Rearrange the furniture

.gitignore

@@ -5,3 +5,4 @@ build
 .classpath
 .project
 .settings/
+.DS_Store

trellis-api/src/main/java/org/trellisldp/api/AppendService.java

@@ -0,0 +1,34 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.trellisldp.api;
+
+import java.util.concurrent.Future;
+
+/**
+ * A service that persists resources by appending to their records. Nothing that
+ * is recorded by {@link #add(Object)} will be deleted by using {@code add} again.
+ * 
+ * @author ajs6f
+ *
+ * @param <T> the type of resource that can be persisted by this service
+ */
+public interface AppendService<T> {
+
+    /**
+     * @param resource a resource to persist
+     * @return whether the resource was successfully persisted
+     */
+    Future<Boolean> add(T resource);
+}

trellis-api/src/main/java/org/trellisldp/api/AuditService.java

@@ -24,7 +24,7 @@
  *
  * @author acoburn
  */
-public interface AuditService {
+public interface AuditService extends AppendService<Resource> {
 
     /**
      * Generate the audit quads for a Create event.

trellis-api/src/main/java/org/trellisldp/api/RDFUtils.java

@@ -13,11 +13,22 @@
  */
 package org.trellisldp.api;
 
+import static java.util.Collections.newSetFromMap;
+import static java.util.Collections.unmodifiableSet;
+import static java.util.EnumSet.of;
+import static java.util.stream.Collector.Characteristics.CONCURRENT;
+import static java.util.stream.Collector.Characteristics.IDENTITY_FINISH;
 import static java.util.stream.Collector.Characteristics.UNORDERED;
-import static java.util.stream.Collector.of;
 
 import java.util.ServiceLoader;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.BiConsumer;
+import java.util.function.BinaryOperator;
+import java.util.function.Function;
+import java.util.function.Supplier;
 import java.util.stream.Collector;
+import java.util.stream.Stream;
 
 import org.apache.commons.rdf.api.Dataset;
 import org.apache.commons.rdf.api.Graph;
@@ -71,7 +82,7 @@ public static RDF getInstance() {
      * @return a graph
      */
     public static Collector<Triple, ?, Graph> toGraph() {
-        return of(rdf::createGraph, Graph::add, (left, right) -> {
+        return Collector.of(rdf::createGraph, Graph::add, (left, right) -> {
             right.iterate().forEach(left::add);
             return left;
         }, UNORDERED);
@@ -80,13 +91,88 @@ public static RDF getInstance() {
     /**
      * Collect a stream of Quads into a Dataset.
      *
-     * @return a dataset
+     * @return a {@link Collector} that accumulates a {@link Stream} of
+     *         {@link Quad}s into a {@link Dataset}
      */
-    public static Collector<Quad, ?, Dataset> toDataset() {
-        return of(rdf::createDataset, Dataset::add, (left, right) -> {
-            right.iterate().forEach(left::add);
-            return left;
-        }, UNORDERED);
+    public static DatasetCollector toDataset() {
+        return new DatasetCollector();
+    }
+
+    static class DatasetCollector implements Collector<Quad, Dataset, Dataset> {
+
+        @Override
+        public Supplier<Dataset> supplier() {
+            return rdf::createDataset;
+        }
+
+        @Override
+        public BiConsumer<Dataset, Quad> accumulator() {
+            return Dataset::add;
+        }
+
+        @Override
+        public BinaryOperator<Dataset> combiner() {
+            return (left, right) -> {
+                right.iterate().forEach(left::add);
+                return left;
+            };
+        }
+
+        @Override
+        public Function<Dataset, Dataset> finisher() {
+            return x -> x;
+        }
+
+        @Override
+        public Set<Characteristics> characteristics() {
+            return unmodifiableSet(of(UNORDERED, IDENTITY_FINISH));
+        }
+
+        /**
+         * Collect a stream of {@link Quad}s into a {@link Dataset} with concurrent
+         * operation.
+         *
+         * @return a {@link Collector} that accumulates a {@link Stream} of
+         *         {@link Quad}s into a {@link Dataset}
+         */
+        public ConcurrentDatasetCollector concurrent() {
+            return new ConcurrentDatasetCollector();
+        }
+    }
+
+    private static class ConcurrentDatasetCollector implements Collector<Quad, Set<Quad>, Dataset> {
+
+        @Override
+        public Supplier<Set<Quad>> supplier() {
+            return () -> newSetFromMap(new ConcurrentHashMap<>());
+        }
+
+        @Override
+        public BiConsumer<Set<Quad>, Quad> accumulator() {
+            return Set::add;
+        }
+
+        @Override
+        public BinaryOperator<Set<Quad>> combiner() {
+            return (s1, s2) -> {
+                s1.addAll(s2);
+                return s1;
+            };
+        }
+
+        @Override
+        public Function<Set<Quad>, Dataset> finisher() {
+            return set -> {
+                final Dataset dataset = rdf.createDataset();
+                set.forEach(dataset::add);
+                return dataset;
+            };
+        }
+
+        @Override
+        public Set<Characteristics> characteristics() {
+            return unmodifiableSet(of(UNORDERED, CONCURRENT));
+        }
     }
 
