First Commit of Voltha-Go-Controller from Radisys

Change-Id: I8e2e908e7ab09a4fe3d86849da18b6d69dcf4ab0
diff --git a/vendor/github.com/uber/jaeger-client-go/utils/http_json.go b/vendor/github.com/uber/jaeger-client-go/utils/http_json.go
new file mode 100644
index 0000000..237211f
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/utils/http_json.go
@@ -0,0 +1,54 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+)
+
+// GetJSON makes an HTTP call to the specified URL and parses the returned JSON into `out`.
+func GetJSON(url string, out interface{}) error {
+	resp, err := http.Get(url)
+	if err != nil {
+		return err
+	}
+	return ReadJSON(resp, out)
+}
+
+// ReadJSON reads JSON from http.Response and parses it into `out`
+func ReadJSON(resp *http.Response, out interface{}) error {
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= 400 {
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return err
+		}
+
+		return fmt.Errorf("StatusCode: %d, Body: %s", resp.StatusCode, body)
+	}
+
+	if out == nil {
+		io.Copy(ioutil.Discard, resp.Body)
+		return nil
+	}
+
+	decoder := json.NewDecoder(resp.Body)
+	return decoder.Decode(out)
+}
diff --git a/vendor/github.com/uber/jaeger-client-go/utils/localip.go b/vendor/github.com/uber/jaeger-client-go/utils/localip.go
new file mode 100644
index 0000000..b51af77
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/utils/localip.go
@@ -0,0 +1,84 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"errors"
+	"net"
+)
+
+// This code is borrowed from https://github.com/uber/tchannel-go/blob/dev/localip.go
+
+// scoreAddr scores how likely the given addr is to be a remote address and returns the
+// IP to use when listening. Any address which receives a negative score should not be used.
+// Scores are calculated as:
+// -1 for any unknown IP addresses.
+// +300 for IPv4 addresses
+// +100 for non-local addresses, extra +100 for "up" interaces.
+func scoreAddr(iface net.Interface, addr net.Addr) (int, net.IP) {
+	var ip net.IP
+	if netAddr, ok := addr.(*net.IPNet); ok {
+		ip = netAddr.IP
+	} else if netIP, ok := addr.(*net.IPAddr); ok {
+		ip = netIP.IP
+	} else {
+		return -1, nil
+	}
+
+	var score int
+	if ip.To4() != nil {
+		score += 300
+	}
+	if iface.Flags&net.FlagLoopback == 0 && !ip.IsLoopback() {
+		score += 100
+		if iface.Flags&net.FlagUp != 0 {
+			score += 100
+		}
+	}
+	return score, ip
+}
+
+// HostIP tries to find an IP that can be used by other machines to reach this machine.
+func HostIP() (net.IP, error) {
+	interfaces, err := net.Interfaces()
+	if err != nil {
+		return nil, err
+	}
+
+	bestScore := -1
+	var bestIP net.IP
+	// Select the highest scoring IP as the best IP.
+	for _, iface := range interfaces {
+		addrs, err := iface.Addrs()
+		if err != nil {
+			// Skip this interface if there is an error.
+			continue
+		}
+
+		for _, addr := range addrs {
+			score, ip := scoreAddr(iface, addr)
+			if score > bestScore {
+				bestScore = score
+				bestIP = ip
+			}
+		}
+	}
+
+	if bestScore == -1 {
+		return nil, errors.New("no addresses to listen on")
+	}
+
+	return bestIP, nil
+}
diff --git a/vendor/github.com/uber/jaeger-client-go/utils/rand.go b/vendor/github.com/uber/jaeger-client-go/utils/rand.go
new file mode 100644
index 0000000..9875f7f
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/utils/rand.go
@@ -0,0 +1,46 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"math/rand"
+	"sync"
+)
+
+// lockedSource allows a random number generator to be used by multiple goroutines concurrently.
+// The code is very similar to math/rand.lockedSource, which is unfortunately not exposed.
+type lockedSource struct {
+	mut sync.Mutex
+	src rand.Source
+}
+
+// NewRand returns a rand.Rand that is threadsafe.
+func NewRand(seed int64) *rand.Rand {
+	return rand.New(&lockedSource{src: rand.NewSource(seed)})
+}
+
+func (r *lockedSource) Int63() (n int64) {
+	r.mut.Lock()
+	n = r.src.Int63()
+	r.mut.Unlock()
+	return
+}
+
+// Seed implements Seed() of Source
+func (r *lockedSource) Seed(seed int64) {
+	r.mut.Lock()
+	r.src.Seed(seed)
+	r.mut.Unlock()
+}
diff --git a/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go b/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go
new file mode 100644
index 0000000..bf2f131
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go
@@ -0,0 +1,112 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"sync"
+	"time"
+)
+
+// RateLimiter is a filter used to check if a message that is worth itemCost units is within the rate limits.
