Datomic blueprints implementation

README.textile

@@ -12,6 +12,7 @@ Blueprints is a "property graph model interface":http://github.com/tinkerpop/gre
 ** "InfiniteGraph":http://www.infinitegraph.com/ (available "here":http://wiki.infinitegraph.com/2.1/w/index.php?title=InfiniteGraph_Tinkerpop_Blueprints_Implementation)
 ** "Titan":http://thinkaurelius.github.com/titan/ (available "here":http://thinkaurelius.github.com/titan/)
 ** "Rexster":http://rexster.tinkerpop.com graph server
+** "Datomic":http://www.datomic.com/ database
 ** "Sesame 2.0":http://www.openrdf.org compliant RDF stores
 **** "MemoryStore":http://www.openrdf.org/doc/sesame2/users/ch08.html#d0e705, "NativeStore":http://www.openrdf.org/doc/sesame2/users/ch08.html#d0e746, "LinkedDataSail":http://code.google.com/p/ripple/wiki/LinkedDataSail, "SPARQLRepository":http://www.openrdf.org/doc/sesame2/api/org/openrdf/repository/sparql/SPARQLRepository.html
 * Ouplementations:

blueprints-core/pom.xml

@@ -34,6 +34,11 @@
             <artifactId>colt</artifactId>
             <version>1.2.0</version>
         </dependency>
+        <dependency>
+            <groupId>joda-time</groupId>
+            <artifactId>joda-time</artifactId>
+            <version>2.1</version>
+        </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>

blueprints-core/src/main/java/com/tinkerpop/blueprints/Features.java

@@ -76,6 +76,10 @@ public class Features {
      * Does the graph persist the graph to disk after shutdown?
      */
     public Boolean isPersistent = null;
+    /**
+     * Does the graph support time-aware versioning of its elements
+     */
+    public Boolean isTimeAware = null;
     /**
      * Is the graph an RDF framework?
      * @deprecated thus far, isRDFModel describes a collection of features. Use actual features to describe your data model.

blueprints-core/src/main/java/com/tinkerpop/blueprints/TimeAwareEdge.java

@@ -0,0 +1,27 @@
+package com.tinkerpop.blueprints;
+
+/**
+ * @author Davy Suvee (http://datablend.be)
+ */
+public interface TimeAwareEdge extends Edge, TimeAwareElement {
+
+    @Override
+    public TimeAwareEdge getPreviousVersion();
+
+    @Override
+    public Iterable<TimeAwareEdge> getPreviousVersions();
+
+    @Override
+    public Iterable<TimeAwareEdge> getPreviousVersions(TimeAwareFilter timeAwareFilter);
+
+    @Override
+    public TimeAwareEdge getNextVersion();
+
+    @Override
+    public Iterable<TimeAwareEdge> getNextVersions();
+
+    @Override
+    public Iterable<TimeAwareEdge> getNextVersions(TimeAwareFilter timeAwareFilter);
+
+
+}