     private RDFUtils() {

trellis-api/src/main/java/org/trellisldp/api/ReplaceService.java

@@ -0,0 +1,34 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.trellisldp.api;
+
+import java.util.concurrent.Future;
+
+/**
+ * A service that persists resources by <i>replacing</i> their records.
+ * 
+ * @author ajs6f
+ *
+ * @param <T> the type of resource that can be persisted by this service
+ */
+public interface ReplaceService<T> extends RetrievalService<T> {
+
+    /**
+     * @param resource a resource to persist
+     * @return whether the resource was successfully persisted
+     */
+    Future<Boolean> put(T resource);
+
+}

trellis-api/src/main/java/org/trellisldp/api/ResourceService.java

@@ -17,6 +17,7 @@
 import static org.trellisldp.api.RDFUtils.TRELLIS_BNODE_PREFIX;
 import static org.trellisldp.api.RDFUtils.TRELLIS_DATA_PREFIX;
 import static org.trellisldp.api.RDFUtils.getInstance;
+import static org.trellisldp.api.RDFUtils.toDataset;
 
 import java.time.Instant;
 import java.util.Collection;
@@ -40,24 +41,12 @@
  *
  * @author acoburn
  */
-public interface ResourceService {
+public interface ResourceService extends ReplaceService<Resource> {
 
-    /**
-     * Get a resource from the given location.
-     *
-     * @param identifier the resource identifier
-     * @return the resource
-     */
-    Optional<? extends Resource> get(IRI identifier);
-
-    /**
-     * Get a resource from the given location and time.
-     *
-     * @param identifier the resource identifier
-     * @param time the time
-     * @return the resource
-     */
-    Optional<? extends Resource> get(IRI identifier, Instant time);
+    @Override
+    default Future<Boolean> put(Resource res) {
+        return put(res.getIdentifier(), res.getInteractionModel(), res.stream().collect(toDataset().concurrent()));
+    }
 
     /**
      * Put a resource into the server.

trellis-api/src/main/java/org/trellisldp/api/RetrievalService.java

@@ -0,0 +1,50 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.trellisldp.api;
+
+import java.time.Instant;
+import java.util.Optional;
+
+import org.apache.commons.rdf.api.IRI;
+
+/**
+ * A service that can retrieve resources of some type, featuring optional
+ * retrieval by time.
+ * 
+ * @author ajs6f
+ *
+ * @param <T> the type of resource available from this service
+ */
+public interface RetrievalService<T> {
+
+    /**
+     * Get a resource by the given identifier.
+     *
+     * @param identifier the resource identifier
+     * @return the resource
+     */
+    Optional<? extends T> get(IRI identifier);
+
+    /**
+     * Get a resource by the given identifier and time.
+     *
+     * @param identifier the resource identifier
+     * @param time the time
+     * @return the resource
+     */
+    default Optional<? extends T> get(IRI identifier, Instant time) {
+        return get(identifier);
+    }
+}

trellis-audit/build.gradle

@@ -39,3 +39,9 @@ jar {
     }
 }
 
+javadoc {
+    options.tags = ["apiNote:a:API Note:",
+                    "implSpec:a:Implementation Requirements:",
+                    "implNote:a:Implementation Note:"]
+}
+

trellis-audit/src/main/java/org/trellisldp/audit/DefaultAuditService.java

@@ -20,23 +20,32 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Future;
 
 import org.apache.commons.rdf.api.BlankNode;
 import org.apache.commons.rdf.api.IRI;
 import org.apache.commons.rdf.api.Quad;
 import org.apache.commons.rdf.api.RDF;
 import org.trellisldp.api.AuditService;
+import org.trellisldp.api.Resource;
 import org.trellisldp.api.Session;
 import org.trellisldp.vocabulary.AS;
 import org.trellisldp.vocabulary.PROV;
 import org.trellisldp.vocabulary.XSD;
 
 /**
- * An {@link AuditService} that generates Audit-related {@link Quad}s for various write operations.
- *
- * <p>This class makes use of the {@link PROV} vocabulary and {@link BlankNode} objects in a
- * {@code http://www.trellisldp.org/ns/trellis#PreferAudit} named graph.
+ * An {@link AuditService} that generates Audit-related {@link Quad}s for
+ * various write operations.
  *
+ * <p>This class makes use of the {@link PROV} vocabulary and {@link BlankNode}
+ * objects in a {@code http://www.trellisldp.org/ns/trellis#PreferAudit} named
+ * graph.
+ * 
+ * @implSpec This implementation of AuditService does not persist audit
+ *           information. Subclass and override {@link #add(Resource)} to add
+ *           persistence.
+ * 
  * @author acoburn
  */
 public class DefaultAuditService implements AuditService {
@@ -70,4 +79,14 @@ private List<Quad> auditData(final IRI subject, final Session session, final Lis
                 data.add(rdf.createQuad(PreferAudit, bnode, PROV.actedOnBehalfOf, delegate)));
         return data;
     }
+
+    /*
+     * Override to provide persistence for audit information.
+     * 
+     * @see org.trellisldp.api.AppendService#add(java.lang.Object)
+     */
+    @Override
+    public Future<Boolean> add(final Resource resource) {
+        return CompletableFuture.completedFuture(false);
+    }
 }

trellis-karaf/src/main/resources/features.xml

@@ -131,6 +131,7 @@
 
     <feature>commons-rdf-jena</feature>
     <feature>trellis-api</feature>
+    <feature>trellis-audit</feature>
     <feature>trellis-vocabulary</feature>
 
     <bundle>mvn:org.trellisldp/trellis-triplestore/${project.version}</bundle>