Ejemplo n.º 1
0
/** property function that accesses a Solr server */
public class TextQueryPF extends PropertyFunctionBase {
  private static Logger log = LoggerFactory.getLogger(TextQueryPF.class);
  /*
   * (?uri ?score) :queryPF (property? "string" limit? score?)
   */

  private TextIndex textIndex = null;
  private boolean warningIssued = false;

  public TextQueryPF() {}

  private String langArg = null;

  private static final Symbol cacheSymbol = Symbol.create("TextQueryPF.cache");
  private static final int CACHE_SIZE = 10;

  @Override
  public void build(
      PropFuncArg argSubject, Node predicate, PropFuncArg argObject, ExecutionContext execCxt) {
    super.build(argSubject, predicate, argObject, execCxt);
    DatasetGraph dsg = execCxt.getDataset();
    textIndex = chooseTextIndex(dsg);

    if (argSubject.isList()) {
      int size = argSubject.getArgListSize();
      if (size != 2 && size != 3) {
        throw new QueryBuildException(
            "Subject has "
                + argSubject.getArgList().size()
                + " elements, not 2 or 3: "
                + argSubject);
      }
    }

    if (argObject.isList()) {
      List<Node> list = argObject.getArgList();

      if (list.size() == 0) throw new QueryBuildException("Zero-length argument list");

      if (list.size() > 4) throw new QueryBuildException("Too many arguments in list : " + list);

      // extract of extra lang arg if present and if is usable.
      // arg is removed from the list to avoid conflict with order and args length
      langArg = extractArg("lang", list);

      if (langArg != null && textIndex.getDocDef().getLangField() == null)
        log.warn("lang argument is ignored if langField not set in the index configuration");
    }
  }

  private static TextIndex chooseTextIndex(DatasetGraph dsg) {

    Context c = dsg.getContext();

    Object obj = dsg.getContext().get(TextQuery.textIndex);

    if (obj != null) {
      try {
        return (TextIndex) obj;
      } catch (ClassCastException ex) {
        Log.warn(
            TextQueryPF.class, "Context setting '" + TextQuery.textIndex + "'is not a TextIndex");
      }
    }

    if (dsg instanceof DatasetGraphText) {
      DatasetGraphText x = (DatasetGraphText) dsg;
      return x.getTextIndex();
    }
    Log.warn(
        TextQueryPF.class,
        "Failed to find the text index : tried context and as a text-enabled dataset");
    return null;
  }

  private String extractArg(String prefix, List<Node> objArgs) {
    String value = null;
    int pos = 0;
    for (Node node : objArgs) {
      if (node.isLiteral()) {
        String arg = node.getLiteral().toString();
        if (arg.startsWith(prefix + ":")) {
          value = arg.split(":")[1];
          break;
        }
      }
      pos++;
    }
    if (value != null) objArgs.remove(pos);

    return value;
  }

  @Override
  public QueryIterator exec(
      Binding binding,
      PropFuncArg argSubject,
      Node predicate,
      PropFuncArg argObject,
      ExecutionContext execCxt) {
    if (textIndex == null) {
      if (!warningIssued) {
        Log.warn(getClass(), "No text index - no text search performed");
        warningIssued = true;
      }
      // Not a text dataset - no-op
      return IterLib.result(binding, execCxt);
    }

    DatasetGraph dsg = execCxt.getDataset();

    argSubject = Substitute.substitute(argSubject, binding);
    argObject = Substitute.substitute(argObject, binding);

    Node s = null;
    Node score = null;
    Node literal = null;

    if (argSubject.isList()) {
      // Length checked in build()
      s = argSubject.getArg(0);
      score = argSubject.getArg(1);

      if (!score.isVariable())
        throw new QueryExecException("Hit score is not a variable: " + argSubject);

      if (argSubject.getArgListSize() > 2) {
        literal = argSubject.getArg(2);
        if (!literal.isVariable())
          throw new QueryExecException("Hit literal is not a variable: " + argSubject);
      }
    } else {
      s = argSubject.getArg();
    }

    if (s.isLiteral())
      // Does not match
      return IterLib.noResults(execCxt);

