Refactor hierarchical resource interface to flat interface.

atomic/src/test/java/net/kuujo/copycat/atomic/DistributedAtomicValueTest.java

@@ -18,7 +18,6 @@
 import net.jodah.concurrentunit.ConcurrentTestCase;
 import net.kuujo.copycat.Copycat;
 import net.kuujo.copycat.CopycatServer;
-import net.kuujo.copycat.Node;
 import net.kuujo.copycat.io.storage.Storage;
 import net.kuujo.copycat.io.transport.LocalServerRegistry;
 import net.kuujo.copycat.io.transport.LocalTransport;
@@ -53,8 +52,7 @@ public void testSetGet() throws Throwable {
 
     Copycat copycat = servers.get(0);
 
-    Node node = copycat.create("/test").get();
-    DistributedAtomicValue<String> reference = node.create(DistributedAtomicValue.class).get();
+    DistributedAtomicValue<String> reference = copycat.create("test", DistributedAtomicValue.class).get();
 
     expectResume();
     reference.set("Hello world!").thenRun(this::resume);
@@ -77,8 +75,7 @@ public void testChangeEvent() throws Throwable {
 
     Copycat copycat = servers.get(0);
 
-    Node node = copycat.create("/test").get();
-    DistributedAtomicValue<String> reference = node.create(DistributedAtomicValue.class).get();
+    DistributedAtomicValue<String> reference = copycat.create("test", DistributedAtomicValue.class).get();
 
     expectResume();
     reference.onChange(value -> {
@@ -198,8 +195,7 @@ public void testMembershipChange() throws Throwable {
     copycat4.open().thenRun(this::resume);
     await();
 
-    Node node = copycat4.create("/test").get();
-    DistributedAtomicValue<String> reference = node.create(DistributedAtomicValue.class).get();
+    DistributedAtomicValue<String> reference = copycat4.create("test", DistributedAtomicValue.class).get();
 
     expectResume();
     reference.set("Hello world!").thenRun(this::resume);
@@ -219,15 +215,13 @@ public void testMembershipChange() throws Throwable {
   public void testCompareAndSet() throws Throwable {
     List<Copycat> servers = createCopycats(3);
 
-    Node node1 = servers.get(0).create("/test").get();
-    DistributedAtomicValue<Integer> reference1 = node1.create(DistributedAtomicValue.class).get();
+    DistributedAtomicValue<Integer> reference1 = servers.get(0).create("test", DistributedAtomicValue.class).get();
 
     expectResume();
     reference1.set(1).thenRun(this::resume);
     await();
 
-    Node node2 = servers.get(0).create("/test").get();
-    DistributedAtomicValue<Integer> reference2 = node2.create(DistributedAtomicValue.class).get();
+    DistributedAtomicValue<Integer> reference2 = servers.get(0).create("test", DistributedAtomicValue.class).get();
 
     expectResume();
     reference2.compareAndSet(1, 2).thenAccept(result -> {

collections/src/test/java/net/kuujo/copycat/collections/DistributedMapTest.java

@@ -18,7 +18,6 @@
 import net.jodah.concurrentunit.ConcurrentTestCase;
 import net.kuujo.copycat.Copycat;
 import net.kuujo.copycat.CopycatServer;
-import net.kuujo.copycat.Node;
 import net.kuujo.copycat.io.storage.Storage;
 import net.kuujo.copycat.io.transport.LocalServerRegistry;
 import net.kuujo.copycat.io.transport.LocalTransport;
@@ -53,8 +52,7 @@ public void testPutGetRemove() throws Throwable {
 
     Copycat copycat = copycats.get(0);
 
-    Node node = copycat.create("/test").get();
-    DistributedMap<String, String> map = node.create(DistributedMap.class).get();
+    DistributedMap<String, String> map = copycat.create("test", DistributedMap.class).get();
 
     expectResume();
     map.put("foo", "Hello world!").thenRun(this::resume);
@@ -93,8 +91,7 @@ public void testMapSize() throws Throwable {
 
