org.jgroups.stack

Class 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.

Field Summary

protected Log
log

Method Summary

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

Field Details

log

protected Log log

Method Details

createProtocol

public Protocol createProtocol(String prot_spec,
                               ProtocolStack stack)
            throws 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


findProtocol

public Protocol findProtocol(Protocol prot_stack,
                             String name)


getBottommostProtocol

public Protocol getBottommostProtocol(Protocol prot_stack)


insertProtocol

public void insertProtocol(Protocol prot,
                           int position,
                           String neighbor_prot,
                           ProtocolStack stack)
            throws 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


main

public static void main(args[] )


parseComponentStrings

public Vector parseComponentStrings(String config_str,
                                    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 Vector parseConfigurations(String configuration)
            throws Exception
Return a number of ProtocolConfigurations in a vector

Parameters:
configuration - protocol-stack configuration string

Returns:
Vector of ProtocolConfigurations


removeProtocol

public void removeProtocol(String prot_name)
            throws 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.


sanityCheck

public void sanityCheck(Vector protocols)
            throws Exception
Throws an exception if sanity check fails. Possible sanity check is uniqueness of all protocol names.


setupProtocolStack

public Protocol setupProtocolStack(String configuration,
                                   ProtocolStack st)
            throws 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     |
   -----------------------
 


startProtocolStack

public void startProtocolStack(Protocol bottom_prot)


stopProtocolStack

public void stopProtocolStack(Protocol start_prot)


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