Fantom-foundation/go-lachesis

package tracing

import (
    "sync"

    "github.com/ethereum/go-ethereum/common"
    "github.com/opentracing/opentracing-go"
)

var (
    enabled   bool
    txSpans   = make(map[common.Hash]opentracing.Span)
    txSpansMu sync.RWMutex

    noopSpan = opentracing.NoopTracer{}.StartSpan("")
)

func SetEnabled(val bool) {
    enabled = val
}

func StartTx(tx common.Hash, operation string) {
    if !enabled {
        return
    }

    txSpansMu.Lock()
    defer txSpansMu.Unlock()

    if _, ok := txSpans[tx]; ok {
        return
    }

    span := opentracing.StartSpan("lifecycle")
    span.SetTag("txhash", tx.String())
    span.SetTag("enter", operation)
    txSpans[tx] = span
}

func FinishTx(tx common.Hash, operation string) {
    if !enabled {
        return
    }

    txSpansMu.Lock()
    defer txSpansMu.Unlock()

    span, ok := txSpans[tx]
    if !ok {
        return
    }

    span.SetTag("exit", operation)
    span.Finish()
    delete(txSpans, tx)
}

func CheckTx(tx common.Hash, operation string) opentracing.Span {
    if !enabled {
        return noopSpan
    }

    txSpansMu.RLock()
    defer txSpansMu.RUnlock()

    span, ok := txSpans[tx]

    if !ok {
        return noopSpan
    }

    return opentracing.GlobalTracer().StartSpan(
        operation,
        opentracing.ChildOf(span.Context()),
    )
}