     Copycat copycat = copycats.get(0);
 
-    Node node = copycat.create("/test").get();
-    DistributedMap<String, String> map = node.create(DistributedMap.class).get();
+    DistributedMap<String, String> map = copycat.create("test", DistributedMap.class).get();
 
     expectResume();
     map.size().thenAccept(size -> {
@@ -137,8 +134,7 @@ public void testMapTtl() throws Throwable {
 
     Copycat copycat = copycats.get(0);
 
-    Node node = copycat.create("/test").get();
-    DistributedMap<String, String> map = node.create(DistributedMap.class).get();
+    DistributedMap<String, String> map = copycat.create("test", DistributedMap.class).get();
 
     expectResume();
     map.put("foo", "Hello world!", Duration.ofSeconds(1)).thenRun(this::resume);

collections/src/test/java/net/kuujo/copycat/collections/DistributedSetTest.java

@@ -18,7 +18,6 @@
 import net.jodah.concurrentunit.ConcurrentTestCase;
 import net.kuujo.copycat.Copycat;
 import net.kuujo.copycat.CopycatServer;
-import net.kuujo.copycat.Node;
 import net.kuujo.copycat.io.storage.Storage;
 import net.kuujo.copycat.io.transport.LocalServerRegistry;
 import net.kuujo.copycat.io.transport.LocalTransport;
@@ -55,12 +54,10 @@ public void testSetAddRemove() throws Throwable {
     Copycat copycat1 = copycats.get(0);
     Copycat copycat2 = copycats.get(1);
 
-    Node node1 = copycat1.create("/test").get();
-    DistributedSet<String> set1 = node1.create(DistributedSet.class).get();
+    DistributedSet<String> set1 = copycat1.create("test", DistributedSet.class).get();
     assertFalse(set1.contains("Hello world!").get());
 
-    Node node2 = copycat2.create("/test").get();
-    DistributedSet<String> set2 = node2.create(DistributedSet.class).get();
+    DistributedSet<String> set2 = copycat2.create("test", DistributedSet.class).get();
     assertFalse(set2.contains("Hello world!").get());
 
     set1.add("Hello world!").join();

coordination/src/test/java/net/kuujo/copycat/coordination/DistributedLeaderElectionTest.java

@@ -18,7 +18,6 @@
 import net.jodah.concurrentunit.ConcurrentTestCase;
 import net.kuujo.copycat.Copycat;
 import net.kuujo.copycat.CopycatServer;
-import net.kuujo.copycat.Node;
 import net.kuujo.copycat.io.storage.Storage;
 import net.kuujo.copycat.io.transport.LocalServerRegistry;
 import net.kuujo.copycat.io.transport.LocalTransport;
@@ -53,8 +52,7 @@ public void testElection() throws Throwable {
 
     Copycat copycat = servers.get(0);
 
-    Node node = copycat.create("/test").get();
-    DistributedLeaderElection election = node.create(DistributedLeaderElection.class).get();
+    DistributedLeaderElection election = copycat.create("test", DistributedLeaderElection.class).get();
 
     expectResumes(2);
     election.onElection(v -> resume()).thenRun(this::resume);

coordination/src/test/java/net/kuujo/copycat/coordination/DistributedLockTest.java

@@ -18,7 +18,6 @@
 import net.jodah.concurrentunit.ConcurrentTestCase;
 import net.kuujo.copycat.Copycat;
 import net.kuujo.copycat.CopycatServer;
-import net.kuujo.copycat.Node;
 import net.kuujo.copycat.io.storage.Storage;
 import net.kuujo.copycat.io.transport.LocalServerRegistry;
 import net.kuujo.copycat.io.transport.LocalTransport;
@@ -53,8 +52,7 @@ public void testLockUnlock() throws Throwable {
 
     Copycat copycat = servers.get(0);
 
