HONEYCOMB-431: add validation support to Writers

This patch introduces FlatWriterRegistry.validateModifications.
Implementation iterates over writersOrder following bulkUpdate logic
to properly support subtree writers case.

Writers are now cabable of validating modifications.
Commonly used implementations (GenericWriter and GenericListWriter)
delegate validation capbility to Validators.

Change-Id: If7a0bb0838c0b8f2c0393c989f3b03853a2ea679
Signed-off-by: Marek Gradzki <mgradzki@cisco.com>

4 files changed, 85 insertions, 22 deletions

diff --git a/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/GenericListWriter.java b/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/GenericListWriter.java
index 92467a8e8..5121eb793 100644
--- a/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/GenericListWriter.java
+++ b/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/GenericListWriter.java
@@ -19,12 +19,13 @@ package io.fd.honeycomb.translate.impl.write;
 import static io.fd.honeycomb.translate.impl.write.GenericWriter.isUpdateSupported;
 
 import io.fd.honeycomb.translate.spi.write.ListWriterCustomizer;
+import io.fd.honeycomb.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.translate.util.RWUtils;
 import io.fd.honeycomb.translate.util.write.AbstractGenericWriter;
 import io.fd.honeycomb.translate.write.ListWriter;
+import io.fd.honeycomb.translate.write.Validator;
 import io.fd.honeycomb.translate.write.WriteContext;
 import io.fd.honeycomb.translate.write.WriteFailedException;
-import io.fd.honeycomb.translate.spi.write.WriterCustomizer;
 import javax.annotation.Nonnull;
 import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.Identifiable;
@@ -45,6 +46,13 @@ public final class GenericListWriter<D extends DataObject & Identifiable<K>, K e
         this.customizer = customizer;
     }
 
+    public GenericListWriter(@Nonnull final InstanceIdentifier<D> type,
+                             @Nonnull final ListWriterCustomizer<D, K> customizer,
+                             @Nonnull final Validator<D> validator) {
+        super(type, isUpdateSupported(customizer), validator);
+        this.customizer = customizer;
+    }
+
     @Override
     protected void writeCurrentAttributes(@Nonnull final InstanceIdentifier<D> id, @Nonnull final D data,
                                           @Nonnull final WriteContext ctx) throws WriteFailedException {
@@ -79,22 +87,25 @@ public final class GenericListWriter<D extends DataObject & Identifiable<K>, K e
     @Override
     protected void writeCurrent(final InstanceIdentifier<D> id, final D data, final WriteContext ctx)
         throws WriteFailedException {
-        super.writeCurrent(getId(id, data), data, ctx);
+        super.writeCurrent(getManagedId(id, data), data, ctx);
     }
 
     @Override
     protected void updateCurrent(final InstanceIdentifier<D> id, final D dataBefore, final D dataAfter,
                                  final WriteContext ctx) throws WriteFailedException {
-        super.updateCurrent(getId(id, dataBefore), dataBefore, dataAfter, ctx);
+        super.updateCurrent(getManagedId(id, dataBefore), dataBefore, dataAfter, ctx);
     }
 
     @Override
     protected void deleteCurrent(final InstanceIdentifier<D> id, final D dataBefore, final WriteContext ctx)
         throws WriteFailedException {
-        super.deleteCurrent(getId(id, dataBefore), dataBefore, ctx);
+        super.deleteCurrent(getManagedId(id, dataBefore), dataBefore, ctx);
     }
 
-    private InstanceIdentifier<D> getId(final InstanceIdentifier<D> id, final D current) {
+    @Override
+    protected InstanceIdentifier<D> getManagedId(@Nonnull final InstanceIdentifier<? extends DataObject> currentId,
+                                                 @Nonnull final D current) {
+        final InstanceIdentifier<D> id = (InstanceIdentifier<D>) currentId;
         // Make sure the key is present
         if (isWildcarded(id)) {
             return getSpecificId(id, current);
diff --git a/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/GenericWriter.java b/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/GenericWriter.java
index 086936e38..bfdf072c0 100644
--- a/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/GenericWriter.java
+++ b/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/GenericWriter.java
@@ -16,9 +16,10 @@
 
 package io.fd.honeycomb.translate.impl.write;
 
