139 lines
3.3 KiB
Go
139 lines
3.3 KiB
Go
// Copyright 2018 Frédéric Guillot. All rights reserved.
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// Use of this source code is governed by the Apache 2.0
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// license that can be found in the LICENSE file.
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package response // import "miniflux.app/http/response"
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import (
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"compress/flate"
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"compress/gzip"
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"fmt"
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"io"
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"net/http"
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"strings"
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"time"
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)
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const compressionThreshold = 1024
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// Builder generates HTTP responses.
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type Builder struct {
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w http.ResponseWriter
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r *http.Request
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statusCode int
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headers map[string]string
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enableCompression bool
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body interface{}
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}
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// WithStatus uses the given status code to build the response.
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func (b *Builder) WithStatus(statusCode int) *Builder {
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b.statusCode = statusCode
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return b
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}
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// WithHeader adds the given HTTP header to the response.
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func (b *Builder) WithHeader(key, value string) *Builder {
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b.headers[key] = value
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return b
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}
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// WithBody uses the given body to build the response.
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func (b *Builder) WithBody(body interface{}) *Builder {
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b.body = body
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return b
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}
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// WithAttachment forces the document to be downloaded by the web browser.
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func (b *Builder) WithAttachment(filename string) *Builder {
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b.headers["Content-Disposition"] = fmt.Sprintf("attachment; filename=%s", filename)
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return b
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}
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// WithoutCompression disables HTTP compression.
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func (b *Builder) WithoutCompression() *Builder {
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b.enableCompression = false
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return b
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}
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// WithCaching adds caching headers to the response.
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func (b *Builder) WithCaching(etag string, duration time.Duration, callback func(*Builder)) {
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b.headers["ETag"] = etag
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b.headers["Cache-Control"] = "public"
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b.headers["Expires"] = time.Now().Add(duration).Format(time.RFC1123)
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if etag == b.r.Header.Get("If-None-Match") {
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b.statusCode = http.StatusNotModified
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b.body = nil
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b.Write()
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} else {
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callback(b)
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}
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}
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// Write generates the HTTP response.
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func (b *Builder) Write() {
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if b.body == nil {
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b.writeHeaders()
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return
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}
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switch v := b.body.(type) {
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case []byte:
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b.compress(v)
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case string:
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b.compress([]byte(v))
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case error:
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b.compress([]byte(v.Error()))
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case io.Reader:
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// Compression not implemented in this case
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b.writeHeaders()
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io.Copy(b.w, v)
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}
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}
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func (b *Builder) writeHeaders() {
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b.headers["X-XSS-Protection"] = "1; mode=block"
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b.headers["X-Content-Type-Options"] = "nosniff"
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b.headers["X-Frame-Options"] = "DENY"
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b.headers["Referrer-Policy"] = "no-referrer"
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for key, value := range b.headers {
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b.w.Header().Set(key, value)
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}
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b.w.WriteHeader(b.statusCode)
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}
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func (b *Builder) compress(data []byte) {
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if b.enableCompression && len(data) > compressionThreshold {
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acceptEncoding := b.r.Header.Get("Accept-Encoding")
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switch {
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case strings.Contains(acceptEncoding, "gzip"):
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b.headers["Content-Encoding"] = "gzip"
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b.writeHeaders()
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gzipWriter := gzip.NewWriter(b.w)
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defer gzipWriter.Close()
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gzipWriter.Write(data)
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return
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case strings.Contains(acceptEncoding, "deflate"):
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b.headers["Content-Encoding"] = "deflate"
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b.writeHeaders()
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flateWriter, _ := flate.NewWriter(b.w, -1)
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defer flateWriter.Close()
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flateWriter.Write(data)
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return
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}
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}
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b.writeHeaders()
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b.w.Write(data)
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}
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// New creates a new response builder.
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func New(w http.ResponseWriter, r *http.Request) *Builder {
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return &Builder{w: w, r: r, statusCode: http.StatusOK, headers: make(map[string]string), enableCompression: true}
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}
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