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[Golang Gzip] #golang #go #gzip #proxy
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package main | |
import ( | |
"compress/gzip" | |
"io" | |
"log" | |
"net/http" | |
"os" | |
"time" | |
) | |
func main() { | |
client := &http.Client{ | |
Timeout: time.Second * time.Duration(5*time.Second), | |
} | |
req, err := http.NewRequest("GET", "https://httpbin.org/gzip", nil) | |
if err != nil { | |
log.Fatalf("http new request error: %s", err) | |
} | |
// NOTE: If Accept-Encoding isn't presented to httpbin server, it won't send gzip response. | |
req.Header.Add("Accept-Encoding", "gzip, deflate, br") | |
resp, err := client.Do(req) | |
if err != nil { | |
log.Fatalf("http error: %s", err) | |
} | |
r, err := gzip.NewReader(resp.Body) | |
if err != nil { | |
log.Fatalf("new reader error: %s", err) | |
} | |
defer r.Close() | |
io.Copy(os.Stdout, r) | |
} |
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package main | |
import ( | |
"bytes" | |
"compress/gzip" | |
"io/ioutil" | |
) | |
func main() { | |
data := []byte("HelloWorld") | |
var b bytes.Buffer | |
w := gzip.NewWriter(&b) | |
w.Write(data) | |
w.Flush() | |
w.Close() | |
r, _ := gzip.NewReader(&b) | |
defer r.Close() | |
rawData, err := ioutil.ReadAll(r) | |
println(string(rawData)) | |
if err != nil { | |
panic(err.Error()) | |
} | |
} |
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package main | |
import ( | |
"net/http" | |
"compress/gzip" | |
"io/ioutil" | |
"strings" | |
"sync" | |
"io" | |
) | |
var gzPool = sync.Pool { | |
New: func() interface{} { | |
w := gzip.NewWriter(ioutil.Discard) | |
return w | |
}, | |
} | |
type gzipResponseWriter struct { | |
io.Writer | |
http.ResponseWriter | |
} | |
func (w *gzipResponseWriter) WriteHeader(status int) { | |
w.Header().Del("Content-Length") | |
w.ResponseWriter.WriteHeader(status) | |
} | |
func (w *gzipResponseWriter) Write(b []byte) (int, error) { | |
return w.Writer.Write(b) | |
} | |
func Gzip(next http.Handler) http.Handler { | |
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { | |
if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") { | |
next.ServeHTTP(w, r) | |
return | |
} | |
w.Header().Set("Content-Encoding", "gzip") | |
gz := gzPool.Get().(*gzip.Writer) | |
defer gzPool.Put(gz) | |
gz.Reset(w) | |
defer gz.Close() | |
next.ServeHTTP(&gzipResponseWriter{ResponseWriter: w, Writer: gz}, r) | |
}) | |
} |
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package main | |
import ( | |
"bytes" | |
"compress/gzip" | |
"encoding/base64" | |
"fmt" | |
"io/ioutil" | |
"math/rand" | |
) | |
func main() { | |
var b bytes.Buffer | |
w := gzip.NewWriter(&b) | |
w.Write(bytes.Repeat([]byte("x"), 800)) | |
w.Flush() | |
w.Close() | |
b1 := bytes.NewReader(b.Bytes()) | |
fmt.Printf("%+v (%T)\n", b1, b1) | |
r, _ := gzip.NewReader(&b) | |
defer r.Close() | |
rawData, err := ioutil.ReadAll(r) | |
println(string(rawData)) | |
if err != nil { | |
panic(err.Error()) | |
} | |
// use "math/rand"'s rand.Read to populate []byte with random data of specified length | |
genBytes := make([]byte, 800) | |
rand.Read(genBytes) // generally won't be readable so might _look_ compressed even when decompressed | |
// so maybe write encoded data to the gzip writer (see below for example). | |
