From 9df018b07fe633b5d788349b613e1981f2ec6f3c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Sun, 1 May 2022 09:33:31 +0800
Subject: [PATCH] Add buffered conn

---
 common/rw/buffer.go | 115 ++++++++++++++++++++++++++++++++++++++++++++
 go.mod              |   5 +-
 go.sum              |   9 ++--
 3 files changed, 121 insertions(+), 8 deletions(-)

diff --git a/common/rw/buffer.go b/common/rw/buffer.go
index ac22ebe..58cacca 100644
--- a/common/rw/buffer.go
+++ b/common/rw/buffer.go
@@ -2,11 +2,126 @@ package rw
 
 import (
 	"io"
+	"net"
+	"time"
 
 	"github.com/sagernet/sing/common"
 	"github.com/sagernet/sing/common/buf"
 )
 
+type CachedReader interface {
+	common.ReaderWithUpstream
+	ReadCached() *buf.Buffer
+}
+
+type BufferedConn struct {
+	net.Conn
+	Buffer *buf.Buffer
+}
+
+func (c *BufferedConn) ReadCached() *buf.Buffer {
+	buffer := c.Buffer
+	c.Buffer = nil
+	return buffer
+}
+
+func (c *BufferedConn) Read(p []byte) (n int, err error) {
+	if c.Buffer != nil {
+		n, err = c.Buffer.Read(p)
+		if err == nil {
+			return
+		}
+		c.Buffer.Release()
+		c.Buffer = nil
+	}
+	return c.Conn.Read(p)
+}
+
+func (c *BufferedConn) WriteTo(w io.Writer) (n int64, err error) {
+	if c.Buffer != nil {
+		wn, wErr := w.Write(c.Buffer.Bytes())
+		if wErr != nil {
+			c.Buffer.Release()
+			c.Buffer = nil
+		}
+		n += int64(wn)
+	}
+	cn, err := Copy(w, c.Conn)
+	n += cn
+	return
+}
+
+func (c *BufferedConn) SetReadDeadline(t time.Time) error {
+	if c.Buffer != nil && !c.Buffer.IsEmpty() {
+		return nil
+	}
+	return c.Conn.SetReadDeadline(t)
+}
+
+func (c *BufferedConn) ReadFrom(r io.Reader) (n int64, err error) {
+	return Copy(c.Conn, r)
+}
+
+func (c *BufferedConn) UpstreamReader() io.Reader {
+	return c.Conn
+}
+
+func (c *BufferedConn) ReaderReplaceable() bool {
+	return c.Buffer == nil
+}
+
+func (c *BufferedConn) UpstreamWriter() io.Writer {
+	return c.Conn
+}
+
+func (c *BufferedConn) WriterReplaceable() bool {
+	return true
+}
+
+type BufferedReader struct {
+	Reader io.Reader
+	Buffer *buf.Buffer
+}
+
+func (c *BufferedReader) ReadCached() *buf.Buffer {
+	buffer := c.Buffer
+	c.Buffer = nil
+	return buffer
+}
+
+func (r *BufferedReader) Read(p []byte) (n int, err error) {
+	if r.Buffer != nil {
+		n, err = r.Buffer.Read(p)
+		if err == nil {
+			return
+		}
+		r.Buffer.Release()
+		r.Buffer = nil
+	}
+	return r.Reader.Read(p)
+}
+
+func (r *BufferedReader) WriteTo(w io.Writer) (n int64, err error) {
+	if r.Buffer != nil {
+		wn, wErr := w.Write(r.Buffer.Bytes())
+		if wErr != nil {
+			return 0, wErr
+		}
+		n += int64(wn)
+	}
+	cn, err := Copy(w, r.Reader)
+	n += cn
+	return
+}
+
+func (w *BufferedReader) UpstreamReader() io.Reader {
+	return w.Reader
+}
+
+func (w *BufferedReader) ReaderReplaceable() bool {
+	return w.Buffer == nil
+}
+
 type BufferedWriter struct {
 	Writer io.Writer
 	Buffer *buf.Buffer
diff --git a/go.mod b/go.mod
index 7cedbba..96ca220 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module github.com/sagernet/sing
 go 1.18
 
