gzip

Documentation

Overview

Package gzip provides a middleware layer that performs gzip compression on the response.

Index

• Constants
• type Config
• type ExtFilter
  • func DefaultExtFilter() ExtFilter
  • func (e ExtFilter) ShouldCompress(r *http.Request) bool
• type Gzip
  • func (g Gzip) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error)
• type LengthFilter
  • func (l LengthFilter) ShouldCompress(w http.ResponseWriter) bool
• type PathFilter
  • func (p PathFilter) ShouldCompress(r *http.Request) bool
• type RequestFilter
• type ResponseFilter
• type ResponseFilterWriter
  • func NewResponseFilterWriter(filters []ResponseFilter, gz *gzipResponseWriter) *ResponseFilterWriter
  • func (r *ResponseFilterWriter) Write(b []byte) (int, error)
  • func (r *ResponseFilterWriter) WriteHeader(code int)
  • func (w ResponseFilterWriter) Writer() io.Writer
• type Set
  • func (s Set) Add(value string)
  • func (s Set) Contains(value string) bool
  • func (s Set) ContainsFunc(f func(string) bool) bool
  • func (s Set) Remove(value string)
• type SkipCompressedFilter
  • func (n SkipCompressedFilter) ShouldCompress(w http.ResponseWriter) bool

Constants

const ExtWildCard = "*"

ExtWildCard is the wildcard for extensions.

Types

type Config

type Config struct {
	RequestFilters  []RequestFilter
	ResponseFilters []ResponseFilter
	Level           int // Compression level
}

Config holds the configuration for Gzip middleware

type ExtFilter

type ExtFilter struct {
	// Exts is the file name extensions to accept
	Exts Set
}

ExtFilter is RequestFilter for file name extensions.

func DefaultExtFilter

func DefaultExtFilter() ExtFilter

DefaultExtFilter creates an ExtFilter with default extensions.

func (ExtFilter) ShouldCompress

func (e ExtFilter) ShouldCompress(r *http.Request) bool

ShouldCompress checks if the request file extension matches any of the registered extensions. It returns true if the extension is found and false otherwise.

type Gzip

type Gzip struct {
	Next    httpserver.Handler
	Configs []Config
}

Gzip is a middleware type which gzips HTTP responses. It is imperative that any handler which writes to a gzipped response specifies the Content-Type, otherwise some clients will assume application/x-gzip and try to download a file.

func (Gzip) ServeHTTP

func (g Gzip) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error)

ServeHTTP serves a gzipped response if the client supports it.

type LengthFilter

type LengthFilter int64

LengthFilter is ResponseFilter for minimum content length.

func (LengthFilter) ShouldCompress

func (l LengthFilter) ShouldCompress(w http.ResponseWriter) bool

ShouldCompress returns if content length is greater than or equals to minimum length.

type PathFilter

type PathFilter struct {
	// IgnoredPaths is the paths to ignore
	IgnoredPaths Set
}

PathFilter is RequestFilter for request path.

func (PathFilter) ShouldCompress

func (p PathFilter) ShouldCompress(r *http.Request) bool

ShouldCompress checks if the request path matches any of the registered paths to ignore. It returns false if an ignored path is found and true otherwise.

type RequestFilter

type RequestFilter interface {
	// ShouldCompress tells if gzip compression
	// should be done on the request.
	ShouldCompress(*http.Request) bool
}

RequestFilter determines if a request should be gzipped.

type ResponseFilter

type ResponseFilter interface {
	ShouldCompress(http.ResponseWriter) bool
}

ResponseFilter determines if the response should be gzipped.

type ResponseFilterWriter

type ResponseFilterWriter struct {
	// contains filtered or unexported fields
}

ResponseFilterWriter validates ResponseFilters. It writes gzip compressed data if ResponseFilters are satisfied or uncompressed data otherwise.

func NewResponseFilterWriter

func NewResponseFilterWriter(filters []ResponseFilter, gz *gzipResponseWriter) *ResponseFilterWriter

NewResponseFilterWriter creates and initializes a new ResponseFilterWriter.

func (*ResponseFilterWriter) Write

func (r *ResponseFilterWriter) Write(b []byte) (int, error)

Write wraps underlying Write method and compresses if filters are satisfied

func (*ResponseFilterWriter) WriteHeader

func (r *ResponseFilterWriter) WriteHeader(code int)

WriteHeader wraps underlying WriteHeader method and compresses if filters are satisfied.

func (ResponseFilterWriter) Writer

func (w ResponseFilterWriter) Writer() io.Writer

Writer use a lazy way to initialize Writer

type Set

type Set map[string]struct{}

Set stores distinct strings.

func (Set) Add

func (s Set) Add(value string)

Add adds an element to the set.

func (Set) Contains

func (s Set) Contains(value string) bool

Contains check if the set contains value.

func (Set) ContainsFunc

func (s Set) ContainsFunc(f func(string) bool) bool

ContainsFunc is similar to Contains. It iterates all the elements in the set and passes each to f. It returns true on the first call to f that returns true and false otherwise.

func (Set) Remove

func (s Set) Remove(value string)

Remove removes an element from the set.

type SkipCompressedFilter

type SkipCompressedFilter struct{}

SkipCompressedFilter is ResponseFilter that will discard already compressed responses

func (SkipCompressedFilter) ShouldCompress

func (n SkipCompressedFilter) ShouldCompress(w http.ResponseWriter) bool

ShouldCompress returns true if served file is not already compressed encodings via https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding