWord(servers[i], "srvr", timeout)
+
+		if err != nil {
+			ss[i] = &ServerStats{Error: err}
+			imOk = false
+			continue
+		}
+
+		matches := re.FindAllStringSubmatch(string(response), -1)
+
+		if matches == nil {
+			err := fmt.Errorf("unable to parse fields from zookeeper response (no regex matches)")
+			ss[i] = &ServerStats{Error: err}
+			imOk = false
+			continue
+		}
+
+		match := matches[0][1:]
+
+		// determine current server
+		var srvrMode Mode
+		switch match[10] {
+		case "leader":
+			srvrMode = ModeLeader
+		case "follower":
+			srvrMode = ModeFollower
+		case "standalone":
+			srvrMode = ModeStandalone
+		default:
+			srvrMode = ModeUnknown
+		}
+
+		buildTime, err := time.Parse("01/02/2006 15:04 MST", match[1])
+
+		if err != nil {
+			ss[i] = &ServerStats{Error: err}
+			imOk = false
+			continue
+		}
+
+		parsedInt, err := strconv.ParseInt(match[9], 0, 64)
+
+		if err != nil {
+			ss[i] = &ServerStats{Error: err}
+			imOk = false
+			continue
+		}
+
+		// the ZxID value is an int64 with two int32s packed inside
+		// the high int32 is the epoch (i.e., number of leader elections)
+		// the low int32 is the counter
+		epoch := int32(parsedInt >> 32)
+		counter := int32(parsedInt & 0xFFFFFFFF)
+
+		// within the regex above, these values must be numerical
+		// so we can avoid useless checking of the error return value
+		minLatency, _ := strconv.ParseInt(match[2], 0, 64)
+		avgLatency, _ := strconv.ParseInt(match[3], 0, 64)
+		maxLatency, _ := strconv.ParseInt(match[4], 0, 64)
+		recv, _ := strconv.ParseInt(match[5], 0, 64)
+		sent, _ := strconv.ParseInt(match[6], 0, 64)
+		cons, _ := strconv.ParseInt(match[7], 0, 64)
+		outs, _ := strconv.ParseInt(match[8], 0, 64)
+		ncnt, _ := strconv.ParseInt(match[11], 0, 64)
+
+		ss[i] = &ServerStats{
+			Sent:        sent,
+			Received:    recv,
+			NodeCount:   ncnt,
+			MinLatency:  minLatency,
+			AvgLatency:  avgLatency,
+			MaxLatency:  maxLatency,
+			Connections: cons,
+			Outstanding: outs,
+			Epoch:       epoch,
+			Counter:     counter,
+			BuildTime:   buildTime,
+			Mode:        srvrMode,
+			Version:     match[0],
+		}
+	}
+
+	return ss, imOk
+}
+
+// FLWRuok is a FourLetterWord helper function. In particular, this function
+// pulls the ruok output from each server.
+func FLWRuok(servers []string, timeout time.Duration) []bool {
+	servers = FormatServers(servers)
+	oks := make([]bool, len(servers))
+
+	for i := range oks {
+		response, err := fourLetterWord(servers[i], "ruok", timeout)
+
+		if err != nil {
+			continue
+		}
+
+		if bytes.Equal(response[:4], []byte("imok")) {
+			oks[i] = true
+		}
+	}
+	return oks
+}
+
+// FLWCons is a FourLetterWord helper function. In particular, this function
+// pulls the ruok output from each server.
+//
+// As with FLWSrvr, the boolean value indicates whether one of the requests had
+// an issue. The Clients struct has an Error value that can be checked.
+func FLWCons(servers []string, timeout time.Duration) ([]*ServerClients, bool) {
+	const (
+		zrAddr = `^ /((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?):(?:\d+))\[\d+\]`
+		zrPac  = `\(queued=(\d+),recved=(\d+),sent=(\d+),sid=(0x[A-Za-z0-9]+),lop=(\w+),est=(\d+),to=(\d+),`
+		zrSesh = `lcxid=(0x[A-Za-z0-9]+),lzxid=(0x[A-Za-z0-9]+),lresp=(\d+),llat=(\d+),minlat=(\d+),avglat=(\d+),maxlat=(\d+)\)`
+	)
+
+	re, err := regexp.Compile(fmt.Sprintf("%v%v%v", zrAddr, zrPac, zrSesh))
+	if err != nil {
+		return nil, false
+	}
+
+	servers = FormatServers(servers)
+	sc := make([]*ServerClients, len(servers))
+	imOk := true
+
+	for i := range sc {
+		response, err := fourLetterWord(servers[i], "cons", timeout)
+
+		if err != nil {
+			sc[i] = &ServerClients{Error: err}
+			imOk = false
+			continue
+		}
+
+		scan := bufio.NewScanner(bytes.NewReader(response))
+
+		var clients []*ServerClient
+
+		for scan.Scan() {
+			line := scan.Bytes()
+
+			if len(line) == 0 {
+				continue
+			}
+
+			m := re.FindAllStringSubmatch(string(line), -1)
+
+			if m == nil {
+				err := fmt.Errorf("unable to parse fields from zookeeper response (no regex matches)")
+				sc[i] = &ServerClients{Error: err}
+				imOk = false
+				continue
+			}
+
+			match := m[0][1:]
+
+			queued, _ := strconv.ParseInt(match[1], 0, 64)
+			recvd, _ := strconv.ParseInt(match[2], 0, 64)
+			sent, _ := strconv.ParseInt(match[3], 0, 64)
+			sid, _ := strconv.ParseInt(match[4], 0, 64)
+			est, _ := strconv.ParseInt(match[6], 0, 64)
+			timeout, _ := strconv.ParseInt(match[7], 0, 32)
+			lcxid, _ := parseInt64(match[8])
+			lzxid, _ := parseInt64(match[9])
+			lresp, _ := strconv.ParseInt(match[10], 0, 64)
+			llat, _ := strconv.ParseInt(match[11], 0, 32)
