From: Robert Varga <robert.varga@pantheon.tech>
Date: Tue, 13 Nov 2018 18:18:30 +0000 (+0100)
Subject: Introduce ReadOperations.exists()
X-Git-Tag: v3.0.2~23
X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F39%2F77739%2F3;p=mdsal.git

Introduce ReadOperations.exists()

This method exists in the DOM API, but for some reason it was left
out if the Binding API. Introduce it as default methods riding on
the read() method and override them in all known implementations,
so the request is efficiently routed.

Change-Id: Id56332d6f720396305ac68e40554e62fd17c34fb
JIRA: MDSAL-389
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
---

diff --git a/binding/mdsal-binding-api/src/main/java/org/opendaylight/mdsal/binding/api/ReadOperations.java b/binding/mdsal-binding-api/src/main/java/org/opendaylight/mdsal/binding/api/ReadOperations.java
index 57afb72988..13c50f0094 100644
--- a/binding/mdsal-binding-api/src/main/java/org/opendaylight/mdsal/binding/api/ReadOperations.java
+++ b/binding/mdsal-binding-api/src/main/java/org/opendaylight/mdsal/binding/api/ReadOperations.java
@@ -8,6 +8,7 @@
 package org.opendaylight.mdsal.binding.api;
 
 import com.google.common.util.concurrent.FluentFuture;
+import com.google.common.util.concurrent.MoreExecutors;
 import java.util.Optional;
 import org.eclipse.jdt.annotation.NonNull;
 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
@@ -29,8 +30,8 @@ public interface ReadOperations {
      *
      * @param store Logical data store from which read should occur.
      * @param path Path which uniquely identifies subtree which client want to read
-     * @return a FluentFuture containing the result of the read. The Future blocks until the commit operation is
-     *         complete. Once complete:
+     * @return a FluentFuture containing the result of the read. The Future blocks until the operation is complete. Once
+     *         complete:
      *         <ul>
      *         <li>If the data at the supplied path exists, the Future returns an Optional object containing the data.
      *         </li>
@@ -39,7 +40,35 @@ public interface ReadOperations {
      *         an exception derived from ReadFailedException.</li>
      *         </ul>
      * @throws NullPointerException if any of the arguments is null
+     * @throws IllegalArgumentException if the path is {@link InstanceIdentifier#isWildcarded()}
      */
     <T extends DataObject> @NonNull FluentFuture<Optional<T>> read(@NonNull LogicalDatastoreType store,
             @NonNull InstanceIdentifier<T> path);
+
+    /**
+     * Determines if data data exists in the provided logical data store located at the provided path.
+     *
+     * <p>
+     * Default implementation just delegates to {@link #read(LogicalDatastoreType, InstanceIdentifier)}. Implementations
+     * are recommended to override with a more efficient implementation.
+     *
+     * @param store Logical data store from which read should occur.
+     * @param path Path which uniquely identifies subtree which client want to read
+     * @return a FluentFuture containing the result of the check. The Future blocks until the operation is complete.
+     *         Once complete:
+     *         <ul>
+     *         <li>If the data at the supplied path exists, the Future returns {@link Boolean#TRUE}.
+     *         </li>
+     *         <li>If the data at the supplied path does not exist, the Future returns {@link Boolean#FALSE}.</li>
+     *         <li>If the check fails, the Future will fail with a {@link ReadFailedException} or an exception derived
+     *             from ReadFailedException.</li>
+     *         </ul>
+     * @throws NullPointerException if any of the arguments is null
+     * @throws IllegalArgumentException if the path is {@link InstanceIdentifier#isWildcarded()} and the implementation
+     *                                  does not support evaluating wildcards.
+     */
+    default @NonNull FluentFuture<Boolean> exists(final @NonNull LogicalDatastoreType store,
+            final @NonNull InstanceIdentifier<?> path) {
+        return read(store, path).transform(Optional::isPresent, MoreExecutors.directExecutor());
+    }
 }
diff --git a/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/AbstractForwardedTransaction.java b/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/AbstractForwardedTransaction.java
index 34d32726b1..28b63ec8b9 100644
--- a/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/AbstractForwardedTransaction.java
+++ b/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/AbstractForwardedTransaction.java
@@ -53,11 +53,18 @@ abstract class AbstractForwardedTransaction<T extends DOMDataTreeTransaction> im
         return codec;
     }
 
