Class Concat

java.lang.Object

io.nosqlbench.virtdata.library.basics.shared.from_long.to_string.Concat

All Implemented Interfaces:

LongFunction<String>

Direct Known Subclasses:

ConcatArray, ConcatChained, ConcatCycle, ConcatFixed, ConcatHashed, ConcatStepped

public class Concat
extends Object
implements LongFunction<String>

This is the core implementation of the Concat style of String binding. It is the newer and recommended version of Template.

Users should use one of these wrappers:

• ConcatCycle - all inputs are the cycle value
• ConcatHashed - all inputs are a hash of (cycle+step)
• ConcatStepped - all inputs are (cycle+step)
• ConcatFixed - all inputs are always the same value
• ConcatChained - all inputs are chained hashes of the previous one

This implementation is available for specialized use when needed, but the above versions are much more self-explanatory and easy to use.

As with previous implementations, the basic input which is fed to the functions is the sum of the input cycle and the step, where the step is simply the index of the insertion point within the template string. These start at 0, so a template string which contains "{}-{}" will have two steps, 0, and 1. For cycle 35, the first function will take input 35, and the second 36. This can create some local neighborhood similarity in test data, so other forms are provided which can hash the values for an added degree of (effective) randomness and one that chains these so that each set of values from a Concat binding are quite distinct from each other.

Binding functions used to populate each step of the template may have their own bounds of output values like Combinations. These are easy to use internally since they work well with the hashing. However, some other functions may operate over the whole space of long values, and come with no built-in cardinality constraints. It is recommended to use those with built-in constraints when you want to render a discrete population of values.

Field Summary

Fields

Modifier and Type	Field	Description
protected final LongBinaryOperator	cycleStepMapper
protected final LongFunction<String>[]	functions
protected final String[]	literals

Constructor Summary

Constructors

Constructor	Description
Concat(String template, Object... functions)
Concat(LongBinaryOperator cycleStepMapper, String template, Object... functions)

Method Summary

Modifier and Type	Method	Description
String	apply(long cycle)

Methods inherited from class java.lang.Object

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

Field Details

cycleStepMapper

protected final LongBinaryOperator cycleStepMapper

literals

protected final String[] literals

functions

protected final LongFunction<String>[] functions

Constructor Details

Concat

public Concat(String template,
 Object... functions)

Concat

public Concat(LongBinaryOperator cycleStepMapper,
 String template,
 Object... functions)

Method Details

apply

public String apply(long cycle)

Specified by:

apply in interface LongFunction<String>