fix: specify size in some map allocations (minio#20764)

Author: arturmelanchyk

cmd/erasure-server-pool.go

@@ -256,7 +256,7 @@ func (z *erasureServerPools) NewNSLock(bucket string, objects ...string) RWLocke
 
 // GetDisksID will return disks by their ID.
 func (z *erasureServerPools) GetDisksID(ids ...string) []StorageAPI {
-	idMap := make(map[string]struct{})
+	idMap := make(map[string]struct{}, len(ids))
 	for _, id := range ids {
 		idMap[id] = struct{}{}
 	}

cmd/signature-v4.go

@@ -60,7 +60,7 @@ const (
 // getCanonicalHeaders generate a list of request headers with their values
 func getCanonicalHeaders(signedHeaders http.Header) string {
 	var headers []string
-	vals := make(http.Header)
+	vals := make(http.Header, len(signedHeaders))
 	for k, vv := range signedHeaders {
 		k = strings.ToLower(k)
 		headers = append(headers, k)