| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.tinkerpop.gremlin.process.traversal.step.util; |
| |
| import org.apache.commons.lang3.ArrayUtils; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.Scoping; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.TraversalParent; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalUtil; |
| import org.apache.tinkerpop.gremlin.structure.Element; |
| import org.apache.tinkerpop.gremlin.structure.T; |
| import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils; |
| |
| import java.io.Serializable; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.function.Supplier; |
| |
| /** |
| * The parameters held by a {@link Traversal}. |
| * |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| * @author Stephen Mallette (http://stephen.genoprime.com) |
| */ |
| public final class Parameters implements Cloneable, Serializable { |
| |
| public static final Parameters EMPTY = new Parameters(); |
| |
| private static final Object[] EMPTY_ARRAY = new Object[0]; |
| |
| private Map<Object, List<Object>> parameters = new HashMap<>(); |
| private Set<String> referencedLabels = new HashSet<>(); |
| |
| /** |
| * A cached list of traversals that serve as parameter values. The list is cached on calls to |
| * {@link #set(TraversalParent, Object...)} because when the parameter map is large the cost of iterating it repeatedly on the |
| * high number of calls to {@link #getTraversals()} is great. |
| */ |
| private List<Traversal.Admin<?, ?>> traversals = new ArrayList<>(); |
| |
| /** |
| * Checks for existence of key in parameter set. |
| * |
| * @param key the key to check |
| * @return {@code true} if the key is present and {@code false} otherwise |
| */ |
| public boolean contains(final Object key) { |
| return this.parameters.containsKey(key); |
| } |
| |
| /** |
| * Renames a key in the parameter set. |
| * |
| * @param oldKey the key to rename |
| * @param newKey the new name of the key |
| */ |
| public void rename(final Object oldKey, final Object newKey) { |
| this.parameters.put(newKey, this.parameters.remove(oldKey)); |
| } |
| |
| /** |
| * Gets the list of values for a key, while resolving the values of any parameters that are {@link Traversal} |
| * objects. |
| */ |
| public <S, E> List<E> get(final Traverser.Admin<S> traverser, final Object key, final Supplier<E> defaultValue) { |
| final List<E> values = (List<E>) this.parameters.get(key); |
| if (null == values) return Collections.singletonList(defaultValue.get()); |
| final List<E> result = new ArrayList<>(); |
| for (final Object value : values) { |
| result.add(value instanceof Traversal.Admin ? TraversalUtil.apply(traverser, (Traversal.Admin<S, E>) value) : (E) value); |
| } |
| return result; |
| } |
| |
| /** |
| * Gets the value of a key and if that key isn't present returns the default value from the {@link Supplier}. |
| * |
| * @param key the key to retrieve |
| * @param defaultValue the default value generator which if null will return an empty list |
| */ |
| public <E> List<E> get(final Object key, final Supplier<E> defaultValue) { |
| final List<E> list = (List<E>) this.parameters.get(key); |
| return (null == list) ? (null == defaultValue ? Collections.emptyList() : Collections.singletonList(defaultValue.get())) : list; |
| |
| } |
| |
| /** |
| * Remove a key from the parameter set. |
| * |
| * @param key the key to remove |
| * @return the value of the removed key |
| */ |
| public Object remove(final Object key) { |
| final List<Object> o = parameters.remove(key); |
| |
| // once a key is removed, it's possible that the traversal/label cache will need to be regenerated |
| if (IteratorUtils.anyMatch(o.iterator(), p -> p instanceof Traversal.Admin)) { |
| traversals.clear(); |
| traversals = new ArrayList<>(); |
| for (final List<Object> list : this.parameters.values()) { |
| for (final Object object : list) { |
| if (object instanceof Traversal.Admin) { |
| final Traversal.Admin t = (Traversal.Admin) object; |
| addTraversal(t); |
| } |
| } |
| } |
| } |
| |
| return o; |
| } |
| |
| /** |
| * Gets the array of keys/values of the parameters while resolving parameter values that contain |
| * {@link Traversal} instances. |
| */ |
| public <S> Object[] getKeyValues(final Traverser.Admin<S> traverser, final Object... exceptKeys) { |
| if (this.parameters.isEmpty()) return EMPTY_ARRAY; |
| final List<Object> keyValues = new ArrayList<>(); |
| for (final Map.Entry<Object, List<Object>> entry : this.parameters.entrySet()) { |
| if (!ArrayUtils.contains(exceptKeys, entry.getKey())) { |
| for (final Object value : entry.getValue()) { |
| keyValues.add(entry.getKey() instanceof Traversal.Admin ? TraversalUtil.apply(traverser, (Traversal.Admin<S, ?>) entry.getKey()) : entry.getKey()); |