+//
+// TODO (breaking change) remove this interface in favor of public struct below
+//
+// Deprecated, use ReconfigurableRateLimiter.
+type RateLimiter interface {
+	CheckCredit(itemCost float64) bool
+}
+
+// ReconfigurableRateLimiter is a rate limiter based on leaky bucket algorithm, formulated in terms of a
+// credits balance that is replenished every time CheckCredit() method is called (tick) by the amount proportional
+// to the time elapsed since the last tick, up to max of creditsPerSecond. A call to CheckCredit() takes a cost
+// of an item we want to pay with the balance. If the balance exceeds the cost of the item, the item is "purchased"
+// and the balance reduced, indicated by returned value of true. Otherwise the balance is unchanged and return false.
+//
+// This can be used to limit a rate of messages emitted by a service by instantiating the Rate Limiter with the
+// max number of messages a service is allowed to emit per second, and calling CheckCredit(1.0) for each message
+// to determine if the message is within the rate limit.
+//
+// It can also be used to limit the rate of traffic in bytes, by setting creditsPerSecond to desired throughput
+// as bytes/second, and calling CheckCredit() with the actual message size.
+//
+// TODO (breaking change) rename to RateLimiter once the interface is removed
+type ReconfigurableRateLimiter struct {
+	lock sync.Mutex
+
+	creditsPerSecond float64
+	balance          float64
+	maxBalance       float64
+	lastTick         time.Time
+
+	timeNow func() time.Time
+}
+
+// NewRateLimiter creates a new ReconfigurableRateLimiter.
+func NewRateLimiter(creditsPerSecond, maxBalance float64) *ReconfigurableRateLimiter {
+	return &ReconfigurableRateLimiter{
+		creditsPerSecond: creditsPerSecond,
+		balance:          maxBalance,
+		maxBalance:       maxBalance,
+		lastTick:         time.Now(),
+		timeNow:          time.Now,
+	}
+}
+
+// CheckCredit tries to reduce the current balance by itemCost provided that the current balance
+// is not lest than itemCost.
+func (rl *ReconfigurableRateLimiter) CheckCredit(itemCost float64) bool {
+	rl.lock.Lock()
+	defer rl.lock.Unlock()
+
+	// if we have enough credits to pay for current item, then reduce balance and allow
+	if rl.balance >= itemCost {
+		rl.balance -= itemCost
+		return true
+	}
+	// otherwise check if balance can be increased due to time elapsed, and try again
+	rl.updateBalance()
+	if rl.balance >= itemCost {
+		rl.balance -= itemCost
+		return true
+	}
+	return false
+}
+
+// updateBalance recalculates current balance based on time elapsed. Must be called while holding a lock.
+func (rl *ReconfigurableRateLimiter) updateBalance() {
+	// calculate how much time passed since the last tick, and update current tick
+	currentTime := rl.timeNow()
+	elapsedTime := currentTime.Sub(rl.lastTick)
+	rl.lastTick = currentTime
+	// calculate how much credit have we accumulated since the last tick
+	rl.balance += elapsedTime.Seconds() * rl.creditsPerSecond
+	if rl.balance > rl.maxBalance {
+		rl.balance = rl.maxBalance
+	}
+}
+
+// Update changes the main parameters of the rate limiter in-place, while retaining
+// the current accumulated balance (pro-rated to the new maxBalance value). Using this method
+// instead of creating a new rate limiter helps to avoid thundering herd when sampling
+// strategies are updated.
+func (rl *ReconfigurableRateLimiter) Update(creditsPerSecond, maxBalance float64) {
+	rl.lock.Lock()
+	defer rl.lock.Unlock()
+
+	rl.updateBalance() // get up to date balance
+	rl.balance = rl.balance * maxBalance / rl.maxBalance
+	rl.creditsPerSecond = creditsPerSecond
+	rl.maxBalance = maxBalance
+}
diff --git a/vendor/github.com/uber/jaeger-client-go/utils/reconnecting_udp_conn.go b/vendor/github.com/uber/jaeger-client-go/utils/reconnecting_udp_conn.go
new file mode 100644
index 0000000..0dffc7f
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/utils/reconnecting_udp_conn.go
@@ -0,0 +1,189 @@
+// Copyright (c) 2020 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"fmt"
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/uber/jaeger-client-go/log"
+)
+
+// reconnectingUDPConn is an implementation of udpConn that resolves hostPort every resolveTimeout, if the resolved address is
+// different than the current conn then the new address is dialed and the conn is swapped.