+			minlat, _ := strconv.ParseInt(match[12], 0, 32)
+			avglat, _ := strconv.ParseInt(match[13], 0, 32)
+			maxlat, _ := strconv.ParseInt(match[14], 0, 32)
+
+			clients = append(clients, &ServerClient{
+				Queued:        queued,
+				Received:      recvd,
+				Sent:          sent,
+				SessionID:     sid,
+				Lcxid:         int64(lcxid),
+				Lzxid:         int64(lzxid),
+				Timeout:       int32(timeout),
+				LastLatency:   int32(llat),
+				MinLatency:    int32(minlat),
+				AvgLatency:    int32(avglat),
+				MaxLatency:    int32(maxlat),
+				Established:   time.Unix(est, 0),
+				LastResponse:  time.Unix(lresp, 0),
+				Addr:          match[0],
+				LastOperation: match[5],
+			})
+		}
+
+		sc[i] = &ServerClients{Clients: clients}
+	}
+
+	return sc, imOk
+}
+
+// parseInt64 is similar to strconv.ParseInt, but it also handles hex values that represent negative numbers
+func parseInt64(s string) (int64, error) {
+	if strings.HasPrefix(s, "0x") {
+		i, err := strconv.ParseUint(s, 0, 64)
+		return int64(i), err
+	}
+	return strconv.ParseInt(s, 0, 64)
+}
+
+func fourLetterWord(server, command string, timeout time.Duration) ([]byte, error) {
+	conn, err := net.DialTimeout("tcp", server, timeout)
+	if err != nil {
+		return nil, err
+	}
+
+	// the zookeeper server should automatically close this socket
+	// once the command has been processed, but better safe than sorry
+	defer conn.Close()
+
+	conn.SetWriteDeadline(time.Now().Add(timeout))
+	_, err = conn.Write([]byte(command))
+	if err != nil {
+		return nil, err
+	}
+
+	conn.SetReadDeadline(time.Now().Add(timeout))
+	return ioutil.ReadAll(conn)
+}

vendor/github.com/samuel/go-zookeeper/zk/lock.go

@@ -0,0 +1,150 @@
+package zk
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+var (
+	// ErrDeadlock is returned by Lock when trying to lock twice without unlocking first
+	ErrDeadlock = errors.New("zk: trying to acquire a lock twice")
+	// ErrNotLocked is returned by Unlock when trying to release a lock that has not first be acquired.
+	ErrNotLocked = errors.New("zk: not locked")
+)
+
+// Lock is a mutual exclusion lock.
+type Lock struct {
+	c        *Conn
+	path     string
+	acl      []ACL
+	lockPath string
+	seq      int
+}
+
+// NewLock creates a new lock instance using the provided connection, path, and acl.
+// The path must be a node that is only used by this lock. A lock instances starts
+// unlocked until Lock() is called.
+func NewLock(c *Conn, path string, acl []ACL) *Lock {
+	return &Lock{
+		c:    c,
+		path: path,
+		acl:  acl,
+	}
+}
+
+func parseSeq(path string) (int, error) {
+	parts := strings.Split(path, "-")
+	return strconv.Atoi(parts[len(parts)-1])
+}
+
+// Lock attempts to acquire the lock. It will wait to return until the lock
+// is acquired or an error occurs. If this instance already has the lock
+// then ErrDeadlock is returned.
+func (l *Lock) Lock() error {
+	if l.lockPath != "" {
+		return ErrDeadlock
+	}
+
+	prefix := fmt.Sprintf("%s/lock-", l.path)
+
+	path := ""
+	var err error
+	for i := 0; i < 3; i++ {
+		path, err = l.c.CreateProtectedEphemeralSequential(prefix, []byte{}, l.acl)
+		if err == ErrNoNode {
+			// Create parent node.
+			parts := strings.Split(l.path, "/")
+			pth := ""
+			for _, p := range parts[1:] {
+				var exists bool
+				pth += "/" + p
+				exists, _, err = l.c.Exists(pth)
+				if err != nil {
+					return err
+				}
+				if exists == true {
+					continue
+				}
+				_, err = l.c.Create(pth, []byte{}, 0, l.acl)
+				if err != nil && err != ErrNodeExists {
+					return err
+				}
+			}
+		} else if err == nil {
+			break
+		} else {
+			return err
+		}
+	}
+	if err != nil {
+		return err
+	}
+
+	seq, err := parseSeq(path)
+	if err != nil {
+		return err
+	}
+
+	for {
+		children, _, err := l.c.Children(l.path)
+		if err != nil {
+			return err
+		}
+
+		lowestSeq := seq
+		prevSeq := -1
+		prevSeqPath := ""
+		for _, p := range children {
+			s, err := parseSeq(p)
+			if err != nil {
+				return err
+			}
+			if s < lowestSeq {
+				lowestSeq = s
+			}
+			if s < seq && s > prevSeq {
+				prevSeq = s
+				prevSeqPath = p
+			}
+		}
+
+		if seq == lowestSeq {
+			// Acquired the lock
+			break
+		}
+
+		// Wait on the node next in line for the lock
+		_, _, ch, err := l.c.GetW(l.path + "/" + prevSeqPath)
+		if err != nil && err != ErrNoNode {
+			return err
+		} else if err != nil && err == ErrNoNode {
+			// try again
+			continue
+		}
+
+		ev := <-ch
+		if ev.Err != nil {
+			return ev.Err
+		}
+	}
+
+	l.seq = seq
+	l.lockPath = path
+	return nil
+}
+
+// Unlock releases an acquired lock. If the lock is not currently acquired by
+// this Lock instance than ErrNotLocked is returned.