-import io.fd.honeycomb.translate.write.WriteContext;
 import io.fd.honeycomb.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.translate.util.write.AbstractGenericWriter;
+import io.fd.honeycomb.translate.write.Validator;
+import io.fd.honeycomb.translate.write.WriteContext;
 import io.fd.honeycomb.translate.write.WriteFailedException;
 import javax.annotation.Nonnull;
 import org.opendaylight.yangtools.yang.binding.DataObject;
@@ -39,7 +40,13 @@ public final class GenericWriter<D extends DataObject> extends AbstractGenericWr
                          @Nonnull final WriterCustomizer<D> customizer) {
         super(type, isUpdateSupported(customizer));
         this.customizer = customizer;
+    }
 
+    public GenericWriter(@Nonnull final InstanceIdentifier<D> type,
+                         @Nonnull final WriterCustomizer<D> customizer,
+                         @Nonnull final Validator<D> validator) {
+        super(type, isUpdateSupported(customizer), validator);
+        this.customizer = customizer;
     }
 
     static boolean isUpdateSupported(final @Nonnull WriterCustomizer<?> customizer) {
diff --git a/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/registry/FlatWriterRegistry.java b/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/registry/FlatWriterRegistry.java
index 67a5da32a..9e36e593f 100644
--- a/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/registry/FlatWriterRegistry.java
+++ b/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/registry/FlatWriterRegistry.java
@@ -28,12 +28,14 @@ import com.google.common.collect.Sets;
 import io.fd.honeycomb.translate.TranslationException;
 import io.fd.honeycomb.translate.util.RWUtils;
 import io.fd.honeycomb.translate.write.DataObjectUpdate;
+import io.fd.honeycomb.translate.write.DataValidationFailedException;
 import io.fd.honeycomb.translate.write.WriteContext;
 import io.fd.honeycomb.translate.write.Writer;
 import io.fd.honeycomb.translate.write.registry.UpdateFailedException;
 import io.fd.honeycomb.translate.write.registry.WriterRegistry;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -76,6 +78,33 @@ final class FlatWriterRegistry implements WriterRegistry {
     }
 
     @Override
+    public void validateModifications(@Nonnull final DataObjectUpdates updates, @Nonnull final WriteContext ctx)
+        throws DataValidationFailedException {
+        // Optimization: validation order is not relevant, so do not merge deletes and updates.
+        validateModifications(updates.getDeletes(), ctx);
+        validateModifications(updates.getUpdates(), ctx);
+    }
+
+    private void validateModifications(
+        @Nonnull final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates,
+        @Nonnull final WriteContext ctx) throws DataValidationFailedException {
+        if (updates.isEmpty()) {
+            return;
+        }
+        // Fail early if some handlers are missing.
+        checkAllTypesCanBeHandled(updates);
+
+        // Validators do not modify anything, so order of validators is not important.
+        // We iterate over writersOrder instead of modifications for consistent handling of subtree writers case.
+        for (InstanceIdentifier<?> writerType : writersOrder) {
+            final Writer<?> writer = getWriter(writerType);
+            for (DataObjectUpdate singleUpdate : getWritersData(updates, writer, writerType, ctx)) {
+                writer.validate(singleUpdate.getId(), singleUpdate.getDataBefore(), singleUpdate.getDataAfter(), ctx);
+            }
+        }
+    }
+
+    @Override
     public void processModifications(@Nonnull final DataObjectUpdates updates,
                                      @Nonnull final WriteContext ctx) throws TranslationException {
         if (updates.isEmpty()) {
@@ -207,26 +236,11 @@ final class FlatWriterRegistry implements WriterRegistry {
         LOG.debug("Performing bulk update for: {}", updates.keySet());
         // Iterate over all writers and call update if there are any related updates
         for (InstanceIdentifier<?> writerType : writersOrder) {
-            Collection<? extends DataObjectUpdate> writersData = updates.get(writerType);
             final Writer<?> writer = getWriter(writerType);
-
-            if (writersData.isEmpty()) {
-                // If there are no data for current writer, but it is a SubtreeWriter and there are updates to
-                // its children, still invoke it with its root data
-                if (writer instanceof SubtreeWriter<?> && isAffected((SubtreeWriter<?>) writer, updates)) {
-                    // Provide parent data for SubtreeWriter for further processing
-                    writersData = getParentDataObjectUpdate(ctx, updates, writer);
-                } else {
-                    // Skipping unaffected writer
-                    // Alternative to this would be modification sort according to the order of writers
-                    continue;
-                }
-            }
-
             LOG.debug("Performing update for: {}", writerType);
             LOG.trace("Performing update with writer: {}", writer);
 