+type reconnectingUDPConn struct {
+	hostPort    string
+	resolveFunc resolveFunc
+	dialFunc    dialFunc
+	logger      log.Logger
+	bufferBytes int64
+
+	connMtx   sync.RWMutex
+	conn      *net.UDPConn
+	destAddr  *net.UDPAddr
+	closeChan chan struct{}
+}
+
+type resolveFunc func(network string, hostPort string) (*net.UDPAddr, error)
+type dialFunc func(network string, laddr, raddr *net.UDPAddr) (*net.UDPConn, error)
+
+// newReconnectingUDPConn returns a new udpConn that resolves hostPort every resolveTimeout, if the resolved address is
+// different than the current conn then the new address is dialed and the conn is swapped.
+func newReconnectingUDPConn(hostPort string, resolveTimeout time.Duration, resolveFunc resolveFunc, dialFunc dialFunc, logger log.Logger) (*reconnectingUDPConn, error) {
+	conn := &reconnectingUDPConn{
+		hostPort:    hostPort,
+		resolveFunc: resolveFunc,
+		dialFunc:    dialFunc,
+		logger:      logger,
+		closeChan:   make(chan struct{}),
+	}
+
+	if err := conn.attemptResolveAndDial(); err != nil {
+		logger.Error(fmt.Sprintf("failed resolving destination address on connection startup, with err: %q. retrying in %s", err.Error(), resolveTimeout))
+	}
+
+	go conn.reconnectLoop(resolveTimeout)
+
+	return conn, nil
+}
+
+func (c *reconnectingUDPConn) reconnectLoop(resolveTimeout time.Duration) {
+	ticker := time.NewTicker(resolveTimeout)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-c.closeChan:
+			return
+		case <-ticker.C:
+			if err := c.attemptResolveAndDial(); err != nil {
+				c.logger.Error(err.Error())
+			}
+		}
+	}
+}
+
+func (c *reconnectingUDPConn) attemptResolveAndDial() error {
+	newAddr, err := c.resolveFunc("udp", c.hostPort)
+	if err != nil {
+		return fmt.Errorf("failed to resolve new addr for host %q, with err: %w", c.hostPort, err)
+	}
+
+	c.connMtx.RLock()
+	curAddr := c.destAddr
+	c.connMtx.RUnlock()
+
+	// dont attempt dial if an addr was successfully dialed previously and, resolved addr is the same as current conn
+	if curAddr != nil && newAddr.String() == curAddr.String() {
+		return nil
+	}
+
+	if err := c.attemptDialNewAddr(newAddr); err != nil {
+		return fmt.Errorf("failed to dial newly resolved addr '%s', with err: %w", newAddr, err)
+	}
+
+	return nil
+}
+
+func (c *reconnectingUDPConn) attemptDialNewAddr(newAddr *net.UDPAddr) error {
+	connUDP, err := c.dialFunc(newAddr.Network(), nil, newAddr)
+	if err != nil {
+		return err
+	}
+
+	if bufferBytes := int(atomic.LoadInt64(&c.bufferBytes)); bufferBytes != 0 {
+		if err = connUDP.SetWriteBuffer(bufferBytes); err != nil {
+			return err
+		}
+	}
+
+	c.connMtx.Lock()
+	c.destAddr = newAddr
+	// store prev to close later
+	prevConn := c.conn
+	c.conn = connUDP
+	c.connMtx.Unlock()
+
+	if prevConn != nil {
+		return prevConn.Close()
+	}
+
+	return nil
+}
+
+// Write calls net.udpConn.Write, if it fails an attempt is made to connect to a new addr, if that succeeds the write is retried before returning
+func (c *reconnectingUDPConn) Write(b []byte) (int, error) {
+	var bytesWritten int
+	var err error
+
+	c.connMtx.RLock()
+	if c.conn == nil {
+		// if connection is not initialized indicate this with err in order to hook into retry logic
+		err = fmt.Errorf("UDP connection not yet initialized, an address has not been resolved")
+	} else {
+		bytesWritten, err = c.conn.Write(b)
+	}
+	c.connMtx.RUnlock()
+
+	if err == nil {
+		return bytesWritten, nil
+	}
+
+	// attempt to resolve and dial new address in case that's the problem, if resolve and dial succeeds, try write again
+	if reconnErr := c.attemptResolveAndDial(); reconnErr == nil {
+		c.connMtx.RLock()
+		defer c.connMtx.RUnlock()
+		return c.conn.Write(b)
+	}
+
+	// return original error if reconn fails
+	return bytesWritten, err
+}
+
+// Close stops the reconnectLoop, then closes the connection via net.udpConn 's implementation
+func (c *reconnectingUDPConn) Close() error {
+	close(c.closeChan)
+