-    Node node = copycat.create("/test").get();
-    DistributedLock lock = node.create(DistributedLock.class).get();
+    DistributedLock lock = copycat.create("test", DistributedLock.class).get();
 
     expectResume();
     lock.lock().thenRun(this::resume);

core/src/main/java/net/kuujo/copycat/Copycat.java

@@ -15,10 +15,9 @@
  */
 package net.kuujo.copycat;
 
-import net.kuujo.copycat.manager.CreatePath;
 import net.kuujo.copycat.manager.CreateResource;
-import net.kuujo.copycat.manager.DeletePath;
-import net.kuujo.copycat.manager.PathExists;
+import net.kuujo.copycat.manager.GetResource;
+import net.kuujo.copycat.manager.ResourceExists;
 import net.kuujo.copycat.raft.RaftClient;
 import net.kuujo.copycat.raft.StateMachine;
 import net.kuujo.copycat.raft.protocol.Command;
@@ -37,9 +36,8 @@
  * creation and management of {@link net.kuujo.copycat.Resource} objects via a filesystem like interface. There is a
  * one-to-one relationship between paths and resources, so each path can be associated with one and only one resource.
  * <p>
- * To create a resource, create a {@link net.kuujo.copycat.Node} and then create the resource by passing the resource
- * {@link java.lang.Class} to the {@link Node#create(Class)} method. When a resource is created, the
- * {@link StateMachine} associated with the resource will be created on each Raft server
+ * To create a resource, pass the resource {@link java.lang.Class} to the {@link Copycat#create(String, Class)} method.
+ * When a resource is created, the {@link StateMachine} associated with the resource will be created on each Raft server
  * and future operations submitted for that resource will be applied to the state machine. Internally, resource state
  * machines are multiplexed across a shared Raft log.
  * <p>
@@ -50,82 +48,36 @@
  * @author <a href="http://github.com/kuujo">Jordan Halterman</a>
  */
 public abstract class Copycat implements Managed<Copycat> {
-  static final String PATH_SEPARATOR = "/";
   protected final RaftClient client;
-  private final Map<String, Node> nodes = new ConcurrentHashMap<>();
   private final Map<Long, ResourceContext> resources = new ConcurrentHashMap<>();
 
   protected Copycat(RaftClient client) {
     this.client = client;
   }
 
-  /**
-   * Returns a reference to the node at the given path.
-   * <p>
-   * The returned node represents the node at the given {@code path}. The node may or may not already exist.
-   * This method does not create the returned node. In order to create the node in the cluster, the user must call
-   * the {@link net.kuujo.copycat.Node#create()} method on the returned {@link net.kuujo.copycat.Node} or alternatively
-   * call {@link #create(String)} directly.
-   *
-   * @param path The path for which to return the node.
-   * @return A reference to the node at the given path.
-   */
-  public Node node(String path) {
-    if (path == null)
-      throw new NullPointerException("path cannot be null");
-    if (!path.startsWith(PATH_SEPARATOR))
-      path = PATH_SEPARATOR + path;
-    if (path.endsWith(PATH_SEPARATOR))
-      path = path.substring(0, path.length() - 1);
-    return nodes.computeIfAbsent(path, p -> new Node(p, this));
-  }
-
   /**
    * Checks whether a path exists.
    *
    * @param path The path to check.
    * @return A completable future indicating whether the given path exists.
    */
   public CompletableFuture<Boolean> exists(String path) {
-    return client.submit(new PathExists(path));
-  }
-
-  /**
-   * Creates a node at the given path.
-   * <p>
-   * If a node at the given path already exists, the existing node will be returned, otherwise a new {@link net.kuujo.copycat.Node}
-   * will be returned. Additionally, if the node's parents don't already exist they'll be created. For instance, calling
-   * this method with {@code /foo/bar/baz} will create {@code foo}, {@code foo/bar}, and {@code foo/bar/baz} if they
-   * don't already exist.
-   *
-   * @param path The path for which to create the node.
-   * @return A completable future to be completed once the node has been created.
-   */
-  public CompletableFuture<Node> create(String path) {
-    return client.submit(CreatePath.builder()
-      .withPath(path)
-      .build())
-      .thenApply(result -> node(path));
+    return client.submit(new ResourceExists(path));
   }
 