    StrMatch match = objectToStruct(argObject, true);
    if (match == null) {
      // can't match
      return IterLib.noResults(execCxt);
    }

    // ----

    QueryIterator qIter =
        (Var.isVar(s))
            ? variableSubject(binding, s, score, literal, match, execCxt)
            : concreteSubject(binding, s, score, literal, match, execCxt);
    if (match.getLimit() >= 0) qIter = new QueryIterSlice(qIter, 0, match.getLimit(), execCxt);
    return qIter;
  }

  private QueryIterator resultsToQueryIterator(
      Binding binding,
      Node s,
      Node score,
      Node literal,
      Collection<TextHit> results,
      ExecutionContext execCxt) {
    Var sVar = Var.isVar(s) ? Var.alloc(s) : null;
    Var scoreVar = (score == null) ? null : Var.alloc(score);
    Var literalVar = (literal == null) ? null : Var.alloc(literal);

    Function<TextHit, Binding> converter =
        (TextHit hit) -> {
          if (score == null && literal == null)
            return sVar != null
                ? BindingFactory.binding(binding, sVar, hit.getNode())
                : BindingFactory.binding(binding);
          BindingMap bmap = BindingFactory.create(binding);
          if (sVar != null) bmap.add(sVar, hit.getNode());
          if (scoreVar != null) bmap.add(scoreVar, NodeFactoryExtra.floatToNode(hit.getScore()));
          if (literalVar != null) bmap.add(literalVar, hit.getLiteral());
          return bmap;
        };

    Iterator<Binding> bIter = Iter.map(results.iterator(), converter);
    QueryIterator qIter = new QueryIterPlainWrapper(bIter, execCxt);
    return qIter;
  }

  private QueryIterator variableSubject(
      Binding binding, Node s, Node score, Node literal, StrMatch match, ExecutionContext execCxt) {
    ListMultimap<String, TextHit> results =
        query(match.getProperty(), match.getQueryString(), match.getLimit(), execCxt);
    Collection<TextHit> r = results.values();
    return resultsToQueryIterator(binding, s, score, literal, r, execCxt);
  }

  private QueryIterator concreteSubject(
      Binding binding, Node s, Node score, Node literal, StrMatch match, ExecutionContext execCxt) {
    if (!s.isURI()) {
      log.warn("Subject not a URI: " + s);
      return IterLib.noResults(execCxt);
    }

    String qs = match.getQueryString();
    ListMultimap<String, TextHit> x =
        query(match.getProperty(), match.getQueryString(), -1, execCxt);

    if (x == null) // null return value - empty result
    return IterLib.noResults(execCxt);

    List<TextHit> r = x.get(s.getURI());

    return resultsToQueryIterator(binding, s, score, literal, r, execCxt);
  }

  private ListMultimap<String, TextHit> query(
      Node property, String queryString, int limit, ExecutionContext execCxt) {
    // use the graph information in the text index if possible
    if (textIndex.getDocDef().getGraphField() != null
        && execCxt.getActiveGraph() instanceof GraphView) {
      GraphView activeGraph = (GraphView) execCxt.getActiveGraph();
      if (!Quad.isUnionGraph(activeGraph.getGraphName())) {
        String uri =
            activeGraph.getGraphName() != null
                ? TextQueryFuncs.graphNodeToString(activeGraph.getGraphName())
                : Quad.defaultGraphNodeGenerated.getURI();
        String escaped = QueryParserBase.escape(uri);
        String qs2 = textIndex.getDocDef().getGraphField() + ":" + escaped;
        queryString = "(" + queryString + ") AND " + qs2;
      }
    }

    // for language-based search extension
    if (textIndex.getDocDef().getLangField() != null) {
      String field = textIndex.getDocDef().getLangField();
      if (langArg != null) {
        String qs2 = !"none".equals(langArg) ? field + ":" + langArg : "-" + field + ":*";
        queryString = "(" + queryString + ") AND " + qs2;
      }
    }

