[🚀] downloader

pkg/downloader/controller/controller.go

@@ -0,0 +1,172 @@
+package controller
+
+import (
+	"golang.org/x/net/proxy"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+	"time"
+)
+
+type Controller interface {
+	Touch(name string, size int64) (file *os.File, err error)
+	Open(name string) (file *os.File, err error)
+	Write(name string, offset int64, buf []byte) (int, error)
+	Close(name string) error
+	ContextDialer() (proxy.Dialer, error)
+	ContextCookie() http.CookieJar
+	ContextTimeout() time.Duration
+	ContextProxy() func(*http.Request) (*url.URL, error)
+}
+
+type Option func(*option)
+
+type option struct {
+	CookieJar http.CookieJar
+	Timeout   time.Duration
+	Dialer    proxy.Dialer
+	Proxy     func(*http.Request) (*url.URL, error)
+}
+
+func WithCookie(cookieJar http.CookieJar) Option {
+	return func(opt *option) {
+		opt.CookieJar = cookieJar
+	}
+}
+
+func WithTimeout(timeout time.Duration) Option {
+	return func(opt *option) {
+		opt.Timeout = timeout
+	}
+}
+
+func WithDialer(dialer proxy.Dialer) Option {
+	return func(opt *option) {
+		opt.Dialer = dialer
+	}
+}
+
+func WithProxy(fn func(*http.Request) (*url.URL, error)) Option {
+	return func(opt *option) {
+		opt.Proxy = fn
+	}
+}
+
+type DefaultController struct {
+	*option
+	Files map[string]*os.File
+}
+
+func NewController(options ...Option) *DefaultController {
+	opt := new(option)
+	for _, f := range options {
+		f(opt)
+	}
+	if opt.Timeout == 0 {
+		opt.Timeout = time.Second * 30
+	}
+	if opt.Dialer == nil {
+		opt.Dialer = proxy.FromEnvironment()
+	}
+	return &DefaultController{
+		Files:  make(map[string]*os.File),
+		option: opt,
+	}
+}
+
+func (c *DefaultController) Touch(name string, size int64) (file *os.File, err error) {
+	file, err = os.Create(name)
+	if size > 0 {
+		err = os.Truncate(name, size)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if err == nil {
+		c.Files[name] = file
+	}
+	return
+}
+
+func (c *DefaultController) Open(name string) (file *os.File, err error) {
+	file, err = os.OpenFile(name, os.O_RDWR, os.ModePerm)
+	if err == nil {
+		c.Files[name] = file
+	}
+	return
+}
+
+func (c *DefaultController) Write(name string, offset int64, buf []byte) (int, error) {
+	return c.Files[name].WriteAt(buf, offset)
+}
+
+func (c *DefaultController) Close(name string) error {
+	err := c.Files[name].Close()
+	delete(c.Files, name)
+	return err
+}
+
+func (c *DefaultController) ContextDialer() (proxy.Dialer, error) {
+	return &DialerWarp{dialer: c.Dialer}, nil
+}
+
+func (c *DefaultController) ContextCookie() http.CookieJar {
+	return c.CookieJar
+}
+
+func (c *DefaultController) ContextTimeout() time.Duration {
+	return c.Timeout
+}
+
+func (c *DefaultController) ContextProxy() func(*http.Request) (*url.URL, error) {
+	return c.Proxy
+}
+
+type DialerWarp struct {
+	dialer proxy.Dialer
+}
+
+type ConnWarp struct {
+	conn net.Conn
+}
+
+func (c *ConnWarp) Read(b []byte) (n int, err error) {
+	return c.conn.Read(b)
+}
+
+func (c *ConnWarp) Write(b []byte) (n int, err error) {
+	return c.conn.Write(b)
+}
+
+func (c *ConnWarp) Close() error {
+	return c.conn.Close()
+}
+
+func (c *ConnWarp) LocalAddr() net.Addr {
+	return c.conn.LocalAddr()
+}
+
+func (c *ConnWarp) RemoteAddr() net.Addr {
+	return c.conn.RemoteAddr()
+}
+
+func (c *ConnWarp) SetDeadline(t time.Time) error {
+	return c.conn.SetDeadline(t)
+}
+
+func (c *ConnWarp) SetReadDeadline(t time.Time) error {
+	return c.conn.SetReadDeadline(t)
+}
+
+func (c *ConnWarp) SetWriteDeadline(t time.Time) error {
+	return c.conn.SetWriteDeadline(t)
+}
+
+func (d *DialerWarp) Dial(network, addr string) (c net.Conn, err error) {
+	conn, err := d.dialer.Dial(network, addr)
+	if err != nil {
+		return nil, err
+	}
+	return &ConnWarp{conn: conn}, nil
+}