simtools.data.buffer
Class Buffer

java.lang.Object
  simtools.data.ValueProvider
      simtools.data.buffer.Buffer

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

Direct Known Subclasses:

SimpleBuffer

public abstract class Buffer
extends ValueProvider
implements java.lang.Cloneable, java.io.Serializable

A Buffer provides a buffering service for values, based on an index. To do that, it asks a ValueProvider for new unbuffered values when necessary. It should implement a strategy in order to minimize calls to the ValueProvider getUnbuffered method. The Buffer is also a ValueProvider itself, of course. A simple strategy is proposed with the AgeBufferPolicy, where the oldest entry is removed to make space for a new entry when the buffer is full. More intelligent or faster policies may be implemented by subclasses, such as using the values access frequency, or managing ranges of index.

Version:

1.0 2001

Author:

Nicolas Brodu

See Also:

Serialized Form

Nested Class Summary

class	Buffer.ByteManipulator This class handles optimization for byte objects.
class	Buffer.DoubleManipulator This class handles optimization for double objects.
class	Buffer.FloatManipulator This class handles optimization for float objects.
class	Buffer.IntegerManipulator This class handles optimization for int objects.
class	Buffer.LongManipulator This class handles optimization for long objects.
static interface	Buffer.Manipulator
class	Buffer.ObjectManipulator This class handles optimization for Object objects.
class	Buffer.ShortManipulator This class handles optimization for short objects.

Field Summary

protected Buffer.ByteManipulator	byteManipulator
protected Buffer.DoubleManipulator	doubleManipulator
protected long	endIndex
protected Buffer.FloatManipulator	floatManipulator
protected Buffer.IntegerManipulator	intManipulator
protected Buffer.LongManipulator	longManipulator
protected Buffer.ObjectManipulator	objectManipulator
protected ValueProvider	provider
protected Buffer.ShortManipulator	shortManipulator
protected long	startIndex

Fields inherited from class simtools.data.ValueProvider

ByteProvider, DoubleProvider, FloatProvider, IntegerProvider, kind, LongProvider, ObjectProvider, ShortProvider

Constructor Summary

Buffer()

Buffer(int type)

Buffer(int type, ValueProvider vp)

Buffer(ValueProvider vp)

Method Summary

void	clear()
java.lang.Object	clone()
protected abstract Buffer.Manipulator	createManipulator(int kind) Manipulator factory Subclasses shall implement it to return their specialized versions of Manipulators.
byte	getByteValue(long index) Optimized accessor for byte values.
double	getDoubleValue(long index) Optimized accessor for double values.
long	getEndIndex()
float	getFloatValue(long index) Optimized accessor for float values.
int	getIntegerValue(long index) Optimized accessor for int values.
int	getKind() The kind of this provider may be used fo optimization purpose.
long	getLongValue(long index) Optimized accessor for long values.
ValueProvider	getProvider()
short	getShortValue(long index) Optimized accessor for short values.
long	getStartIndex()
java.lang.Object	getValue(long index)
boolean	setByteValue(long index, byte value)
boolean	setDoubleValue(long index, double value)
boolean	setFloatValue(long index, float value)
boolean	setIntegerValue(long index, int value)
boolean	setLongValue(long index, long value)
void	setProvider(ValueProvider vp)
boolean	setShortValue(long index, short value)
void	setSlice(long min, long max) Sets a region of interest in the buffer.
boolean	setValue(long index, java.lang.Object value) Sets a new value in the buffer, if possible.

Methods inherited from class simtools.data.ValueProvider

getObjectValue, valueClass

Methods inherited from class java.lang.Object

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

Field Detail

provider

protected transient ValueProvider provider

objectManipulator

protected transient Buffer.ObjectManipulator objectManipulator

byteManipulator

protected transient Buffer.ByteManipulator byteManipulator

shortManipulator

protected transient Buffer.ShortManipulator shortManipulator

intManipulator

protected transient Buffer.IntegerManipulator intManipulator

longManipulator

protected transient Buffer.LongManipulator longManipulator

floatManipulator

protected transient Buffer.FloatManipulator floatManipulator

doubleManipulator

protected transient Buffer.DoubleManipulator doubleManipulator

startIndex

protected transient long startIndex

endIndex

protected transient long endIndex

Constructor Detail

Buffer

public Buffer()

Buffer

public Buffer(int type)

Buffer

public Buffer(ValueProvider vp)

Buffer

public Buffer(int type,
              ValueProvider vp)

Method Detail

setProvider

public void setProvider(ValueProvider vp)

getProvider

public ValueProvider getProvider()

setValue

public boolean setValue(long index,
                        java.lang.Object value)
                 throws DataException

Sets a new value in the buffer, if possible. With getValue(), the buffer is polling information from ValueProviders With setValue(), an external source may push information to the buffer The buffer implementation may, or may not, take the new value into account. But if it does, this may lead to quite a big optimization. For example, pathIterators in graphical shapes are run one after the other. But a collective data source may read those values in the same file, all the source values for a given index on the same line. So, the pathIterators would run through the file n times, when they could have run through it only once if only they were doing their job in parallel. Since it's not possible to change that, the data source collection pushes the other values read on the same line directly to the data source buffers.