+func (l *Lock) Unlock() error {
+	if l.lockPath == "" {
+		return ErrNotLocked
+	}
+	if err := l.c.Delete(l.lockPath, -1); err != nil {
+		return err
+	}
+	l.lockPath = ""
+	l.seq = 0
+	return nil
+}

vendor/github.com/samuel/go-zookeeper/zk/server_help.go

@@ -0,0 +1,216 @@
+package zk
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"math/rand"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+type TestServer struct {
+	Port int
+	Path string
+	Srv  *Server
+}
+
+type TestCluster struct {
+	Path    string
+	Servers []TestServer
+}
+
+func StartTestCluster(size int, stdout, stderr io.Writer) (*TestCluster, error) {
+	tmpPath, err := ioutil.TempDir("", "gozk")
+	if err != nil {
+		return nil, err
+	}
+	success := false
+	startPort := int(rand.Int31n(6000) + 10000)
+	cluster := &TestCluster{Path: tmpPath}
+	defer func() {
+		if !success {
+			cluster.Stop()
+		}
+	}()
+	for serverN := 0; serverN < size; serverN++ {
+		srvPath := filepath.Join(tmpPath, fmt.Sprintf("srv%d", serverN))
+		if err := os.Mkdir(srvPath, 0700); err != nil {
+			return nil, err
+		}
+		port := startPort + serverN*3
+		cfg := ServerConfig{
+			ClientPort: port,
+			DataDir:    srvPath,
+		}
+		for i := 0; i < size; i++ {
+			cfg.Servers = append(cfg.Servers, ServerConfigServer{
+				ID:                 i + 1,
+				Host:               "127.0.0.1",
+				PeerPort:           startPort + i*3 + 1,
+				LeaderElectionPort: startPort + i*3 + 2,
+			})
+		}
+		cfgPath := filepath.Join(srvPath, "zoo.cfg")
+		fi, err := os.Create(cfgPath)
+		if err != nil {
+			return nil, err
+		}
+		err = cfg.Marshall(fi)
+		fi.Close()
+		if err != nil {
+			return nil, err
+		}
+
+		fi, err = os.Create(filepath.Join(srvPath, "myid"))
+		if err != nil {
+			return nil, err
+		}
+		_, err = fmt.Fprintf(fi, "%d\n", serverN+1)
+		fi.Close()
+		if err != nil {
+			return nil, err
+		}
+
+		srv := &Server{
+			ConfigPath: cfgPath,
+			Stdout:     stdout,
+			Stderr:     stderr,
+		}
+		if err := srv.Start(); err != nil {
+			return nil, err
+		}
+		cluster.Servers = append(cluster.Servers, TestServer{
+			Path: srvPath,
+			Port: cfg.ClientPort,
+			Srv:  srv,
+		})
+	}
+	if err := cluster.waitForStart(10, time.Second); err != nil {
+		return nil, err
+	}
+	success = true
+	return cluster, nil
+}
+
+func (tc *TestCluster) Connect(idx int) (*Conn, error) {
+	zk, _, err := Connect([]string{fmt.Sprintf("127.0.0.1:%d", tc.Servers[idx].Port)}, time.Second*15)
+	return zk, err
+}
+
+func (tc *TestCluster) ConnectAll() (*Conn, <-chan Event, error) {
+	return tc.ConnectAllTimeout(time.Second * 15)
+}
+
+func (tc *TestCluster) ConnectAllTimeout(sessionTimeout time.Duration) (*Conn, <-chan Event, error) {
+	return tc.ConnectWithOptions(sessionTimeout)
+}
+
+func (tc *TestCluster) ConnectWithOptions(sessionTimeout time.Duration, options ...connOption) (*Conn, <-chan Event, error) {
+	hosts := make([]string, len(tc.Servers))
+	for i, srv := range tc.Servers {
+		hosts[i] = fmt.Sprintf("127.0.0.1:%d", srv.Port)
+	}
+	zk, ch, err := Connect(hosts, sessionTimeout, options...)