-            for (DataObjectUpdate singleUpdate : writersData) {
+            for (DataObjectUpdate singleUpdate : getWritersData(updates, writer, writerType, ctx)) {
                 try {
                     writer.processModification(singleUpdate.getId(), singleUpdate.getDataBefore(),
                             singleUpdate.getDataAfter(), ctx);
@@ -240,6 +254,29 @@ final class FlatWriterRegistry implements WriterRegistry {
         }
     }
 
+    private Collection<? extends DataObjectUpdate> getWritersData(
+        final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates, final Writer<?> writer,
+        final InstanceIdentifier<?> writerType, final WriteContext ctx) {
+        Collection<? extends DataObjectUpdate> writersData = updates.get(writerType);
+
+        if (writersData.isEmpty()) {
+            // If there are no data for current writer, but it is a SubtreeWriter and there are updates to
+            // its children, still invoke it with its root data.
+            // Notice that child updates will be ignored if the set of all modifications
+            // contain both parent update and child updates. But this is ok, since all changes are already expressed in
+            // the parent update.
+            if (writer instanceof SubtreeWriter<?> && isAffected((SubtreeWriter<?>) writer, updates)) {
+                // Provide parent data for SubtreeWriter for further processing
+                writersData = getParentDataObjectUpdate(ctx, updates, writer);
+            } else {
+                // Skipping unaffected writer
+                // Alternative to this would be modification sort according to the order of writers
+                return Collections.emptyList();
+            }
+        }
+        return writersData;
+    }
+
     private void checkAllTypesCanBeHandled(
             @Nonnull final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates) {
 
diff --git a/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/registry/SubtreeWriter.java b/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/registry/SubtreeWriter.java
index a1a5f3fd0..e510bc33c 100644
--- a/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/registry/SubtreeWriter.java
+++ b/infra/translate-impl/src/main/java/io/fd/honeycomb/translate/impl/write/registry/SubtreeWriter.java
@@ -19,6 +19,7 @@ package io.fd.honeycomb.translate.impl.write.registry;
 import static com.google.common.base.Preconditions.checkArgument;
 
 import com.google.common.collect.Iterables;
+import io.fd.honeycomb.translate.write.DataValidationFailedException;
 import io.fd.honeycomb.translate.write.WriteContext;
 import io.fd.honeycomb.translate.write.WriteFailedException;
 import io.fd.honeycomb.translate.write.Writer;
@@ -68,6 +69,13 @@ final class SubtreeWriter<D extends DataObject> implements Writer<D> {
     }
 
     @Override
+    public void validate(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                         @Nullable final DataObject dataBefore, @Nullable final DataObject dataAfter,
+                         @Nonnull final WriteContext ctx) throws DataValidationFailedException {
+        delegate.validate(id, dataBefore, dataAfter, ctx);
+    }
+
+    @Override
     public void processModification(
             @Nonnull final InstanceIdentifier<? extends DataObject> id,
             @Nullable final DataObject dataBefore,