-    protected final <D extends DataObject> FluentFuture<Optional<D>> doRead(final DOMDataTreeReadOperations readOps,
-            final LogicalDatastoreType store, final InstanceIdentifier<D> path) {
+    protected final <D extends DataObject> @NonNull FluentFuture<Optional<D>> doRead(
+            final DOMDataTreeReadOperations readOps, final LogicalDatastoreType store,
+            final InstanceIdentifier<D> path) {
         checkArgument(!path.isWildcarded(), "Invalid read of wildcarded path %s", path);
 
         return readOps.read(store, codec.toYangInstanceIdentifierBlocking(path))
                 .transform(codec.getCodecRegistry().deserializeFunction(path)::apply, MoreExecutors.directExecutor());
     }
+
+    protected final @NonNull FluentFuture<Boolean> doExists(final DOMDataTreeReadOperations readOps,
+            final LogicalDatastoreType store, final InstanceIdentifier<?> path) {
+        checkArgument(!path.isWildcarded(), "Invalid exists of wildcarded path %s", path);
+        return readOps.exists(store, codec.toYangInstanceIdentifierBlocking(path));
+    }
 }
diff --git a/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/BindingDOMReadTransactionAdapter.java b/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/BindingDOMReadTransactionAdapter.java
index 0cf1a4b47b..a088ac00d0 100644
--- a/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/BindingDOMReadTransactionAdapter.java
+++ b/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/BindingDOMReadTransactionAdapter.java
@@ -26,7 +26,12 @@ final class BindingDOMReadTransactionAdapter extends AbstractForwardedTransactio
     @Override
     public <T extends DataObject> FluentFuture<Optional<T>> read(final LogicalDatastoreType store,
             final InstanceIdentifier<T> path) {
-        return doRead(getDelegate(),store, path);
+        return doRead(getDelegate(), store, path);
+    }
+
+    @Override
+    public FluentFuture<Boolean> exists(final LogicalDatastoreType store, final InstanceIdentifier<?> path) {
+        return doExists(getDelegate(), store, path);
     }
 
     @Override
diff --git a/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/BindingDOMReadWriteTransactionAdapter.java b/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/BindingDOMReadWriteTransactionAdapter.java
index 7bb2dfd891..a8868b6547 100644
--- a/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/BindingDOMReadWriteTransactionAdapter.java
+++ b/binding/mdsal-binding-dom-adapter/src/main/java/org/opendaylight/mdsal/binding/dom/adapter/BindingDOMReadWriteTransactionAdapter.java
@@ -28,4 +28,9 @@ class BindingDOMReadWriteTransactionAdapter extends BindingDOMWriteTransactionAd
             final InstanceIdentifier<T> path) {
         return doRead(getDelegate(), store, path);
     }
+
+    @Override
+    public FluentFuture<Boolean> exists(final LogicalDatastoreType store, final InstanceIdentifier<?> path) {
+        return doExists(getDelegate(), store, path);
+    }
 }
diff --git a/binding/mdsal-binding-spi/src/main/java/org/opendaylight/mdsal/binding/spi/ForwardingReadTransaction.java b/binding/mdsal-binding-spi/src/main/java/org/opendaylight/mdsal/binding/spi/ForwardingReadTransaction.java
index 9d6892c432..86e3d0f922 100644
--- a/binding/mdsal-binding-spi/src/main/java/org/opendaylight/mdsal/binding/spi/ForwardingReadTransaction.java
+++ b/binding/mdsal-binding-spi/src/main/java/org/opendaylight/mdsal/binding/spi/ForwardingReadTransaction.java
@@ -37,6 +37,11 @@ public class ForwardingReadTransaction extends ForwardingTransaction implements
         return delegate.read(store, path);
     }
 
