metadata

Documentation

Overview

Package metadata define the structure of the metadata supported by gRPC library. Please refer to http://www.grpc.io/docs/guides/wire.html for more information about custom-metadata.

Index

• func DecodeKeyValue(k, v string) (string, string, error)
• func NewContext(ctx context.Context, md MD) context.Context
• type MD
  • func FromContext(ctx context.Context) (md MD, ok bool)
  • func Join(mds ...MD) MD
  • func New(m map[string]string) MD
  • func Pairs(kv ...string) MD
  • func (md MD) Copy() MD
  • func (md MD) Len() int

Functions

func DecodeKeyValue

func DecodeKeyValue(k, v string) (string, string, error)

DecodeKeyValue returns the original key and value corresponding to the encoded data in k, v. If k is a binary header and v contains comma, v is split on comma before decoded, and the decoded v will be joined with comma before returned.

func NewContext

func NewContext(ctx context.Context, md MD) context.Context

NewContext creates a new context with md attached.

Types

type MD

type MD map[string][]string

MD is a mapping from metadata keys to values. Users should use the following two convenience functions New and Pairs to generate MD.

func FromContext

func FromContext(ctx context.Context) (md MD, ok bool)

FromContext returns the MD in ctx if it exists. The returned md should be immutable, writing to it may cause races. Modification should be made to the copies of the returned md.

func Join

func Join(mds ...MD) 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 New

func New(m map[string]string) MD

New creates a MD from given key-value map. Keys are automatically converted to lowercase. And for keys having "-bin" as suffix, their values will be applied Base64 encoding.

func Pairs

func Pairs(kv ...string) MD

Pairs returns an MD formed by the mapping of key, value ... Pairs panics if len(kv) is odd. Keys are automatically converted to lowercase. And for keys having "-bin" as suffix, their values will be appplied Base64 encoding.

func (MD) Copy

func (md MD) Copy() MD

Copy returns a copy of md.

func (MD) Len

func (md MD) Len() int

Len returns the number of items in md.