terraform/vendor/github.com/newrelic/go-agent/internal/txn_trace.go

316 lines
8.4 KiB
Go

package internal
import (
"bytes"
"container/heap"
"encoding/json"
"sort"
"time"
"github.com/newrelic/go-agent/internal/jsonx"
)
// See https://source.datanerd.us/agents/agent-specs/blob/master/Transaction-Trace-LEGACY.md
type traceNodeHeap []traceNode
// traceNodeParams is used for trace node parameters. A struct is used in place
// of a map[string]interface{} to facilitate testing and reduce JSON Marshal
// overhead. If too many fields get added here, it probably makes sense to
// start using a map. This struct is not embedded into traceNode to minimize
// the size of traceNode: Not all nodes will have parameters.
type traceNodeParams struct {
StackTrace *StackTrace
CleanURL string
Database string
Host string
PortPathOrID string
Query string
queryParameters queryParameters
}
func (p *traceNodeParams) WriteJSON(buf *bytes.Buffer) {
w := jsonFieldsWriter{buf: buf}
buf.WriteByte('{')
if nil != p.StackTrace {
w.writerField("backtrace", p.StackTrace)
}
if "" != p.CleanURL {
w.stringField("uri", p.CleanURL)
}
if "" != p.Database {
w.stringField("database_name", p.Database)
}
if "" != p.Host {
w.stringField("host", p.Host)
}
if "" != p.PortPathOrID {
w.stringField("port_path_or_id", p.PortPathOrID)
}
if "" != p.Query {
w.stringField("query", p.Query)
}
if nil != p.queryParameters {
w.writerField("query_parameters", p.queryParameters)
}
buf.WriteByte('}')
}
// MarshalJSON is used for testing.
func (p *traceNodeParams) MarshalJSON() ([]byte, error) {
buf := &bytes.Buffer{}
p.WriteJSON(buf)
return buf.Bytes(), nil
}
type traceNode struct {
start segmentTime
stop segmentTime
duration time.Duration
params *traceNodeParams
name string
}
func (h traceNodeHeap) Len() int { return len(h) }
func (h traceNodeHeap) Less(i, j int) bool { return h[i].duration < h[j].duration }
func (h traceNodeHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
// Push and Pop are unused: only heap.Init and heap.Fix are used.
func (h traceNodeHeap) Push(x interface{}) {}
func (h traceNodeHeap) Pop() interface{} { return nil }
// TxnTrace contains the work in progress transaction trace.
type TxnTrace struct {
Enabled bool
SegmentThreshold time.Duration
StackTraceThreshold time.Duration
nodes traceNodeHeap
maxNodes int
}
// considerNode exists to prevent unnecessary calls to witnessNode: constructing
// the metric name and params map requires allocations.
func (trace *TxnTrace) considerNode(end segmentEnd) bool {
return trace.Enabled && (end.duration >= trace.SegmentThreshold)
}
func (trace *TxnTrace) witnessNode(end segmentEnd, name string, params *traceNodeParams) {
node := traceNode{
start: end.start,
stop: end.stop,
duration: end.duration,
name: name,
params: params,
}
if !trace.considerNode(end) {
return
}
if trace.nodes == nil {
max := trace.maxNodes
if 0 == max {
max = maxTxnTraceNodes
}
trace.nodes = make(traceNodeHeap, 0, max)
}
if end.exclusive >= trace.StackTraceThreshold {
if node.params == nil {
p := new(traceNodeParams)
node.params = p
}
// skip the following stack frames:
// this method
// function in tracing.go (EndBasicSegment, EndExternalSegment, EndDatastoreSegment)
// function in internal_txn.go (endSegment, endExternal, endDatastore)
// segment end method
skip := 4
node.params.StackTrace = GetStackTrace(skip)
}
if len(trace.nodes) < cap(trace.nodes) {
trace.nodes = append(trace.nodes, node)
if len(trace.nodes) == cap(trace.nodes) {
heap.Init(trace.nodes)
}
return
}
if node.duration <= trace.nodes[0].duration {
return
}
trace.nodes[0] = node
heap.Fix(trace.nodes, 0)
}
// HarvestTrace contains a finished transaction trace ready for serialization to
// the collector.
type HarvestTrace struct {
Start time.Time
Duration time.Duration
MetricName string
CleanURL string
Trace TxnTrace
ForcePersist bool
GUID string
SyntheticsResourceID string
Attrs *Attributes
}
type nodeDetails struct {
name string
relativeStart time.Duration
relativeStop time.Duration
params *traceNodeParams
}
func printNodeStart(buf *bytes.Buffer, n nodeDetails) {
// time.Seconds() is intentionally not used here. Millisecond
// precision is enough.
