uk.ac.starlink.hapi

Class HapiType<S,A>

java.lang.Object

uk.ac.starlink.hapi.HapiType<S,A>

Type Parameters:

S - scalar output type

A - array output type

public abstract class HapiType<S,A>
extends Object

Data type for a HAPI parameter.

Since:

11 Jan 2024

Author:

Mark Taylor

Field Summary

Fields

Modifier and Type	Field and Description
static HapiType<Double,double[]>	DOUBLE Floating point type.
static HapiType<Integer,int[]>	INTEGER Integer type.
static HapiType<String,String[]>	ISOTIME Restricted ISO-8601 timestamp type.
static HapiType<String,String[]>	STRING String type.

Method Summary

Modifier and Type	Method and Description
abstract void	adjustInfo(DefaultValueInfo info) Performs customisation appropriate to this type on a metadata info object that will represent it.
abstract void	applyFills(A array, S fill) Replaces array elements matching a given fill value in place with a suitable blank value representation.
static HapiType<?,?>	fromText(String txt) Returns a type value given the identifier string as found in the "type" member of a Parameter JSON object.
Class<A>	getArrayClass() Returns the output class for array values.
int	getByteCount(int paramLength) Returns the number of bytes required for a scalar element with this type and the supplied length value.
String	getIdentifier() Returns the name for this type, which is also the value of the "type" member in a corresponding Parameter JSON object.
Class<S>	getScalarClass() Returns the output class for scalar values.
abstract A	readBinaryArray(byte[] buf, int ipos, int elSize, int nel) Returns an array value of this type from a binary buffer.
abstract S	readBinaryScalar(byte[] buf, int ipos, int leng) Returns a scalar value of this type from its binary representation.
abstract A	readStringArray(String[] txts, int ipos, int nel) Returns an array value of this type from an array of string representations.
abstract S	readStringScalar(String txt) Returns a scalar value of this type from its text representation.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

STRING

public static final HapiType<String,String[]> STRING

String type.

ISOTIME

public static final HapiType<String,String[]> ISOTIME

Restricted ISO-8601 timestamp type.

DOUBLE

public static final HapiType<Double,double[]> DOUBLE

Floating point type.

INTEGER

public static final HapiType<Integer,int[]> INTEGER

Integer type.

Method Detail

getIdentifier

public String getIdentifier()

Returns the name for this type, which is also the value of the "type" member in a corresponding Parameter JSON object.

Returns:

type name

getScalarClass

public Class<S> getScalarClass()

Returns the output class for scalar values.

Returns:

scalar class

getArrayClass

public Class<A> getArrayClass()

Returns the output class for array values.

Returns:

array class

getByteCount

public int getByteCount(int paramLength)

Returns the number of bytes required for a scalar element with this type and the supplied length value. The paramLength is as supplied by HapiParam.getLength().

Parameters:

paramLength - string length, or -1 for non-string types

Returns:

binary byte count for a scalar element of this type

readStringScalar

public abstract S readStringScalar(String txt)

Returns a scalar value of this type from its text representation.

Parameters:

txt - text field as found in CSV

Returns:

typed scalar value

readBinaryScalar

public abstract S readBinaryScalar(byte[] buf,
                                   int ipos,
                                   int leng)

Returns a scalar value of this type from its binary representation.

Parameters:

buf - bytes representing value as found in binary format stream

ipos - starting position of value in buf

leng - length of value in bytes

Returns:

typed scalar value

readStringArray

public abstract A readStringArray(String[] txts,
                                  int ipos,
                                  int nel)

Returns an array value of this type from an array of string representations.

Parameters:

txts - text fields as found in CSV, elements may be null

ipos - index of first element in txts to read

nel - number of elements in txts to read

Returns:

typed array value, same length as input

readBinaryArray

public abstract A readBinaryArray(byte[] buf,
                                  int ipos,
                                  int elSize,
                                  int nel)

Returns an array value of this type from a binary buffer.

Parameters:

buf - bytes representing values as found in binary format stream

ipos - starting position of values in buf

elSize - number of bytes per value

nel - number of values to decode

Returns:

typed array value with nel elements

applyFills

public abstract void applyFills(A array,
                                S fill)

Replaces array elements matching a given fill value in place with a suitable blank value representation.

Parameters:

array - array whose elements can be replaced

fill - non-null value for which corresponding array elements should be blanked

adjustInfo

public abstract void adjustInfo(DefaultValueInfo info)

Performs customisation appropriate to this type on a metadata info object that will represent it. This only changes less-essential metadata, basic things like content class will be handled elsewhere. The correct action may be a no-op.

Parameters:

info - metadata object to modify in place

toString

public String toString()

Overrides:

toString in class Object

fromText

public static HapiType<?,?> fromText(String txt)

Returns a type value given the identifier string as found in the "type" member of a Parameter JSON object.

Parameters:

txt - identifier string

Returns:

type instance, or null if no match