From 77d5b4eaeec7d96dd0b6763b99d2570e33829cd1 Mon Sep 17 00:00:00 2001
From: David Wobrock <david.wobrock@backmarket.com>
Date: Sat, 28 Jan 2023 16:53:25 +0100
Subject: [PATCH] feat: add cache to Koanf.validatePipelineConfig

---
 driver/configuration/provider_koanf.go | 49 ++++++++++++++++++++------
 1 file changed, 39 insertions(+), 10 deletions(-)

diff --git a/driver/configuration/provider_koanf.go b/driver/configuration/provider_koanf.go
index 0b972aa688..844d626460 100644
--- a/driver/configuration/provider_koanf.go
+++ b/driver/configuration/provider_koanf.go
@@ -6,6 +6,7 @@ package configuration
 import (
 	"bytes"
 	"context"
+	"crypto/sha256"
 	"encoding/json"
 	"fmt"
 	"net/url"
@@ -14,6 +15,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/dgraph-io/ristretto"
+
 	"github.com/google/uuid"
 	"github.com/knadh/koanf"
 	"github.com/pkg/errors"
@@ -40,11 +43,7 @@ type (
 		l      *logrusx.Logger
 		ctx    context.Context
 
-		enabledMutex sync.RWMutex
-		enabledCache map[uint64]bool
-
-		configMutex sync.RWMutex
-		configCache map[uint64]json.RawMessage
+		configValidationCache *ristretto.Cache
 
 		subscriptions subscriptions
 	}
@@ -60,13 +59,24 @@ type (
 var _ Provider = new(KoanfProvider)
 
 func NewKoanfProvider(ctx context.Context, flags *pflag.FlagSet, l *logrusx.Logger, opts ...configx.OptionModifier) (kp *KoanfProvider, err error) {
+	maxItems := int64(5000)
+	cache, _ := ristretto.NewCache(&ristretto.Config{
+		NumCounters:        maxItems * 10,
+		MaxCost:            maxItems,
+		BufferItems:        64,
+		Metrics:            false,
+		IgnoreInternalCost: true,
+		Cost: func(value interface{}) int64 {
+			return 1
+		},
+	})
+
 	kp = &KoanfProvider{
 		ctx: ctx,
 		l:   l,
 
-		enabledCache:  make(map[uint64]bool),
-		configCache:   make(map[uint64]json.RawMessage),
-		subscriptions: subscriptions{data: make(map[SubscriptionID]callback)},
+		configValidationCache: cache,
+		subscriptions:         subscriptions{data: make(map[SubscriptionID]callback)},
 	}
 	kp.source, err = configx.New(
 		ctx,
@@ -283,6 +293,20 @@ func (v *KoanfProvider) pipelineIsEnabled(prefix, id string) bool {
 	return v.source.Bool(fmt.Sprintf("%s.%s.enabled", prefix, id))
 }
 
+func (v *KoanfProvider) hashPipelineConfig(prefix, id string, marshalled []byte) string {
+	slices := [][]byte{
+		[]byte(prefix),
+		[]byte(id),
+		marshalled,
+	}
+
+	var hashSlices []byte
+	for _, s := range slices {
+		hashSlices = append(hashSlices, s...)
+	}
+	return fmt.Sprintf("%x", sha256.Sum256(hashSlices))
+}
+
 func (v *KoanfProvider) PipelineConfig(prefix, id string, override json.RawMessage, dest interface{}) error {
 	if dest == nil {
 		return nil
@@ -302,8 +326,13 @@ func (v *KoanfProvider) PipelineConfig(prefix, id string, override json.RawMessa
 		return errors.WithStack(err)
 	}
 
-	if err = v.validatePipelineConfig(prefix, id, marshalled); err != nil {
-		return errors.WithStack(err)
+	hash := v.hashPipelineConfig(prefix, id, marshalled)
+	item, found := v.configValidationCache.Get(hash)
+	if !found || !item.(bool) {
+		if err = v.validatePipelineConfig(prefix, id, marshalled); err != nil {
+			return errors.WithStack(err)
+		}
+		v.configValidationCache.Set(hash, true, 0)
 	}
 
 	if err := json.NewDecoder(bytes.NewBuffer(marshalled)).Decode(dest); err != nil {