File Information
Library: RemotingNG/TCP
Package: TCP
Header: Poco/RemotingNG/TCP/Frame.h
Description
This class represents a network frame used by the TCP transport connection.
A frame consists of a header, followed by payload. Header format is as follows:
- Frame Type: 32 bit unsigned integer.
- Channel: 32 bit unsigned integer.
- Flags: 16 bit unsigned integer.
- Payload Size: 16 bit unsigned integer.
All integers are in network byte order. Payload sizes are 16 bit, although practically only payloads up to a size of 1012 bytes are used.
Inheritance
Direct Base Classes: Poco::RefCountedObject
All Base Classes: Poco::RefCountedObject
Member Summary
Member Functions: bufferBegin, bufferEnd, bufferSize, channel, flags, frameSize, getPayloadSize, maxPayloadSize, payloadBegin, payloadEnd, setPayloadSize, type, updateFlags
Inherited Functions: duplicate, referenceCount, release
Types Aliases
Ptr
using Ptr = Poco::AutoPtr < Frame >;
Enumerations
Capabilities
CAPA_REMOTING_PROTOCOL_1_0 = 0x524D0100
The endpoint understands the Remoting NG binary protocol, version 1.0
CAPA_REMOTING_PROTOCOL_1_1 = 0x524D0101
The endpoint understands the Remoting NG binary protocol, version 1.1 (including authentication)
Flags
FRAME_FLAG_EOM = 0x0001
End Of Message - the last frame of a message.
FRAME_FLAG_CONT = 0x0002
Continuation frame - set on all frames except the first one in a multi-frame message.
FRAME_FLAG_ONEWAY = 0x0004
One Way Message - no reply expected.
FRAME_FLAG_DEFLATE = 0x0008
Frame/message payload is compressed using zlib deflate algorithm.
FRAME_FLAG_AUTH = 0x0010
Frame contains authentication token.
FRAME_FLAG_EXTHDR = 0x8000
Extended header - reserved for future use.
Sizes
FRAME_HEADER_SIZE = 12
Size of frame header.
FRAME_MAX_SIZE = 1024
Maximum frame size (header + payload) currently used by protocol.
FRAME_MAX_PAYLOAD_SIZE = FRAME_MAX_SIZE - FRAME_HEADER_SIZE
Maximum frame payload size currently used by protocol.
Types
FRAME_TYPE_HELO = 0x48454C4F
"HELO" - first frame to be sent over channel 0 after connection has been established. Sent by both parties. Payload is protocol major version (8 bit unsigned), followed by protocol minor version (8 bit unsigned), followed by flags (8 bit unsigned, currently unused), followed by number of capabilities (8 bit unsigned), followed by list of capabilities as 32 bit integers.
FRAME_TYPE_BYE = 0x42594521
"BYE!" - last frame to be sent over channel. The endpoint wishing to close the connection sends a BYE! frame, and the other side acknowledges by responding also with a BYE! frame. After acknowledgement, the underlying TCP connection is closed.
The frame has no payload.
FRAME_TYPE_AUTH = 0x41555448
"AUTH" - A Remoting NG authentication request message.
Payload:
- mechanism: string
- payload: serialized credentials (key-value pairs)
FRAME_TYPE_AUTC = 0x41555443
"AUTC" - A Remoting NG authentication continuation message.
Payload:
- conversation ID: UInt32
- payload: serialized credentials (key-value pairs)
FRAME_TYPE_AUTR = 0x41555452
"AUTR" - A Remoting NG authentication response message.
Payload is:
FRAME_TYPE_REQU = 0x52455155
"REQU" - A Remoting NG request message.
Payload is serialized request (see Poco::RemotingNG::BinarySerializer).
FRAME_TYPE_REPL = 0x5245504C
"RESP" - A Remoting NG reply message.
Payload is serialized reply (see Poco::RemotingNG::BinarySerializer).
FRAME_TYPE_EVNT = 0x45564E54
"EVNT" - A Remoting NG event message.
Payload is serialized event (see Poco::RemotingNG::BinarySerializer).
FRAME_TYPE_EVNR = 0x45564E52
"EVNR" - A Remoting NG event reply message.
Payload is serialized event reply (see Poco::RemotingNG::BinarySerializer).
FRAME_TYPE_EVSU = 0x45565355
"EVSU" - A Remoting NG event subscribe/renewal message.
FRAME_TYPE_EVUN = 0x4556554E
"EVUN" - A Remoting NG event unsubscribe message.
Version
Constructors
Frame
Frame(
Poco::UInt32 type,
Poco::UInt32 channel,
Poco::UInt16 flags,
Poco::UInt16 bufferSize
);
Creates a frame with the given type, flags and buffer size.
Buffer size must be sufficient for both header and payload. Minimum buffer size is the size of the header, which is 12 bytes.
The initial payload size is 0.
Destructor
~Frame 
~Frame();
Destroys the frame.
Member Functions
bufferBegin 
char * bufferBegin();
Returns a pointer to the begin of the buffer.
bufferBegin
const char * bufferBegin() const;
Returns a pointer to the begin of the buffer.
bufferEnd
char * bufferEnd();
Returns a pointer to the end (one past last byte) of the buffer.
bufferEnd
const char * bufferEnd() const;
Returns a pointer to the end (one past last byte) of the buffer.
bufferSize
Poco::UInt16 bufferSize() const;
Returns the buffer size.
channel
Poco::UInt32 channel() const;
Returns the channel.
flags
Poco::UInt16 flags() const;
Returns the flags.
frameSize
Poco::UInt16 frameSize() const;
Returns the frame size, which is header size plus payload size.
getPayloadSize
Poco::UInt16 getPayloadSize() const;
Returns the payload size.
maxPayloadSize
Poco::UInt16 maxPayloadSize() const;
Returns the maximum payload size, which is buffer size minus header size.
payloadBegin
char * payloadBegin();
Returns a pointer to the begin of the payload in the buffer.
payloadBegin
const char * payloadBegin() const;
Returns a pointer to the begin of the payload in the buffer.
payloadEnd
char * payloadEnd();
Returns a pointer to the end (one past last byte) of the payload in the buffer.
payloadEnd
const char * payloadEnd() const;
Returns a pointer to the end (one past last byte) of the payload in the buffer.
setPayloadSize
void setPayloadSize(
Poco::UInt16 size
);
Sets the payload size, which must not exceed the buffer size minus header size.
type
Poco::UInt32 type() const;
Returns the frame type.
updateFlags
void updateFlags(
Poco::UInt16 flags
);
Updates the flags.