relativeStartMillis := n.relativeStart.Nanoseconds() / (1000 * 1000)
relativeStopMillis := n.relativeStop.Nanoseconds() / (1000 * 1000)
buf.WriteByte('[')
jsonx.AppendInt(buf, relativeStartMillis)
buf.WriteByte(',')
jsonx.AppendInt(buf, relativeStopMillis)
buf.WriteByte(',')
jsonx.AppendString(buf, n.name)
buf.WriteByte(',')
if nil == n.params {
buf.WriteString("{}")
} else {
n.params.WriteJSON(buf)
}
buf.WriteByte(',')
buf.WriteByte('[')
}
func printChildren(buf *bytes.Buffer, traceStart time.Time, nodes sortedTraceNodes, next int, stop segmentStamp) int {
firstChild := true
for next < len(nodes) && nodes[next].start.Stamp < stop {
if firstChild {
firstChild = false
} else {
buf.WriteByte(',')
}
printNodeStart(buf, nodeDetails{
name: nodes[next].name,
relativeStart: nodes[next].start.Time.Sub(traceStart),
relativeStop: nodes[next].stop.Time.Sub(traceStart),
params: nodes[next].params,
})
next = printChildren(buf, traceStart, nodes, next+1, nodes[next].stop.Stamp)
buf.WriteString("]]")
}
return next
}
type sortedTraceNodes []*traceNode
func (s sortedTraceNodes) Len() int { return len(s) }
func (s sortedTraceNodes) Less(i, j int) bool { return s[i].start.Stamp < s[j].start.Stamp }
func (s sortedTraceNodes) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
func traceDataJSON(trace *HarvestTrace) []byte {
estimate := 100 * len(trace.Trace.nodes)
buf := bytes.NewBuffer(make([]byte, 0, estimate))
nodes := make(sortedTraceNodes, len(trace.Trace.nodes))
for i := 0; i < len(nodes); i++ {
nodes[i] = &trace.Trace.nodes[i]
}
sort.Sort(nodes)
buf.WriteByte('[') // begin trace data
// If the trace string pool is used, insert another array here.
jsonx.AppendFloat(buf, 0.0) // unused timestamp
buf.WriteByte(',') //
buf.WriteString("{}") // unused: formerly request parameters
buf.WriteByte(',') //
buf.WriteString("{}") // unused: formerly custom parameters
buf.WriteByte(',') //
printNodeStart(buf, nodeDetails{ // begin outer root
name: "ROOT",
relativeStart: 0,
relativeStop: trace.Duration,
})
printNodeStart(buf, nodeDetails{ // begin inner root
name: trace.MetricName,
relativeStart: 0,
relativeStop: trace.Duration,
})
if len(nodes) > 0 {
lastStopStamp := nodes[len(nodes)-1].stop.Stamp + 1
printChildren(buf, trace.Start, nodes, 0, lastStopStamp)
}
buf.WriteString("]]") // end outer root
buf.WriteString("]]") // end inner root
buf.WriteByte(',')
buf.WriteByte('{')
buf.WriteString(`"agentAttributes":`)
agentAttributesJSON(trace.Attrs, buf, destTxnTrace)
buf.WriteByte(',')
buf.WriteString(`"userAttributes":`)
userAttributesJSON(trace.Attrs, buf, destTxnTrace)
buf.WriteByte(',')
buf.WriteString(`"intrinsics":{}`) // TODO intrinsics
buf.WriteByte('}')
// If the trace string pool is used, end another array here.
buf.WriteByte(']') // end trace data
return buf.Bytes()
}
// MarshalJSON prepares the trace in the JSON expected by the collector.
func (trace *HarvestTrace) MarshalJSON() ([]byte, error) {
return json.Marshal([]interface{}{
trace.Start.UnixNano() / 1000,
trace.Duration.Seconds() * 1000.0,
trace.MetricName,
trace.CleanURL,
JSONString(traceDataJSON(trace)),
trace.GUID,
nil, // reserved for future use
trace.ForcePersist,
nil, // X-Ray sessions not supported
trace.SyntheticsResourceID,
})
}
type harvestTraces struct {
trace *HarvestTrace
}
func newHarvestTraces() *harvestTraces {
return &harvestTraces{}
}
func (traces *harvestTraces) Witness(trace HarvestTrace) {
if nil == traces.trace || traces.trace.Duration < trace.Duration {
cpy := new(HarvestTrace)
*cpy = trace
traces.trace = cpy
}
}
func (traces *harvestTraces) Data(agentRunID string, harvestStart time.Time) ([]byte, error) {
if nil == traces.trace {
return nil, nil
}
return json.Marshal([]interface{}{
agentRunID,
[]interface{}{
traces.trace,
},
})
}
func (traces *harvestTraces) MergeIntoHarvest(h *Harvest) {}