+	// acquire rw lock before closing conn to ensure calls to Write drain
+	c.connMtx.Lock()
+	defer c.connMtx.Unlock()
+
+	if c.conn != nil {
+		return c.conn.Close()
+	}
+
+	return nil
+}
+
+// SetWriteBuffer defers to the net.udpConn SetWriteBuffer implementation wrapped with a RLock. if no conn is currently held
+// and SetWriteBuffer is called store bufferBytes to be set for new conns
+func (c *reconnectingUDPConn) SetWriteBuffer(bytes int) error {
+	var err error
+
+	c.connMtx.RLock()
+	if c.conn != nil {
+		err = c.conn.SetWriteBuffer(bytes)
+	}
+	c.connMtx.RUnlock()
+
+	if err == nil {
+		atomic.StoreInt64(&c.bufferBytes, int64(bytes))
+	}
+
+	return err
+}
diff --git a/vendor/github.com/uber/jaeger-client-go/utils/udp_client.go b/vendor/github.com/uber/jaeger-client-go/utils/udp_client.go
new file mode 100644
index 0000000..4c59ae9
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/utils/udp_client.go
@@ -0,0 +1,149 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"time"
+
+	"github.com/uber/jaeger-client-go/log"
+	"github.com/uber/jaeger-client-go/thrift"
+
+	"github.com/uber/jaeger-client-go/thrift-gen/agent"
+	"github.com/uber/jaeger-client-go/thrift-gen/jaeger"
+	"github.com/uber/jaeger-client-go/thrift-gen/zipkincore"
+)
+
+// UDPPacketMaxLength is the max size of UDP packet we want to send, synced with jaeger-agent
+const UDPPacketMaxLength = 65000
+
+// AgentClientUDP is a UDP client to Jaeger agent that implements agent.Agent interface.
+type AgentClientUDP struct {
+	agent.Agent
+	io.Closer
+
+	connUDP       udpConn
+	client        *agent.AgentClient
+	maxPacketSize int                   // max size of datagram in bytes
+	thriftBuffer  *thrift.TMemoryBuffer // buffer used to calculate byte size of a span
+}
+
+type udpConn interface {
+	Write([]byte) (int, error)
+	SetWriteBuffer(int) error
+	Close() error
+}
+
+// AgentClientUDPParams allows specifying options for initializing an AgentClientUDP. An instance of this struct should
+// be passed to NewAgentClientUDPWithParams.
+type AgentClientUDPParams struct {
+	HostPort                   string
+	MaxPacketSize              int
+	Logger                     log.Logger
+	DisableAttemptReconnecting bool
+	AttemptReconnectInterval   time.Duration
+}
+
+// NewAgentClientUDPWithParams creates a client that sends spans to Jaeger Agent over UDP.
+func NewAgentClientUDPWithParams(params AgentClientUDPParams) (*AgentClientUDP, error) {
+	// validate hostport
+	if _, _, err := net.SplitHostPort(params.HostPort); err != nil {
+		return nil, err
+	}
+
+	if params.MaxPacketSize == 0 {
+		params.MaxPacketSize = UDPPacketMaxLength
+	}
+
+	if params.Logger == nil {
+		params.Logger = log.StdLogger
+	}
+
+	if !params.DisableAttemptReconnecting && params.AttemptReconnectInterval == 0 {
+		params.AttemptReconnectInterval = time.Second * 30
+	}
+
+	thriftBuffer := thrift.NewTMemoryBufferLen(params.MaxPacketSize)
+	protocolFactory := thrift.NewTCompactProtocolFactory()
+	client := agent.NewAgentClientFactory(thriftBuffer, protocolFactory)
+
+	var connUDP udpConn
+	var err error
+
+	if params.DisableAttemptReconnecting {
+		destAddr, err := net.ResolveUDPAddr("udp", params.HostPort)
+		if err != nil {
+			return nil, err
+		}
+
+		connUDP, err = net.DialUDP(destAddr.Network(), nil, destAddr)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		// host is hostname, setup resolver loop in case host record changes during operation
+		connUDP, err = newReconnectingUDPConn(params.HostPort, params.AttemptReconnectInterval, net.ResolveUDPAddr, net.DialUDP, params.Logger)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if err := connUDP.SetWriteBuffer(params.MaxPacketSize); err != nil {
+		return nil, err
+	}
+
+	return &AgentClientUDP{
+		connUDP:       connUDP,
+		client:        client,
+		maxPacketSize: params.MaxPacketSize,
+		thriftBuffer:  thriftBuffer,
+	}, nil
+}
+
+// NewAgentClientUDP creates a client that sends spans to Jaeger Agent over UDP.
