ReprUtil (math 3.1.2 API)

java.lang.Object
- org.cryptimeleon.math.serialization.annotations.ReprUtil

```
public class ReprUtil
extends java.lang.Object
```
A class for almost automatic creation of and restoration from representations.
Typical usage example:
1. Your class is StandaloneRepresentable, i.e. you need to give a constructor with Representation argument and a getRepresentation() method.
2. In your class, annotate all fields that need to be part of the representation with @Represented. For example, @Represented private Group group.
3. If some objects need help being deserialized (e.g., GroupElement instances are deserialized by their group), define a restorer in the @Represented annotation. For example, @Represented(restorer="group") private GroupElement x;. The restorer can either be another field of your class (like group in the example above), or another handler, which you'd have to register using register(RepresentationRestorer, String).
4. In the constructor with argument Representation repr}, call new ReprUtil(this).deserialize(repr);.
5. In getRepresentation(), call ReprUtil.serialize(this);
You can also refer to a restorer as, for example, "bilGroup::getG1", where bilGroup is as above (another field of the class or something registered) and getG1 is a method that returns a RepresentationRestorer.
The framework can handle lists, sets, and maps as well. For example, @Represented(restorer="[group]") handles a list or set of group elements and @Represented(restorer="String -> [group]") handles a map of strings to lists of group elements. Check Represented.restorer() for details.
An example including a bilinear pairing:
Suppose your object depends on public parameters (e.g., a publicly known bilinear group bilGroup, consisting of groups G1, G2, GT). You'd annotate GroupElement members with @Represented(restorer="G1"), @Represented(restorer="G2"), @Represented(restorer="GT"), depending on which of the three groups each of them belongs to. Your constructor would take these public parameters pp and a Representation repr as input and then call new ReprUtil(this).register(bilGroup).deserialize(repr);. getRepresentation() would still just call ReprUtil.serialize(this);.
For more information, consult the documentation.

Field Summary

Fields
Modifier and Type	Field and Description
`protected java.lang.Object`	`instance` Either stores the recreated object during deserialization, or the object to serialize.
`protected java.util.HashMap<java.lang.String,RepresentationRestorer>`	`restorers` Maps representation restorer identifiers to the corresponding `RepresentationRestorer` instances.

Constructor Summary

Constructors
Constructor and Description

ReprUtil(java.lang.Object instance)
Create ReprUtil for a specific target instance.

Constructors
Constructor and Description
`ReprUtil(java.lang.Object instance)` Create `ReprUtil` for a specific target instance.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`deserialize(java.lang.Object instance, Representation repr)` Restores the instance from the given representation, storing the result in the given object.
`void`	`deserialize(Representation repr)` Deserializes the given representation, storing the result in the instance given when initializing this `ReprUtil`.
`protected static org.cryptimeleon.math.serialization.annotations.RepresentationHandler`	`getHandler(java.lang.reflect.Type type, java.lang.String restorerString)` Derives the representation handler for a certain type and restorer string.
`protected static org.cryptimeleon.math.serialization.annotations.RepresentationHandler`	`getHandlerForField(java.lang.reflect.Field field)` Retrieves the representation handler for the given field.
`protected static org.cryptimeleon.math.serialization.annotations.RepresentationHandler`	`getHandlerWithoutRestorerString(java.lang.reflect.Type type)` Derives the representation handler for a certain type and empty restorer string.
`protected static org.cryptimeleon.math.serialization.annotations.RepresentationHandler`	`getHandlerWithRestorerString(java.lang.reflect.Type type, java.lang.String restorerString)` Derives the representation handler for a certain type and non-empty restorer string.
`ReprUtil`	`register(BilinearGroup bilinearGroup)` Registers \(\mathbb{G}_1\), \(\mathbb{G}_2\) and \(\mathbb{G}_T\) from the given bilinear group as restorers with names `"G1"`, `"G2"` and `"GT"`, respectively.
`ReprUtil`	`register(BilinearMap bilinearMap)` Registers \(\mathbb{G}_1\), \(\mathbb{G}_2\) and \(\mathbb{G}_T\) from the given bilinear map as restorers with names `"G1"`, `"G2"` and `"GT"`, respectively.
`ReprUtil`	`register(java.util.function.Function<? super Representation,?> restorer, java.lang.String name)` Register a custom restorer function, which takes a `Representation` and recreates the object.
`ReprUtil`	`register(RepresentationRestorer restorer, java.lang.String name)` Register a representation restorer using the given name.
`Representation`	`serialize()` Represents the the instance given when initializing this `ReprUtil` as a `Representation`.
`static Representation`	`serialize(java.lang.Object instance)` Represents the given instance as a `Representation`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - restorers
```
protected java.util.HashMap<java.lang.String,RepresentationRestorer> restorers
```
    Maps representation restorer identifiers to the corresponding RepresentationRestorer instances.
    Used to help with deserialization of fields that need a representation restorer to be deserialized.
  - instance
```
protected java.lang.Object instance
```
    Either stores the recreated object during deserialization, or the object to serialize.
- Constructor Detail
  - ReprUtil
```
public ReprUtil(java.lang.Object instance)
```
    Create ReprUtil for a specific target instance.
    For deserialization, the target instance will be filled with field values from the deserialized representation. For serialization, the target instance will be used to create the representation.
- Method Detail
  - register
```
public ReprUtil register(RepresentationRestorer restorer,
                         java.lang.String name)
```
    Register a representation restorer using the given name.
    Annotate the fields that should use this restorer with @Represented(restorer = "name").
    
