tcputil

package
v1.1.37 Latest Latest
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 Go to latest Published: Nov 4, 2022 License: MIT Imports: 16 Imported by: 0

Documentation

Index

Constants

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const (
	// PrefixInt32 32-bit prefix.
	PrefixInt32 = iota
)

Variables

View Source 
var ErrPacketTooBig = errors.New("packet too big")

ErrPacketTooBig indicated that a packet has exceeded specified max size during read operation.

Functions

func ReadBool added in v1.1.14 

func ReadBool(reader io.Reader) (bool, error)

ReadBool reads bool from given reader.

func ReadByte added in v1.1.14 

func ReadByte(reader io.Reader) (byte, error)

ReadByte reads byte from given reader.

func ReadByteArray added in v1.1.14 

func ReadByteArray(reader io.Reader) ([]byte, error)

ReadByteArray reads byte array from given reader.

func ReadBytes added in v1.1.14 

func ReadBytes(reader io.Reader, n int) ([]byte, error)

ReadBytes reads bytes from given reader.

func ReadFloat32 added in v1.1.14 

func ReadFloat32(reader io.Reader) (float32, error)

ReadFloat32 reads float32 from given reader.

func ReadFloat64 added in v1.1.14 

func ReadFloat64(reader io.Reader) (float64, error)

ReadFloat64 reads float64 from given reader.

func ReadInt16 added in v1.1.14 

func ReadInt16(reader io.Reader) (int16, error)

ReadInt16 reads int16 from given reader.

func ReadInt32 added in v1.1.14 

func ReadInt32(reader io.Reader) (int32, error)

ReadInt32 reads int32 from given reader.

func ReadInt64 added in v1.1.14 

func ReadInt64(reader io.Reader) (int64, error)

ReadInt64 reads int64 from given reader.

func ReadLengthPrefixedPacket added in v1.1.27 

func ReadLengthPrefixedPacket(socket *ClientSocket, prefixSize int, maxPacketSize int) ([]byte, error)

ReadLengthPrefixedPacket tries to read packet data from socket. Packet is expected to be prefixed with little-endian encoded binary value, indicating size of the packet in bytes. Size of the prefix is given in the prefixSize argument. Packet will only be read up to maxPacketSize bytes.

func ReadSeparatedPacket added in v1.1.27 

func ReadSeparatedPacket(socket *ClientSocket, separator []byte, maxPacketSize int) ([]byte, error)

ReadSeparatedPacket tries to read packet data from socket. Packet is read to the buffer until either maxPacketSize limit is exceeded or a sequence of bytes, given in the separator argument is encountered.

func ReadString added in v1.1.14 

func ReadString(reader io.Reader) (string, error)

ReadString reads string from given reader.

func ReadVarInt added in v1.1.14 

func ReadVarInt(reader io.Reader) (int, error)

ReadVarInt reads var int from given reader.

func ReadVarLong added in v1.1.14 

func ReadVarLong(reader io.Reader) (int64, error)

ReadVarLong reads var int64 from given reader.

func WriteBool added in v1.1.14 

func WriteBool(writer io.Writer, value bool) error

WriteBool writes a bool into given writer.

func WriteByte added in v1.1.14 

func WriteByte(writer io.Writer, value byte) error

WriteByte writes a byte into given writer.

func WriteByteArray added in v1.1.14 

func WriteByteArray(writer io.Writer, value []byte) error

WriteByteArray writes byte array into given writer.

func WriteBytes added in v1.1.14 

func WriteBytes(writer io.Writer, value []byte) error

WriteBytes writes a byte into given writer.

func WriteFloat32 added in v1.1.14 

func WriteFloat32(writer io.Writer, value float32) error

WriteFloat32 writes float32 into given writer.

func WriteFloat64 added in v1.1.14 

func WriteFloat64(writer io.Writer, value float64) error

WriteFloat64 writes float64 into given writer.

func WriteInt16 added in v1.1.14 

func WriteInt16(writer io.Writer, value int16) error

WriteInt16 writes int16 into given writer.

func WriteInt32 added in v1.1.14 

func WriteInt32(writer io.Writer, value int32) error

WriteInt32 writes int32 into given writer.

func WriteInt64 added in v1.1.14 

func WriteInt64(writer io.Writer, value int64) error

WriteInt64 writes int64 into given writer.

func WriteString added in v1.1.14 

func WriteString(writer io.Writer, value string) error

WriteString writes string into given writer.

func WriteVarInt added in v1.1.14 

func WriteVarInt(writer io.Writer, value int) error

WriteVarInt writes var int into given writer.

func WriteVarLong added in v1.1.14 

func WriteVarLong(writer io.Writer, value int64) error

WriteVarLong writes var long into given writer.