blueprints-core/src/main/java/com/tinkerpop/blueprints/TimeAwareElement.java

@@ -0,0 +1,85 @@
+package com.tinkerpop.blueprints;
+
+import org.joda.time.Interval;
+
+/**
+ * A TimeAwareElement is the base interface for time-aware elements (i.e. time-aware vertices and edges).
+ * It extends the base blueprints Element interface with time-based operations
+ *
+ * @author Davy Suvee (http://datablend.be)
+ */
+public interface TimeAwareElement extends Element {
+
+    /**
+     * An identifier that specifies the time-scope in which it exists
+     *
+     * @return the time identifier of the element
+     */
+    public Object getTimeId();
+
+    /**
+     * Returns true if this element instance is the current version
+     *
+     * @return true if this element instance is the current version
+     */
+    public boolean isCurrentVersion();
+
+    /**
+     * Returns true if this element no longer exists (it is still the current version, but no longer an active element in the graph)
+     *
+     * @return true if this element instance is deleted
+     */
+    public boolean isDeleted();
+
+    /**
+     * Returns the previous version of this element
+     *
+     * @return the previous (time-aware) version of this element
+     */
+    public TimeAwareElement getPreviousVersion();
+
+    /**
+     * Returns the previous versions of this element
+     *
+     * @return an iterable of previous versions
+     */
+    public Iterable<? extends TimeAwareElement> getPreviousVersions();
+
+    /**
+     * Returns the previous versions of this element that satisfy a particular condition implemented as a filter
+     *
+     * @param timeAwareFilter the particular time aware filter
+     * @return an iterable of previous versions
+     */
+    public Iterable<? extends TimeAwareElement> getPreviousVersions(TimeAwareFilter timeAwareFilter);
+
+    /**
+     * Returns the next version of this element
+     *
+     * @return the next (time-aware) version of this element
+     */
+    public TimeAwareElement getNextVersion();
+
+    /**
+     * Returns the next versions of this element
+     *
+     * @return an iterable of previous versions
+     */
+    public Iterable<? extends TimeAwareElement> getNextVersions();
+
+    /**
+     * Returns the next versions of this element that satisfy a particular condition implemented as a filter
+     *
+     * @param timeAwareFilter the particular time aware filter
+     * @return an iterable of previous versions
+     */
+    public Iterable<? extends TimeAwareElement> getNextVersions(TimeAwareFilter timeAwareFilter);
+
+    /**
+     * Returns the time interval in which this version of this node is scoped
+     *
+     * @return the joda time interval
+     */
+    public Interval getTimeInterval();
+
+}

blueprints-core/src/main/java/com/tinkerpop/blueprints/TimeAwareFilter.java

@@ -0,0 +1,18 @@
+package com.tinkerpop.blueprints;
+
+/**
+ * Filters for time aware elements
+ *
+ * @author Davy Suvee (http://datablend.be)
+ */
+public interface TimeAwareFilter {
+
+    /**
+     * Returns the time aware element if a particular condition, implemented by the filter holds.
+     *
+     * @param timeAwareElement the time aware element to filter
+     * @return the original input or null in case the element does not satisfy the particular condition
+     */
+    public TimeAwareElement filter(TimeAwareElement timeAwareElement);
+
+}

blueprints-core/src/main/java/com/tinkerpop/blueprints/TimeAwareGraph.java

@@ -0,0 +1,25 @@
+package com.tinkerpop.blueprints;
+
+import java.util.Date;
+
+/**
+ * A time aware graph supports an explicit notion of time for all graph elements (vertices and edges). Each element has a specific scope in time and allows for time-scoped iteration
+ * where a user can retrieve previous or next versions of each element
+ *
+ * @author Davy Suvee (http://datablend.be)
+ */
+public interface TimeAwareGraph extends Graph {
+
+    /**
+     * Sets the time scope of the graph on a specific date
+     * @param time the time at which the scope should be placed
+     */
+    public void setCheckpointTime(Date time);
+
+    /**
+     * Sets the time scope at which new elements (vertices and edges) need to be added
+     * @param time the time at which the transaction scope should be placed
+     */
+    public void setTransactionTime(Date time);
+
+}

blueprints-core/src/main/java/com/tinkerpop/blueprints/TimeAwareVertex.java

@@ -0,0 +1,26 @@
+package com.tinkerpop.blueprints;
+
+/**
+ * @author Davy Suvee (http://datablend.be)
+ */
+public interface TimeAwareVertex extends Vertex, TimeAwareElement {
+
+    @Override
+    public TimeAwareVertex getPreviousVersion();
+
+    @Override
+    public Iterable<TimeAwareVertex> getPreviousVersions();
+
+    @Override
+    public Iterable<TimeAwareVertex> getPreviousVersions(TimeAwareFilter timeAwareFilter);
+
+    @Override
+    public TimeAwareVertex getNextVersion();
+
+    @Override
+    public Iterable<TimeAwareVertex> getNextVersions();
+
+    @Override
+    public Iterable<TimeAwareVertex> getNextVersions(TimeAwareFilter timeAwareFilter);
+
+}

blueprints-core/src/main/java/com/tinkerpop/blueprints/util/StringFactory.java

@@ -1,10 +1,6 @@
 package com.tinkerpop.blueprints.util;
 
