Copper Multicodec is a Java library that implements Multicodec and Multihash, enabling efficient encoding and decoding of data.
- Static Codec Registry: Predefined codecs for efficient access.
- Direct Static Access to Codecs: Eliminates runtime searches for codecs.
- Custom Codec Support: Allows customization of supported codecs.
- Multihash Support: Provides compatibility with multihash encoding.
- Unsigned VarInt Support: Handles unsigned variable-length integers.
- Zero Third-Party Dependencies: Ensures a lightweight and self-contained implementation.
/* encode an input as P-521 public key */
byte[] encoded = KeyCodec.P521_PUBLIC_KEY.encode(input);
/* encode an input as an identity */
byte[] encoded = MultihashCodec.IDENTITY.encode(input);
/* get decoder instance initialized with all supported codecs */
var decoder = MulticodecDecoder.getInstance();
/* get custom decoder initialized with codecs tagged as key and hash */
var decoder = MulticodecDecoder.getInstance(Tag.Key, Tag.Hash);
/* get custom decoder initialized with custom codec set */
var decoder = MulticodecDecoder.getInstance(codecs...);
/* decode */
byte[] decoded = decoder.decode(encoded);
/* or check if encoding is supported */
Multicodec codec = decoder.getCodec(encoded).orElseThrow(() -> new IllegalArgumentException("Unsupported codec."));
byte[] decoded = codec.decode(encoded);
/* or directly when only one codec is supported */
byte[] decoded = KeyCodec.P521_PUBLIC_KEY.decode(encoded);
/* check if byte array is encoded with a codec */
if (KeyCodec.P521_PUBLIC_KEY.isEncoded(encoded)) {
...
}
/* create a custom codec */
var codec = Multicodec.of(name, tag, code);
/* get registry instance initialized with all supported codecs */
var registry = MulticodecRegistry.getInstance();
/* get custom registry initialized with codecs tagged as key and hash */
var registry = MulticodecRegistry.getInstance(Tag.Key, Tag.Hash);
/* get custom registry initialized with custom codec set */
var registry = MulticodecRegistry.getInstance(codecs...);
/* get codec */
var codec = registry.getCodec(code).orElseThrow(() -> new IllegalArgumentException("Unsupported codec."));
byte[] encoded = codec.encode(input);/* get multihash decoder initialized with all multihash codecs */
var decoder = MulticodecDecoder.getInstance(Tag.Multihash);
/* decode; digest size is checked and removed */
byte[] decoded = decoder.decode(encoded);
/* or check if supported */
var codec = decoder.get(encoded).orElseThrow(() -> new IllegalArgumentException("Unsupported multihash."));
byte[] decoded = codec.decode(encoded);
/* or directly */
byte[] decoded = MultihashCodec.SHA2_384.decode(encoded);
/*
/* check if byte array is encoded with multihash codec */
if (MultihashCodec.SHA2_384.isEncoded(encoded)) {
...
}
/* get registry initialized with all multihash codecs */
var registry = MulticodecRegistry.getInstance(Tag.Multihash);
/* encode an input as multihash */
var codec = registry.get(code).orElseThrow(() -> new IllegalArgumentException("Unsupported multihash."));
byte[] encoded = codec.encode(input);To include Copper Multicodec in your project, add the following dependency to your pom.xml:
<dependency>
<groupId>com.apicatalog</groupId>
<artifactId>copper-multicodec</artifactId>
<version>1.1.0</version>
</dependency>
All PR's welcome!
Fork and clone the project repository.
> cd copper-multicodec
> mvn clean package