Types

type BulkBroadcaster added in v1.1.33 

type BulkBroadcaster struct {
	// contains filtered or unexported fields
}

BulkBroadcaster is a high-performance data pump for broadcasting server packets to multiple clients. BulkBroadcaster uses an underlying workers pool. Workers are goroutines that constantly fetch data to broadcast and are responsible for sending fetched data to their subset of clients, specified as recipients. This approach is inefficient for small numbers of recipients but may be useful for some less-common scenarios, that involve interacting with huge number of clients.

func StartBulkBroadcaster added in v1.1.33 

func StartBulkBroadcaster(workersCount, poolSize int, writeQuantum time.Duration) *BulkBroadcaster

StartBulkBroadcaster creates and starts BulkBroadcaster. workersCount is a number of workers to start. poolSize is a number of messages to schedule for a single worker in one iteration. writeQuantum is the maximum amount of time that should be allocated to Write() operation on a single socket.

func (*BulkBroadcaster) Broadcast added in v1.1.33 

func (b *BulkBroadcaster) Broadcast(data []byte, targets []*ClientSocket) error

Broadcast schedules data to be written to all the sockets specified by targets array. The work will be split between workers for efficient processing.

func (*BulkBroadcaster) Stop added in v1.1.33 

func (b *BulkBroadcaster) Stop()

Stop stops all the workers owned by the BulkBroadcaster.

type Client added in v1.1.14 

type Client struct {
	// contains filtered or unexported fields
}

Client represents a TCP/TLS client.

func Dial added in v1.1.14 

func Dial(address string) (*Client, error)

Dial connects to the TCP socket and creates new Client.

func DialTLS added in v1.1.14 

func DialTLS(address string, tlsConfig *tls.Config) (*Client, error)

DialTLS connects to the TCP socket and performs TLS handshake, and then creates new Client. Connection is TLS secured.

func (*Client) Close added in v1.1.14 

func (c *Client) Close()

Close closes the socket.

func (*Client) OnClose added in v1.1.14 

func (c *Client) OnClose(handler func())

OnClose sets a handler called on closing connection (either by client or server).

func (*Client) Read added in v1.1.14 

func (c *Client) Read(b []byte) (int, error)

Read conforms to the io.Reader interface.

func (*Client) Unwrap added in v1.1.14 

func (c *Client) Unwrap() net.Conn

Unwrap returns underlying TCP connection.

func (*Client) UnwrapTLS added in v1.1.14 

func (c *Client) UnwrapTLS() (*tls.Conn, bool)

UnwrapTLS tries to return underlying tls.Conn instance.

func (*Client) Write added in v1.1.14 

func (c *Client) Write(b []byte) (int, error)

Write conforms to the io.Writer interface.

type ClientSocket 

type ClientSocket struct {
	// contains filtered or unexported fields
}

ClientSocket represents a dedicated socket for given TCP client.

func (*ClientSocket) Close 

func (cs *ClientSocket) Close()

Close closes TCP connection.

func (*ClientSocket) ConnectedAt added in v1.1.14 

func (cs *ClientSocket) ConnectedAt() time.Time

ConnectedAt returns an exact time the client has connected.

func (*ClientSocket) Id added in v1.1.22 

func (cs *ClientSocket) Id() int64

Id returns a unique id associated with this socket.

func (*ClientSocket) IsClosed added in v1.1.27 

func (cs *ClientSocket) IsClosed() bool

IsClosed check whether this connection has been closed, either by the server or the client.

func (*ClientSocket) OnClose added in v1.1.12 

func (cs *ClientSocket) OnClose(handler func())

