public final class ChannelAccessReadSyncMessage extends ChannelAccessMessage
CA_PROTO_READ_SYNC
message. This message is
sent from a client to a server via TCP in order to cancel all read requests
that have been sent by the client but not been fulfilled yet. The server
replies with the same message, having the same header values (except for the
payload size) but no payload. Usually, the message sent by the client also
does not have a payload. Typically, this message is only used by old clients
(EPICS 3.13 and older). Newer clients might use it with old servers, as an
alternative to the CA_PROTO_ECHO
message, that is not supported
in old Channel Access versions.ChannelAccessCommand.CA_PROTO_READ_SYNC
command, originalMessageHeader
Constructor and Description |
---|
ChannelAccessReadSyncMessage()
Constructor for creating a
CA_PROTO_READ_SYNC message. |
ChannelAccessReadSyncMessage(ChannelAccessReadSyncMessage messageFromClient)
Constructor for creating a
CA_PROTO_READ_SYNC message. |
Modifier and Type | Method and Description |
---|---|
protected static ChannelAccessReadSyncMessage |
deserialize(ChannelAccessMessageHeader messageHeader,
ByteSource byteSource,
boolean headerOnly)
Constructs a message from a header and a byte source.
|
boolean |
equals(Object obj)
Tells whether the specified object represents the same message.
|
int |
hashCode()
Returns a hash code value for this message.
|
protected void |
serialize(ByteSink byteSink,
ChannelAccessVersion version,
int maxPayloadSize,
Charset charset)
Serializes this message to a byte sink.
|
String |
toString()
Returns a string representation of this message.
|
protected void |
verify(ChannelAccessVersion version,
int maxPayloadSize,
Charset charset)
Verifies that this message can be serialized.
|
addByteArrayToStringBuilder, calculatePaddingSize, getCommand, getOriginalMessageHeader, hasOriginalMessageHeader, serializeHeader, verifyHeader
public ChannelAccessReadSyncMessage()
CA_PROTO_READ_SYNC
message. This
constructor should be used for messages that are sent from a client to a
server.public ChannelAccessReadSyncMessage(ChannelAccessReadSyncMessage messageFromClient)
CA_PROTO_READ_SYNC
message. This
constructor should be used for messages that are sent from server to a
client in reply to a CA_PROTO_READ_SYNC
message that has
been received from the client. The header fields from the supplied
message are used to initialize the header fields of this message.messageFromClient
- the message that has been received from the client, to which
this message is a reply.protected void serialize(ByteSink byteSink, ChannelAccessVersion version, int maxPayloadSize, Charset charset)
ChannelAccessMessage
ChannelAccessMessageCodec
.serialize
in class ChannelAccessMessage
byteSink
- byte sink that is used for writing the serialized data.version
- protocol version to stay compatible with. This is the protocol
version of the peer the message is sent to.maxPayloadSize
- maximum size of the payload.charset
- encoding to use for serializing the string data (e.g. channel
names, error strings, string data-values).protected void verify(ChannelAccessVersion version, int maxPayloadSize, Charset charset)
ChannelAccessMessage
ChannelAccessMessageCodec
.verify
in class ChannelAccessMessage
version
- protocol version to stay compatible with. This is the protocol
version of the peer the message is sent to.maxPayloadSize
- maximum size of the payload.charset
- encoding to use for serializing the string data (e.g. channel
names, error strings, string data-values).public boolean equals(Object obj)
ChannelAccessMessage
Tells whether the specified object represents the same message.
Two messages are considered equal if they are of the same type and have the same headers and payload. For comparing the types, the actual Java type and not just the Channel Access command is compared.
equals
in class ChannelAccessMessage
obj
- reference object with which this object is compared.true
if obj
is a message that is of the
same type and has the same headers and payload as this message.
false
if obj
is null
or of
a different type than this message or differs in the headers or
payload.public int hashCode()
ChannelAccessMessage
Returns a hash code value for this message. This method is supported for the benefit of hash tables. The hash code is calculated as a combination of the hash codes of this messages headers (including the Channel Access command) and its payload (if present).
If two messages are equal (as indicated by the return value of
ChannelAccessMessage.equals(Object)
), they also have the same hash code. However, the
fact that two messages have the same hash code does not imply that they
are equal.
hashCode
in class ChannelAccessMessage
public String toString()
ChannelAccessMessage
toString
in class ChannelAccessMessage
protected static ChannelAccessReadSyncMessage deserialize(ChannelAccessMessageHeader messageHeader, ByteSource byteSource, boolean headerOnly)
ChannelAccessMessageCodec
.messageHeader
- CA message header.byteSource
- byte source for reading the message's payload (if any).headerOnly
- if true
this method will not try to read the
payload but just read the header. This is useful for reading a
message that is sent in the payload of a
ChannelAccessErrorMessage
. Such a message will have
all headers but no payload (even so the payload size might be
non-zero).headerOnly
is
false
).BufferUnderflowException
- if there is not enough data in the byte source to read the
complete message (including he payload if
headerOnly
is false
).Copyright © 2014–2017 aquenos GmbH. All rights reserved.