First Commit of Voltha-Go-Controller from Radisys
Change-Id: I8e2e908e7ab09a4fe3d86849da18b6d69dcf4ab0
diff --git a/vendor/github.com/uber/jaeger-client-go/span_context.go b/vendor/github.com/uber/jaeger-client-go/span_context.go
new file mode 100644
index 0000000..5b2307b
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/span_context.go
@@ -0,0 +1,418 @@
+// 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 jaeger
+
+import (
+ "errors"
+ "fmt"
+ "strconv"
+ "strings"
+ "sync"
+
+ "go.uber.org/atomic"
+)
+
+const (
+ flagSampled = 1
+ flagDebug = 2
+ flagFirehose = 8
+)
+
+var (
+ errEmptyTracerStateString = errors.New("Cannot convert empty string to tracer state")
+ errMalformedTracerStateString = errors.New("String does not match tracer state format")
+
+ emptyContext = SpanContext{}
+)
+
+// TraceID represents unique 128bit identifier of a trace
+type TraceID struct {
+ High, Low uint64
+}
+
+// SpanID represents unique 64bit identifier of a span
+type SpanID uint64
+
+// SpanContext represents propagated span identity and state
+type SpanContext struct {
+ // traceID represents globally unique ID of the trace.
+ // Usually generated as a random number.
+ traceID TraceID
+
+ // spanID represents span ID that must be unique within its trace,
+ // but does not have to be globally unique.
+ spanID SpanID
+
+ // parentID refers to the ID of the parent span.
+ // Should be 0 if the current span is a root span.
+ parentID SpanID
+
+ // Distributed Context baggage. The is a snapshot in time.
+ baggage map[string]string
+
+ // debugID can be set to some correlation ID when the context is being
+ // extracted from a TextMap carrier.
+ //
+ // See JaegerDebugHeader in constants.go
+ debugID string
+
+ // samplingState is shared across all spans
+ samplingState *samplingState
+
+ // remote indicates that span context represents a remote parent
+ remote bool
+}
+
+type samplingState struct {
+ // Span context's state flags that are propagated across processes. Only lower 8 bits are used.
+ // We use an int32 instead of byte to be able to use CAS operations.
+ stateFlags atomic.Int32
+
+ // When state is not final, sampling will be retried on other span write operations,
+ // like SetOperationName / SetTag, and the spans will remain writable.
+ final atomic.Bool
+
+ // localRootSpan stores the SpanID of the first span created in this process for a given trace.
+ localRootSpan SpanID
+
+ // extendedState allows samplers to keep intermediate state.
+ // The keys and values in this map are completely opaque: interface{} -> interface{}.
+ extendedState sync.Map
+}
+
+func (s *samplingState) isLocalRootSpan(id SpanID) bool {
+ return id == s.localRootSpan
+}
+
+func (s *samplingState) setFlag(newFlag int32) {
+ swapped := false
+ for !swapped {
+ old := s.stateFlags.Load()
+ swapped = s.stateFlags.CAS(old, old|newFlag)
+ }
+}
+
+func (s *samplingState) unsetFlag(newFlag int32) {
+ swapped := false
+ for !swapped {
+ old := s.stateFlags.Load()
+ swapped = s.stateFlags.CAS(old, old&^newFlag)
+ }
+}
+
+func (s *samplingState) setSampled() {
+ s.setFlag(flagSampled)
+}
+
+func (s *samplingState) unsetSampled() {
+ s.unsetFlag(flagSampled)
+}
+
+func (s *samplingState) setDebugAndSampled() {
+ s.setFlag(flagDebug | flagSampled)
+}
+
+func (s *samplingState) setFirehose() {
+ s.setFlag(flagFirehose)
+}
+
+func (s *samplingState) setFlags(flags byte) {
+ s.stateFlags.Store(int32(flags))
+}
+
+func (s *samplingState) setFinal() {
+ s.final.Store(true)
+}
+
+func (s *samplingState) flags() byte {
+ return byte(s.stateFlags.Load())
+}
+
+func (s *samplingState) isSampled() bool {
+ return s.stateFlags.Load()&flagSampled == flagSampled
+}
+
+func (s *samplingState) isDebug() bool {
+ return s.stateFlags.Load()&flagDebug == flagDebug
+}
+
+func (s *samplingState) isFirehose() bool {
+ return s.stateFlags.Load()&flagFirehose == flagFirehose
+}
+
+func (s *samplingState) isFinal() bool {
+ return s.final.Load()
+}
+
+func (s *samplingState) extendedStateForKey(key interface{}, initValue func() interface{}) interface{} {
+ if value, ok := s.extendedState.Load(key); ok {
+ return value
+ }
+ value := initValue()
+ value, _ = s.extendedState.LoadOrStore(key, value)
+ return value
+}
+
+// ForeachBaggageItem implements ForeachBaggageItem() of opentracing.SpanContext
+func (c SpanContext) ForeachBaggageItem(handler func(k, v string) bool) {
+ for k, v := range c.baggage {
+ if !handler(k, v) {
+ break
+ }
+ }
+}
+
+// IsSampled returns whether this trace was chosen for permanent storage
+// by the sampling mechanism of the tracer.