OnClose registers a handler that is called when underlying TCP connection is being closed.

func (*ClientSocket) Read added in v1.1.14 

func (cs *ClientSocket) Read(b []byte) (int, error)

Read conforms to the io.Reader interface.

func (*ClientSocket) ReadsPerSecond added in v1.1.15 

func (cs *ClientSocket) ReadsPerSecond() uint64

ReadsPerSecond returns a total number of bytes read through socket this second.

func (*ClientSocket) RemoteAddress 

func (cs *ClientSocket) RemoteAddress() string

RemoteAddress returns a remote address of the client.

func (*ClientSocket) TotalRead added in v1.1.14 

func (cs *ClientSocket) TotalRead() uint64

TotalRead returns a total number of bytes read through this socket.

func (*ClientSocket) TotalWritten added in v1.1.14 

func (cs *ClientSocket) TotalWritten() uint64

TotalWritten returns a total number of bytes written through this socket.

func (*ClientSocket) Unwrap 

func (cs *ClientSocket) Unwrap() net.Conn

Unwrap returns underlying net.Conn instance from ClientSocket.

func (*ClientSocket) UnwrapTLS 

func (cs *ClientSocket) UnwrapTLS() (*tls.Conn, bool)

UnwrapTLS tries to return underlying tls.Conn instance from ClientSocket.

func (*ClientSocket) WrapReader added in v1.1.27 

func (cs *ClientSocket) WrapReader(wrapper func(io.Reader) io.Reader)

WrapReader allows to wrap reader object into user defined wrapper.

func (*ClientSocket) WrapWriter added in v1.1.27 

func (cs *ClientSocket) WrapWriter(wrapper func(io.Writer) io.Writer)

WrapWriter allows to wrap writer object into user defined wrapper.

func (*ClientSocket) Write added in v1.1.14 

func (cs *ClientSocket) Write(b []byte) (int, error)

Write conforms to the io.Writer interface.

func (*ClientSocket) WritesPerSecond added in v1.1.15 

func (cs *ClientSocket) WritesPerSecond() uint64

WritesPerSecond returns a total number of bytes written through socket this second.

type ClientSocketHandler added in v1.1.18 

type ClientSocketHandler func(*ClientSocket)

ClientSocketHandler represents a signature of function used by Server to handle new connections.

type ForkingStrategy added in v1.1.27 

type ForkingStrategy interface {
	// OnStart is called once, after server start.
	OnStart()

	// OnAccept is called for every connection accepted by the server.
	// The implementation should handle all the interactions with the socket,
	// closing it after use and recovering from any potential panic.
	OnAccept(socket *ClientSocket)

	// OnMetricsUpdate is called every time the server updates its metrics.
	OnMetricsUpdate(metrics *ServerMetrics)

	// OnStop is called once, after server stops.
	OnStop()
}

ForkingStrategy defines the way new connections are handled by the associated TCP server. Most naive implementation is to start a new goroutine for each new connection, and make this goroutine responsible for the whole lifecycle of the connection. This implementation might not fit the needs of some highly-concurrent servers, so other implementations (like recvWorker pool) may be implemented on top of this interface.

func GoroutinePerConnection added in v1.1.27 

func GoroutinePerConnection(handler ClientSocketHandler) ForkingStrategy

GoroutinePerConnection is the most naive implementation of the ForkingStrategy. This is the recommended implementation for most of the general-purpose TCP servers. It starts a new goroutine for every new connection. The handler associated with the connection will be responsible for handling blocking operations on this connection. Connections are automatically closed after their handler finishes.

func WorkerPool added in v1.1.27 

func WorkerPool(
	handler ReadPoolEventHandler,
	maxPoolSize int,
	readBufferSize int,
	readQuantum time.Duration,
) ForkingStrategy

WorkerPool is a forking strategy that handles new connections using a pool of worker goroutines. This strategy is expected to provide better performance than GoroutinePerConnection in scenarios in which receiving data from clients isn't critical, and can be postponed to provide lower resource overhead. New connection are added to pools that have a max size of maxPoolSize. Pools continuously read readBufferSize bytes from each of their connections for a time quantum specified by readQuantum. WorkerPool uses provided ReadPoolEventHandler as data handling implementation.