 require (
-	github.com/cloudflare/cloudflare-go v0.38.0
+	github.com/cloudflare/cloudflare-go v0.30.0
 	github.com/go-acme/lego/v4 v4.6.0
 	github.com/go-resty/resty/v2 v2.7.0
 	github.com/openacid/low v0.1.21
@@ -19,7 +19,7 @@ require (
 	github.com/vishvananda/netlink v1.1.0
 	golang.org/x/crypto v0.0.0-20220427172511-eb4f295cb31f
 	golang.org/x/net v0.0.0-20220425223048-2871e0cb64e4
-	golang.org/x/sys v0.0.0-20220422013727-9388b58f7150
+	golang.org/x/sys v0.0.0-20220429233432-b5fbb4746d32
 	golang.zx2c4.com/wireguard v0.0.0-20220407013110-ef5c587f782d
 	google.golang.org/protobuf v1.28.0
 	lukechampine.com/blake3 v1.1.7
@@ -30,7 +30,6 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dgryski/go-metro v0.0.0-20211217172704-adc40b04c140 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
-	github.com/google/go-querystring v1.1.0 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/klauspost/cpuid/v2 v2.0.12 // indirect
 	github.com/kr/text v0.2.0 // indirect
diff --git a/go.sum b/go.sum
index f5eb9ff..7f995eb 100644
--- a/go.sum
+++ b/go.sum
@@ -67,8 +67,8 @@ github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5P
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cloudflare/cloudflare-go v0.20.0/go.mod h1:sPWL/lIC6biLEdyGZwBQ1rGQKF1FhM7N60fuNiFdYTI=
-github.com/cloudflare/cloudflare-go v0.38.0 h1:Qf/oVlDmQgb4RfCxqkR0hJoEUQKHvDE4A09MHWssa/w=
-github.com/cloudflare/cloudflare-go v0.38.0/go.mod h1:tWDVF03nA9VS9TvFRTrOeY78uSFQzS+n429EcBZszzg=
+github.com/cloudflare/cloudflare-go v0.30.0 h1:ho2ObQ1iZfjMqP9RcovvT1Jwp/ZW4Ji5baWVwl2T//A=
+github.com/cloudflare/cloudflare-go v0.30.0/go.mod h1:B55yGpU9NdzhWPYu0CDq8smftKrqB/PSDQAdIBEKApw=
 github.com/coreos/bbolt v1.3.2/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkEiiKk=
 github.com/coreos/etcd v3.3.13+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
 github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
@@ -162,7 +162,6 @@ github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
 github.com/google/go-github/v32 v32.1.0/go.mod h1:rIEpZD9CTDQwDK9GDrtMTycQNA4JU3qBsCizh3q2WCI=
 github.com/google/go-querystring v1.0.0/go.mod h1:odCYkC5MyYFN7vkCjXpyrEuKhc/BUO6wN/zVPAxq5ck=
-github.com/google/go-querystring v1.1.0 h1:AnCroh3fv4ZBgVIf1Iwtovgjaw/GiKJo8M8yD/fhyJ8=
 github.com/google/go-querystring v1.1.0/go.mod h1:Kcdr2DB4koayq7X8pmAG4sNG59So17icRSOU623lUBU=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
@@ -606,8 +605,8 @@ golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220422013727-9388b58f7150 h1:xHms4gcpe1YE7A3yIllJXP16CMAGuqwO2lX1mTyyRRc=
-golang.org/x/sys v0.0.0-20220422013727-9388b58f7150/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220429233432-b5fbb4746d32 h1:Js08h5hqB5xyWR789+QqueR6sDE8mk+YvpETZ+F6X9Y=
+golang.org/x/sys v0.0.0-20220429233432-b5fbb4746d32/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=