simpledb

Class Utility

java.lang.Object

simpledb.Utility

public class Utility
extends java.lang.Object

Helper methods used for testing and implementing random features.

Constructor Summary

Constructors

Constructor and Description
Utility()

Method Summary

Modifier and Type	Method and Description
static HeapFile	createEmptyHeapFile(java.lang.String path, int cols) A utility method to create a new HeapFile with a single empty page, assuming the path does not already exist.
static Tuple	getHeapTuple(int n)
static Tuple	getHeapTuple(int[] tupdata)
static Tuple	getHeapTuple(int n, int width)
static java.lang.String[]	getStrings(int len, java.lang.String val)
static Tuple	getTuple(int[] tupledata, int width)
static TupleDesc	getTupleDesc(int n)
static TupleDesc	getTupleDesc(int n, java.lang.String name)
static Type[]	getTypes(int len)
static java.lang.String	listToString(java.util.ArrayList<java.lang.Integer> list)
static HeapFile	openHeapFile(int cols, java.io.File f) Opens a HeapFile and adds it to the catalog.
static HeapFile	openHeapFile(int cols, java.lang.String colPrefix, java.io.File f)

Methods inherited from class java.lang.Object

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

Constructor Detail

Utility

public Utility()

Method Detail

getTypes

public static Type[] getTypes(int len)

Returns:

a Type array of length len populated with Type.INT_TYPE

getStrings

public static java.lang.String[] getStrings(int len,
                                            java.lang.String val)

Returns:

a String array of length len populated with the (possibly null) strings in val, and an appended increasing integer at the end (val1, val2, etc.).

getTupleDesc

public static TupleDesc getTupleDesc(int n,
                                     java.lang.String name)

Returns:

a TupleDesc with n fields of type Type.INT_TYPE, each named name + n (name1, name2, etc.).

getTupleDesc

public static TupleDesc getTupleDesc(int n)

Returns:

a TupleDesc with n fields of type Type.INT_TYPE

getHeapTuple

public static Tuple getHeapTuple(int n)

Returns:

a Tuple with a single IntField with value n and with RecordId(HeapPageId(1,2), 3)

getHeapTuple

public static Tuple getHeapTuple(int[] tupdata)

Returns:

a Tuple with an IntField for every element of tupdata and RecordId(HeapPageId(1, 2), 3)

getHeapTuple

public static Tuple getHeapTuple(int n,
                                 int width)

Returns:

a Tuple with a 'width' IntFields each with value n and with RecordId(HeapPageId(1, 2), 3)

getTuple

public static Tuple getTuple(int[] tupledata,
                             int width)

Returns:

a Tuple with a 'width' IntFields with the value tupledata[i] in each field. do not set it's RecordId, hence do not distinguish which sort of file it belongs to.

createEmptyHeapFile

public static HeapFile createEmptyHeapFile(java.lang.String path,
                                           int cols)
                                    throws java.io.IOException

A utility method to create a new HeapFile with a single empty page, assuming the path does not already exist. If the path exists, the file will be overwritten. The new table will be added to the Catalog with the specified number of columns as IntFields.

Throws:

java.io.IOException

openHeapFile

public static HeapFile openHeapFile(int cols,
                                    java.io.File f)

Opens a HeapFile and adds it to the catalog.

Parameters:

cols - number of columns in the table.

f - location of the file storing the table.

Returns:

the opened table.

openHeapFile

public static HeapFile openHeapFile(int cols,
                                    java.lang.String colPrefix,
                                    java.io.File f)

listToString

public static java.lang.String listToString(java.util.ArrayList<java.lang.Integer> list)