context.arch.storage
Class VectorStorage

java.lang.Object
  context.arch.storage.VectorStorage

All Implemented Interfaces:

Storage

public class VectorStorage

extends java.lang.Object

implements Storage

This class allows storage and retrieval of data in String, Integer, Long, Float, Double, or Short format. It implements the Storage interface, using a Vector to store data temporarily. It can flush locally stored data to persistent data upon request.

Field Summary

static long	DEFAULT_FLUSH_CONDITION Default flush condition is 2 (i.e.
static int	DEFAULT_FLUSH_TYPE Default flush type is by number of stores
static char	NEW_SEPARATOR Separator used by database in structured info
static java.lang.String	NEW_SEPARATOR_STRING Separator used by database in structured info - String
static char	OLD_SEPARATOR Separator used in structured info
static java.lang.String	OLD_SEPARATOR_STRING Separator used in structured info - String

Fields inherited from interface context.arch.storage.Storage

DATA, EQUAL, GREATERTHAN, GREATERTHANEQUAL, LESSTHAN, LESSTHANEQUAL, NO_STORAGE, TIME

Constructor Summary

VectorStorage(java.lang.String table)
Basic constructor that uses the default flush condition

VectorStorage(java.lang.String tableName, java.lang.Integer flushType, java.lang.Long flushCondition)
Basic constructor that uses the given flush type and condition

Method Summary

boolean	checkFlushCondition() Checks condition under which local data is sent to persistent storage.
void	flushStorage() Flushes local data to persistent storage
RetrievalResults	retrieveAttributes(Retrieval retrieval) This method returns a Vector containing AttributeNameValue objects that match the given conditions in the Retrieval object.
RetrievalResults	retrieveAttributes(java.lang.String accessorId, Retrieval retrieval) This method returns a Vector containing AttributeNameValue objects that match the given conditions in the Retrieval object.
void	setAttributes(Attributes attributes, java.util.Hashtable attTypes) This method sets the attributes to use for storage.
void	store(Attributes atts) This method stores the given AttributeNameValues object

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_FLUSH_TYPE

public static final int DEFAULT_FLUSH_TYPE

Default flush type is by number of stores

See Also:

Constant Field Values

DEFAULT_FLUSH_CONDITION

public static final long DEFAULT_FLUSH_CONDITION

Default flush condition is 2 (i.e. flush after 2 stores)

See Also:

Constant Field Values

OLD_SEPARATOR

public static final char OLD_SEPARATOR

Separator used in structured info

See Also:

Constant Field Values

OLD_SEPARATOR_STRING

public static final java.lang.String OLD_SEPARATOR_STRING

Separator used in structured info - String

NEW_SEPARATOR

public static final char NEW_SEPARATOR

Separator used by database in structured info

See Also:

Constant Field Values

NEW_SEPARATOR_STRING

public static final java.lang.String NEW_SEPARATOR_STRING

Separator used by database in structured info - String

Constructor Detail

VectorStorage

public VectorStorage(java.lang.String table)
              throws java.sql.SQLException

Basic constructor that uses the default flush condition

Parameters:

table - Name of table to use

Throws:

java.sql.SQLException - if errors in accessing table info

VectorStorage

public VectorStorage(java.lang.String tableName,
                     java.lang.Integer flushType,
                     java.lang.Long flushCondition)
              throws java.sql.SQLException

Basic constructor that uses the given flush type and condition

Parameters:

flushType - Flush to database based on TIME or DATA

flushCondition - Condition to flush local storage to database

Throws:

java.sql.SQLException - if errors in accessing table info

Method Detail

store

public void store(Attributes atts)

This method stores the given AttributeNameValues object

Specified by:

store in interface Storage

Parameters:

atts - AttributeNameValues to store

retrieveAttributes

public RetrievalResults retrieveAttributes(java.lang.String accessorId,
                                           Retrieval retrieval)

This method returns a Vector containing AttributeNameValue objects that match the given conditions in the Retrieval object. It takes in the accessorId of the "user" requesting the information, but does nothing with it currently.

Specified by:

retrieveAttributes in interface Storage

Parameters:

accessorId - Id of the "user" trying to retrieve the data

retrieval - Retrievals object containing conditions for data retrieval

Returns:

RetrievalResults containing AttributeNameValues objects that match the given conditions

retrieveAttributes

public RetrievalResults retrieveAttributes(Retrieval retrieval)

This method returns a Vector containing AttributeNameValue objects that match the given conditions in the Retrieval object.

Specified by:

retrieveAttributes in interface Storage

Parameters:

retrieval - Retrievals object containing conditions for data retrieval

Returns:

RetrievalResults containing AttributeNameValues objects that match the given conditions

checkFlushCondition

public boolean checkFlushCondition()

Checks condition under which local data is sent to persistent storage.

Specified by:

checkFlushCondition in interface Storage

Returns:

Boolean value which indicates flushing is necessary or not

flushStorage

public void flushStorage()

Flushes local data to persistent storage

Specified by:

flushStorage in interface Storage

setAttributes

public void setAttributes(Attributes attributes,
                          java.util.Hashtable attTypes)

This method sets the attributes to use for storage. The attributes are used to set up the columns in a database table.

Specified by:

setAttributes in interface Storage

Parameters:

attributes - Attributes object containing attributes and type info

attTypes - Flattened hashtable version of Attributes