+func (c SpanContext) IsSampled() bool {
+ return c.samplingState.isSampled()
+}
+
+// IsDebug indicates whether sampling was explicitly requested by the service.
+func (c SpanContext) IsDebug() bool {
+ return c.samplingState.isDebug()
+}
+
+// IsSamplingFinalized indicates whether the sampling decision has been finalized.
+func (c SpanContext) IsSamplingFinalized() bool {
+ return c.samplingState.isFinal()
+}
+
+// IsFirehose indicates whether the firehose flag was set
+func (c SpanContext) IsFirehose() bool {
+ return c.samplingState.isFirehose()
+}
+
+// ExtendedSamplingState returns the custom state object for a given key. If the value for this key does not exist,
+// it is initialized via initValue function. This state can be used by samplers (e.g. x.PrioritySampler).
+func (c SpanContext) ExtendedSamplingState(key interface{}, initValue func() interface{}) interface{} {
+ return c.samplingState.extendedStateForKey(key, initValue)
+}
+
+// IsValid indicates whether this context actually represents a valid trace.
+func (c SpanContext) IsValid() bool {
+ return c.traceID.IsValid() && c.spanID != 0
+}
+
+// SetFirehose enables firehose mode for this trace.
+func (c SpanContext) SetFirehose() {
+ c.samplingState.setFirehose()
+}
+
+func (c SpanContext) String() string {
+ var flags int32
+ if c.samplingState != nil {
+ flags = c.samplingState.stateFlags.Load()
+ }
+ if c.traceID.High == 0 {
+ return fmt.Sprintf("%016x:%016x:%016x:%x", c.traceID.Low, uint64(c.spanID), uint64(c.parentID), flags)
+ }
+ return fmt.Sprintf("%016x%016x:%016x:%016x:%x", c.traceID.High, c.traceID.Low, uint64(c.spanID), uint64(c.parentID), flags)
+}
+
+// ContextFromString reconstructs the Context encoded in a string
+func ContextFromString(value string) (SpanContext, error) {
+ var context SpanContext
+ if value == "" {
+ return emptyContext, errEmptyTracerStateString
+ }
+ parts := strings.Split(value, ":")
+ if len(parts) != 4 {
+ return emptyContext, errMalformedTracerStateString
+ }
+ var err error
+ if context.traceID, err = TraceIDFromString(parts[0]); err != nil {
+ return emptyContext, err
+ }
+ if context.spanID, err = SpanIDFromString(parts[1]); err != nil {
+ return emptyContext, err
+ }
+ if context.parentID, err = SpanIDFromString(parts[2]); err != nil {
+ return emptyContext, err
+ }
+ flags, err := strconv.ParseUint(parts[3], 10, 8)
+ if err != nil {
+ return emptyContext, err
+ }
+ context.samplingState = &samplingState{}
+ context.samplingState.setFlags(byte(flags))
+ return context, nil
+}
+
+// TraceID returns the trace ID of this span context
+func (c SpanContext) TraceID() TraceID {
+ return c.traceID
+}
+
+// SpanID returns the span ID of this span context
+func (c SpanContext) SpanID() SpanID {
+ return c.spanID
+}
+
+// ParentID returns the parent span ID of this span context
+func (c SpanContext) ParentID() SpanID {
+ return c.parentID
+}
+
+// Flags returns the bitmap containing such bits as 'sampled' and 'debug'.
+func (c SpanContext) Flags() byte {
+ return c.samplingState.flags()
+}
+
+// Span can be written to if it is sampled or the sampling decision has not been finalized.
+func (c SpanContext) isWriteable() bool {
+ state := c.samplingState
+ return !state.isFinal() || state.isSampled()
+}
+
+func (c SpanContext) isSamplingFinalized() bool {
+ return c.samplingState.isFinal()
+}
+
+// NewSpanContext creates a new instance of SpanContext
+func NewSpanContext(traceID TraceID, spanID, parentID SpanID, sampled bool, baggage map[string]string) SpanContext {
+ samplingState := &samplingState{}
+ if sampled {
+ samplingState.setSampled()
+ }
+
+ return SpanContext{
+ traceID: traceID,
+ spanID: spanID,
+ parentID: parentID,
+ samplingState: samplingState,
+ baggage: baggage}
+}
+
+// CopyFrom copies data from ctx into this context, including span identity and baggage.
