From 450b2d9f09611f3c8313ca2c64b4d1c34610bb5b Mon Sep 17 00:00:00 2001
From: Robert Varga <robert.varga@pantheon.tech>
Date: Thu, 12 Jul 2018 11:14:45 +0200
Subject: [PATCH] Add support for incremental Prerequisites

We really need a method which would allow us to follow a path,
hooking incrementally to each of the elements as they appear.

This patch adds the mechanics to support that lookup, rendering
SchemaNodeIdentifierBuildNamespace largely superfluous, as we
can perform equivalent lookups on ChildSchemaNodeNamespace.

JIRA: YANGTOOLS-859
Change-Id: I7dae9559555ee6ddc95faf1f874cebac9f915c1b
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
---
 .../parser/stmt/reactor/ModifierImpl.java     | 52 +++++++++++++++++--
 .../parser/spi/meta/ModelActionBuilder.java   |  6 +++
 2 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/yang/yang-parser-reactor/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/reactor/ModifierImpl.java b/yang/yang-parser-reactor/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/reactor/ModifierImpl.java
index bf77d86805..3b7972b26f 100644
--- a/yang/yang-parser-reactor/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/reactor/ModifierImpl.java
+++ b/yang/yang-parser-reactor/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/reactor/ModifierImpl.java
@@ -128,9 +128,7 @@ final class ModifierImpl implements ModelActionBuilder {
                     final K key, final ModelProcessingPhase phase) {
         checkNotRegistered();
 
-        PhaseModificationInNamespace<C> mod = new PhaseModificationInNamespace<>(phase);
-        addReq(mod);
-        addMutation(mod);
+        PhaseModificationInNamespace<C> mod = createModification(phase);
         contextImpl(context).onNamespaceItemAddedAction((Class) namespace, key, mod);
         return mod;
     }
@@ -246,6 +244,54 @@ final class ModifierImpl implements ModelActionBuilder {
         return mutatesCtxImpl(context, namespace, key, EFFECTIVE_MODEL);
     }
 
+    @Nonnull
+    @Override
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public <K, E extends EffectiveStatement<?, ?>, N extends IdentifierNamespace<K, ? extends StmtContext<?, ?, ?>>>
+            AbstractPrerequisite<Mutable<?, ?, E>> mutatesEffectiveCtxPath(final StmtContext<?, ?, ?> context,
+                    final Class<N> namespace, final Iterable<K> keys) {
+        final Iterator<K> it = keys.iterator();
+        Preconditions.checkArgument(it.hasNext(), "Namespace %s keys may not be empty", namespace);
+        checkNotRegistered();
+
+        final PhaseModificationInNamespace<Mutable<?, ?, E>> ret = createModification(EFFECTIVE_MODEL);
+        contextImpl(context).onNamespaceItemAddedAction((Class) namespace, it.next(),
+            (parent, ns, foundKey, foundValue) -> {
+                checkResult((Mutable<?, ?, E>)foundValue, namespace, it, ret);
+            });
+        return ret;
+    }
+
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    private <K, C extends Mutable<?, ?, ?>, N extends IdentifierNamespace<K, ? extends StmtContext<?, ?, ?>>>
+            void mutateNextKey(final StmtContext<?, ?, ?> context, final Class<N> namespace,
+                    final Iterator<K> it, final AbstractPrerequisite<C> result) {
+        final PhaseModificationInNamespace<C> mod = createModification(EFFECTIVE_MODEL);
+        contextImpl(context).onNamespaceItemAddedAction((Class) namespace, it.next(),
+            (parent, ns, foundKey, foundValue) -> {
+                checkResult((C) foundValue, namespace, it, result);
+                mod.resolvePrereq((C) foundValue);
+            });
+    }
+
+    private <C extends Mutable<?, ?, ?>> PhaseModificationInNamespace<C> createModification(
+            final ModelProcessingPhase phase) {
+        final PhaseModificationInNamespace<C> ret = new PhaseModificationInNamespace<>(EFFECTIVE_MODEL);
+        addReq(ret);
+        addMutation(ret);
+        return ret;
+    }
+
+    private <K, C extends Mutable<?, ?, ?>, N extends IdentifierNamespace<K, ? extends StmtContext<?, ?, ?>>>
+            void checkResult(final C context, final Class<N> namespace, final Iterator<K> it,
+                    final AbstractPrerequisite<C> result) {
+        if (it.hasNext()) {
+            mutateNextKey(context, namespace, it, result);
+        } else {
+            result.resolvePrereq(context);
+        }
+    }
+
     @Override
     @SuppressWarnings("checkstyle:hiddenField")
     public void apply(final InferenceAction action) {
diff --git a/yang/yang-parser-spi/src/main/java/org/opendaylight/yangtools/yang/parser/spi/meta/ModelActionBuilder.java b/yang/yang-parser-spi/src/main/java/org/opendaylight/yangtools/yang/parser/spi/meta/ModelActionBuilder.java
index 08d01cb9f1..2e674d02ef 100644
--- a/yang/yang-parser-spi/src/main/java/org/opendaylight/yangtools/yang/parser/spi/meta/ModelActionBuilder.java
+++ b/yang/yang-parser-spi/src/main/java/org/opendaylight/yangtools/yang/parser/spi/meta/ModelActionBuilder.java
@@ -174,6 +174,12 @@ public interface ModelActionBuilder {
     @Nonnull <K, E extends EffectiveStatement<?, ?>, N extends IdentifierNamespace<K, ? extends StmtContext<?, ?, ?>>>
         Prerequisite<Mutable<?, ?, E>> mutatesEffectiveCtx(StmtContext<?, ?, ?> context, Class<N> namespace, K key);
 
+    default @Nonnull <K, E extends EffectiveStatement<?, ?>,
+            N extends IdentifierNamespace<K, ? extends StmtContext<?, ?, ?>>> Prerequisite<Mutable<?, ?, E>>
+                mutatesEffectiveCtxPath(StmtContext<?, ?, ?> context, Class<N> namespace, Iterable<K> keys) {
+        throw new UnsupportedOperationException(getClass() + " does not implement mutatesEffectiveCtxPath()");
+    }
+
     /**
      * Action mutates the specified statement in the specified phase. Target statement cannot complete specified
      * phase before this action is applier.
-- 
2.36.6