From e8c87a1a18c38505e3f2222b295208bce5b66850 Mon Sep 17 00:00:00 2001
From: evgeniy-scherbina <evgeniy.shcherbina.es@gmail.com>
Date: Mon, 9 Oct 2023 14:37:59 -0400
Subject: [PATCH] TMP Commit

---
 clients/cache/cache.go    |  5 ++++-
 clients/cache/inmemory.go |  6 +++---
 clients/cache/redis.go    | 12 ++++++++----
 service/cachemdw/cache.go | 27 +++++++++++++--------------
 4 files changed, 28 insertions(+), 22 deletions(-)

diff --git a/clients/cache/cache.go b/clients/cache/cache.go
index 1d5e8cb..addf846 100644
--- a/clients/cache/cache.go
+++ b/clients/cache/cache.go
@@ -2,11 +2,14 @@ package cache
 
 import (
 	"context"
+	"errors"
 	"time"
 )
 
+var ErrNotFound = errors.New("value not found in the cache")
+
 type Cache interface {
 	Set(ctx context.Context, key string, data []byte, expiration time.Duration) error
-	Get(ctx context.Context, key string) ([]byte, bool)
+	Get(ctx context.Context, key string) ([]byte, error)
 	Delete(ctx context.Context, key string) error
 }
diff --git a/clients/cache/inmemory.go b/clients/cache/inmemory.go
index 437f935..f298958 100644
--- a/clients/cache/inmemory.go
+++ b/clients/cache/inmemory.go
@@ -54,7 +54,7 @@ func (c *InMemoryCache) Set(
 }
 
 // Get retrieves the value of a key from the cache.
-func (c *InMemoryCache) Get(ctx context.Context, key string) ([]byte, bool) {
+func (c *InMemoryCache) Get(ctx context.Context, key string) ([]byte, error) {
 	c.mutex.RLock()
 	defer c.mutex.RUnlock()
 
@@ -63,10 +63,10 @@ func (c *InMemoryCache) Get(ctx context.Context, key string) ([]byte, bool) {
 		// Not a real ttl but just replicates it for fetching
 		delete(c.data, key)
 
-		return nil, false
+		return nil, ErrNotFound
 	}
 
-	return item.data, true
+	return item.data, nil
 }
 
 // GetAll returns all the non-expired data in the cache.
diff --git a/clients/cache/redis.go b/clients/cache/redis.go
index 8610663..b400a30 100644
--- a/clients/cache/redis.go
+++ b/clients/cache/redis.go
@@ -58,12 +58,16 @@ func (rc *RedisCache) Set(
 func (rc *RedisCache) Get(
 	ctx context.Context,
 	key string,
-) ([]byte, bool) {
+) ([]byte, error) {
 	val, err := rc.client.Get(ctx, key).Bytes()
+	if err == redis.Nil {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
 
-	// Mo error == found. This throws away any other errors that aren't "key not
-	// found" errors.
-	return val, err == nil
+	return val, nil
 }
 
 // Delete deletes the value for the given key in the cache.
diff --git a/service/cachemdw/cache.go b/service/cachemdw/cache.go
index 664ff42..9384e83 100644
--- a/service/cachemdw/cache.go
+++ b/service/cachemdw/cache.go
@@ -58,24 +58,23 @@ func (c *ServiceCache) GetCachedQueryResponse(
 	ctx context.Context,
 	requestHost string,
 	req *decode.EVMRPCRequestEnvelope,
-) ([]byte, bool) {
+) ([]byte, error) {
 	chainID, err := c.GetAndCacheChainID(ctx, requestHost)
-	found := err == nil // TODO(yevhenii): refactor
-	if !found {
-		return nil, false
+	if err != nil {
+		return nil, err
 	}
 
 	key, err := GetQueryKey(chainID, req)
 	if err != nil {
-		return nil, false
+		return nil, err
 	}
 
-	value, found := c.cacheClient.Get(ctx, key)
-	if !found {
-		return nil, false
+	value, err := c.cacheClient.Get(ctx, key)
+	if err != nil {
+		return nil, err
 	}
 
-	return value, true
+	return value, nil
 }
 
 func (c *ServiceCache) CacheQueryResponse(
@@ -133,15 +132,15 @@ func (c *ServiceCache) ValidateAndCacheQueryResponse(
 func (c *ServiceCache) GetCachedChainID(
 	ctx context.Context,
 	host string,
-) (string, bool) {
+) (string, error) {
 	key := GetChainKey(host)
 
-	chainID, found := c.cacheClient.Get(ctx, key)
-	if !found {
-		return "", false
+	chainID, err := c.cacheClient.Get(ctx, key)
+	if err != nil {
+		return "", err
 	}
 
-	return string(chainID), true
+	return string(chainID), nil
 }
 
 func (c *ServiceCache) GetAndCacheChainID(