/
chain.go
53 lines (45 loc) · 1.18 KB
/
chain.go
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package eth
import (
"context"
"math/big"
"time"
ethereum "github.com/ethereum/go-ethereum"
"github.com/ethereum/go-ethereum/core/types"
log "github.com/golang/glog"
)
// RetryChainReader is a ChainReader that includes some version of ChainReader
// functions that are wrapped by a retry mechanism
type RetryChainReader struct {
ethereum.ChainReader
}
// HeaderByNumberWithRetry is a version of HeaderByNumber that has a retry
// mechanism
func (r *RetryChainReader) HeaderByNumberWithRetry(blockNumber uint64, maxAttempts int,
baseWaitMs int) (*types.Header, error) {
blockNum := big.NewInt(0)
blockNum.SetUint64(blockNumber)
attempt := 1
var header *types.Header
var err error
for {
header, err = r.HeaderByNumber(context.Background(), blockNum)
if err != nil {
if err != ethereum.NotFound {
return nil, err
}
log.Infof(
"block not found, sleep/attempt again, waiting %v ms...",
baseWaitMs*attempt,
)
// Take a break and see if the block can be found
time.Sleep(time.Duration(baseWaitMs) * time.Duration(attempt) * time.Millisecond)
if attempt > maxAttempts {
return nil, err
}
attempt++
continue
}
break
}
return header, nil
}