fix(kcp): prevent zero-value override of window/buffer params causing 10x perf drop

The metadata parser unconditionally assigned GetInt results (which
return 0 for missing keys) to all KCP config fields, overwriting
defaults like SndWnd=1024, RcvWnd=1024, StreamBuf=2097152 with 0.

KCP's WndSize only applies positive values, so snd_wnd=0 caused
the write path condition waitsnd < s.kcp.snd_wnd to never succeed,
effectively stalling throughput at ~10Mbps instead of 400Mbps+.

- Only apply metadata values when the key actually exists (IsExists check)
- Use Clone() instead of sharing the global DefaultConfig pointer
- Add Config.Clone() deep-copy method
This commit is contained in:
sagitchu
2026-04-21 10:20:21 +08:00
parent bb48ab00bd
commit 37341af2d1
3 changed files with 99 additions and 28 deletions
+45 -14
View File
@@ -40,21 +40,52 @@ func (d *kcpDialer) parseMetadata(md mdata.Metadata) (err error) {
d.md.config = cfg
}
if d.md.config == nil {
d.md.config = kcp_util.DefaultConfig
d.md.config = kcp_util.DefaultConfig.Clone()
} else {
d.md.config = d.md.config.Clone()
}
if md != nil {
if md.IsExists("kcp.tcp") {
d.md.config.TCP = mdutil.GetBool(md, "kcp.tcp")
}
if md.IsExists("kcp.key") {
d.md.config.Key = mdutil.GetString(md, "kcp.key")
}
if md.IsExists("kcp.crypt") {
d.md.config.Crypt = mdutil.GetString(md, "kcp.crypt")
}
if md.IsExists("kcp.mode") {
d.md.config.Mode = mdutil.GetString(md, "kcp.mode")
}
if md.IsExists("kcp.keepalive") {
d.md.config.KeepAlive = mdutil.GetInt(md, "kcp.keepalive")
}
if md.IsExists("kcp.interval") {
d.md.config.Interval = mdutil.GetInt(md, "kcp.interval")
}
if md.IsExists("kcp.mtu") {
d.md.config.MTU = mdutil.GetInt(md, "kcp.mtu")
}
if md.IsExists("kcp.rcvwnd") {
d.md.config.RcvWnd = mdutil.GetInt(md, "kcp.rcvwnd")
}
if md.IsExists("kcp.sndwnd") {
d.md.config.SndWnd = mdutil.GetInt(md, "kcp.sndwnd")
}
if md.IsExists("kcp.smuxver") {
d.md.config.SmuxVer = mdutil.GetInt(md, "kcp.smuxver")
}
if md.IsExists("kcp.smuxbuf") {
d.md.config.SmuxBuf = mdutil.GetInt(md, "kcp.smuxbuf")
}
if md.IsExists("kcp.streambuf") {
d.md.config.StreamBuf = mdutil.GetInt(md, "kcp.streambuf")
}
if md.IsExists("kcp.nocomp") {
d.md.config.NoComp = mdutil.GetBool(md, "kcp.nocomp")
}
}
d.md.config.TCP = mdutil.GetBool(md, "kcp.tcp")
d.md.config.Key = mdutil.GetString(md, "kcp.key")
d.md.config.Crypt = mdutil.GetString(md, "kcp.crypt")
d.md.config.Mode = mdutil.GetString(md, "kcp.mode")
d.md.config.KeepAlive = mdutil.GetInt(md, "kcp.keepalive")
d.md.config.Interval = mdutil.GetInt(md, "kcp.interval")
d.md.config.MTU = mdutil.GetInt(md, "kcp.mtu")
d.md.config.RcvWnd = mdutil.GetInt(md, "kcp.rcvwnd")
d.md.config.SndWnd = mdutil.GetInt(md, "kcp.sndwnd")
d.md.config.SmuxVer = mdutil.GetInt(md, "kcp.smuxver")
d.md.config.SmuxBuf = mdutil.GetInt(md, "kcp.smuxbuf")
d.md.config.StreamBuf = mdutil.GetInt(md, "kcp.streambuf")
d.md.config.NoComp = mdutil.GetBool(md, "kcp.nocomp")
d.md.handshakeTimeout = mdutil.GetDuration(md, handshakeTimeout)
return