| keyValues.add(value instanceof Traversal.Admin ? TraversalUtil.apply(traverser, (Traversal.Admin<S, ?>) value) : value); |
| } |
| } |
| } |
| return keyValues.toArray(new Object[keyValues.size()]); |
| } |
| |
| /** |
| * Gets an immutable set of the parameters without evaluating them in the context of a {@link Traverser} as |
| * is done in {@link #getKeyValues(Traverser.Admin, Object...)}. |
| * |
| * @param exceptKeys keys to not include in the returned {@link Map} |
| */ |
| public Map<Object, List<Object>> getRaw(final Object... exceptKeys) { |
| if (parameters.isEmpty()) return Collections.emptyMap(); |
| final List<Object> exceptions = Arrays.asList(exceptKeys); |
| final Map<Object, List<Object>> raw = new HashMap<>(); |
| for (Map.Entry<Object, List<Object>> entry : parameters.entrySet()) { |
| if (!exceptions.contains(entry.getKey())) raw.put(entry.getKey(), entry.getValue()); |
| } |
| |
| return Collections.unmodifiableMap(raw); |
| } |
| |
| /** |
| * Set parameters given key/value pairs. |
| */ |
| public void set(final TraversalParent parent, final Object... keyValues) { |
| if (keyValues.length % 2 != 0) |
| throw Element.Exceptions.providedKeyValuesMustBeAMultipleOfTwo(); |
| |
| for (int ix = 0; ix < keyValues.length; ix = ix + 2) { |
| if (!(keyValues[ix] instanceof String) && !(keyValues[ix] instanceof T) && !(keyValues[ix] instanceof Traversal)) |
| throw new IllegalArgumentException("The provided key/value array must have a String, T, or Traversal on even array indices"); |
| |
| if (keyValues[ix + 1] != null) { |
| |
| // check both key and value for traversal instances. track the list of traversals that are present so |
| // that elsewhere in Parameters there is no need to iterate all values to not find any. also grab |
| // available labels in traversal values |
| for (int iy = 0; iy < 2; iy++) { |
| if (keyValues[ix + iy] instanceof Traversal.Admin) { |
| final Traversal.Admin t = (Traversal.Admin) keyValues[ix + iy]; |
| addTraversal(t); |
| if (parent != null) parent.integrateChild(t); |
| } |
| } |
| |
| List<Object> values = this.parameters.get(keyValues[ix]); |
| if (null == values) { |
| values = new ArrayList<>(); |
| values.add(keyValues[ix + 1]); |
| this.parameters.put(keyValues[ix], values); |
| } else { |
| values.add(keyValues[ix + 1]); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Gets all the {@link Traversal.Admin} objects in the map of parameters. |
| */ |
| public <S, E> List<Traversal.Admin<S, E>> getTraversals() { |
| // stupid generics - just need to return "traversals" |
| return (List<Traversal.Admin<S, E>>) (Object) this.traversals; |
| } |
| |
| /** |
| * Gets a list of all labels held in parameters that have a traversal as a value. |
| */ |
| public Set<String> getReferencedLabels() { |
| return referencedLabels; |
| } |
| |
| public Parameters clone() { |
| try { |
| final Parameters clone = (Parameters) super.clone(); |
| clone.parameters = new HashMap<>(); |
| clone.traversals = new ArrayList<>(); |
| for (final Map.Entry<Object, List<Object>> entry : this.parameters.entrySet()) { |
| final List<Object> values = new ArrayList<>(); |
| for (final Object value : entry.getValue()) { |
| if (value instanceof Traversal.Admin) { |
| final Traversal.Admin<?, ?> traversalClone = ((Traversal.Admin) value).clone(); |
| clone.traversals.add(traversalClone); |
| values.add(traversalClone); |
| } else |
| values.add(value); |
| } |
| if (entry.getKey() instanceof Traversal.Admin) { |
| final Traversal.Admin<?, ?> traversalClone = ((Traversal.Admin) entry.getKey()).clone(); |
| clone.traversals.add(traversalClone); |
| clone.parameters.put(traversalClone, values); |
| } else |
| clone.parameters.put(entry.getKey(), values); |
| } |
| clone.referencedLabels = new HashSet<>(this.referencedLabels); |
| return clone; |
| } catch (final CloneNotSupportedException e) { |
| throw new IllegalStateException(e.getMessage(), e); |
| } |
| } |
| |
| public int hashCode() { |
| int result = 1; |
| for (final Map.Entry<Object, List<Object>> entry : this.parameters.entrySet()) { |
| result ^= entry.getKey().hashCode(); |
| for (final Object value : entry.getValue()) { |
| result ^= Integer.rotateLeft(value.hashCode(), entry.getKey().hashCode()); |
| } |
| } |
| return result; |
| } |
| |
| public String toString() { |
| return this.parameters.toString(); |
| } |
| |
| private void addTraversal(final Traversal.Admin t) { |
| this.traversals.add(t); |
| for (final Object ss : t.getSteps()) { |
| if (ss instanceof Scoping) { |
| for (String label : ((Scoping) ss).getScopeKeys()) { |
| this.referencedLabels.add(label); |
| } |
| } |
| } |
| } |
| } |