var mockWriter bytes.Buffer | |
w := gzip.NewWriter(&mockWriter) | |
w.Write(genBytes) | |
w.Flush() | |
w.Close() | |
debugReadCloser := ioutil.NopCloser(bytes.NewReader(mockWriter.Bytes())) | |
// encoded example | |
genBytes := make([]byte, 406715) | |
rand.Read(genBytes) | |
encoded := make([]byte, 542288) | |
base64.StdEncoding.Encode(encoded, genBytes) | |
var mockWriter bytes.Buffer | |
w := gzip.NewWriter(&mockWriter) | |
w.Write(encoded) | |
w.Flush() | |
w.Close() | |
debugReadCloser := ioutil.NopCloser(bytes.NewReader(mockWriter.Bytes())) | |
} |
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// https://github.com/golang/go/issues/14975 | |
// slightly broken in the sense of not handling gz.Close() | |
// | |
// https://gist.github.com/erikdubbelboer/7df2b2b9f34f9f839a84 | |
// updated fork with fix + other refactorings + tests | |
package main | |
import ( | |
"compress/gzip" | |
"fmt" | |
"io" | |
"io/ioutil" | |
"net/http" | |
"net/http/httputil" | |
"net/url" | |
"strings" | |
"time" | |
) | |
// Gzip from https://gist.github.com/the42/1956518 | |
type gzipResponseWriter struct { | |
io.Writer | |
http.ResponseWriter | |
} | |
func (w gzipResponseWriter) Write(b []byte) (int, error) { | |
return w.Writer.Write(b) | |
} | |
func (w gzipResponseWriter) WriteHeader(code int) { | |
fmt.Printf("Writing header: %v\n", code) | |
w.Header().Del("Content-Length") | |
w.ResponseWriter.WriteHeader(code) | |
} | |
func makeGzipHandler(fn http.HandlerFunc) http.HandlerFunc { | |
return func(w http.ResponseWriter, r *http.Request) { | |
if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") { | |
fn(w, r) | |
return | |
} | |
w.Header().Set("Content-Encoding", "gzip") | |
gz := gzip.NewWriter(w) | |
defer func() { | |
err := gz.Close() | |
if err != nil { | |
fmt.Printf("Error closing gzip: %+v\n", err) | |
} | |
}() | |
gzr := gzipResponseWriter{Writer: gz, ResponseWriter: w} | |
fn(gzr, r) | |
} | |
} | |
// Handler that does not set a content length, so, golang uses chunking. | |
func handler(w http.ResponseWriter, r *http.Request) { | |
message := "Hello, world!" | |
w.Header().Set("Content-Type", "text/plain") | |
w.Write([]byte(message)) | |
} | |
// Constructs a reverse proxy to the given port. | |
func reverseProxy(port string) func(http.ResponseWriter, *http.Request) { | |
url, err := url.Parse("http://127.0.0.1" + port) | |
if err != nil { | |
panic(err) | |
} | |
return httputil.NewSingleHostReverseProxy(url).ServeHTTP | |
} | |
// Gets the content from the given server, then returns the error from reading the body. | |
func get(server http.Server) error { | |
resp, err := http.Get("http://127.0.0.1" + server.Addr) | |
if err != nil { | |
panic(err) | |
} | |
defer resp.Body.Close() | |
_, err = ioutil.ReadAll(resp.Body) | |
return err | |
} | |
func main() { | |
server := http.Server{ | |
Addr: ":2000", | |
Handler: http.HandlerFunc(handler), | |
} | |
go server.ListenAndServe() | |
proxyServer := http.Server{ | |
Addr: ":4000", | |
Handler: makeGzipHandler(reverseProxy(server.Addr)), | |
} | |
go proxyServer.ListenAndServe() | |
time.Sleep(10 * time.Millisecond) | |
fmt.Printf("Server err: %v\n", get(server)) | |
fmt.Printf("Proxy server err: %v\n", get(proxyServer)) | |
} |
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