com.sleepycat.je.rep.impl
Class TextProtocol

java.lang.Object
  com.sleepycat.je.rep.impl.TextProtocol

Direct Known Subclasses:

NodeStateProtocol, Protocol, Protocol, RepGroupProtocol

public abstract class TextProtocol
extends Object

SimpleProtocol provides the support for implementing simple low performance protocols involving replication nodes. The protocol is primarily text based, and checks group membership and version matches with every message favoring flexibility over performance. The base class is primarily responsible for the message formatting and message envelope validation. The subclasses define the specific messages that constitute the protocol and the request/response semantics. Every message has the format: |||| is the version of the protocol in use. identifies a group participating in an election. It avoids accidental cross-talk across groups holding concurrent elections. identifies the originator of the message within the group. the operation identified by the specific message. the payload associated with the particular operation.

Nested Class Summary

class	TextProtocol.Fail
static class	TextProtocol.InvalidMessageException Used to indicate a message format or invalid content exception.
class	TextProtocol.Message Base message class for all messages exchanged in the protocol.
static class	TextProtocol.MessageError
class	TextProtocol.MessageExchange Use to parallelize message exchanges via Futures.
static class	TextProtocol.MessageOp The Operations that are part of the protocol.
class	TextProtocol.OK
class	TextProtocol.ProtocolError
class	TextProtocol.RequestMessage Base class for all Request messages
class	TextProtocol.ResponseMessage Base classes for response messages.
protected static class	TextProtocol.StringFormatable
static class	TextProtocol.TOKENS Represents the tokens on a message line.
protected static interface	TextProtocol.WireFormatable

Field Summary

protected EnvironmentImpl	envImpl
TextProtocol.MessageOp	FAIL_RESP
protected Formatter	formatter
protected Logger	logger
protected String	messagePrefixNocheck
TextProtocol.MessageOp	OK_RESP
TextProtocol.MessageOp	PROTOCOL_ERROR
static String	SEPARATOR
static String	SEPARATOR_REGEXP

Constructor Summary

TextProtocol(String version, String groupName, NameIdPair nameIdPair, EnvironmentImpl envImpl)
Creates an instance of the Protocol.

Method Summary

int	getOpenTimeout()
int	getReadTimeout()
TextProtocol.RequestMessage	getRequestMessage(SocketChannel channel) Reads the channel and returns a read request.
protected void	initializeMessageOps(TextProtocol.MessageOp[] protocolOps) The messages as defined by the subclass.
int	messageCount()
TextProtocol.Message	parse(String line) Parses a line into a Request/Response message.
TextProtocol.RequestMessage	parseRequest(String requestLine) Converts a request line into a requestMessage.
(package private) TextProtocol.ResponseMessage	parseResponse(String responseLine) Converts a response line into a ResponseMessage.
TextProtocol.ResponseMessage	process(Object requestProcessor, TextProtocol.RequestMessage requestMessage)
protected void	setTimeouts(RepImpl repImpl, DurationConfigParam openTimeoutConfig, DurationConfigParam readTimeoutConfig) Set the network timeouts associated with uses of this protocol instance.
void	updateNodeIds(Set<Integer> newMemberIds) Updates the current set of nodes that constitutes the group.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

messagePrefixNocheck

protected final String messagePrefixNocheck

SEPARATOR

public static final String SEPARATOR

See Also:

Constant Field Values

SEPARATOR_REGEXP

public static final String SEPARATOR_REGEXP

See Also:

Constant Field Values

PROTOCOL_ERROR

public final TextProtocol.MessageOp PROTOCOL_ERROR

OK_RESP

public final TextProtocol.MessageOp OK_RESP

FAIL_RESP

public final TextProtocol.MessageOp FAIL_RESP

logger

protected final Logger logger

formatter

protected final Formatter formatter

envImpl

protected final EnvironmentImpl envImpl

Constructor Detail

TextProtocol

public TextProtocol(String version,
                    String groupName,
                    NameIdPair nameIdPair,
                    EnvironmentImpl envImpl)

Creates an instance of the Protocol.

Parameters:

nameIdPair - a unique identifier for this node

envImpl - for logging, may be null

Method Detail

setTimeouts

protected void setTimeouts(RepImpl repImpl,
                           DurationConfigParam openTimeoutConfig,
                           DurationConfigParam readTimeoutConfig)

Set the network timeouts associated with uses of this protocol instance.

initializeMessageOps

protected void initializeMessageOps(TextProtocol.MessageOp[] protocolOps)

The messages as defined by the subclass. Note that PROTOCOL_ERROR is a pre-defined message that is defined by this class. The initialization is not considered until this method after been invoked typically in the constructor itself. This two-step is unfortunately necessary since the creation of MessageOps instances requires that this class be completely initialized, otherwise the MessageOp list could have been passed in as a constructor argument.

Parameters:

protocolOps - the message ops defined by the subclass.

getOpenTimeout

public int getOpenTimeout()

getReadTimeout

public int getReadTimeout()

messageCount

public int messageCount()

updateNodeIds

public void updateNodeIds(Set<Integer> newMemberIds)

Updates the current set of nodes that constitutes the group. Also update the id used in the header, in case it was null and isn't anymore.

Parameters:

newMemberIds -

parse

public TextProtocol.Message parse(String line)
                           throws TextProtocol.InvalidMessageException

Parses a line into a Request/Response message.

Parameters:

line - containing the message

Returns:

a message instance

Throws:

TextProtocol.InvalidMessageException

parseResponse

TextProtocol.ResponseMessage parseResponse(String responseLine)
                                     throws TextProtocol.InvalidMessageException

Converts a response line into a ResponseMessage.

Parameters:

responseLine -

Returns:

the response message

Throws:

TextProtocol.InvalidMessageException

parseRequest

public TextProtocol.RequestMessage parseRequest(String requestLine)
                                         throws TextProtocol.InvalidMessageException

Converts a request line into a requestMessage.

Parameters:

requestLine -

Returns:

the request message

Throws:

TextProtocol.InvalidMessageException

getRequestMessage

public TextProtocol.RequestMessage getRequestMessage(SocketChannel channel)
                                              throws IOException

Reads the channel and returns a read request. If the message format was bad, it sends a ProtocolError response back over the channel and no further action is needed by the caller.

Parameters:

channel - the channel delivering the request

Returns:

null if EOF was reached or the message format was bad

Throws:

IOException

process

public TextProtocol.ResponseMessage process(Object requestProcessor,
                                            TextProtocol.RequestMessage requestMessage)