lint

proxyd/lvc.go

-package proxyd
-
-import (
-	"context"
-	"time"
-
-	"github.com/ethereum/go-ethereum/ethclient"
-	"github.com/ethereum/go-ethereum/log"
-)
-
-const cacheSyncRate = 1 * time.Second
-
-type lvcUpdateFn func(context.Context, *ethclient.Client) (string, error)
-
-type EthLastValueCache struct {
-	client  *ethclient.Client
-	cache   Cache
-	key     string
-	updater lvcUpdateFn
-	quit    chan struct{}
-}
-
-func newLVC(client *ethclient.Client, cache Cache, cacheKey string, updater lvcUpdateFn) *EthLastValueCache {
-	return &EthLastValueCache{
-		client:  client,
-		cache:   cache,
-		key:     cacheKey,
-		updater: updater,
-		quit:    make(chan struct{}),
-	}
-}
-
-func (h *EthLastValueCache) Start() {
-	go func() {
-		ticker := time.NewTicker(cacheSyncRate)
-		defer ticker.Stop()
-
-		for {
-			select {
-			case <-ticker.C:
-				lvcPollTimeGauge.WithLabelValues(h.key).SetToCurrentTime()
-
-				value, err := h.getUpdate()
-				if err != nil {
-					log.Error("error retrieving latest value", "key", h.key, "error", err)
-					continue
-				}
-				log.Trace("polling latest value", "value", value)
-
-				if err := h.cache.Put(context.Background(), h.key, value); err != nil {
-					log.Error("error writing last value to cache", "key", h.key, "error", err)
-				}
-
-			case <-h.quit:
-				return
-			}
-		}
-	}()
-}
-
-func (h *EthLastValueCache) getUpdate() (string, error) {
-	const maxRetries = 5
-	var err error
-
-	for i := 0; i <= maxRetries; i++ {
-		var value string
-		value, err = h.updater(context.Background(), h.client)
-		if err != nil {
-			backoff := calcBackoff(i)
-			log.Warn("http operation failed. retrying...", "error", err, "backoff", backoff)
-			lvcErrorsTotal.WithLabelValues(h.key).Inc()
-			time.Sleep(backoff)
-			continue
-		}
-		return value, nil
-	}
-
-	return "", wrapErr(err, "exceeded retries")
-}
-
-func (h *EthLastValueCache) Stop() {
-	close(h.quit)
-}
-
-func (h *EthLastValueCache) Read(ctx context.Context) (string, error) {
-	return h.cache.Get(ctx, h.key)
-}

proxyd/methods.go

@@ -3,9 +3,10 @@ package proxyd
 import (
 	"context"
 	"encoding/json"
-	"github.com/ethereum/go-ethereum/log"
 	"strings"
 	"sync"
+
+	"github.com/ethereum/go-ethereum/log"
 )
 
 type RPCMethodHandler interface {

proxyd/metrics.go

@@ -190,22 +190,6 @@ var (
 		"method",
 	})
 
-	lvcErrorsTotal = promauto.NewCounterVec(prometheus.CounterOpts{
-		Namespace: MetricsNamespace,
-		Name:      "lvc_errors_total",
-		Help:      "Count of lvc errors.",
-	}, []string{
-		"key",
-	})
-
-	lvcPollTimeGauge = promauto.NewGaugeVec(prometheus.GaugeOpts{
-		Namespace: MetricsNamespace,
-		Name:      "lvc_poll_time_gauge",
-		Help:      "Gauge of lvc poll time.",
-	}, []string{
-		"key",
-	})
-
 	batchRPCShortCircuitsTotal = promauto.NewCounter(prometheus.CounterOpts{
 		Namespace: MetricsNamespace,
 		Name:      "batch_rpc_short_circuits_total",

proxyd/proxyd.go

 package proxyd
 
 import (
-	"context"
 	"crypto/tls"
 	"errors"
 	"fmt"
 	"net/http"
 	"os"
-	"strconv"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common/math"
@@ -370,39 +368,3 @@ func configureBackendTLS(cfg *BackendConfig) (*tls.Config, error) {
 
 	return tlsConfig, nil
 }
-
-func makeUint64LastValueFn(client *ethclient.Client, cache Cache, key string, updater lvcUpdateFn) (*EthLastValueCache, func(context.Context) (uint64, error)) {
-	lvc := newLVC(client, cache, key, updater)
-	lvc.Start()
-	return lvc, func(ctx context.Context) (uint64, error) {
-		value, err := lvc.Read(ctx)
-		if err != nil {
-			return 0, err
-		}
-		if value == "" {
-			return 0, fmt.Errorf("%s is unavailable", key)
-		}
-		valueUint, err := strconv.ParseUint(value, 10, 64)
-		if err != nil {
-			return 0, err
-		}
-		return valueUint, nil
-	}
-}
-
-func makeGetLatestBlockNumFn(client *ethclient.Client, cache Cache) (*EthLastValueCache, GetLatestBlockNumFn) {
-	return makeUint64LastValueFn(client, cache, "lvc:block_number", func(ctx context.Context, c *ethclient.Client) (string, error) {
-		blockNum, err := c.BlockNumber(ctx)
-		return strconv.FormatUint(blockNum, 10), err
-	})
-}
-
-func makeGetLatestGasPriceFn(client *ethclient.Client, cache Cache) (*EthLastValueCache, GetLatestGasPriceFn) {
-	return makeUint64LastValueFn(client, cache, "lvc:gas_price", func(ctx context.Context, c *ethclient.Client) (string, error) {
-		gasPrice, err := c.SuggestGasPrice(ctx)
-		if err != nil {
-			return "", err
-		}
-		return gasPrice.String(), nil
-	})
-}