caddy/modules/caddyhttp/encode/gzip/gzip.go

100 lines
2.6 KiB
Go

// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package caddygzip
import (
"compress/flate"
"compress/gzip" // TODO: consider using https://github.com/klauspost/compress/gzip
"fmt"
"strconv"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
"github.com/caddyserver/caddy/v2/modules/caddyhttp/encode"
)
func init() {
caddy.RegisterModule(Gzip{})
}
// Gzip can create gzip encoders.
type Gzip struct {
Level int `json:"level,omitempty"`
}
// CaddyModule returns the Caddy module information.
func (Gzip) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
Name: "http.encoders.gzip",
New: func() caddy.Module { return new(Gzip) },
}
}
// UnmarshalCaddyfile sets up the handler from Caddyfile tokens.
func (g *Gzip) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
for d.Next() {
if !d.NextArg() {
continue
}
levelStr := d.Val()
level, err := strconv.Atoi(levelStr)
if err != nil {
return err
}
g.Level = level
}
return nil
}
// Provision provisions g's configuration.
func (g *Gzip) Provision(ctx caddy.Context) error {
if g.Level == 0 {
g.Level = defaultGzipLevel
}
return nil
}
// Validate validates g's configuration.
func (g Gzip) Validate() error {
if g.Level < flate.NoCompression {
return fmt.Errorf("quality too low; must be >= %d", flate.NoCompression)
}
if g.Level > flate.BestCompression {
return fmt.Errorf("quality too high; must be <= %d", flate.BestCompression)
}
return nil
}
// AcceptEncoding returns the name of the encoding as
// used in the Accept-Encoding request headers.
func (Gzip) AcceptEncoding() string { return "gzip" }
// NewEncoder returns a new gzip writer.
func (g Gzip) NewEncoder() encode.Encoder {
writer, _ := gzip.NewWriterLevel(nil, g.Level)
return writer
}
// Informed from http://blog.klauspost.com/gzip-performance-for-go-webservers/
var defaultGzipLevel = 5
// Interface guards
var (
_ encode.Encoding = (*Gzip)(nil)
_ caddy.Provisioner = (*Gzip)(nil)
_ caddy.Validator = (*Gzip)(nil)
_ caddyfile.Unmarshaler = (*Gzip)(nil)
)