+	return zk, ch, err
+}
+
+func (tc *TestCluster) Stop() error {
+	for _, srv := range tc.Servers {
+		srv.Srv.Stop()
+	}
+	defer os.RemoveAll(tc.Path)
+	return tc.waitForStop(5, time.Second)
+}
+
+// waitForStart blocks until the cluster is up
+func (tc *TestCluster) waitForStart(maxRetry int, interval time.Duration) error {
+	// verify that the servers are up with SRVR
+	serverAddrs := make([]string, len(tc.Servers))
+	for i, s := range tc.Servers {
+		serverAddrs[i] = fmt.Sprintf("127.0.0.1:%d", s.Port)
+	}
+
+	for i := 0; i < maxRetry; i++ {
+		_, ok := FLWSrvr(serverAddrs, time.Second)
+		if ok {
+			return nil
+		}
+		time.Sleep(interval)
+	}
+	return fmt.Errorf("unable to verify health of servers")
+}
+
+// waitForStop blocks until the cluster is down
+func (tc *TestCluster) waitForStop(maxRetry int, interval time.Duration) error {
+	// verify that the servers are up with RUOK
+	serverAddrs := make([]string, len(tc.Servers))
+	for i, s := range tc.Servers {
+		serverAddrs[i] = fmt.Sprintf("127.0.0.1:%d", s.Port)
+	}
+
+	var success bool
+	for i := 0; i < maxRetry && !success; i++ {
+		success = true
+		for _, ok := range FLWRuok(serverAddrs, time.Second) {
+			if ok {
+				success = false
+			}
+		}
+		if !success {
+			time.Sleep(interval)
+		}
+	}
+	if !success {
+		return fmt.Errorf("unable to verify servers are down")
+	}
+	return nil
+}
+
+func (tc *TestCluster) StartServer(server string) {
+	for _, s := range tc.Servers {
+		if strings.HasSuffix(server, fmt.Sprintf(":%d", s.Port)) {
+			s.Srv.Start()
+			return
+		}
+	}
+	panic(fmt.Sprintf("Unknown server: %s", server))
+}
+
+func (tc *TestCluster) StopServer(server string) {
+	for _, s := range tc.Servers {
+		if strings.HasSuffix(server, fmt.Sprintf(":%d", s.Port)) {
+			s.Srv.Stop()
+			return
+		}
+	}
+	panic(fmt.Sprintf("Unknown server: %s", server))
+}
+
+func (tc *TestCluster) StartAllServers() error {
+	for _, s := range tc.Servers {
+		if err := s.Srv.Start(); err != nil {
+			return fmt.Errorf(
+				"Failed to start server listening on port `%d` : %+v", s.Port, err)
+		}
+	}
+
+	return nil
+}
+
+func (tc *TestCluster) StopAllServers() error {
+	for _, s := range tc.Servers {
+		if err := s.Srv.Stop(); err != nil {
+			return fmt.Errorf(
+				"Failed to stop server listening on port `%d` : %+v", s.Port, err)
+		}
+	}
+
+	return nil
+}

vendor/github.com/samuel/go-zookeeper/zk/server_java.go

@@ -0,0 +1,136 @@
+package zk
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+type ErrMissingServerConfigField string
+
+func (e ErrMissingServerConfigField) Error() string {
+	return fmt.Sprintf("zk: missing server config field '%s'", string(e))
+}
+
+const (
+	DefaultServerTickTime                 = 2000
+	DefaultServerInitLimit                = 10
+	DefaultServerSyncLimit                = 5
+	DefaultServerAutoPurgeSnapRetainCount = 3
+	DefaultPeerPort                       = 2888
+	DefaultLeaderElectionPort             = 3888
+)
+
+type ServerConfigServer struct {
+	ID                 int
+	Host               string
+	PeerPort           int
+	LeaderElectionPort int
+}
+
+type ServerConfig struct {
+	TickTime                 int    // Number of milliseconds of each tick
+	InitLimit                int    // Number of ticks that the initial synchronization phase can take
+	SyncLimit                int    // Number of ticks that can pass between sending a request and getting an acknowledgement
+	DataDir                  string // Direcrory where the snapshot is stored
+	ClientPort               int    // Port at which clients will connect
+	AutoPurgeSnapRetainCount int    // Number of snapshots to retain in dataDir
+	AutoPurgePurgeInterval   int    // Purge task internal in hours (0 to disable auto purge)
+	Servers                  []ServerConfigServer
+}
+
+func (sc ServerConfig) Marshall(w io.Writer) error {
+	if sc.DataDir == "" {
+		return ErrMissingServerConfigField("dataDir")
+	}
+	fmt.Fprintf(w, "dataDir=%s\n", sc.DataDir)
+	if sc.TickTime <= 0 {
+		sc.TickTime = DefaultServerTickTime
+	}
+	fmt.Fprintf(w, "tickTime=%d\n", sc.TickTime)
+	if sc.InitLimit <= 0 {
+		sc.InitLimit = DefaultServerInitLimit
+	}
+	fmt.Fprintf(w, "initLimit=%d\n", sc.InitLimit)
+	if sc.SyncLimit <= 0 {
+		sc.SyncLimit = DefaultServerSyncLimit
+	}
+	fmt.Fprintf(w, "syncLimit=%d\n", sc.SyncLimit)
+	if sc.ClientPort <= 0 {
+		sc.ClientPort = DefaultPort
+	}
+	fmt.Fprintf(w, "clientPort=%d\n", sc.ClientPort)