    Explain.explain(execCxt.getContext(), "Text query: " + queryString);
    if (log.isDebugEnabled()) log.debug("Text query: {} ({})", queryString, limit);

    String cacheKey = limit + " " + property + " " + queryString;
    Cache<String, ListMultimap<String, TextHit>> queryCache =
        (Cache<String, ListMultimap<String, TextHit>>) execCxt.getContext().get(cacheSymbol);
    if (queryCache == null) {
        /* doesn't yet exist, need to create it */
      queryCache = CacheFactory.createCache(CACHE_SIZE);
      execCxt.getContext().put(cacheSymbol, queryCache);
    }

    final String queryStr = queryString; // final needed for the lambda function
    ListMultimap<String, TextHit> results =
        queryCache.getOrFill(
            cacheKey,
            () -> {
              List<TextHit> resultList = textIndex.query(property, queryStr, limit);
              ListMultimap<String, TextHit> resultMultimap = LinkedListMultimap.create();
              for (TextHit result : resultList) {
                resultMultimap.put(result.getNode().getURI(), result);
              }
              return resultMultimap;
            });
    return results;
  }

  /**
   * Deconstruct the node or list object argument and make a StrMatch The 'executionTime' flag
   * indciates whether this is for a build time static check, or for runtime execution.
   */
  private StrMatch objectToStruct(PropFuncArg argObject, boolean executionTime) {
    EntityDefinition docDef = textIndex.getDocDef();
    if (argObject.isNode()) {
      Node o = argObject.getArg();
      if (!o.isLiteral()) {
        if (executionTime) log.warn("Object to text query is not a literal");
        return null;
      }

      RDFDatatype dt = o.getLiteralDatatype();
      if (dt != null && dt != XSDDatatype.XSDstring) {
        log.warn("Object to text query is not a string");
        return null;
      }

      String qs = o.getLiteralLexicalForm();
      return new StrMatch(null, qs, -1, 0);
    }

    List<Node> list = argObject.getArgList();
    if (list.size() == 0 || list.size() > 3)
      throw new TextIndexException("Change in object list size");

    Node predicate = null;
    String field = null; // Do not prepend the field name - rely on default field
    int idx = 0;
    Node x = list.get(0);
    // Property?
    if (x.isURI()) {
      predicate = x;
      idx++;
      if (idx >= list.size())
        throw new TextIndexException("Property specificed but no query string : " + list);
      x = list.get(idx);
      field = docDef.getField(predicate);
      if (field == null) {
        log.warn("Predicate not indexed: " + predicate);
        return null;
      }
    }

    // String!
    if (!x.isLiteral()) {
      if (executionTime) log.warn("Text query string is not a literal " + list);
      return null;
    }

    if (x.getLiteralDatatype() != null && !x.getLiteralDatatype().equals(XSDDatatype.XSDstring)) {
      log.warn("Text query is not a string " + list);
      return null;
    }
    String queryString = x.getLiteralLexicalForm();
    idx++;

    int limit = -1;
    float score = 0;

    if (idx < list.size()) {
      // Limit?
      x = list.get(idx);
      idx++;
      if (!x.isLiteral()) {
        if (executionTime) log.warn("Text query limit is not an integer " + x);
        return null;
      }

      int v = NodeFactoryExtra.nodeToInt(x);
      limit = (v < 0) ? -1 : v;
    }

    String qs = queryString;
    if (field != null) qs = field + ":" + qs;

    return new StrMatch(predicate, qs, limit, score);
  }

  class StrMatch {
    private final Node property;
    private final String queryString;
    private final int limit;
    private final float scoreLimit;

    public StrMatch(Node property, String queryString, int limit, float scoreLimit) {
      super();
      this.property = property;
      this.queryString = queryString;
      this.limit = limit;
      this.scoreLimit = scoreLimit;
    }