+    @Override
+    public FluentFuture<Boolean> exists(final LogicalDatastoreType store, final InstanceIdentifier<?> path) {
+        return delegate.exists(store, path);
+    }
+
     @Override
     public void close() {
         delegate.close();
diff --git a/binding/mdsal-binding-spi/src/main/java/org/opendaylight/mdsal/binding/spi/ForwardingReadWriteTransaction.java b/binding/mdsal-binding-spi/src/main/java/org/opendaylight/mdsal/binding/spi/ForwardingReadWriteTransaction.java
index 3336299d9b..10ddc5ff0e 100644
--- a/binding/mdsal-binding-spi/src/main/java/org/opendaylight/mdsal/binding/spi/ForwardingReadWriteTransaction.java
+++ b/binding/mdsal-binding-spi/src/main/java/org/opendaylight/mdsal/binding/spi/ForwardingReadWriteTransaction.java
@@ -51,6 +51,11 @@ public class ForwardingReadWriteTransaction extends ForwardingTransaction implem
         return delegate.read(store, path);
     }
 
+    @Override
+    public FluentFuture<Boolean> exists(final LogicalDatastoreType store, final InstanceIdentifier<?> path) {
+        return delegate.exists(store, path);
+    }
+
     @Override
     public boolean cancel() {
         return delegate.cancel();
diff --git a/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TransactionAdapter.java b/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TransactionAdapter.java
index 2a856877a2..0178224b2e 100644
--- a/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TransactionAdapter.java
+++ b/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TransactionAdapter.java
@@ -151,5 +151,11 @@ public final class TransactionAdapter {
             checkStore(store);
             return delegate().read(path);
         }
+
+        @Override
+        public FluentFuture<Boolean> exists(final LogicalDatastoreType store,final InstanceIdentifier<?> path) {
+            checkStore(store);
+            return delegate().exists(path);
+        }
     }
 }
diff --git a/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadTransaction.java b/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadTransaction.java
index f42e69203d..845923191f 100644
--- a/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadTransaction.java
+++ b/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadTransaction.java
@@ -8,6 +8,7 @@
 package org.opendaylight.mdsal.binding.util;
 
 import com.google.common.util.concurrent.FluentFuture;
+import com.google.common.util.concurrent.MoreExecutors;
 import java.util.Optional;
 import org.opendaylight.mdsal.binding.api.ReadTransaction;
 import org.opendaylight.mdsal.binding.api.Transaction;
@@ -34,4 +35,18 @@ public interface TypedReadTransaction<D extends Datastore> extends Transaction {
      * @return A future providing access to the result of the read, when it’s available, or any error encountered.
      */
     <T extends DataObject> FluentFuture<Optional<T>> read(InstanceIdentifier<T> path);
+
+    /**
+     * Determines if an object exists at the given path. Default implementation just delegates to
+     * {@link #read(InstanceIdentifier)}. Implementations are recommended to override with a more efficient
+     * implementation.
+     *
+     * @see ReadTransaction#exists(LogicalDatastoreType, InstanceIdentifier)
+     *
+     * @param path The path to read from.
+     * @return A future providing access to the result of the check, when it’s available, or any error encountered.
+     */
+    default FluentFuture<Boolean> exists(final InstanceIdentifier<?> path) {
+        return read(path).transform(Optional::isPresent, MoreExecutors.directExecutor());
+    }
 }
diff --git a/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadTransactionImpl.java b/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadTransactionImpl.java
index 3176b924e1..31ee12788e 100644
--- a/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadTransactionImpl.java
+++ b/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadTransactionImpl.java
@@ -28,4 +28,9 @@ final class TypedReadTransactionImpl<D extends Datastore> extends TypedTransacti
     public <T extends DataObject> FluentFuture<Optional<T>> read(final InstanceIdentifier<T> path) {
         return delegate().read(getDatastoreType(), path);
     }
+
+    @Override
+    public FluentFuture<Boolean> exists(final InstanceIdentifier<?> path) {
+        return delegate().exists(getDatastoreType(), path);
+    }
 }
diff --git a/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadWriteTransactionImpl.java b/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadWriteTransactionImpl.java
index ae121603f3..1927853905 100644
--- a/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadWriteTransactionImpl.java
+++ b/binding/mdsal-binding-util/src/main/java/org/opendaylight/mdsal/binding/util/TypedReadWriteTransactionImpl.java
@@ -29,4 +29,9 @@ class TypedReadWriteTransactionImpl<D extends Datastore>
     public final <T extends DataObject> FluentFuture<Optional<T>> read(final InstanceIdentifier<T> path) {
         return delegate().read(getDatastoreType(), path);
     }
+
+    @Override
+    public FluentFuture<Boolean> exists(final InstanceIdentifier<?> path) {
+        return delegate().exists(getDatastoreType(), path);
+    }
 }