Package org.stianloader.remapper

Interface MappingLookup

All Known Implementing Classes:

HierarchyAwareMappingDelegator, SimpleHierarchyAwareMappingLookup, SimpleMappingLookup

public interface MappingLookup

A MappingLookup stores mappings which can be obtained by the specified accessor methods. While the MappingLookup interface on it's own is strictly read-only, implementations may mutate the mappings between calls and are allowed to implement interfaces that introduce mapping writing properties such as MappingSink. That being said, callers should generally be safe in that assumption that one an element maps to a certain value, the association will stay over a longer duration.

Concrete implements of this interface such as HierarchyAwareMappingDelegator or SimpleMappingLookup, which implement MappingSink, should thus not be mutated after performing the first map requests. However, implementations (which include the implementations listed previously) are not required to ensure such immutability.

Method overloading, inheritance and other remapping restrictions

Implementations of MappingLookup are generally encouraged to implement inheritance, and may also support overloading if chosen. However, MappingLookup does not explicitly define a behaviour here and implementations such as SimpleMappingLookup may choose to handle inheritance and method overloading at all. For more insight as to why inheritance and overloading may be beneficial, see the appropriate section in Remapper.

The methods provided by MappingLookup should avoid returning illegal names wherever possible. However, beware that getRemappedMethodName(String, String, String) is likely to be called with the static initialization block <clinit> or the constructor <init>, which should not map to anything but these names. This means that implementations of MappingLookup should not try to be smart and refuse seemingly illegal mapping requests (one can still return the name of the member in the source namespace though) - this behaviour is employed for performance reasons

If an implementation of MappingLookup chooses to handle method hierarchies, it must be aware that similar hierarchy structures exist for fields, too. Furthermore, it should be aware that getRemappedFieldName(String, String, String) and getRemappedMethodName(String, String, String) may be called with member it may not know (this can be the case with different JDKs - even older ones! Breaking changes did happen in the past even within the public APIs).

Concurrency and thread safety

While a MappingLookup instance on it's own is read-only and thus usually fine to use in concurrent environments, there may be implementations that are either not completely in-memory or allow mutation which thus may compromise any thread safety guarantees. As such the usual advice applies here, too: Consult the manual of your implementation regarding thread safety and prefer to err on the side of caution if not known. The MappingLookup interface otherwise makes no thread safety and concurrency guarantees.

Method Summary

Modifier and Type	Method	Description
@NotNull String	getRemappedClassName(@NotNull String srcName)	Obtains the name of the class in the destination namespace (or in laymen's terms the remapped name).
default @Nullable String	getRemappedClassNameFast(@NotNull String srcName)	Obtains the name of the class in the destination namespace (or in laymen's terms the remapped name).
@NotNull String	getRemappedFieldName(@NotNull String srcOwner, @NotNull String srcName, @NotNull String srcDesc)	Obtains the name of a field in the destination namespace (or the mapped name).
@NotNull String	getRemappedMethodName(@NotNull String srcOwner, @NotNull String srcName, @NotNull String srcDesc)	Obtains the name of a field in the destination namespace (or the mapped name).
default @Nullable String	getRemappedParameterName(@NotNull String srcOwner, @NotNull String srcName, @NotNull String srcDesc, int paramIndex, boolean isStaticMethod)	Obtains the name of the parameter in the destination namespace (or in laymen's terms the remapped name of the parameter).

Method Details

getRemappedClassName

@NotNull
@Contract(pure=true)
@NotNull String getRemappedClassName(@NotNull
 @NotNull String srcName)

Obtains the name of the class in the destination namespace (or in laymen's terms the remapped name). If the class name in the source namespace is equal to the name in the destination namespace (e.g. because there is no mapping), then the name in the source namespace must be returned.

It is valid to have getRemappedClassNameFast(String) and getRemappedClassName(String) be the same implementation for as long as getRemappedClassName(String) never returns null, however doing so might incur a slight performance reduction.

srcName and the returned value are in the same format as Type.getInternalName().