    public Node getProperty() {
      return property;
    }

    public String getQueryString() {
      return queryString;
    }

    public int getLimit() {
      return limit;
    }

    public float getScoreLimit() {
      return scoreLimit;
    }
  }
}
Ejemplo n.º 2
0
public class SpatialQuery {
  private static volatile boolean initialized = false;
  private static Object lock = new Object();

  public static String NS = "http://jena.apache.org/spatial#";
  public static String IRI = "http://jena.apache.org/#spatial";
  public static final Symbol spatialIndex = Symbol.create(NS + "index");
  public static final String PATH = "org.apache.jena.query.spatial";

  private static String metadataLocation = "org/apache/jena/query/spatial/properties.xml";
  private static Metadata metadata = new Metadata(metadataLocation);
  public static final String NAME = "ARQ Spatial Query";

  public static final String VERSION = metadata.get(PATH + ".version", "unknown");
  public static final String BUILD_DATE = metadata.get(PATH + ".build.datetime", "unset");

  public static SpatialContext ctx = SpatialContext.GEO;

  // an optional feature for WKT literals, loaded when necessary, but not required
  public static final String JTS_SPATIAL_CONTEXT_FACTORY_CLASS =
      "com.spatial4j.core.context.jts.JtsSpatialContextFactory";

  static {
    JenaSystem.init();
  }

  public static void init() {
    if (initialized) return;
    synchronized (lock) {
      if (initialized) {
        JenaSystem.logLifecycle("SpatialQuery.init - skip");
        return;
      }
      initialized = true;
      JenaSystem.logLifecycle("SpatialQuery.init - start");

      SpatialAssembler.init();

      SystemInfo sysInfo = new SystemInfo(IRI, PATH, VERSION, BUILD_DATE);
      SystemARQ.registerSubSystem(sysInfo);

      PropertyFunctionRegistry.get()
          .put(
              "http://jena.apache.org/spatial#withinCircle",
              new PropertyFunctionFactory() {
                @Override
                public PropertyFunction create(String uri) {
                  return new IsWithinCirclePF();
                }
              });
      PropertyFunctionRegistry.get()
          .put(
              "http://jena.apache.org/spatial#nearby",
              new PropertyFunctionFactory() {
                @Override
                public PropertyFunction create(String uri) {
                  return new IsNearByPF();
                }
              });

      PropertyFunctionRegistry.get()
          .put(
              "http://jena.apache.org/spatial#withinBox",
              new PropertyFunctionFactory() {
                @Override
                public PropertyFunction create(String uri) {
                  return new IsWithinBoxPF();
                }
              });

      PropertyFunctionRegistry.get()
          .put(
              "http://jena.apache.org/spatial#intersectBox",
              new PropertyFunctionFactory() {
                @Override
                public PropertyFunction create(String uri) {
                  return new IntersectsBoxPF();
                }
              });

      PropertyFunctionRegistry.get()
          .put(
              "http://jena.apache.org/spatial#north",
              new PropertyFunctionFactory() {
                @Override
                public PropertyFunction create(String uri) {
                  return new NorthPF();
                }
              });

      PropertyFunctionRegistry.get()
          .put(
              "http://jena.apache.org/spatial#south",
              new PropertyFunctionFactory() {
                @Override
                public PropertyFunction create(String uri) {
                  return new SouthPF();
                }
              });

      PropertyFunctionRegistry.get()
          .put(
              "http://jena.apache.org/spatial#east",
              new PropertyFunctionFactory() {
                @Override
                public PropertyFunction create(String uri) {
                  return new EastPF();
                }
              });

      PropertyFunctionRegistry.get()
          .put(
              "http://jena.apache.org/spatial#west",
              new PropertyFunctionFactory() {
                @Override
                public PropertyFunction create(String uri) {
                  return new WestPF();
                }
              });

      JenaSystem.logLifecycle("SpatialQuery.init - finish");
    }
  }
}