Merge pull request #22 from ipld/fix/add-lookup-by-ipld-name

add lookup by IPLD name

Author: ianopolous

src/main/java/io/ipfs/cid/Cid.java

@@ -38,16 +38,33 @@ public enum Codec {
         }
 
         private static Map<Long, Codec> lookup = new TreeMap<>();
+        private static Map<String, Codec> nameLookup = new TreeMap<>();
         static {
             for (Codec c: Codec.values())
                 lookup.put(c.type, c);
+            // https://github.com/multiformats/multicodec/blob/master/table.csv
+            nameLookup.put("raw", Raw);
+            nameLookup.put("dag-pb", DagProtobuf);
+            nameLookup.put("dag-cbor", DagCbor);
+            nameLookup.put("libp2p-key", Libp2pKey);
+            nameLookup.put("eth-block", EthereumBlock);
+            nameLookup.put("eth-block-list", EthereumTx);
+            nameLookup.put("bitcoin-block", BitcoinBlock);
+            nameLookup.put("bitcoin-tx", BitcoinTx);
+            nameLookup.put("zcash-block", ZcashBlock);
+            nameLookup.put("zcash-tx", ZcashTx);
         }
 
         public static Codec lookup(long c) {
             if (!lookup.containsKey(c))
                 throw new IllegalStateException("Unknown Codec type: " + c);
             return lookup.get(c);
         }
+        public static Codec lookupIPLDName(String name) {
+            if (!nameLookup.containsKey(name))
+                throw new IllegalStateException("Unknown Codec type: " + name);
+            return nameLookup.get(name);
+        }
     }
 
     public final long version;

src/test/java/io/ipfs/cid/CidTest.java

@@ -66,4 +66,12 @@ public void version0Error() throws Exception {
             throw new RuntimeException();
         } catch (IllegalStateException e) {}
     }
+
+    @Test
+    public void lookByOfficialIPLDName() {
+        Cid.Codec raw = Cid.Codec.lookupIPLDName("raw");
+        Assert.assertTrue("Raw Codec", raw.name().equals("Raw"));
+        Cid.Codec dagcbor = Cid.Codec.lookupIPLDName("dag-cbor");
+        Assert.assertTrue("DagCbor Codec", dagcbor.name().equals("DagCbor"));
+    }
 }