snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

balancer/ringhash/config.go

@@ -0,0 +1,77 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package ringhash
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"google.golang.org/grpc/internal/envconfig"
+	"google.golang.org/grpc/internal/metadata"
+	iringhash "google.golang.org/grpc/internal/ringhash"
+)
+
+const (
+	defaultMinSize         = 1024
+	defaultMaxSize         = 4096
+	ringHashSizeUpperBound = 8 * 1024 * 1024 // 8M
+)
+
+func parseConfig(c json.RawMessage) (*iringhash.LBConfig, error) {
+	var cfg iringhash.LBConfig
+	if err := json.Unmarshal(c, &cfg); err != nil {
+		return nil, err
+	}
+	if cfg.MinRingSize > ringHashSizeUpperBound {
+		return nil, fmt.Errorf("min_ring_size value of %d is greater than max supported value %d for this field", cfg.MinRingSize, ringHashSizeUpperBound)
+	}
+	if cfg.MaxRingSize > ringHashSizeUpperBound {
+		return nil, fmt.Errorf("max_ring_size value of %d is greater than max supported value %d for this field", cfg.MaxRingSize, ringHashSizeUpperBound)
+	}
+	if cfg.MinRingSize == 0 {
+		cfg.MinRingSize = defaultMinSize
+	}
+	if cfg.MaxRingSize == 0 {
+		cfg.MaxRingSize = defaultMaxSize
+	}
+	if cfg.MinRingSize > cfg.MaxRingSize {
+		return nil, fmt.Errorf("min %v is greater than max %v", cfg.MinRingSize, cfg.MaxRingSize)
+	}
+	if cfg.MinRingSize > envconfig.RingHashCap {
+		cfg.MinRingSize = envconfig.RingHashCap
+	}
+	if cfg.MaxRingSize > envconfig.RingHashCap {
+		cfg.MaxRingSize = envconfig.RingHashCap
+	}
+	if !envconfig.RingHashSetRequestHashKey {
+		cfg.RequestHashHeader = ""
+	}
+	if cfg.RequestHashHeader != "" {
+		cfg.RequestHashHeader = strings.ToLower(cfg.RequestHashHeader)
+		// See rules in https://github.com/grpc/proposal/blob/master/A76-ring-hash-improvements.md#explicitly-setting-the-request-hash-key
+		if err := metadata.ValidateKey(cfg.RequestHashHeader); err != nil {
+			return nil, fmt.Errorf("invalid requestHashHeader %q: %v", cfg.RequestHashHeader, err)
+		}
+		if strings.HasSuffix(cfg.RequestHashHeader, "-bin") {
+			return nil, fmt.Errorf("invalid requestHashHeader %q: key must not end with \"-bin\"", cfg.RequestHashHeader)
+		}
+	}
+	return &cfg, nil
+}