+	if sc.AutoPurgePurgeInterval > 0 {
+		if sc.AutoPurgeSnapRetainCount <= 0 {
+			sc.AutoPurgeSnapRetainCount = DefaultServerAutoPurgeSnapRetainCount
+		}
+		fmt.Fprintf(w, "autopurge.snapRetainCount=%d\n", sc.AutoPurgeSnapRetainCount)
+		fmt.Fprintf(w, "autopurge.purgeInterval=%d\n", sc.AutoPurgePurgeInterval)
+	}
+	if len(sc.Servers) > 0 {
+		for _, srv := range sc.Servers {
+			if srv.PeerPort <= 0 {
+				srv.PeerPort = DefaultPeerPort
+			}
+			if srv.LeaderElectionPort <= 0 {
+				srv.LeaderElectionPort = DefaultLeaderElectionPort
+			}
+			fmt.Fprintf(w, "server.%d=%s:%d:%d\n", srv.ID, srv.Host, srv.PeerPort, srv.LeaderElectionPort)
+		}
+	}
+	return nil
+}
+
+var jarSearchPaths = []string{
+	"zookeeper-*/contrib/fatjar/zookeeper-*-fatjar.jar",
+	"../zookeeper-*/contrib/fatjar/zookeeper-*-fatjar.jar",
+	"/usr/share/java/zookeeper-*.jar",
+	"/usr/local/zookeeper-*/contrib/fatjar/zookeeper-*-fatjar.jar",
+	"/usr/local/Cellar/zookeeper/*/libexec/contrib/fatjar/zookeeper-*-fatjar.jar",
+}
+
+func findZookeeperFatJar() string {
+	var paths []string
+	zkPath := os.Getenv("ZOOKEEPER_PATH")
+	if zkPath == "" {
+		paths = jarSearchPaths
+	} else {
+		paths = []string{filepath.Join(zkPath, "contrib/fatjar/zookeeper-*-fatjar.jar")}
+	}
+	for _, path := range paths {
+		matches, _ := filepath.Glob(path)
+		// TODO: could sort by version and pick latest
+		if len(matches) > 0 {
+			return matches[0]
+		}
+	}
+	return ""
+}
+
+type Server struct {
+	JarPath        string
+	ConfigPath     string
+	Stdout, Stderr io.Writer
+
+	cmd *exec.Cmd
+}
+
+func (srv *Server) Start() error {
+	if srv.JarPath == "" {
+		srv.JarPath = findZookeeperFatJar()
+		if srv.JarPath == "" {
+			return fmt.Errorf("zk: unable to find server jar")
+		}
+	}
+	srv.cmd = exec.Command("java", "-jar", srv.JarPath, "server", srv.ConfigPath)
+	srv.cmd.Stdout = srv.Stdout
+	srv.cmd.Stderr = srv.Stderr
+	return srv.cmd.Start()
+}
+
+func (srv *Server) Stop() error {
+	srv.cmd.Process.Signal(os.Kill)
+	return srv.cmd.Wait()
+}

vendor/github.com/samuel/go-zookeeper/zk/structs.go

@@ -0,0 +1,609 @@
+package zk
+
+import (
+	"encoding/binary"
+	"errors"
+	"log"
+	"reflect"
+	"runtime"
+	"time"
+)
+
+var (
+	ErrUnhandledFieldType = errors.New("zk: unhandled field type")
+	ErrPtrExpected        = errors.New("zk: encode/decode expect a non-nil pointer to struct")
+	ErrShortBuffer        = errors.New("zk: buffer too small")
+)
+
+type defaultLogger struct{}
+
+func (defaultLogger) Printf(format string, a ...interface{}) {
+	log.Printf(format, a...)
+}
+
+type ACL struct {
+	Perms  int32
+	Scheme string
+	ID     string
+}
+
+type Stat struct {
+	Czxid          int64 // The zxid of the change that caused this znode to be created.
+	Mzxid          int64 // The zxid of the change that last modified this znode.
+	Ctime          int64 // The time in milliseconds from epoch when this znode was created.
+	Mtime          int64 // The time in milliseconds from epoch when this znode was last modified.
+	Version        int32 // The number of changes to the data of this znode.
+	Cversion       int32 // The number of changes to the children of this znode.
+	Aversion       int32 // The number of changes to the ACL of this znode.
+	EphemeralOwner int64 // The session id of the owner of this znode if the znode is an ephemeral node. If it is not an ephemeral node, it will be zero.
+	DataLength     int32 // The length of the data field of this znode.
+	NumChildren    int32 // The number of children of this znode.
+	Pzxid          int64 // last modified children
+}
+
+// ServerClient is the information for a single Zookeeper client and its session.
+// This is used to parse/extract the output fo the `cons` command.
+type ServerClient struct {
+	Queued        int64
+	Received      int64
+	Sent          int64
+	SessionID     int64
+	Lcxid         int64
+	Lzxid         int64
+	Timeout       int32
+	LastLatency   int32
+	MinLatency    int32
+	AvgLatency    int32
+	MaxLatency    int32
+	Established   time.Time
+	LastResponse  time.Time
+	Addr          string
+	LastOperation string // maybe?
+	Error         error
+}
+
+// ServerClients is a struct for the FLWCons() function. It's used to provide
+// the list of Clients.
+//
+// This is needed because FLWCons() takes multiple servers.
+type ServerClients struct {
+	Clients []*ServerClient
+	Error   error
+}
+
+// ServerStats is the information pulled from the Zookeeper `stat` command.