+// TODO This is only used by interop.go. Remove once TChannel Go supports OpenTracing.
+func (c *SpanContext) CopyFrom(ctx *SpanContext) {
+ c.traceID = ctx.traceID
+ c.spanID = ctx.spanID
+ c.parentID = ctx.parentID
+ c.samplingState = ctx.samplingState
+ if l := len(ctx.baggage); l > 0 {
+ c.baggage = make(map[string]string, l)
+ for k, v := range ctx.baggage {
+ c.baggage[k] = v
+ }
+ } else {
+ c.baggage = nil
+ }
+}
+
+// WithBaggageItem creates a new context with an extra baggage item.
+// Delete a baggage item if provided blank value.
+//
+// The SpanContext is designed to be immutable and passed by value. As such,
+// it cannot contain any locks, and should only hold immutable data, including baggage.
+// Another reason for why baggage is immutable is when the span context is passed
+// as a parent when starting a new span. The new span's baggage cannot affect the parent
+// span's baggage, so the child span either needs to take a copy of the parent baggage
+// (which is expensive and unnecessary since baggage rarely changes in the life span of
+// a trace), or it needs to do a copy-on-write, which is the approach taken here.
+func (c SpanContext) WithBaggageItem(key, value string) SpanContext {
+ var newBaggage map[string]string
+ // unset baggage item
+ if value == "" {
+ if _, ok := c.baggage[key]; !ok {
+ return c
+ }
+ newBaggage = make(map[string]string, len(c.baggage))
+ for k, v := range c.baggage {
+ newBaggage[k] = v
+ }
+ delete(newBaggage, key)
+ return SpanContext{c.traceID, c.spanID, c.parentID, newBaggage, "", c.samplingState, c.remote}
+ }
+ if c.baggage == nil {
+ newBaggage = map[string]string{key: value}
+ } else {
+ newBaggage = make(map[string]string, len(c.baggage)+1)
+ for k, v := range c.baggage {
+ newBaggage[k] = v
+ }
+ newBaggage[key] = value
+ }
+ // Use positional parameters so the compiler will help catch new fields.
+ return SpanContext{c.traceID, c.spanID, c.parentID, newBaggage, "", c.samplingState, c.remote}
+}
+
+// isDebugIDContainerOnly returns true when the instance of the context is only
+// used to return the debug/correlation ID from extract() method. This happens
+// in the situation when "jaeger-debug-id" header is passed in the carrier to
+// the extract() method, but the request otherwise has no span context in it.
+// Previously this would've returned opentracing.ErrSpanContextNotFound from the
+// extract method, but now it returns a dummy context with only debugID filled in.
+//
+// See JaegerDebugHeader in constants.go
+// See TextMapPropagator#Extract
+func (c *SpanContext) isDebugIDContainerOnly() bool {
+ return !c.traceID.IsValid() && c.debugID != ""
+}
+
+// ------- TraceID -------
+
+func (t TraceID) String() string {
+ if t.High == 0 {
+ return fmt.Sprintf("%016x", t.Low)
+ }
+ return fmt.Sprintf("%016x%016x", t.High, t.Low)
+}
+
+// TraceIDFromString creates a TraceID from a hexadecimal string
+func TraceIDFromString(s string) (TraceID, error) {
+ var hi, lo uint64
+ var err error
+ if len(s) > 32 {
+ return TraceID{}, fmt.Errorf("TraceID cannot be longer than 32 hex characters: %s", s)
+ } else if len(s) > 16 {
+ hiLen := len(s) - 16
+ if hi, err = strconv.ParseUint(s[0:hiLen], 16, 64); err != nil {
+ return TraceID{}, err
+ }
+ if lo, err = strconv.ParseUint(s[hiLen:], 16, 64); err != nil {
+ return TraceID{}, err
+ }
+ } else {
+ if lo, err = strconv.ParseUint(s, 16, 64); err != nil {
+ return TraceID{}, err
+ }
+ }
+ return TraceID{High: hi, Low: lo}, nil
+}
+
+// IsValid checks if the trace ID is valid, i.e. not zero.
+func (t TraceID) IsValid() bool {
+ return t.High != 0 || t.Low != 0
+}
+
+// ------- SpanID -------
+
+func (s SpanID) String() string {
+ return fmt.Sprintf("%016x", uint64(s))
+}
+
+// SpanIDFromString creates a SpanID from a hexadecimal string
+func SpanIDFromString(s string) (SpanID, error) {
+ if len(s) > 16 {
+ return SpanID(0), fmt.Errorf("SpanID cannot be longer than 16 hex characters: %s", s)
+ }
+ id, err := strconv.ParseUint(s, 16, 64)
+ if err != nil {
+ return SpanID(0), err
+ }
+ return SpanID(id), nil
+}