Implemented object.patch

Author: ianopolous

src/main/java/org/ipfs/api/IPFS.java

@@ -8,6 +8,7 @@
 public class IPFS {
     public enum PinType {all, direct, indirect, recursive}
     public List<String> ObjectTemplates = Arrays.asList("unixfs-dir");
+    public List<String> ObjectPatchTypes = Arrays.asList("add-link", "rm-link", "set-data", "append-data");
 
     public final String host;
     public final int port;
@@ -205,7 +206,38 @@ public MerkleNode _new(Optional<String> template) throws IOException {
             return MerkleNode.fromJSON(json);
         }
 
-        // TODO patch
+        public MerkleNode patch(Multihash base, String command, Optional<byte[]> data, Optional<String> name, Optional<Multihash> target) throws IOException {
+            if (!ObjectPatchTypes.contains(command))
+                throw new IllegalStateException("Illegal Object.patch command type: "+command);
+            String targetPath = "object/patch?arg=" + base.toBase58() + "&arg=" + command;
+            if (name.isPresent())
+                targetPath += "&arg=" + name.get();
+            if (target.isPresent())
+                targetPath += "&arg=" + target.get().toBase58();
+
+            switch (command) {
+                case "add-link":
+                    if (!name.isPresent() || !target.isPresent())
+                        throw new IllegalStateException("add-link requires name and target!");
+                    return MerkleNode.fromJSON(retrieveMap(targetPath));
+                case "rm-link":
+                    if (!name.isPresent())
+                        throw new IllegalStateException("rm-link requires name!");
+                    return MerkleNode.fromJSON(retrieveMap(targetPath));
+                case "set-data":
+                    if (!data.isPresent())
+                        throw new IllegalStateException("set-data requires data!");
+                    targetPath += "&arg="+new String(data.get());
+                    return MerkleNode.fromJSON(retrieveMap(targetPath));
+                case "append-data":
+                    if (!data.isPresent())
+                        throw new IllegalStateException("append-data requires data!");
+                    targetPath += "&arg="+new String(data.get());
+                    return MerkleNode.fromJSON(retrieveMap(targetPath));
+                default:
+                    throw new IllegalStateException("Unimplemented");
+            }
+        }
     }
 
     public class Name {

src/test/java/org/ipfs/api/Test.java

@@ -82,6 +82,41 @@ public void pinTest() {
         }
     }
 
+    @org.junit.Test
+    public void objectPatch() {
+        try {
+            MerkleNode obj = ipfs.object._new(Optional.empty());
+            Multihash base = obj.hash;
+            // link tests
+            String linkName = "alink";
+            MerkleNode addLink = ipfs.object.patch(base, "add-link", Optional.empty(), Optional.of(linkName), Optional.of(base));
+            MerkleNode withLink = ipfs.object.get(addLink.hash);
+            if (withLink.links.size() != 1 || !withLink.links.get(0).hash.equals(base) || !withLink.links.get(0).name.get().equals(linkName))
+                throw new RuntimeException("Added link not correct!");
+            MerkleNode rmLink = ipfs.object.patch(addLink.hash, "rm-link", Optional.empty(), Optional.of(linkName), Optional.empty());
+            if (!rmLink.hash.equals(base))
+                throw new RuntimeException("Adding not inverse of removing link!");
+
+            // data tests
+            byte[] data = "somerandomdata".getBytes();
+            MerkleNode patched = ipfs.object.patch(base, "set-data", Optional.of(data), Optional.empty(), Optional.empty());
+            MerkleNode patchedResult = ipfs.object.get(patched.hash);
+            if (!Arrays.equals(patchedResult.data.get(), data))
+                throw new RuntimeException("object.patch: returned data != stored data!");
+
+            MerkleNode twicePatched = ipfs.object.patch(patched.hash, "append-data", Optional.of(data), Optional.empty(), Optional.empty());
+            MerkleNode twicePatchedResult = ipfs.object.get(twicePatched.hash);
+            byte[] twice = new byte[2*data.length];
+            for (int i=0; i < 2; i++)
+                System.arraycopy(data, 0, twice, i*data.length, data.length);
+            if (!Arrays.equals(twicePatchedResult.data.get(), twice))
+                throw new RuntimeException("object.patch: returned data after append != stored data!");
+
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     @org.junit.Test
     public void refsTest() {
         try {