simpledb

Interface PageId

All Known Implementing Classes:

HeapPageId

public interface PageId

PageId is an interface to a specific page of a specific table.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o) Compares one PageId to another.
int	getTableId()
int	hashCode()
int	pageNumber()
int[]	serialize() Return a representation of this page id object as a collection of integers (used for logging) This class MUST have a constructor that accepts n integer parameters, where n is the number of integers returned in the array from serialize.

Method Detail

serialize

int[] serialize()

Return a representation of this page id object as a collection of integers (used for logging) This class MUST have a constructor that accepts n integer parameters, where n is the number of integers returned in the array from serialize.

getTableId

int getTableId()

Returns:

the unique tableid hashcode with this PageId

hashCode

int hashCode()

Overrides:

hashCode in class java.lang.Object

Returns:

a hash code for this page, represented by the concatenation of the table number and the page number (needed if a PageId is used as a key in a hash table in the BufferPool, for example.)

See Also:

BufferPool

equals

boolean equals(java.lang.Object o)

Compares one PageId to another.

Overrides:

equals in class java.lang.Object

Parameters:

o - The object to compare against (must be a PageId)

Returns:

true if the objects are equal (e.g., page numbers and table ids are the same)

pageNumber

int pageNumber()