org.apache.pig.newplan
Interface OperatorPlan

All Known Implementing Classes:

BaseOperatorPlan, LogicalExpressionPlan, LogicalPlan, OperatorSubPlan, PatternPlan, PigStats.JobGraph

@InterfaceAudience.Private
@InterfaceStability.Unstable
public interface OperatorPlan

An interface that defines graph operations on plans. Plans are modeled as graphs with restrictions on the types of connections and operations allowed.

Method Summary

void	add(Operator op) Add a new operator to the plan.
void	connect(Operator from, int fromPos, Operator to, int toPos) Connect two operators in the plan, controlling which position in the edge lists that the from and to edges are placed.
void	connect(Operator from, Operator to) Connect two operators in the plan.
void	createSoftLink(Operator from, Operator to) Create an soft edge between two nodes.
Pair<Integer,Integer>	disconnect(Operator from, Operator to) Disconnect two operators in the plan.
Iterator<Operator>	getOperators() Get an iterator of all operators in this plan
List<Operator>	getPredecessors(Operator op) For a given operator, get all operators immediately before it in the plan.
List<Operator>	getSinks() Get all operators in the plan that have no successors.
List<Operator>	getSoftLinkPredecessors(Operator op) For a given operator, get all operators softly immediately before it in the plan.
List<Operator>	getSoftLinkSuccessors(Operator op) For a given operator, get all operators softly immediately after it.
List<Operator>	getSources() Get all operators in the plan that have no predecessors.
List<Operator>	getSuccessors(Operator op) For a given operator, get all operators immediately after it.
void	insertBetween(Operator pred, Operator operatorToInsert, Operator succ) This method insert node operatorToInsert between pred and succ.
boolean	isEqual(OperatorPlan other) This is like a shallow comparison.
boolean	pathExists(Operator load, Operator store) check if there is a path in the plan graph between the load operator to the store operator.
void	remove(Operator op) Remove an operator from the plan.
void	removeAndReconnect(Operator operatorToRemove) This method remove a node operatorToRemove.
void	removeSoftLink(Operator from, Operator to) Remove an soft edge
void	replace(Operator oldOperator, Operator newOperator) This method replace the oldOperator with the newOperator, make all connection to the new operator in the place of old operator
int	size() Get number of nodes in the plan.

Method Detail

size

int size()

Get number of nodes in the plan.

Returns:

number of nodes in the plan

getSources

List<Operator> getSources()

Get all operators in the plan that have no predecessors.

Returns:

all operators in the plan that have no predecessors, or an empty list if the plan is empty.

getSinks

List<Operator> getSinks()

Get all operators in the plan that have no successors.

Returns:

all operators in the plan that have no successors, or an empty list if the plan is empty.

getPredecessors

List<Operator> getPredecessors(Operator op)

For a given operator, get all operators immediately before it in the plan.

Parameters:

op - operator to fetch predecessors of

Returns:

list of all operators immediately before op, or an empty list if op is a root.

getSuccessors

List<Operator> getSuccessors(Operator op)

For a given operator, get all operators immediately after it.

Parameters:

op - operator to fetch successors of

Returns:

list of all operators immediately after op, or an empty list if op is a leaf.

getSoftLinkPredecessors

List<Operator> getSoftLinkPredecessors(Operator op)

For a given operator, get all operators softly immediately before it in the plan.

Parameters:

op - operator to fetch predecessors of

Returns:

list of all operators immediately before op, or an empty list if op is a root.

getSoftLinkSuccessors

List<Operator> getSoftLinkSuccessors(Operator op)

For a given operator, get all operators softly immediately after it.

Parameters:

op - operator to fetch successors of

Returns:

list of all operators immediately after op, or an empty list if op is a leaf.

add

void add(Operator op)

Add a new operator to the plan. It will not be connected to any existing operators.

Parameters:

op - operator to add

remove

void remove(Operator op)
            throws FrontendException

Remove an operator from the plan.

Parameters:

op - Operator to be removed

Throws:

FrontendException - if the remove operation attempts to remove an operator that is still connected to other operators.

connect

void connect(Operator from,
             int fromPos,
             Operator to,
             int toPos)

Connect two operators in the plan, controlling which position in the edge lists that the from and to edges are placed.

Parameters:

from - Operator edge will come from

fromPos - Position in the array for the from edge

to - Operator edge will go to

toPos - Position in the array for the to edge

connect

void connect(Operator from,
             Operator to)

Connect two operators in the plan.

Parameters:

from - Operator edge will come from

to - Operator edge will go to

createSoftLink

void createSoftLink(Operator from,
                    Operator to)

Create an soft edge between two nodes.

Parameters:

from - Operator dependent upon

to - Operator having the dependency

removeSoftLink

void removeSoftLink(Operator from,
                    Operator to)

Remove an soft edge

Parameters:

from - Operator dependent upon

to - Operator having the dependency

disconnect

Pair<Integer,Integer> disconnect(Operator from,
                                 Operator to)
                                 throws FrontendException

Disconnect two operators in the plan.

Parameters:

from - Operator edge is coming from

to - Operator edge is going to

Returns:

pair of positions, indicating the position in the from and to arrays.

Throws:

FrontendException - if the two operators aren't connected.

getOperators

Iterator<Operator> getOperators()

Get an iterator of all operators in this plan

Returns:

an iterator of all operators in this plan

isEqual

boolean isEqual(OperatorPlan other)
                throws FrontendException

This is like a shallow comparison. Two plans are equal if they have equivalent operators and equivalent structure.

Parameters:

other - object to compare

Returns:

boolean if both the plans are equivalent

Throws:

FrontendException

replace

void replace(Operator oldOperator,
             Operator newOperator)
             throws FrontendException

This method replace the oldOperator with the newOperator, make all connection to the new operator in the place of old operator

Parameters:

oldOperator - operator to be replaced

newOperator - operator to replace

Throws:

FrontendException

removeAndReconnect

void removeAndReconnect(Operator operatorToRemove)
                        throws FrontendException

This method remove a node operatorToRemove. It also Connect all its successors to predecessor/connect all it's predecessors to successor

Parameters:

operatorToRemove - operator to remove

Throws:

FrontendException

insertBetween

void insertBetween(Operator pred,
                   Operator operatorToInsert,
                   Operator succ)
                   throws FrontendException

This method insert node operatorToInsert between pred and succ. Both pred and succ cannot be null

Parameters:

pred - predecessor of inserted node after this method

operatorToInsert - operato to insert

succ - successor of inserted node after this method

Throws:

FrontendException

pathExists

boolean pathExists(Operator load,
                   Operator store)

check if there is a path in the plan graph between the load operator to the store operator.

Parameters:

load - load operator

store - store operator

Returns:

true if yes, no otherwise.