Files
minio/internal/grid/types.go
Klaus Post 51aa59a737 perf: websocket grid connectivity for all internode communication (#18461)
This PR adds a WebSocket grid feature that allows servers to communicate via 
a single two-way connection.

There are two request types:

* Single requests, which are `[]byte => ([]byte, error)`. This is for efficient small
  roundtrips with small payloads.

* Streaming requests which are `[]byte, chan []byte => chan []byte (and error)`,
  which allows for different combinations of full two-way streams with an initial payload.

Only a single stream is created between two machines - and there is, as such, no
server/client relation since both sides can initiate and handle requests. Which server
initiates the request is decided deterministically on the server names.

Requests are made through a mux client and server, which handles message
passing, congestion, cancelation, timeouts, etc.

If a connection is lost, all requests are canceled, and the calling server will try
to reconnect. Registered handlers can operate directly on byte 
slices or use a higher-level generics abstraction.

There is no versioning of handlers/clients, and incompatible changes should
be handled by adding new handlers.

The request path can be changed to a new one for any protocol changes.

First, all servers create a "Manager." The manager must know its address 
as well as all remote addresses. This will manage all connections.
To get a connection to any remote, ask the manager to provide it given
the remote address using.

```
func (m *Manager) Connection(host string) *Connection
```

All serverside handlers must also be registered on the manager. This will
make sure that all incoming requests are served. The number of in-flight 
requests and responses must also be given for streaming requests.

The "Connection" returned manages the mux-clients. Requests issued
to the connection will be sent to the remote.

* `func (c *Connection) Request(ctx context.Context, h HandlerID, req []byte) ([]byte, error)`
   performs a single request and returns the result. Any deadline provided on the request is
   forwarded to the server, and canceling the context will make the function return at once.

* `func (c *Connection) NewStream(ctx context.Context, h HandlerID, payload []byte) (st *Stream, err error)`
   will initiate a remote call and send the initial payload.

```Go
// A Stream is a two-way stream.
// All responses *must* be read by the caller.
// If the call is canceled through the context,
//The appropriate error will be returned.
type Stream struct {
	// Responses from the remote server.
	// Channel will be closed after an error or when the remote closes.
	// All responses *must* be read by the caller until either an error is returned or the channel is closed.
	// Canceling the context will cause the context cancellation error to be returned.
	Responses <-chan Response

	// Requests sent to the server.
	// If the handler is defined with 0 incoming capacity this will be nil.
	// Channel *must* be closed to signal the end of the stream.
	// If the request context is canceled, the stream will no longer process requests.
	Requests chan<- []byte
}

type Response struct {
	Msg []byte
	Err error
}
```

There are generic versions of the server/client handlers that allow the use of type
safe implementations for data types that support msgpack marshal/unmarshal.
2023-11-20 17:09:35 -08:00

173 lines
4.3 KiB
Go

// Copyright (c) 2015-2023 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package grid
import (
"errors"
"github.com/tinylib/msgp/msgp"
)
// MSS is a map[string]string that can be serialized.
// It is not very efficient, but it is only used for easy parameter passing.
type MSS map[string]string
// Get returns the value for the given key.
func (m *MSS) Get(key string) string {
if m == nil {
return ""
}
return (*m)[key]
}
// UnmarshalMsg deserializes m from the provided byte slice and returns the
// remainder of bytes.
func (m *MSS) UnmarshalMsg(bts []byte) (o []byte, err error) {
if m == nil {
return bts, errors.New("MSS: UnmarshalMsg on nil pointer")
}
if msgp.IsNil(bts) {
bts = bts[1:]
*m = nil
return bts, nil
}
var zb0002 uint32
zb0002, bts, err = msgp.ReadMapHeaderBytes(bts)
if err != nil {
err = msgp.WrapError(err, "Values")
return
}
dst := *m
if dst == nil {
dst = make(map[string]string, zb0002)
} else if len(dst) > 0 {
for key := range dst {
delete(dst, key)
}
}
for zb0002 > 0 {
var za0001 string
var za0002 string
zb0002--
za0001, bts, err = msgp.ReadStringBytes(bts)
if err != nil {
err = msgp.WrapError(err, "Values")
return
}
za0002, bts, err = msgp.ReadStringBytes(bts)
if err != nil {
err = msgp.WrapError(err, "Values", za0001)
return
}
dst[za0001] = za0002
}
*m = dst
return bts, nil
}
// MarshalMsg appends the bytes representation of b to the provided byte slice.
func (m *MSS) MarshalMsg(bytes []byte) (o []byte, err error) {
if m == nil || *m == nil {
return msgp.AppendNil(bytes), nil
}
o = msgp.AppendMapHeader(bytes, uint32(len(*m)))
for za0001, za0002 := range *m {
o = msgp.AppendString(o, za0001)
o = msgp.AppendString(o, za0002)
}
return o, nil
}
// Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message.
func (m *MSS) Msgsize() int {
if m == nil || *m == nil {
return msgp.NilSize
}
s := msgp.MapHeaderSize
for za0001, za0002 := range *m {
s += msgp.StringPrefixSize + len(za0001) + msgp.StringPrefixSize + len(za0002)
}
return s
}
// NewMSS returns a new MSS.
func NewMSS() *MSS {
m := MSS(make(map[string]string))
return &m
}
// NewMSSWith returns a new MSS with the given map.
func NewMSSWith(m map[string]string) *MSS {
m2 := MSS(m)
return &m2
}
// NewBytes returns a new Bytes.
func NewBytes() *Bytes {
b := Bytes(GetByteBuffer()[:0])
return &b
}
// NewBytesWith returns a new Bytes with the provided content.
func NewBytesWith(b []byte) *Bytes {
bb := Bytes(b)
return &bb
}
// Bytes provides a byte slice that can be serialized.
type Bytes []byte
// UnmarshalMsg deserializes b from the provided byte slice and returns the
// remainder of bytes.
func (b *Bytes) UnmarshalMsg(bytes []byte) ([]byte, error) {
if b == nil {
return bytes, errors.New("Bytes: UnmarshalMsg on nil pointer")
}
if bytes, err := msgp.ReadNilBytes(bytes); err == nil {
*b = nil
return bytes, nil
}
val, bytes, err := msgp.ReadBytesZC(bytes)
if err != nil {
return bytes, err
}
if cap(*b) >= len(val) {
*b = (*b)[:len(val)]
copy(*b, val)
} else {
*b = append(make([]byte, 0, len(val)), val...)
}
return bytes, nil
}
// MarshalMsg appends the bytes representation of b to the provided byte slice.
func (b *Bytes) MarshalMsg(bytes []byte) ([]byte, error) {
if b == nil || *b == nil {
return msgp.AppendNil(bytes), nil
}
return msgp.AppendBytes(bytes, *b), nil
}
// Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message.
func (b *Bytes) Msgsize() int {
if b == nil || *b == nil {
return msgp.NilSize
}
return msgp.ArrayHeaderSize + len(*b)
}