type FramingProtocol added in v1.1.37 

type FramingProtocol interface {
	// ExtractPacket splits the buffer into packet and "the rest".
	// Returns ok == true if the meaningful packet has been extracted.
	ExtractPacket(readBuffer []byte) (packetData []byte, newReadBuffer []byte, ok bool)
}

FramingProtocol defines a strategy of extracting meaningful chunks of data out of read buffer, sourced by the underlying read pool. Job of the FramingProtocol is to search for packets inside the larger byte buffer.

func SplitBySeparator added in v1.1.37 

func SplitBySeparator(separator []byte) FramingProtocol

SplitBySeparator is a FramingProtocol strategy that expects each packet to end with a sequence of bytes given as separator. It is a good strategy for tasks like handling Telnet sessions (packets are separated by a newline).

type PacketHandler added in v1.1.12 

type PacketHandler interface {
	// OnAccept is called right after accepting the connection represented by the passed socket.
	OnAccept(socket *ClientSocket)

	// OnPacket is called after receiving full package by socket (according to chosen FramingProtocol).
	OnPacket(socket *ClientSocket, packetData []byte)
}

PacketHandler is an interface over WorkerPool forking strategy. PacketHandler handles client data after packet framing performed by selected FramingProtocol.

type ReadPoolEventHandler added in v1.1.37 

type ReadPoolEventHandler interface {
	// OnAccept is called each time new connection is accepted in the pool.
	OnAccept(socket *ClientSocket)

	// OnRead is called each time some bytes have been read from a socket.
	OnRead(socket *ClientSocket, data []byte)
}

ReadPoolEventHandler defines interaction with socket when using WorkerPool forking strategy.

func PacketFraming added in v1.1.37 

func PacketFraming(maxPacketSize int, framingProtocol FramingProtocol, handler PacketHandler) ReadPoolEventHandler

PacketFraming returns a ReadPoolEventHandler that performs packet framing, as defined by provided FramingProtocol. This allows to handle the incoming connections using PacketHandler interface. Each connection is assigned a read buffer with the maximum size equal to maxPacketSize. After reading maxPacketSize without finding a packet, all the accumulated data is discarded.

type Server 

type Server struct {
	// contains filtered or unexported fields
}

Server represents a TCP server, and conforms to the coreutil.Service interface.

func NewServer 

func NewServer(config *config.Config) *Server

NewServer returns new Server instance.

func (*Server) ForkingStrategy added in v1.1.27 

func (s *Server) ForkingStrategy(forkingStrategy ForkingStrategy)

ForkingStrategy sets forking strategy used by this server (see ForkingStrategy).

func (*Server) Metrics added in v1.1.22 

func (s *Server) Metrics() ServerMetrics

Metrics returns aggregated server metrics.

func (*Server) OnMetricsUpdate added in v1.1.22 

func (s *Server) OnMetricsUpdate(handler func())

OnMetricsUpdate sets a handler that is called everytime the server metrics are updated.

func (*Server) Sockets added in v1.1.14 

func (s *Server) Sockets() []*ClientSocket

Sockets returns a list of all client sockets currently connected.

func (*Server) Start 

func (s *Server) Start() error

Start implements the interface of coreutil.Service.

func (*Server) Stop 

func (s *Server) Stop()

Stop implements the interface of coreutil.Service.

type ServerMetrics added in v1.1.22 

type ServerMetrics struct {
	// TotalRead is total number of bytes read by server since start.
	TotalRead uint64

	// TotalRead is total number of bytes written by server since start.
	TotalWritten uint64

	// ReadsPerSecond is total number of bytes read by server last second.
	ReadsPerSecond uint64

	// ReadsPerSecond is total number of bytes written by server last second.
	WritesPerSecond uint64

	// Connections is total number of clients connected during last second.
	Connections int

	// MaxConnections is maximum number of clients connected at a single time.
	MaxConnections int

	// Goroutines is total number of goroutines active during last second.
	Goroutines int

	// MaxGoroutines is maximum number of goroutines active at a single time.
	MaxGoroutines int
}

ServerMetrics contains basic metrics gathered from TCP server.

Source Files

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