+type ServerStats struct {
+	Sent        int64
+	Received    int64
+	NodeCount   int64
+	MinLatency  int64
+	AvgLatency  int64
+	MaxLatency  int64
+	Connections int64
+	Outstanding int64
+	Epoch       int32
+	Counter     int32
+	BuildTime   time.Time
+	Mode        Mode
+	Version     string
+	Error       error
+}
+
+type requestHeader struct {
+	Xid    int32
+	Opcode int32
+}
+
+type responseHeader struct {
+	Xid  int32
+	Zxid int64
+	Err  ErrCode
+}
+
+type multiHeader struct {
+	Type int32
+	Done bool
+	Err  ErrCode
+}
+
+type auth struct {
+	Type   int32
+	Scheme string
+	Auth   []byte
+}
+
+// Generic request structs
+
+type pathRequest struct {
+	Path string
+}
+
+type PathVersionRequest struct {
+	Path    string
+	Version int32
+}
+
+type pathWatchRequest struct {
+	Path  string
+	Watch bool
+}
+
+type pathResponse struct {
+	Path string
+}
+
+type statResponse struct {
+	Stat Stat
+}
+
+//
+
+type CheckVersionRequest PathVersionRequest
+type closeRequest struct{}
+type closeResponse struct{}
+
+type connectRequest struct {
+	ProtocolVersion int32
+	LastZxidSeen    int64
+	TimeOut         int32
+	SessionID       int64
+	Passwd          []byte
+}
+
+type connectResponse struct {
+	ProtocolVersion int32
+	TimeOut         int32
+	SessionID       int64
+	Passwd          []byte
+}
+
+type CreateRequest struct {
+	Path  string
+	Data  []byte
+	Acl   []ACL
+	Flags int32
+}
+
+type createResponse pathResponse
+type DeleteRequest PathVersionRequest
+type deleteResponse struct{}
+
+type errorResponse struct {
+	Err int32
+}
+
+type existsRequest pathWatchRequest
+type existsResponse statResponse
+type getAclRequest pathRequest
+
+type getAclResponse struct {
+	Acl  []ACL
+	Stat Stat
+}
+
+type getChildrenRequest pathRequest
+
+type getChildrenResponse struct {
+	Children []string
+}
+
+type getChildren2Request pathWatchRequest
+
+type getChildren2Response struct {
+	Children []string
+	Stat     Stat
+}
+
+type getDataRequest pathWatchRequest
+
+type getDataResponse struct {
+	Data []byte
+	Stat Stat
+}
+
+type getMaxChildrenRequest pathRequest
+
+type getMaxChildrenResponse struct {
+	Max int32
+}
+
+type getSaslRequest struct {
+	Token []byte
+}
+
+type pingRequest struct{}
+type pingResponse struct{}
+
+type setAclRequest struct {
+	Path    string
+	Acl     []ACL
+	Version int32
+}
+
+type setAclResponse statResponse
+
+type SetDataRequest struct {
+	Path    string
+	Data    []byte
+	Version int32
+}
+
+type setDataResponse statResponse
+
+type setMaxChildren struct {
+	Path string
+	Max  int32
+}
+
+type setSaslRequest struct {
+	Token string
+}
+
+type setSaslResponse struct {
+	Token string
+}
+
+type setWatchesRequest struct {
+	RelativeZxid int64
+	DataWatches  []string
+	ExistWatches []string
+	ChildWatches []string
+}
+
+type setWatchesResponse struct{}
+
+type syncRequest pathRequest
+type syncResponse pathResponse
+
+type setAuthRequest auth
+type setAuthResponse struct{}
+
+type multiRequestOp struct {
+	Header multiHeader
+	Op     interface{}
+}
+type multiRequest struct {
+	Ops        []multiRequestOp
+	DoneHeader multiHeader
+}
+type multiResponseOp struct {
+	Header multiHeader
+	String string
+	Stat   *Stat
+	Err    ErrCode
+}
+type multiResponse struct {
+	Ops        []multiResponseOp
+	DoneHeader multiHeader
+}
+
+func (r *multiRequest) Encode(buf []byte) (int, error) {
+	total := 0
+	for _, op := range r.Ops {
+		op.Header.Done = false
+		n, err := encodePacketValue(buf[total:], reflect.ValueOf(op))
+		if err != nil {
+			return total, err
+		}
+		total += n
+	}
+	r.DoneHeader.Done = true
+	n, err := encodePacketValue(buf[total:], reflect.ValueOf(r.DoneHeader))
+	if err != nil {
+		return total, err
+	}
+	total += n
+
+	return total, nil
+}
+
+func (r *multiRequest) Decode(buf []byte) (int, error) {
+	r.Ops = make([]multiRequestOp, 0)
+	r.DoneHeader = multiHeader{-1, true, -1}
+	total := 0
+	for {
+		header := &multiHeader{}
+		n, err := decodePacketValue(buf[total:], reflect.ValueOf(header))
+		if err != nil {
+			return total, err
+		}
+		total += n
+		if header.Done {
+			r.DoneHeader = *header
+			break
+		}
+
+		req := requestStructForOp(header.Type)
+		if req == nil {
+			return total, ErrAPIError
+		}
+		n, err = decodePacketValue(buf[total:], reflect.ValueOf(req))
+		if err != nil {
+			return total, err
+		}
+		total += n
+		r.Ops = append(r.Ops, multiRequestOp{*header, req})
+	}
+	return total, nil
+}
+
+func (r *multiResponse) Decode(buf []byte) (int, error) {
+	var multiErr error
+
+	r.Ops = make([]multiResponseOp, 0)
+	r.DoneHeader = multiHeader{-1, true, -1}
+	total := 0
+	for {
+		header := &multiHeader{}
+		n, err := decodePacketValue(buf[total:], reflect.ValueOf(header))
+		if err != nil {
+			return total, err
+		}
+		total += n
+		if header.Done {
+			r.DoneHeader = *header
+			break
+		}
+
+		res := multiResponseOp{Header: *header}
+		var w reflect.Value
+		switch header.Type {
+		default:
+			return total, ErrAPIError
+		case opError:
+			w = reflect.ValueOf(&res.Err)
+		case opCreate:
+			w = reflect.ValueOf(&res.String)
+		case opSetData:
+			res.Stat = new(Stat)
+			w = reflect.ValueOf(res.Stat)
+		case opCheck, opDelete:
+		}
+		if w.IsValid() {
+			n, err := decodePacketValue(buf[total:], w)
+			if err != nil {
+				return total, err
+			}
+			total += n
+		}
+		r.Ops = append(r.Ops, res)
+		if multiErr == nil && res.Err != errOk {
+			// Use the first error as the error returned from Multi().