Parameters:

index - The index for which a new value is given

value - The new value

Returns:

true if the new value could be put in the buffer.

Throws:

DataException

setSlice

public void setSlice(long min,
                     long max)

Sets a region of interest in the buffer. This is a purely informative function, but the buffer may use this information to optimize itself on this specific range.

clone

public java.lang.Object clone()

Overrides:

clone in class java.lang.Object

getEndIndex

public long getEndIndex()

Returns:

long

getStartIndex

public long getStartIndex()

Returns:

long

getValue

public java.lang.Object getValue(long index)
                          throws DataException

Specified by:

getValue in class ValueProvider

Throws:

DataException

getByteValue

public byte getByteValue(long index)
                  throws DataException

Description copied from class: ValueProvider

Optimized accessor for byte values. If the provider can provide bytes directly, then it should override this method. Otherwise, the default implementation will do its best to convert the Object returned by getValue() to a byte. This conversion also parses strings, and returns 0 if it failed. An exception is thrown if, and only if, getValue throws it.

Overrides:

getByteValue in class ValueProvider

Throws:

DataException

setByteValue

public boolean setByteValue(long index,
                            byte value)
                     throws DataException

Throws:

DataException

getShortValue

public short getShortValue(long index)
                    throws DataException

Description copied from class: ValueProvider

Optimized accessor for short values. If the provider can provide shorts directly, then it should override this method. Otherwise, the default implementation will do its best to convert the Object returned by getValue() to a short. This conversion also parses strings, and returns 0 if it failed. An exception is thrown if, and only if, getValue throws it.

Overrides:

getShortValue in class ValueProvider

Throws:

DataException

setShortValue

public boolean setShortValue(long index,
                             short value)
                      throws DataException

Throws:

DataException

getIntegerValue

public int getIntegerValue(long index)
                    throws DataException

Description copied from class: ValueProvider

Optimized accessor for int values. If the provider can provide ints directly, then it should override this method. Otherwise, the default implementation will do its best to convert the Object returned by getValue() to a int. This conversion also parses strings, and returns 0 if it failed. An exception is thrown if, and only if, getValue throws it.

Overrides:

getIntegerValue in class ValueProvider

Throws:

DataException

setIntegerValue

public boolean setIntegerValue(long index,
                               int value)
                        throws DataException

Throws:

DataException

getLongValue

public long getLongValue(long index)
                  throws DataException

Description copied from class: ValueProvider

Optimized accessor for long values. If the provider can provide longs directly, then it should override this method. Otherwise, the default implementation will do its best to convert the Object returned by getValue() to a long. This conversion also parses strings, and returns 0 if it failed. An exception is thrown if, and only if, getValue throws it.

Overrides:

getLongValue in class ValueProvider

Throws:

DataException

setLongValue

public boolean setLongValue(long index,
                            long value)
                     throws DataException

Throws:

DataException

getFloatValue

public float getFloatValue(long index)
                    throws DataException

Description copied from class: ValueProvider

Optimized accessor for float values. If the provider can provide floats directly, then it should override this method. Otherwise, the default implementation will do its best to convert the Object returned by getValue() to a float. This conversion also parses strings, and returns 0 if it failed. An exception is thrown if, and only if, getValue throws it.

Overrides:

getFloatValue in class ValueProvider

Throws:

DataException

setFloatValue

public boolean setFloatValue(long index,
                             float value)
                      throws DataException

Throws:

DataException

getDoubleValue

public double getDoubleValue(long index)
                      throws DataException

Description copied from class: ValueProvider

Optimized accessor for double values. If the provider can provide doubles directly, then it should override this method. Otherwise, the default implementation will do its best to convert the Object returned by getValue() to a double. This conversion also parses strings, and returns 0 if it failed. An exception is thrown if, and only if, getValue throws it.

Overrides:

getDoubleValue in class ValueProvider

Throws:

DataException

setDoubleValue

public boolean setDoubleValue(long index,
                              double value)
                       throws DataException

Throws:

DataException

createManipulator

protected abstract Buffer.Manipulator createManipulator(int kind)

Manipulator factory Subclasses shall implement it to return their specialized versions of Manipulators.

Parameters:

kind -

Returns:

Manipulator a Manipulator which must be a subclass of the corresponding TypeManipulator.

getKind

public int getKind()

Description copied from class: ValueProvider

The kind of this provider may be used fo optimization purpose. This is just an indication for getXXXValue typed functions.

Overrides:

getKind in class ValueProvider

Returns:

the buffer type as one of the constants defined in this class

clear

public void clear()