io.github.dmlloyd.classfile.attribute.ModuleHashesAttribute Maven / Gradle / Ivy
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package io.github.dmlloyd.classfile.attribute;
import io.github.dmlloyd.classfile.Attribute;
import io.github.dmlloyd.classfile.ClassElement;
import java.util.List;
import io.github.dmlloyd.classfile.ClassModel;
import io.github.dmlloyd.classfile.constantpool.Utf8Entry;
import io.github.dmlloyd.classfile.impl.BoundAttribute;
import io.github.dmlloyd.classfile.impl.TemporaryConstantPool;
import io.github.dmlloyd.classfile.impl.UnboundAttribute;
import io.github.dmlloyd.classfile.extras.PreviewFeature;
/**
* Models the {@code ModuleHashes} attribute, which can
* appear on classes that represent module descriptors. This is a JDK-specific
* attribute, which captures the hashes of a set of co-delivered modules.
* Delivered as a {@link ClassElement} when
* traversing the elements of a {@link ClassModel}.
*
* The specification of the {@code ModuleHashes} attribute is:
*
{@code
*
* ModuleHashes_attribute {
* // index to CONSTANT_utf8_info structure in constant pool representing
* // the string "ModuleHashes"
* u2 attribute_name_index;
* u4 attribute_length;
*
* // index to CONSTANT_utf8_info structure with algorithm name
* u2 algorithm_index;
*
* // the number of entries in the hashes table
* u2 hashes_count;
* { u2 module_name_index (index to CONSTANT_Module_info structure)
* u2 hash_length;
* u1 hash[hash_length];
* } hashes[hashes_count];
*
* }
* }
*
* The attribute does not permit multiple instances in a given location.
* Subsequent occurrence of the attribute takes precedence during the attributed
* element build or transformation.
*
* @since 22
*/
@PreviewFeature(feature = PreviewFeature.Feature.CLASSFILE_API)
public sealed interface ModuleHashesAttribute
extends Attribute, ClassElement
permits BoundAttribute.BoundModuleHashesAttribute, UnboundAttribute.UnboundModuleHashesAttribute {
/**
* {@return the algorithm name used to compute the hash}
*/
Utf8Entry algorithm();
/**
* {@return the hash information about related modules}
*/
List hashes();
/**
* {@return a {@code ModuleHashes} attribute}
* @param algorithm the hashing algorithm
* @param hashes the hash descriptions
*/
static ModuleHashesAttribute of(String algorithm,
List hashes) {
return of(TemporaryConstantPool.INSTANCE.utf8Entry(algorithm), hashes);
}
/**
* {@return a {@code ModuleHashes} attribute}
* @param algorithm the hashing algorithm
* @param hashes the hash descriptions
*/
static ModuleHashesAttribute of(String algorithm,
ModuleHashInfo... hashes) {
return of(algorithm, List.of(hashes));
}
/**
* {@return a {@code ModuleHashes} attribute}
* @param algorithm the hashing algorithm
* @param hashes the hash descriptions
*/
static ModuleHashesAttribute of(Utf8Entry algorithm,
List hashes) {
return new UnboundAttribute.UnboundModuleHashesAttribute(algorithm, hashes);
}
/**
* {@return a {@code ModuleHashes} attribute}
* @param algorithm the hashing algorithm
* @param hashes the hash descriptions
*/
static ModuleHashesAttribute of(Utf8Entry algorithm,
ModuleHashInfo... hashes) {
return of(algorithm, List.of(hashes));
}
}