   /**
-   * Creates a resource at the given path.
-   * <p>
-   * If a node at the given path already exists, the existing node will be returned, otherwise a new {@link net.kuujo.copycat.Node}
-   * will be returned. Additionally, if the node's parents don't already exist they'll be created. For instance, calling
-   * this method with {@code /foo/bar/baz} will create {@code foo}, {@code foo/bar}, and {@code foo/bar/baz} if they
-   * don't already exist.
+   * Gets the resource at the given path.
    *
-   * @param path The path at which to create the resource.
-   * @param type The resource type to create.
+   * @param path The path at which to get the resource.
+   * @param type The expected resource type.
    * @param <T> The resource type.
-   * @return A completable future to be completed once the resource has been created.
+   * @return A completable future to be completed once the resource has been loaded.
    */
   @SuppressWarnings("unchecked")
-  public <T extends Resource> CompletableFuture<T> create(String path, Class<? super T> type) {
+  public <T extends Resource> CompletableFuture<T> get(String path, Class<? super T> type) {
     try {
       T resource = (T) type.newInstance();
-      return client.submit(CreateResource.builder()
+      return client.submit(GetResource.builder()
         .withPath(path)
         .withType(resource.stateMachine())
         .build())
@@ -139,57 +91,33 @@ public <T extends Resource> CompletableFuture<T> create(String path, Class<? sup
   }
 
   /**
-   * Creates a configurable resource at the given path.
+   * Creates a resource at the given path.
    * <p>
-   * If a node at the given path already exists, the existing node will be returned, otherwise a new {@link net.kuujo.copycat.Node}
-   * will be returned. Additionally, if the node's parents don't already exist they'll be created. For instance, calling
-   * this method with {@code /foo/bar/baz} will create {@code foo}, {@code foo/bar}, and {@code foo/bar/baz} if they
-   * don't already exist.
+   * If a resource at the given path already exists, the existing resource will be returned, otherwise a new
+   * resource of the given {@code type} will be created.
    *
    * @param path The path at which to create the resource.
    * @param type The resource type to create.
-   * @param options The resource options.
    * @param <T> The resource type.
-   * @param <U> The resource configuration type.
    * @return A completable future to be completed once the resource has been created.
    */
   @SuppressWarnings("unchecked")
-  public <T extends Resource & Configurable<U>, U extends Options> CompletableFuture<T> create(String path, Class<? super T> type, U options) {
+  public <T extends Resource> CompletableFuture<T> create(String path, Class<? super T> type) {
     try {
       T resource = (T) type.newInstance();
       return client.submit(CreateResource.builder()
         .withPath(path)
         .withType(resource.stateMachine())
         .build())
         .thenApply(id -> {
-          resource.open(resources.computeIfAbsent(id, i -> {
-            ResourceContext context = new ResourceContext(id, client);
-            resource.configure(options);
-            return context;
-          }));
+          resource.open(resources.computeIfAbsent(id, i -> new ResourceContext(id, client)));
           return resource;
         });
     } catch (InstantiationException | IllegalAccessException e) {
       throw new ResourceException("failed to instantiate resource: " + type, e);
     }
   }
 
-  /**
-   * Deletes a node at the given path.
-   * <p>
-   * Both the {@link net.kuujo.copycat.Node} at the given path and any {@link net.kuujo.copycat.Resource} associated
-   * with the node will be permanently deleted, and state stored at the node will not be recoverable.
-   *
-   * @param path The path at which to delete the node.
-   * @return A completable future to be completed once the node has been deleted.
-   */
-  public CompletableFuture<Copycat> delete(String path) {
-    return client.submit(DeletePath.builder()
-      .withPath(path)
-      .build())
-      .thenApply(result -> this);
-  }
-
   @Override
   public CompletableFuture<Copycat> open() {
     return client.open().thenApply(v -> this);