com.unister.semweb.drums
Class GlobalParameters<Data extends AbstractKVStorable>

java.lang.Object
  com.unister.semweb.drums.GlobalParameters<Data>

Type Parameters:

Data - an implementation of AbstractKVStorable, e.g. GeneralStorable

public class GlobalParameters<Data extends AbstractKVStorable>
extends java.lang.Object

This class represents all parameters, which are used globally in a DRUMS-Instance. The instance of GlobalParameters should be available in all internal Objects used by DRUMS.

Author:

Martin Nettling

Field Summary

long	BUCKET_MEMORY The amount of bytes all buckets are allowed to use.
java.lang.String	databaseDirectory The database directory.
int	elementSize The number bytes needed by an instance of AbstractKVStorable.
long	FILE_CHUNK_SIZE The size of one chunk in an HeaderIndexFile
int	HEADER_FILE_LOCK_RETRY the number of retries if a file is locked by another process
int	ID a identification number of this parameter set.
int	INITIAL_FILE_SIZE the initial size of a HeaderIndexFile.
int	INITIAL_INCREMENT_SIZE the initial size by which the file is enlarged, when no more records will fit into the file.
static java.util.concurrent.atomic.AtomicInteger	INSTANCE_COUNT A global count of all instances of GlobalParameters.
int	keySize The size of the key of the implementation of AbstractKVStorable.
java.lang.String	linkDataFileExtension File extension of the database files that store the AbstractKVStorable.
long	MAX_BUCKET_STORAGE_TIME The maximal time in milliseconds a bucket is held in memory without synchronization attempt.
long	MAX_MEMORY_PER_BUCKET The maximal size of a bucket in bytes.
int	MEMORY_CHUNK the size of one chunk in memory
int	MIN_ELEMENT_IN_BUCKET_BEFORE_SYNC The minimal number of elements which must be in one bucket, before this bucket is allowed to be synchronized.
int	NUMBER_OF_SYNCHRONIZER_THREADS The number of threads used for synchronizing.
java.lang.String	PARAMETER_FILE The name of the underlying parameter file.
long	SYNC_CHUNK_SIZE The number of bytes, which are read and written at once during synchronization

Constructor Summary

GlobalParameters(Data prototype)
The standard constructor.

GlobalParameters(java.lang.String paramFile, Data prototype)
Initialize global parameters by those from the given parameter-file.

Method Summary

void	configToLogInfo() Outputs the configuration to the Logger.
Data	getPrototype() Returns a clone of the prototype.
void	initParameters() Initialises all Parameters.
static long	parseSize(java.lang.String s) This methods parses the given String, which should represent a size, to a long.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE_COUNT

public static java.util.concurrent.atomic.AtomicInteger INSTANCE_COUNT

A global count of all instances of GlobalParameters. This variable is needed if more than one DRUMS will run in one JVM.

databaseDirectory

public java.lang.String databaseDirectory

The database directory. All records are written to files in this directory.

PARAMETER_FILE

public java.lang.String PARAMETER_FILE

The name of the underlying parameter file.

ID

public final int ID

a identification number of this parameter set. This variable is needed if more than one DRUMS is instantiated in one JVM.

BUCKET_MEMORY

public long BUCKET_MEMORY

The amount of bytes all buckets are allowed to use.

MAX_MEMORY_PER_BUCKET

public long MAX_MEMORY_PER_BUCKET

The maximal size of a bucket in bytes. If this size is exceeded, no more elements for this bucket are accepted, until it is synchronized to disk.

MEMORY_CHUNK

public int MEMORY_CHUNK

the size of one chunk in memory

HEADER_FILE_LOCK_RETRY

public int HEADER_FILE_LOCK_RETRY

the number of retries if a file is locked by another process

SYNC_CHUNK_SIZE

public long SYNC_CHUNK_SIZE

The number of bytes, which are read and written at once during synchronization

FILE_CHUNK_SIZE

public long FILE_CHUNK_SIZE

The size of one chunk in an HeaderIndexFile

NUMBER_OF_SYNCHRONIZER_THREADS

public int NUMBER_OF_SYNCHRONIZER_THREADS

The number of threads used for synchronizing.

MIN_ELEMENT_IN_BUCKET_BEFORE_SYNC

public int MIN_ELEMENT_IN_BUCKET_BEFORE_SYNC

The minimal number of elements which must be in one bucket, before this bucket is allowed to be synchronized.

linkDataFileExtension

public java.lang.String linkDataFileExtension

File extension of the database files that store the AbstractKVStorable.

INITIAL_INCREMENT_SIZE

public int INITIAL_INCREMENT_SIZE

the initial size by which the file is enlarged, when no more records will fit into the file.

INITIAL_FILE_SIZE

public int INITIAL_FILE_SIZE

the initial size of a HeaderIndexFile.

keySize

public final int keySize

The size of the key of the implementation of AbstractKVStorable.

elementSize

public final int elementSize

The number bytes needed by an instance of AbstractKVStorable.

MAX_BUCKET_STORAGE_TIME

public long MAX_BUCKET_STORAGE_TIME

The maximal time in milliseconds a bucket is held in memory without synchronization attempt.

Constructor Detail

GlobalParameters

public GlobalParameters(java.lang.String paramFile,
                        Data prototype)

Initialize global parameters by those from the given parameter-file.

Parameters:

paramFile - The name of the parameter-file

prototype - a prototype of the Data of this DRUMS

GlobalParameters

public GlobalParameters(Data prototype)

The standard constructor. Loads all parameters from drums.properties

Parameters:

prototype - a prototype of the Data of this DRUMS

Method Detail

getPrototype

public Data getPrototype()

Returns a clone of the prototype. If you need to access the prototype several times, you should create a pointer on your own instance.

Returns:

clone of the internal prototype

initParameters

public void initParameters()

Initialises all Parameters.

configToLogInfo

public void configToLogInfo()

Outputs the configuration to the Logger.

parseSize

public static long parseSize(java.lang.String s)

This methods parses the given String, which should represent a size, to a long. 'K' is interpreted as 1024, 'M' as 1024^2 and 'G' as 1024^3.

Parameters:

s - the String to parse

Returns:

size in byte. -1 if the String was not parsable.