org.javagroups.stack
Class Configurator

java.lang.Object
  |
  +--org.javagroups.stack.Configurator

public class Configurator

extends java.lang.Object

The task if this class is to setup and configure the protocol stack. A string describing the desired setup, which is both the layering and the configuration of each layer, is given to the configurator which creates and configures the protocol stack and returns a reference to the top layer (Protocol).

Future functionality will include the capability to dynamically modify the layering of the protocol stack and the properties of each layer.

Author:

Bela Ban

Nested Class Summary

class

Configurator.ProtocolConfiguration Parses and encapsulates the specification for 1 protocol of the protocol stack, e.g.

Constructor Summary

Configurator()

Method Summary

Protocol	createProtocol(java.lang.String prot_spec, ProtocolStack stack) Creates a new protocol given the protocol specification.
Protocol	findProtocol(Protocol prot_stack, java.lang.String name)
Protocol	getBottommostProtocol(Protocol prot_stack)
void	insertProtocol(Protocol prot, int position, java.lang.String neighbor_prot, ProtocolStack stack) Inserts an already created (and initialized) protocol into the protocol list.
static void	main(java.lang.String[] args)
java.util.Vector	parseComponentStrings(java.lang.String config_str, java.lang.String delimiter) Get a string of the form "P1(config_str1):P2:P3(config_str3)" and return ProtocolConfigurations for it.
java.util.Vector	parseConfigurations(java.lang.String configuration) Return a number of ProtocolConfigurations in a vector
void	removeProtocol(java.lang.String prot_name) Removes a protocol from the stack.
void	sanityCheck(java.util.Vector protocols) Throws an exception if sanity check fails.
Protocol	setupProtocolStack(java.lang.String configuration, ProtocolStack st) The configuration string has a number of entries, separated by a ':' (colon).
void	startProtocolStack(Protocol bottom_prot)
void	stopProtocolStack(Protocol start_prot)

Methods inherited from class java.lang.Object

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

Constructor Detail

Configurator

public Configurator()

Method Detail

setupProtocolStack

public Protocol setupProtocolStack(java.lang.String configuration,
                                   ProtocolStack st)
                            throws java.lang.Exception

The configuration string has a number of entries, separated by a ':' (colon). Each entry consists of the name of the protocol, followed by an optional configuration of that protocol. The configuration is enclosed in parentheses, and contains entries which are name/value pairs connected with an assignment sign (=) and separated by a semicolon.

UDP(in_port=5555;out_port=4445):FRAG(frag_size=1024)

The first entry defines the bottommost layer, the string is parsed left to right and the protocol stack constructed bottom up. Example: the string "UDP(in_port=5555):FRAG(frag_size=32000):DEBUG" results is the following stack:

   -----------------------
  | DEBUG                 |
  |-----------------------|
  | FRAG frag_size=32000  |
  |-----------------------|
  | UDP in_port=32000     |
   -----------------------
 

java.lang.Exception

startProtocolStack

public void startProtocolStack(Protocol bottom_prot)

stopProtocolStack

public void stopProtocolStack(Protocol start_prot)

findProtocol

public Protocol findProtocol(Protocol prot_stack,
                             java.lang.String name)

getBottommostProtocol

public Protocol getBottommostProtocol(Protocol prot_stack)
                               throws java.lang.Exception

java.lang.Exception

createProtocol

public Protocol createProtocol(java.lang.String prot_spec,
                               ProtocolStack stack)
                        throws java.lang.Exception

Creates a new protocol given the protocol specification. Initializes the properties and starts the up and down handler threads.

Parameters:

prot_spec - The specification of the protocol. Same convention as for specifying a protocol stack. An exception will be thrown if the class cannot be created. Example:

"VERIFY_SUSPECT(timeout=1500)"

Note that no colons (:) have to be specified

stack - The protocol stack

Returns:

Protocol The newly created protocol

Throws:

java.lang.Exception - Will be thrown when the new protocol cannot be created

insertProtocol

public void insertProtocol(Protocol prot,
                           int position,
                           java.lang.String neighbor_prot,
                           ProtocolStack stack)
                    throws java.lang.Exception

Inserts an already created (and initialized) protocol into the protocol list. Sets the links to the protocols above and below correctly and adjusts the linked list of protocols accordingly.

Parameters:

prot - The protocol to be inserted. Before insertion, a sanity check will ensure that none of the existing protocols have the same name as the new protocol.

position - Where to place the protocol with respect to the neighbor_prot (ABOVE, BELOW)

neighbor_prot - The name of the neighbor protocol. An exception will be thrown if this name is not found

stack - The protocol stack

Throws:

java.lang.Exception - Will be thrown when the new protocol cannot be created, or inserted.

removeProtocol

public void removeProtocol(java.lang.String prot_name)
                    throws java.lang.Exception

Removes a protocol from the stack. Stops the protocol and readjusts the linked lists of protocols.

Parameters:

prot_name - The name of the protocol. Since all protocol names in a stack have to be unique (otherwise the stack won't be created), the name refers to just 1 protocol.

Throws:

java.lang.Exception - Thrown if the protocol cannot be stopped correctly.

parseComponentStrings

public java.util.Vector parseComponentStrings(java.lang.String config_str,
                                              java.lang.String delimiter)

Get a string of the form "P1(config_str1):P2:P3(config_str3)" and return ProtocolConfigurations for it. That means, parse "P1(config_str1)", "P2" and "P3(config_str3)"

Parameters:

config_str - Configuration string

Returns:

Vector of ProtocolConfigurations

parseConfigurations

public java.util.Vector parseConfigurations(java.lang.String configuration)
                                     throws java.lang.Exception

Return a number of ProtocolConfigurations in a vector

Parameters:

configuration - protocol-stack configuration string

Returns:

Vector of ProtocolConfigurations

java.lang.Exception

sanityCheck

public void sanityCheck(java.util.Vector protocols)
                 throws java.lang.Exception

Throws an exception if sanity check fails. Possible sanity check is uniqueness of all protocol names.

java.lang.Exception

main

public static void main(java.lang.String[] args)