A java implementation of patricia-merkle-trie data structure. Uses Protobuff
to encode TrieNodes and sha256
to generate keys.
Add below dependency and repository to your pom.xml
<dependency>
<groupId>org.serdaroquai.pml</groupId>
<artifactId>patricia-merkle-trie</artifactId>
<version>0.0.3</version>
</dependency>
//..
<repositories>
<repository>
<id>serdaroquai</id>
<url>https://raw.github.com/serdaroquai/patricia-merkle-trie/repository/</url>
</repository>
</repositories>
Trie<String,String> trie = new Trie.TrieBuilder<String,String>()
.keySerializer(Serializer.STRING_UTF8)
.valueSerializer(Serializer.STRING_UTF8)
.build(); // creates an in memory trie
t.put("do", "verb");
t.get("do") // returns "verb"
t.put("dog", "puppy");
// root hash returned by a put operation cryptographically represents the entire contents
ByteBuffer rootHash = t.put("doge", "coin"); // a 32 byte merkle root representing all state
ByteBuffer newRootHash = t.put("doge", "no-coin"); // rootHash != newRootHash
// you can access any past state by passing its root hash
t.get("doge"); // returns no-coin
t.get(rootHash, "doge") // returns coin
// build a map
t.toMap(); // returns a Map<String,String> of all key-value pairs
t.toMap(someOldRootHash); // also works for any past state
// you can query differences between a past state
Map<String,String> remove = new HashMap<>();
Map<String,String> update = new HashMap<>();
t.difference(rootHash, remove, update); // remove: <doge, coin> , update: <doge, no-coin>