edu.harvard.deas.hyperenc.vsat
Class NNPageDatabase

java.lang.Object
  java.lang.Thread
      edu.harvard.deas.hyperenc.vsat.NNPageDatabase

All Implemented Interfaces:

PageDatabase, Serializable, Runnable

public class NNPageDatabase
extends Thread
implements Serializable, PageDatabase

Contains an index of the pages we will provide. Does the book-keeping to make sure that each page is only accessed twice, returns pages based on the Nearest Neighbor lookup

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

static int

MAX_NUM_PAGES The number of pages this database will contain

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

NNPageDatabase()
Creates a new NNPageDatabase.

Method Summary

byte[]	getClosestPage(int key) Equivalent to getPage.
int	getMaxPages()
int	getNumPages()
byte[]	getPage(int key) Use the key to return the closest available page.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, run, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

MAX_NUM_PAGES

public static final int MAX_NUM_PAGES

The number of pages this database will contain

See Also:

Constant Field Values

Constructor Detail

NNPageDatabase

public NNPageDatabase()

Creates a new NNPageDatabase. Generates MAX_NUM_PAGES and inserts them into the database.

Method Detail

getNumPages

public int getNumPages()

Specified by:

getNumPages in interface PageDatabase

Returns:

Number of pages currently stored in the page database.

getMaxPages

public int getMaxPages()

Specified by:

getMaxPages in interface PageDatabase

Returns:

Maximum number of pages that can be stored in the page database.

getClosestPage

public byte[] getClosestPage(int key)

Equivalent to getPage.

getPage

public byte[] getPage(int key)

Use the key to return the closest available page.

Specified by:

getPage in interface PageDatabase

Parameters:

key - The key we are trying to match.

Returns:

The page whose key was closest to the request, or null if the database is empty.