org.jlab.coda.jevio

Class StructureTransformer

java.lang.Object

org.jlab.coda.jevio.StructureTransformer

public class StructureTransformer
extends java.lang.Object

This class contains methods to transform structures from one type to another, for example changing an EvioSegment into an EvioBank. Date: Oct 1, 2010

Author:

timmer

Constructor Summary

Constructors

Constructor and Description
StructureTransformer()

Method Summary

Modifier and Type	Method and Description
static EvioSegment	transform(EvioBank bank) Create an EvioSegment object from an EvioBank.
static EvioTagSegment	transform(EvioBank bank, int dummy) Create an EvioTagSegment object from an EvioBank.
static EvioTagSegment	transform(EvioSegment segment) Create an EvioTagSegment object from an EvioSegment.
static EvioBank	transform(EvioSegment segment, int num) Create an EvioBank object from an EvioSegment.
static EvioSegment	transform(EvioTagSegment tagsegment) Create an EvioSegment object from an EvioTagSegment.
static EvioBank	transform(EvioTagSegment tagsegment, int num) Create an EvioBank object from an EvioTagSegment.

Methods inherited from class java.lang.Object

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

Constructor Detail

StructureTransformer

public StructureTransformer()

Method Detail

transform

public static EvioBank transform(EvioSegment segment,
                                 int num)

Create an EvioBank object from an EvioSegment. The new object has all data copied over, except that the segment's children were are added (not deep cloned) to the bank. Because a segment has no num, the user supplies that as an arg.

Parameters:

segment - EvioSegment object to transform.

num - num of the created EvioBank.

Returns:

the created EvioBank.

transform

public static EvioBank transform(EvioTagSegment tagsegment,
                                 int num)

Create an EvioBank object from an EvioTagSegment. The new object has all data copied over, except that the tagsegment's children were are added (not deep cloned) to the bank. Because a segment has no num, the user supplies that as an arg.

NOTE: A tagsegment has no associated padding data. However, the bank.transform() method will calculate it and set it in the bank header.

Parameters:

tagsegment - EvioTagSegment object to transform.

num - num of the created EvioBank.

Returns:

the created EvioBank.

transform

public static EvioTagSegment transform(EvioSegment segment)

Create an EvioTagSegment object from an EvioSegment. The new object has all data copied over, except that the segment's children were are added (not deep cloned) to the tagsegment.

NOTE: No data should be lost in this transformaton since even though the segment serializes 6 bits of data type when being written out while the tag segment serializes 4, only 4 bits are needed to contain the equivalent type data. And, the segment's tag is serialized into 8 bits while the tagsegment's tag uses 12 bits so no problem there.

Parameters:

segment - EvioSegment object to transform.

Returns:

the created EvioTagSegment.

transform

public static EvioSegment transform(EvioTagSegment tagsegment)

Create an EvioSegment object from an EvioTagSegment. The new object has all data copied over, except that the tagsegment's children were are added (not deep cloned) to the segment.

NOTE: A tagsegment has no associated padding data. However, the transform() method will calculate it and set it in the segment header. Tags are stored in a 16 bit int and so this transformation will never lose any tag data. Only when a segment's tag is written out or serialized into 8 bits will this become an issue since a tagsegment's tag is serialized as 12 bits.

Parameters:

tagsegment - EvioTagSegment object to transform.

Returns:

the created EvioSegment.

transform

public static EvioSegment transform(EvioBank bank)
                             throws EvioException

Create an EvioSegment object from an EvioBank. The new object has all data copied over, except that the bank's children were are added (not deep cloned) to the segment.

TAG: Tags are stored in a 16 bit int and so this transformation will never lose any tag data. Only when a segment's tag is written out or serialized into 8 bits will this become an issue since a bank's tag is serialized as 16 bits.

NUM: A segment has no num data and so the bank's num is lost. The bank's num is actually copied into segment header so in that sense it still exists, but will never be written out or serialized.

LENGTH: It is possible that the length of the bank (32 bits) is too big for the segment (16 bits). This condition will cause an exception.

Parameters:

bank - EvioBank object to transform.

Returns:

the created EvioSegment.

Throws:

EvioException - if the bank is too long to change into a segment

transform

public static EvioTagSegment transform(EvioBank bank,
                                       int dummy)
                                throws EvioException

Create an EvioTagSegment object from an EvioBank. The new object has all data copied over, except that the bank's children were are added (not deep cloned) to the segment.

TAG: Tags are stored in a 16 bit int and so this transformation will never lose any tag data. Only when a tagsegment's tag is written out or serialized into 12 bits will this become an issue since a bank's tag is serialized as 16 bits.

NUM: A tagsegment has no num data and so the bank's num is lost. The bank's num is actually copied into tagsegment header so in that sense it still exists, but will never be written out or serialized.

LENGTH: It is possible that the length of the bank (32 bits) is too big for the tagsegment (16 bits). This condition will cause an exception.

TYPE: No data should be lost in this transformaton since even though the bank serializes 6 bits of data type when being written out while the tagsegment serializes 4, only 4 bits are needed to contain the equivalent type data.

Parameters:

bank - EvioBank object to transform.

dummy - only used to distinguish this method from transform(EvioBank).

Returns:

the created EvioTagSegment.

Throws:

EvioException - if the bank is too long to change into a tagsegment