    Parameters:
    
    restorer - a class that knows how to restore values from Representation (e.g., a Group knows how to restore its GroupElements)
    
    name - the name for this restorer (same as in the @Represented annotation)
    
    Returns:
    
    this (for chaining)
  - register
```
public ReprUtil register(BilinearGroup bilinearGroup)
```
    Registers \(\mathbb{G}_1\), \(\mathbb{G}_2\) and \(\mathbb{G}_T\) from the given bilinear group as restorers with names "G1", "G2" and "GT", respectively.
    
    Parameters:
    
    bilinearGroup - the bilinear group to register restorers for
    
    Returns:
    
    this (for chaining)
  - register
```
public ReprUtil register(BilinearMap bilinearMap)
```
    Registers \(\mathbb{G}_1\), \(\mathbb{G}_2\) and \(\mathbb{G}_T\) from the given bilinear map as restorers with names "G1", "G2" and "GT", respectively.
    
    Parameters:
    
    bilinearMap - the bilinear map to register restorers for
    
    Returns:
    
    this (for chaining)
  - register
```
public ReprUtil register(java.util.function.Function<? super Representation,?> restorer,
                         java.lang.String name)
```
    Register a custom restorer function, which takes a Representation and recreates the object.
    Annotate the field that should use this with @Represented(restorer = "name").
    You should usually not need this. Instead, use register(RepresentationRestorer, String) to register a RepresentationRestorer.
    
    Parameters:
    
    restorer - a function that takes in a Representation and restores the corresponding object.
    
    name - the name for this restorer function (same as in the @Represented annotation)
    
    Returns:
    
    this (for chaining)
  - serialize
```
public Representation serialize()
```
    Represents the the instance given when initializing this ReprUtil as a Representation.
    
    Returns:
    
    the representation
  - serialize
```
public static Representation serialize(java.lang.Object instance)
```
    Represents the given instance as a Representation.
    
    Parameters:
    
    instance - the object to serialize
    
    Returns:
    
    a Representation
  - deserialize
```
public static void deserialize(java.lang.Object instance,
                               Representation repr)
```
    Restores the instance from the given representation, storing the result in the given object.
    For more control over the deserialization process, e.g. if using custom representation restorers, use new ReprUtil(this).register(...).deserialize(repr) instead.
    
    Parameters:
    
    instance - the object whose attribute values to restore
    
    repr - the representation from which to restore the object
  - deserialize
```
public void deserialize(Representation repr)
```
    Deserializes the given representation, storing the result in the instance given when initializing this ReprUtil.
    
    Parameters:
    
    repr - the representation to deserialize
  - getHandlerForField
```
protected static org.cryptimeleon.math.serialization.annotations.RepresentationHandler getHandlerForField(java.lang.reflect.Field field)
```
    Retrieves the representation handler for the given field.
  - getHandler
```
protected static org.cryptimeleon.math.serialization.annotations.RepresentationHandler getHandler(java.lang.reflect.Type type,
                                                                                                  java.lang.String restorerString)
```
    Derives the representation handler for a certain type and restorer string. This is done statically, i.e. with static type information.
  - getHandlerWithRestorerString
```
protected static org.cryptimeleon.math.serialization.annotations.RepresentationHandler getHandlerWithRestorerString(java.lang.reflect.Type type,
                                                                                                                    java.lang.String restorerString)
```
    Derives the representation handler for a certain type and non-empty restorer string. This is done statically, i.e. with static type information.
  - getHandlerWithoutRestorerString
```
protected static org.cryptimeleon.math.serialization.annotations.RepresentationHandler getHandlerWithoutRestorerString(java.lang.reflect.Type type)
```
    Derives the representation handler for a certain type and empty restorer string. This is done statically, i.e. with static type information.

Class ReprUtil

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

restorers

instance

Constructor Detail

ReprUtil

Method Detail

register

register

register

register

serialize

serialize

deserialize

deserialize

getHandlerForField

getHandler

getHandlerWithRestorerString

getHandlerWithoutRestorerString