+			multiErr = res.Err.toError()
+		}
+	}
+	return total, multiErr
+}
+
+type watcherEvent struct {
+	Type  EventType
+	State State
+	Path  string
+}
+
+type decoder interface {
+	Decode(buf []byte) (int, error)
+}
+
+type encoder interface {
+	Encode(buf []byte) (int, error)
+}
+
+func decodePacket(buf []byte, st interface{}) (n int, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			if e, ok := r.(runtime.Error); ok && e.Error() == "runtime error: slice bounds out of range" {
+				err = ErrShortBuffer
+			} else {
+				panic(r)
+			}
+		}
+	}()
+
+	v := reflect.ValueOf(st)
+	if v.Kind() != reflect.Ptr || v.IsNil() {
+		return 0, ErrPtrExpected
+	}
+	return decodePacketValue(buf, v)
+}
+
+func decodePacketValue(buf []byte, v reflect.Value) (int, error) {
+	rv := v
+	kind := v.Kind()
+	if kind == reflect.Ptr {
+		if v.IsNil() {
+			v.Set(reflect.New(v.Type().Elem()))
+		}
+		v = v.Elem()
+		kind = v.Kind()
+	}
+
+	n := 0
+	switch kind {
+	default:
+		return n, ErrUnhandledFieldType
+	case reflect.Struct:
+		if de, ok := rv.Interface().(decoder); ok {
+			return de.Decode(buf)
+		} else if de, ok := v.Interface().(decoder); ok {
+			return de.Decode(buf)
+		} else {
+			for i := 0; i < v.NumField(); i++ {
+				field := v.Field(i)
+				n2, err := decodePacketValue(buf[n:], field)
+				n += n2
+				if err != nil {
+					return n, err
+				}
+			}
+		}
+	case reflect.Bool:
+		v.SetBool(buf[n] != 0)
+		n++
+	case reflect.Int32:
+		v.SetInt(int64(binary.BigEndian.Uint32(buf[n : n+4])))
+		n += 4
+	case reflect.Int64:
+		v.SetInt(int64(binary.BigEndian.Uint64(buf[n : n+8])))
+		n += 8
+	case reflect.String:
+		ln := int(binary.BigEndian.Uint32(buf[n : n+4]))
+		v.SetString(string(buf[n+4 : n+4+ln]))
+		n += 4 + ln
+	case reflect.Slice:
+		switch v.Type().Elem().Kind() {
+		default:
+			count := int(binary.BigEndian.Uint32(buf[n : n+4]))
+			n += 4
+			values := reflect.MakeSlice(v.Type(), count, count)
+			v.Set(values)
+			for i := 0; i < count; i++ {
+				n2, err := decodePacketValue(buf[n:], values.Index(i))
+				n += n2
+				if err != nil {
+					return n, err
+				}
+			}
+		case reflect.Uint8:
+			ln := int(int32(binary.BigEndian.Uint32(buf[n : n+4])))
+			if ln < 0 {
+				n += 4
+				v.SetBytes(nil)
+			} else {
+				bytes := make([]byte, ln)
+				copy(bytes, buf[n+4:n+4+ln])
+				v.SetBytes(bytes)
+				n += 4 + ln
+			}
+		}
+	}
+	return n, nil
+}
+
+func encodePacket(buf []byte, st interface{}) (n int, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			if e, ok := r.(runtime.Error); ok && e.Error() == "runtime error: slice bounds out of range" {
+				err = ErrShortBuffer
+			} else {
+				panic(r)
+			}
+		}
+	}()
+
+	v := reflect.ValueOf(st)
+	if v.Kind() != reflect.Ptr || v.IsNil() {
+		return 0, ErrPtrExpected
+	}
+	return encodePacketValue(buf, v)
+}
+
+func encodePacketValue(buf []byte, v reflect.Value) (int, error) {
+	rv := v
+	for v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface {
+		v = v.Elem()
+	}
+
+	n := 0
+	switch v.Kind() {
+	default:
+		return n, ErrUnhandledFieldType
+	case reflect.Struct:
+		if en, ok := rv.Interface().(encoder); ok {
+			return en.Encode(buf)
+		} else if en, ok := v.Interface().(encoder); ok {
+			return en.Encode(buf)
+		} else {
+			for i := 0; i < v.NumField(); i++ {
+				field := v.Field(i)
+				n2, err := encodePacketValue(buf[n:], field)
+				n += n2
+				if err != nil {
+					return n, err
+				}
+			}
+		}
+	case reflect.Bool:
+		if v.Bool() {
+			buf[n] = 1
+		} else {
+			buf[n] = 0
+		}
+		n++
+	case reflect.Int32:
+		binary.BigEndian.PutUint32(buf[n:n+4], uint32(v.Int()))
+		n += 4
+	case reflect.Int64:
+		binary.BigEndian.PutUint64(buf[n:n+8], uint64(v.Int()))
+		n += 8
+	case reflect.String:
+		str := v.String()
+		binary.BigEndian.PutUint32(buf[n:n+4], uint32(len(str)))
+		copy(buf[n+4:n+4+len(str)], []byte(str))
+		n += 4 + len(str)
+	case reflect.Slice:
+		switch v.Type().Elem().Kind() {
+		default:
+			count := v.Len()
+			startN := n
+			n += 4
+			for i := 0; i < count; i++ {
+				n2, err := encodePacketValue(buf[n:], v.Index(i))
+				n += n2
+				if err != nil {
+					return n, err
+				}
+			}
+			binary.BigEndian.PutUint32(buf[startN:startN+4], uint32(count))
