BUG-997: Evolve the SchemaRegistry concepts

[yangtools.git] / yang / yang-model-api / src / main / java / org / opendaylight / yangtools / yang / model / repo / api / SchemaSourceFilter.java

diff --git a/yang/yang-model-api/src/main/java/org/opendaylight/yangtools/yang/model/repo/api/SchemaSourceFilter.java b/yang/yang-model-api/src/main/java/org/opendaylight/yangtools/yang/model/repo/api/SchemaSourceFilter.java
index 188f83c0c592c47b6134bf080d4ed0a99924dfce..f881900754a53642d3696bfab3e67e2a47934ac2 100644 (file)
--- a/yang/yang-model-api/src/main/java/org/opendaylight/yangtools/yang/model/repo/api/SchemaSourceFilter.java
+++ b/yang/yang-model-api/src/main/java/org/opendaylight/yangtools/yang/model/repo/api/SchemaSourceFilter.java
@@ -7,9 +7,55 @@
  */
 package org.opendaylight.yangtools.yang.model.repo.api;
 
+import com.google.common.annotations.Beta;
+import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 
+import java.util.Collections;
+
+/*
+ * A filter of schema sources. This is used to restrict which sources representation
+ * instances are allowed to participate in construction of a schema context. This
+ * allows, for example, to create an non-shared island, or require the sources to
+ * be certified before use.
+ */
+@Beta
 public interface SchemaSourceFilter {
+    /**
+     * A {@link SchemaSourceFilter} which accepts any schema source it is presented with.
+     */
+    public static final SchemaSourceFilter ALWAYS_ACCEPT = new SchemaSourceFilter() {
+        private final Iterable<Class<? extends SchemaSourceRepresentation>> REPRESENTATIONS =
+                Collections.<Class<? extends SchemaSourceRepresentation>>singletonList(SchemaSourceRepresentation.class);
+
+        @Override
+        public Iterable<Class<? extends SchemaSourceRepresentation>> supportedRepresentations() {
+            return REPRESENTATIONS;
+        }
+
+        @Override
+        public ListenableFuture<Boolean> apply(final SchemaSourceRepresentation schemaSource) {
+            return Futures.immediateFuture(Boolean.TRUE);
+        }
+    };
+
+    /**
+     * Get the representations this filter supports. A schema source is translated
+     * into one of these representations before it is presented for filtering.
+     *
+     * @return Set of supported representations.
+     */
     Iterable<Class<? extends SchemaSourceRepresentation>> supportedRepresentations();
+
+    /**
+     * Check if a particular schema source is acceptable to the filter. The process
+     * of checking may be asynchronous, but at some point it needs to produce an
+     * affirmative or negative answer before the schema context construction can
+     * proceed.
+     *
+     * @param schemaSource Schema source to be filtered
+     * @return Promise of a filtering decision. The result should be {@link Boolean#TRUE}
+     *         if the source is acceptable.
+     */
     ListenableFuture<Boolean> apply(SchemaSourceRepresentation schemaSource);
 }