encode

Documentation

Overview

Package encode implements an encoder middleware for Kengine. The initial enhancements related to Accept-Encoding, minimum content length, and buffer/writer pools were adapted from https://github.com/xi2/httpgzip then modified heavily to accommodate modular encoders and fix bugs. Code borrowed from that repository is Copyright (c) 2015 The Httpgzip Authors.

Index

• func AcceptedEncodings(r *http.Request, preferredOrder []string) []string
• type Encode
  • func (Encode) KengineModule() kengine.ModuleInfo
  • func (enc *Encode) Match(rw *responseWriter) bool
  • func (enc *Encode) Provision(ctx kengine.Context) error
  • func (enc *Encode) ServeHTTP(w http.ResponseWriter, r *http.Request, next kenginehttp.Handler) error
  • func (enc *Encode) UnmarshalKenginefile(d *kenginefile.Dispenser) error
  • func (enc *Encode) Validate() error
• type Encoder
• type Encoding
• type Precompressed

Functions

func AcceptedEncodings

func AcceptedEncodings(r *http.Request, preferredOrder []string) []string

AcceptedEncodings returns the list of encodings that the client supports, in descending order of preference. The client preference via q-factor and the server preference via Prefer setting are taken into account. If the Sec-WebSocket-Key header is present then non-identity encodings are not considered. See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html.

Types

type Encode

type Encode struct {
	// Selection of compression algorithms to choose from. The best one
	// will be chosen based on the client's Accept-Encoding header.
	EncodingsRaw kengine.ModuleMap `json:"encodings,omitempty" kengine:"namespace=http.encoders"`

	// If the client has no strong preference, choose these encodings in order.
	Prefer []string `json:"prefer,omitempty"`

	// Only encode responses that are at least this many bytes long.
	MinLength int `json:"minimum_length,omitempty"`

	// Only encode responses that match against this ResponseMmatcher.
	// The default is a collection of text-based Content-Type headers.
	Matcher *kenginehttp.ResponseMatcher `json:"match,omitempty"`
	// contains filtered or unexported fields
}

Encode is a middleware which can encode responses.

func (Encode) KengineModule

func (Encode) KengineModule() kengine.ModuleInfo

KengineModule returns the Kengine module information.

func (*Encode) Match

func (enc *Encode) Match(rw *responseWriter) bool

Match determines, if encoding should be done based on the ResponseMatcher.

func (*Encode) Provision

func (enc *Encode) Provision(ctx kengine.Context) error

Provision provisions enc.

func (*Encode) ServeHTTP

func (enc *Encode) ServeHTTP(w http.ResponseWriter, r *http.Request, next kenginehttp.Handler) error

func (*Encode) UnmarshalKenginefile

func (enc *Encode) UnmarshalKenginefile(d *kenginefile.Dispenser) error

UnmarshalKenginefile sets up the handler from Kenginefile tokens. Syntax:

encode [<matcher>] <formats...> {
    gzip           [<level>]
    zstd
    minimum_length <length>
    # response matcher block
    match {
        status <code...>
        header <field> [<value>]
    }
    # or response matcher single line syntax
    match [header <field> [<value>]] | [status <code...>]
}

Specifying the formats on the first line will use those formats' defaults.

func (*Encode) Validate

func (enc *Encode) Validate() error

Validate ensures that enc's configuration is valid.

type Encoder

type Encoder interface {
	io.WriteCloser
	Reset(io.Writer)
	Flush() error // encoder by default buffers data to maximize compressing rate
}

Encoder is a type which can encode a stream of data.

type Encoding

type Encoding interface {
	AcceptEncoding() string
	NewEncoder() Encoder
}

Encoding is a type which can create encoders of its kind and return the name used in the Accept-Encoding header.

type Precompressed

type Precompressed interface {
	AcceptEncoding() string
	Suffix() string
}

Precompressed is a type which returns filename suffix of precompressed file and Accept-Encoding header to use when serving this file.