+		case reflect.Uint8:
+			if v.IsNil() {
+				binary.BigEndian.PutUint32(buf[n:n+4], uint32(0xffffffff))
+				n += 4
+			} else {
+				bytes := v.Bytes()
+				binary.BigEndian.PutUint32(buf[n:n+4], uint32(len(bytes)))
+				copy(buf[n+4:n+4+len(bytes)], bytes)
+				n += 4 + len(bytes)
+			}
+		}
+	}
+	return n, nil
+}
+
+func requestStructForOp(op int32) interface{} {
+	switch op {
+	case opClose:
+		return &closeRequest{}
+	case opCreate:
+		return &CreateRequest{}
+	case opDelete:
+		return &DeleteRequest{}
+	case opExists:
+		return &existsRequest{}
+	case opGetAcl:
+		return &getAclRequest{}
+	case opGetChildren:
+		return &getChildrenRequest{}
+	case opGetChildren2:
+		return &getChildren2Request{}
+	case opGetData:
+		return &getDataRequest{}
+	case opPing:
+		return &pingRequest{}
+	case opSetAcl:
+		return &setAclRequest{}
+	case opSetData:
+		return &SetDataRequest{}
+	case opSetWatches:
+		return &setWatchesRequest{}
+	case opSync:
+		return &syncRequest{}
+	case opSetAuth:
+		return &setAuthRequest{}
+	case opCheck:
+		return &CheckVersionRequest{}
+	case opMulti:
+		return &multiRequest{}
+	}
+	return nil
+}

vendor/github.com/samuel/go-zookeeper/zk/util.go

@@ -0,0 +1,116 @@
+package zk
+
+import (
+	"crypto/sha1"
+	"encoding/base64"
+	"fmt"
+	"math/rand"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+// AuthACL produces an ACL list containing a single ACL which uses the
+// provided permissions, with the scheme "auth", and ID "", which is used
+// by ZooKeeper to represent any authenticated user.
+func AuthACL(perms int32) []ACL {
+	return []ACL{{perms, "auth", ""}}
+}
+
+// WorldACL produces an ACL list containing a single ACL which uses the
+// provided permissions, with the scheme "world", and ID "anyone", which
+// is used by ZooKeeper to represent any user at all.
+func WorldACL(perms int32) []ACL {
+	return []ACL{{perms, "world", "anyone"}}
+}
+
+func DigestACL(perms int32, user, password string) []ACL {
+	userPass := []byte(fmt.Sprintf("%s:%s", user, password))
+	h := sha1.New()
+	if n, err := h.Write(userPass); err != nil || n != len(userPass) {
+		panic("SHA1 failed")
+	}
+	digest := base64.StdEncoding.EncodeToString(h.Sum(nil))
+	return []ACL{{perms, "digest", fmt.Sprintf("%s:%s", user, digest)}}
+}
+
+// FormatServers takes a slice of addresses, and makes sure they are in a format
+// that resembles <addr>:<port>. If the server has no port provided, the
+// DefaultPort constant is added to the end.
+func FormatServers(servers []string) []string {
+	for i := range servers {
+		if !strings.Contains(servers[i], ":") {
+			servers[i] = servers[i] + ":" + strconv.Itoa(DefaultPort)
+		}
+	}
+	return servers
+}
+
+// stringShuffle performs a Fisher-Yates shuffle on a slice of strings
+func stringShuffle(s []string) {
+	for i := len(s) - 1; i > 0; i-- {
+		j := rand.Intn(i + 1)
+		s[i], s[j] = s[j], s[i]
+	}
+}
+
+// validatePath will make sure a path is valid before sending the request
+func validatePath(path string, isSequential bool) error {
+	if path == "" {
+		return ErrInvalidPath
+	}
+
+	if path[0] != '/' {
+		return ErrInvalidPath
+	}
+
+	n := len(path)
+	if n == 1 {
+		// path is just the root
+		return nil
+	}
+
+	if !isSequential && path[n-1] == '/' {
+		return ErrInvalidPath
+	}
+
+	// Start at rune 1 since we already know that the first character is
+	// a '/'.
+	for i, w := 1, 0; i < n; i += w {
+		r, width := utf8.DecodeRuneInString(path[i:])
+		switch {
+		case r == '\u0000':
+			return ErrInvalidPath
+		case r == '/':
+			last, _ := utf8.DecodeLastRuneInString(path[:i])
+			if last == '/' {
+				return ErrInvalidPath
+			}
+		case r == '.':
+			last, lastWidth := utf8.DecodeLastRuneInString(path[:i])
+
+			// Check for double dot
+			if last == '.' {
+				last, _ = utf8.DecodeLastRuneInString(path[:i-lastWidth])
+			}
+
+			if last == '/' {
+				if i+1 == n {
+					return ErrInvalidPath
+				}
+
+				next, _ := utf8.DecodeRuneInString(path[i+w:])
+				if next == '/' {
+					return ErrInvalidPath
+				}
+			}
+		case r >= '\u0000' && r <= '\u001f',
+			r >= '\u007f' && r <= '\u009f',
+			r >= '\uf000' && r <= '\uf8ff',
+			r >= '\ufff0' && r < '\uffff':
+			return ErrInvalidPath
+		}
+		w = width
+	}
+	return nil
+}