-import com.tinkerpop.blueprints.Direction;
-import com.tinkerpop.blueprints.Edge;
-import com.tinkerpop.blueprints.Graph;
-import com.tinkerpop.blueprints.Index;
-import com.tinkerpop.blueprints.Vertex;
+import com.tinkerpop.blueprints.*;
 
 
 /**
@@ -18,6 +14,7 @@ public class StringFactory {
     public static final String E = "e";
     public static final String L_BRACKET = "[";
     public static final String R_BRACKET = "]";
+    public static final String AT = " @ ";
     public static final String DASH = "-";
     public static final String ARROW = "->";
     public static final String COLON = ":";
@@ -30,10 +27,20 @@ public static String vertexString(final Vertex vertex) {
         return V + L_BRACKET + vertex.getId() + R_BRACKET;
     }
 
+    public static String vertexString(final TimeAwareVertex vertex) {
+        return V + L_BRACKET + vertex.getId() + AT + vertex.getTimeId() + R_BRACKET;
+    }
+
     public static String edgeString(final Edge edge) {
         return E + L_BRACKET + edge.getId() + R_BRACKET + L_BRACKET + edge.getVertex(Direction.OUT).getId() + DASH + edge.getLabel() + ARROW + edge.getVertex(Direction.IN).getId() + R_BRACKET;
     }
 
+    public static String edgeString(final TimeAwareEdge edge) {
+        return E + L_BRACKET + edge.getId() + AT + edge.getTimeId() + R_BRACKET +
+                   L_BRACKET + edge.getVertex(Direction.OUT).getId() + AT + ((TimeAwareVertex)edge.getVertex(Direction.OUT)).getTimeId() +
+                   " " + DASH + edge.getLabel() + ARROW + " " + edge.getVertex(Direction.IN).getId() + AT + ((TimeAwareVertex)edge.getVertex(Direction.IN)).getTimeId() + R_BRACKET;
+    }
+
     public static String graphString(final Graph graph, final String internalString) {
         return graph.getClass().getSimpleName().toLowerCase() + L_BRACKET + internalString + R_BRACKET;
     }

blueprints-datomic-graph/pom.xml

@@ -0,0 +1,89 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>com.tinkerpop.blueprints</groupId>
+        <artifactId>blueprints</artifactId>
+        <version>2.1.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+    <artifactId>blueprints-datomic-graph</artifactId>
+    <version>2.1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>Blueprints-DatomicGraph</name>
+    <description>Blueprints property graph implementation for the Datomic database</description>
+    <repositories>
+        <repository>
+            <id>sonatype-nexus-snapshots</id>
+            <name>Sonatype Nexus Snapshots</name>
+            <url>https://oss.sonatype.org/content/repositories/snapshots</url>
+        </repository>
+        <repository>
+            <id>clojars.org</id>
+            <url>http://clojars.org/repo</url>
+        </repository>
+    </repositories>
+    <dependencies>
+        <dependency>
+            <groupId>com.datomic</groupId>
+            <artifactId>datomic-free</artifactId>
+            <version>0.8.3488</version>
+        </dependency>
+        <dependency>
+            <groupId>com.tinkerpop.blueprints</groupId>
+            <artifactId>blueprints-core</artifactId>
+            <version>${blueprints.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.tinkerpop.blueprints</groupId>
+            <artifactId>blueprints-test</artifactId>
+            <version>${blueprints.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+    <build>
+        <directory>${basedir}/target</directory>
+        <finalName>${project.artifactId}-${project.version}</finalName>
+        <resources>
+            <resource>
+                <directory>${basedir}/src/main/resources
+                </directory>
+            </resource>
+        </resources>
+        <testResources>
+            <testResource>
+                <directory>${basedir}/src/test/resources
+                </directory>
+            </testResource>
+        </testResources>
+        <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>2.3.2</version>
+                <configuration>
+                    <source>1.6</source>
+                    <target>1.6</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.4.2</version>
+                <configuration>
+                    <systemProperties>
+                        <!-- DATOMICGRAPH TEST PROPERTIES -->
+                        <property>
+                            <name>testDatomicGraph</name>
+                            <value>true</value>
+                        </property>
+                        <property>
+                            <name>datomicGraphDirectory</name>
+                            <value>/tmp/blueprints_test</value>
+                        </property>
+                    </systemProperties>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>