1 files changed, 204 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/internal/channelz/trace.go b/vendor/google.golang.org/grpc/internal/channelz/trace.go
new file mode 100644
index 000000000..36b867403
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/channelz/trace.go
@@ -0,0 +1,204 @@
+/*
+ *
+ * Copyright 2018 gRPC 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 channelz
+
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+const (
+	defaultMaxTraceEntry int32 = 30
+)
+
+var maxTraceEntry = defaultMaxTraceEntry
+
+// SetMaxTraceEntry sets maximum number of trace entries per entity (i.e.
+// channel/subchannel).  Setting it to 0 will disable channel tracing.
+func SetMaxTraceEntry(i int32) {
+	atomic.StoreInt32(&maxTraceEntry, i)
+}
+
+// ResetMaxTraceEntryToDefault resets the maximum number of trace entries per
+// entity to default.
+func ResetMaxTraceEntryToDefault() {
+	atomic.StoreInt32(&maxTraceEntry, defaultMaxTraceEntry)
+}
+
+func getMaxTraceEntry() int {
+	i := atomic.LoadInt32(&maxTraceEntry)
+	return int(i)
+}
+
+// traceEvent is an internal representation of a single trace event
+type traceEvent struct {
+	// Desc is a simple description of the trace event.
+	Desc string
+	// Severity states the severity of this trace event.
+	Severity Severity
+	// Timestamp is the event time.
+	Timestamp time.Time
+	// RefID is the id of the entity that gets referenced in the event. RefID is 0 if no other entity is
+	// involved in this event.
+	// e.g. SubChannel (id: 4[]) Created. --> RefID = 4, RefName = "" (inside [])
+	RefID int64
+	// RefName is the reference name for the entity that gets referenced in the event.
+	RefName string
+	// RefType indicates the referenced entity type, i.e Channel or SubChannel.
+	RefType RefChannelType
+}
+
+// TraceEvent is what the caller of AddTraceEvent should provide to describe the
+// event to be added to the channel trace.
+//
+// The Parent field is optional. It is used for an event that will be recorded
+// in the entity's parent trace.
+type TraceEvent struct {
+	Desc     string
+	Severity Severity
+	Parent   *TraceEvent
+}
+
+type ChannelTrace struct {
+	cm           *channelMap
+	clearCalled  bool
+	CreationTime time.Time
+	EventNum     int64
+	mu           sync.Mutex
+	Events       []*traceEvent
+}
+
+func (c *ChannelTrace) copy() *ChannelTrace {
+	return &ChannelTrace{
+		CreationTime: c.CreationTime,
+		EventNum:     c.EventNum,
+		Events:       append(([]*traceEvent)(nil), c.Events...),
+	}
+}
+
+func (c *ChannelTrace) append(e *traceEvent) {
+	c.mu.Lock()
+	if len(c.Events) == getMaxTraceEntry() {
+		del := c.Events[0]
+		c.Events = c.Events[1:]
+		if del.RefID != 0 {
+			// start recursive cleanup in a goroutine to not block the call originated from grpc.
+			go func() {
+				// need to acquire c.cm.mu lock to call the unlocked attemptCleanup func.
+				c.cm.mu.Lock()
+				c.cm.decrTraceRefCount(del.RefID)
+				c.cm.mu.Unlock()
+			}()
+		}
+	}
+	e.Timestamp = time.Now()
+	c.Events = append(c.Events, e)
+	c.EventNum++
+	c.mu.Unlock()
+}
+
+func (c *ChannelTrace) clear() {
+	if c.clearCalled {
+		return
+	}
+	c.clearCalled = true
+	c.mu.Lock()
+	for _, e := range c.Events {
+		if e.RefID != 0 {
+			// caller should have already held the c.cm.mu lock.
+			c.cm.decrTraceRefCount(e.RefID)
+		}
+	}
+	c.mu.Unlock()
+}
+
+// Severity is the severity level of a trace event.
+// The canonical enumeration of all valid values is here:
+// https://github.com/grpc/grpc-proto/blob/9b13d199cc0d4703c7ea26c9c330ba695866eb23/grpc/channelz/v1/channelz.proto#L126.
+type Severity int
+
+const (
+	// CtUnknown indicates unknown severity of a trace event.
+	CtUnknown Severity = iota
+	// CtInfo indicates info level severity of a trace event.
+	CtInfo
+	// CtWarning indicates warning level severity of a trace event.
+	CtWarning
+	// CtError indicates error level severity of a trace event.
+	CtError
+)
+
+// RefChannelType is the type of the entity being referenced in a trace event.
+type RefChannelType int
+
+const (
+	// RefUnknown indicates an unknown entity type, the zero value for this type.
+	RefUnknown RefChannelType = iota
+	// RefChannel indicates the referenced entity is a Channel.
+	RefChannel
+	// RefSubChannel indicates the referenced entity is a SubChannel.
+	RefSubChannel
+	// RefServer indicates the referenced entity is a Server.
+	RefServer
+	// RefListenSocket indicates the referenced entity is a ListenSocket.
+	RefListenSocket
+	// RefNormalSocket indicates the referenced entity is a NormalSocket.
+	RefNormalSocket
+)
+
+var refChannelTypeToString = map[RefChannelType]string{
+	RefUnknown:      "Unknown",
+	RefChannel:      "Channel",
+	RefSubChannel:   "SubChannel",
+	RefServer:       "Server",
+	RefListenSocket: "ListenSocket",
+	RefNormalSocket: "NormalSocket",
+}
+
+func (r RefChannelType) String() string {
+	return refChannelTypeToString[r]
+}
+
+// AddTraceEvent adds trace related to the entity with specified id, using the
+// provided TraceEventDesc.
+//
+// If channelz is not turned ON, this will simply log the event descriptions.
+func AddTraceEvent(l grpclog.DepthLoggerV2, e Entity, depth int, desc *TraceEvent) {
+	// Log only the trace description associated with the bottom most entity.
+	d := fmt.Sprintf("[%s]%s", e, desc.Desc)
+	switch desc.Severity {
+	case CtUnknown, CtInfo:
+		l.InfoDepth(depth+1, d)
+	case CtWarning:
+		l.WarningDepth(depth+1, d)
+	case CtError:
+		l.ErrorDepth(depth+1, d)
+	}
+
+	if getMaxTraceEntry() == 0 {
+		return
+	}
+	if IsOn() {
+		db.traceEvent(e.id(), desc)
+	}
+}