+++ /dev/null
-/*
- *
- * Copyright 2014 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 metadata define the structure of the metadata supported by gRPC library.
-// Please refer to https://grpc.io/docs/guides/wire.html for more information about custom-metadata.
-package metadata // import "google.golang.org/grpc/metadata"
-
-import (
- "fmt"
- "strings"
-
- "golang.org/x/net/context"
-)
-
-// DecodeKeyValue returns k, v, nil. It is deprecated and should not be used.
-func DecodeKeyValue(k, v string) (string, string, error) {
- return k, v, nil
-}
-
-// MD is a mapping from metadata keys to values. Users should use the following
-// two convenience functions New and Pairs to generate MD.
-type MD map[string][]string
-
-// New creates an MD from a given key-value map.
-//
-// Only the following ASCII characters are allowed in keys:
-// - digits: 0-9
-// - uppercase letters: A-Z (normalized to lower)
-// - lowercase letters: a-z
-// - special characters: -_.
-// Uppercase letters are automatically converted to lowercase.
-//
-// Keys beginning with "grpc-" are reserved for grpc-internal use only and may
-// result in errors if set in metadata.
-func New(m map[string]string) MD {
- md := MD{}
- for k, val := range m {
- key := strings.ToLower(k)
- md[key] = append(md[key], val)
- }
- return md
-}
-
-// Pairs returns an MD formed by the mapping of key, value ...
-// Pairs panics if len(kv) is odd.
-//
-// Only the following ASCII characters are allowed in keys:
-// - digits: 0-9
-// - uppercase letters: A-Z (normalized to lower)
-// - lowercase letters: a-z
-// - special characters: -_.
-// Uppercase letters are automatically converted to lowercase.
-//
-// Keys beginning with "grpc-" are reserved for grpc-internal use only and may
-// result in errors if set in metadata.
-func Pairs(kv ...string) MD {
- if len(kv)%2 == 1 {
- panic(fmt.Sprintf("metadata: Pairs got the odd number of input pairs for metadata: %d", len(kv)))
- }
- md := MD{}
- var key string
- for i, s := range kv {
- if i%2 == 0 {
- key = strings.ToLower(s)
- continue
- }
- md[key] = append(md[key], s)
- }
- return md
-}
-
-// Len returns the number of items in md.
-func (md MD) Len() int {
- return len(md)
-}
-
-// Copy returns a copy of md.
-func (md MD) Copy() MD {
- return Join(md)
-}
-
-// Join joins any number of mds into a single MD.
-// The order of values for each key is determined by the order in which
-// the mds containing those values are presented to Join.
-func Join(mds ...MD) MD {
- out := MD{}
- for _, md := range mds {
- for k, v := range md {
- out[k] = append(out[k], v...)
- }
- }
- return out
-}
-
-type mdIncomingKey struct{}
-type mdOutgoingKey struct{}
-
-// NewIncomingContext creates a new context with incoming md attached.
-func NewIncomingContext(ctx context.Context, md MD) context.Context {
- return context.WithValue(ctx, mdIncomingKey{}, md)
-}
-
-// NewOutgoingContext creates a new context with outgoing md attached.
-func NewOutgoingContext(ctx context.Context, md MD) context.Context {
- return context.WithValue(ctx, mdOutgoingKey{}, md)
-}
-
-// FromIncomingContext returns the incoming metadata in ctx if it exists. The
-// returned MD should not be modified. Writing to it may cause races.
-// Modification should be made to copies of the returned MD.
-func FromIncomingContext(ctx context.Context) (md MD, ok bool) {
- md, ok = ctx.Value(mdIncomingKey{}).(MD)
- return
-}
-
-// FromOutgoingContext returns the outgoing metadata in ctx if it exists. The
-// returned MD should not be modified. Writing to it may cause races.
-// Modification should be made to the copies of the returned MD.
-func FromOutgoingContext(ctx context.Context) (md MD, ok bool) {
- md, ok = ctx.Value(mdOutgoingKey{}).(MD)
- return
-}
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