Parameters:

srcName - The name of the class in the source namespace

Returns:

The mapped name in the destination namespace, or the name in the source namespace if no mapping exists.

getRemappedClassNameFast

@Nullable
@Contract(pure=true)
default @Nullable String getRemappedClassNameFast(@NotNull
 @NotNull String srcName)

Obtains the name of the class in the destination namespace (or in laymen's terms the remapped name). If the class name in the source namespace is equal to the name in the destination namespace (e.g. because there is no mapping), then null can be returned for performance reasons.

This is especially done when some string manipulation can be skipped if the source name equals the destination name.

It is valid to have getRemappedClassNameFast(String) and getRemappedClassName(String) be the same implementation for as long as getRemappedClassName(String) never returns null, however doing so might incur a slight performance reduction.

srcName and the returned value are in the same format as Type.getInternalName().

Parameters:

srcName - The name of the class in the source namespace

Returns:

The name in the destination namespace, or null if the name is the same as the source namespace

getRemappedFieldName

@NotNull
@Contract(pure=true)
@NotNull String getRemappedFieldName(@NotNull
 @NotNull String srcOwner,
 @NotNull
 @NotNull String srcName,
 @NotNull
 @NotNull String srcDesc)

Obtains the name of a field in the destination namespace (or the mapped name). If the field is not known or if no mapping exists for the field, then the name in the source namespace must be returned (that is the srcName parameter).

srcOwner is in the same format as Type.getInternalName().

Implementations of this interface are encouraged to not throw if possible.

Parameters:

srcOwner - The name of the owner of the member in the source namespace

srcName - The name of the member in the source namespace

srcDesc - The descriptor of the member (where as classes are all in the source namespace)

Returns:

The mapped name in the destination namespace, or the name in the source namespace if no mapping exists.

getRemappedMethodName

@NotNull
@Contract(pure=true)
@NotNull String getRemappedMethodName(@NotNull
 @NotNull String srcOwner,
 @NotNull
 @NotNull String srcName,
 @NotNull
 @NotNull String srcDesc)

Obtains the name of a field in the destination namespace (or the mapped name). If the field is not known or if no mapping exists for the field, then the name in the source namespace must be returned (that is the srcName parameter).

srcOwner is in the same format as Type.getInternalName().

Implementations of this interface are encouraged to not throw if possible.

Parameters:

srcOwner - The name of the owner of the member in the source namespace

srcName - The name of the member in the source namespace

srcDesc - The descriptor of the member (where as classes are all in the source namespace)

Returns:

The mapped name in the destination namespace, or the name in the source namespace if no mapping exists.

getRemappedParameterName

@Nullable
@Contract(pure=true)
@AvailableSince("0.2.0-a20251220")
default @Nullable String getRemappedParameterName(@NotNull
 @NotNull String srcOwner,
 @NotNull
 @NotNull String srcName,
 @NotNull
 @NotNull String srcDesc,
 int paramIndex,
 boolean isStaticMethod)

Obtains the name of the parameter in the destination namespace (or in laymen's terms the remapped name of the parameter). Should the name of the parameter not be known in the destination namespace, then null is returned. This is the default behaviour of this method.

The paramIndex argument is 0-indexed. It does not distinguish between computational categories. Or in other words, for both (IZ)V and (JZ)V the boolean parameter corresponds to a paramIndex value of 1, while the integer and long have a value of 0.

Callers may throw an IndexOutOfBoundsException if paramIndex is below 0 or above the amount of parameters as discernible by srcDesc. As such, this method cannot be used to remap LVT entries, even though they are quite similar in structure. This is because LVT entries can be reused. By default this method does not do any checks whether paramIndex is a valid value. This is done for performance reasons.

Implementations of this method are encouraged to not throw if possible, unless for reasons described above. While it theoretically makes sense to throw an exception in cases where a method is known to not exist, this is generally rarely the case.

If this MappingLookup instance does not support remapping parameters, then null should be returned unconditionally, without throwing outside of aforementioned reasons.

Parameters:

srcOwner - The name of the owner of the member in the source namespace.

srcName - The name of the member in the source namespace.

srcDesc - The descriptor of the member (where as classes are all in the source namespace).

paramIndex - The index of the parameter, excluding the implied this parameter.

isStaticMethod - Whether the method is static. Used when working with mappings formats such as Enigma, TINYv2, or TSRG.

Returns:

The name of the parameter in the destination namespace, or null if not applicable.

Since:

0.2.0-a20251220