+func NewAgentClientUDP(hostPort string, maxPacketSize int) (*AgentClientUDP, error) {
+	return NewAgentClientUDPWithParams(AgentClientUDPParams{
+		HostPort:      hostPort,
+		MaxPacketSize: maxPacketSize,
+	})
+}
+
+// EmitZipkinBatch implements EmitZipkinBatch() of Agent interface
+func (a *AgentClientUDP) EmitZipkinBatch(context.Context, []*zipkincore.Span) error {
+	return errors.New("Not implemented")
+}
+
+// EmitBatch implements EmitBatch() of Agent interface
+func (a *AgentClientUDP) EmitBatch(ctx context.Context, batch *jaeger.Batch) error {
+	a.thriftBuffer.Reset()
+	if err := a.client.EmitBatch(ctx, batch); err != nil {
+		return err
+	}
+	if a.thriftBuffer.Len() > a.maxPacketSize {
+		return fmt.Errorf("data does not fit within one UDP packet; size %d, max %d, spans %d",
+			a.thriftBuffer.Len(), a.maxPacketSize, len(batch.Spans))
+	}
+	_, err := a.connUDP.Write(a.thriftBuffer.Bytes())
+	return err
+}
+
+// Close implements Close() of io.Closer and closes the underlying UDP connection.
+func (a *AgentClientUDP) Close() error {
+	return a.connUDP.Close()
+}
diff --git a/vendor/github.com/uber/jaeger-client-go/utils/utils.go b/vendor/github.com/uber/jaeger-client-go/utils/utils.go
new file mode 100644
index 0000000..ac3c325
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/utils/utils.go
@@ -0,0 +1,87 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"encoding/binary"
+	"errors"
+	"net"
+	"strconv"
+	"strings"
+	"time"
+)
+
+var (
+	// ErrEmptyIP an error for empty ip strings
+	ErrEmptyIP = errors.New("empty string given for ip")
+
+	// ErrNotHostColonPort an error for invalid host port string
+	ErrNotHostColonPort = errors.New("expecting host:port")
+
+	// ErrNotFourOctets an error for the wrong number of octets after splitting a string
+	ErrNotFourOctets = errors.New("Wrong number of octets")
+)
+
+// ParseIPToUint32 converts a string ip (e.g. "x.y.z.w") to an uint32
+func ParseIPToUint32(ip string) (uint32, error) {
+	if ip == "" {
+		return 0, ErrEmptyIP
+	}
+
+	if ip == "localhost" {
+		return 127<<24 | 1, nil
+	}
+
+	octets := strings.Split(ip, ".")
+	if len(octets) != 4 {
+		return 0, ErrNotFourOctets
+	}
+
+	var intIP uint32
+	for i := 0; i < 4; i++ {
+		octet, err := strconv.Atoi(octets[i])
+		if err != nil {
+			return 0, err
+		}
+		intIP = (intIP << 8) | uint32(octet)
+	}
+
+	return intIP, nil
+}
+
+// ParsePort converts port number from string to uin16
+func ParsePort(portString string) (uint16, error) {
+	port, err := strconv.ParseUint(portString, 10, 16)
+	return uint16(port), err
+}
+
+// PackIPAsUint32 packs an IPv4 as uint32
+func PackIPAsUint32(ip net.IP) uint32 {
+	if ipv4 := ip.To4(); ipv4 != nil {
+		return binary.BigEndian.Uint32(ipv4)
+	}
+	return 0
+}
+
+// TimeToMicrosecondsSinceEpochInt64 converts Go time.Time to a long
+// representing time since epoch in microseconds, which is used expected
+// in the Jaeger spans encoded as Thrift.
+func TimeToMicrosecondsSinceEpochInt64(t time.Time) int64 {
+	// ^^^ Passing time.Time by value is faster than passing a pointer!
+	// BenchmarkTimeByValue-8	2000000000	         1.37 ns/op
+	// BenchmarkTimeByPtr-8  	2000000000	         1.98 ns/op
+
+	return t.UnixNano() / 1000
+}