Merge pull request #114 from filip26/feat/uvarint-write

2.3.0

Author: filip26

README.md

@@ -24,7 +24,7 @@ encoding and decoding of self-describing data formats.
 [![Maven Central](https://img.shields.io/maven-central/v/com.apicatalog/copper-multicodec.svg?label=Maven%20Central)](https://search.maven.org/search?q=g:com.apicatalog%20AND%20a:copper-multicodec)
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
 
-## Features
+## ✨ Features
 
 - Static codec registry with predefined codecs for efficient access  
 - Direct static access to codecs without runtime lookups  
@@ -56,8 +56,8 @@ byte[] decoded = decoder.decode(encoded);
 
 /* or check if encoding is supported  */
 byte[] decoded = decoder.getCodec(encoded)
-                          .map(codec -> codec.decode(encoded))
-                          .orElseThrow(() -> new IllegalArgumentException("Unsupported codec."));
+                        .map(codec -> codec.decode(encoded))
+                        .orElseThrow(() -> new IllegalArgumentException("Unsupported codec."));
 
 /* or directly when only one codec is supported */
 byte[] decoded = KeyCodec.P521_PUBLIC_KEY.decode(encoded);
@@ -106,16 +106,16 @@ byte[] decoded = MultihashCodec.SHA2_384.decode(encoded);
 
 /* check if byte array is encoded with multihash codec */
 if (MultihashCodec.SHA2_384.isEncoded(encoded)) {
+  var digestLength = MultihashCodec.SHA2_384.digestLength(encoded);
   ...
 }
 
-/* get registry initialized with all multihash codecs */
-var registry = MulticodecRegistry.getInstance(Tag.Multihash);
+/* determine digest index  */
+var index = decoder.getCodec(encoded)
+                    .map(Multihash.class::cast)
+                    .mapToInt(codec -> encoded.length - codec.digestLength(encoded))
+                    .orElseThrow(() -> new IllegalArgumentException("Unsupported multihash."));
 
-/* encode an input as multihash */
-byte[] encoded = registry.getCodec(code)
-                         .map(codec -> codec.encode(input))
-                         .orElseThrow(() -> new IllegalArgumentException("Unsupported multihash."));
 ```
 
 ## Installation
@@ -128,13 +128,13 @@ To include Copper Multicodec in your project, add the following dependency to yo
 <dependency>
     <groupId>com.apicatalog</groupId>
     <artifactId>copper-multicodec</artifactId>
-    <version>2.2.0</version>
+    <version>2.3.0</version>
 </dependency>
 ```
 
-## ld-cli
+## 🛠️ LD-CLI
 
-[ld-cli](https://github.com/filip26/ld-cli) is a command-line utility for
+[LD-CLI](https://github.com/filip26/ld-cli) is a command-line utility for
 working with multiformats including multibase, multicodec, and multihash,
 as well as JSON-LD and related specifications.
 

pom.xml

@@ -5,7 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.apicatalog</groupId>
     <artifactId>copper-multicodec</artifactId>
-    <version>2.3.0-SNAPSHOT</version>
+    <version>2.3.0</version>
     <packaging>jar</packaging>
     <url>https://github.com/filip26/copper-multicodec</url>
     <scm>

src/main/java/com/apicatalog/multihash/Multihash.java

@@ -214,31 +214,19 @@ public byte[] decode(byte[] encoded, int index, int length) {
             throw new IllegalArgumentException(
                     "The requested decode length (" + length + ") is greater than the available bytes (" + (encoded.length - index) + ").");
         }
+        
+        long digestLength = digestLength(encoded, index, length);
+        int varintDigestLength = UVarInt.byteLength(digestLength);
 
-        if (length < (codeVarint.length + 2)) {
-            throw new IllegalArgumentException(
-                    "The value to decode must be a non-empty byte array with a minimum length of "
-                            + (codeVarint.length + 2) + " bytes, but the actual length is " + length + " bytes.");
-        }
-
-        if (!IntStream.range(0, codeVarint.length).allMatch(i -> codeVarint[i] == encoded[i + index])) {
-            throw new IllegalArgumentException(
-                    "The provided value is not encoded with this multihash: " + toString() + ".");
-        }
-
-        // Get digest size
-        long size = UVarInt.decode(encoded, index + codeVarint.length);
-        int sizeVarintLength = UVarInt.byteLength(size);
-
-        if (size != (length - codeVarint.length - sizeVarintLength)) {
+        if (digestLength != (length - codeVarint.length - varintDigestLength)) {
             throw new IllegalArgumentException(
-                    "Digest size mismatch: declared size is " + size + " bytes, but the actual digest size is " +
-                            (length - codeVarint.length - sizeVarintLength) + " bytes.");
+                    "Digest size mismatch: declared size is " + digestLength + " bytes, but the actual digest size is " +
+                            (length - codeVarint.length - varintDigestLength) + " bytes.");
         }
 
         // Extract digest
         return Arrays.copyOfRange(encoded,
-                index + codeVarint.length + sizeVarintLength,
+                index + codeVarint.length + varintDigestLength,
                 length + index);
     }
 
@@ -261,7 +249,7 @@ public byte[] decode(byte[] encoded, int index, int length) {
      *                                  with this multihash's code
      */
     public long digestLength(byte[] encoded) {
-        return digestLength(encoded, 0);
+        return digestLength(encoded, 0, encoded.length);
     }
 
     /**
@@ -288,12 +276,16 @@ public long digestLength(byte[] encoded) {
      *                                   available range
      */
     public long digestLength(byte[] encoded, int index) {
+        return digestLength(encoded, index, encoded.length - index);
+    }
+
+    protected long digestLength(byte[] encoded, int index, int length) {
         Objects.requireNonNull(encoded);
 
-        if (encoded.length < (codeVarint.length + 2)) {
+        if (length < (codeVarint.length + 2)) {
             throw new IllegalArgumentException(
                     "The value to decode must be a non-empty byte array with a minimum length of "
-                            + (codeVarint.length + 2) + " bytes, but the actual length is " + encoded.length + " bytes.");
+                            + (codeVarint.length + 2) + " bytes, but the actual length is " + length + " bytes.");
         }
 
         if (!IntStream.range(0, codeVarint.length).allMatch(i -> codeVarint[i] == encoded[i + index])) {

src/test/java/com/apicatalog/multihash/MultihashTest.java

@@ -14,6 +14,7 @@
 import com.apicatalog.multicodec.Multicodec.Tag;
 import com.apicatalog.multicodec.MulticodecDecoder;
 import com.apicatalog.multicodec.codec.MultihashCodec;
+import com.apicatalog.uvarint.UVarInt;
 
 class MultihashTest {
 
@@ -66,6 +67,8 @@ void testDecodeFromIndex(byte[] input, Multihash codec, byte[] expected) {
 
         System.arraycopy(input, 0, array, index, input.length);
         assertArrayEquals(expected, codec.decode(array, index));
+        assertEquals(expected.length, codec.digestLength(array, index));
+        assertEquals(codec.length() + UVarInt.byteLength(expected.length), input.length - codec.digestLength(array, index));
     }
 
     @ParameterizedTest(name = "{index}")
@@ -80,6 +83,8 @@ void testDecodeRange(byte[] input, Multihash codec, byte[] expected) {
 
         System.arraycopy(input, 0, array, index, input.length);
         assertArrayEquals(expected, codec.decode(array, index, input.length));
+        assertEquals(expected.length, codec.digestLength(array, index));
+        assertEquals(codec.length() + UVarInt.byteLength(expected.length), input.length - codec.digestLength(array, index));        
     }
 
     @ParameterizedTest(name = "{index}")