001/*
002 * Portions of this software was developed by employees of the National Institute
003 * of Standards and Technology (NIST), an agency of the Federal Government and is
004 * being made available as a public service. Pursuant to title 17 United States
005 * Code Section 105, works of NIST employees are not subject to copyright
006 * protection in the United States. This software may be subject to foreign
007 * copyright. Permission in the United States and in foreign countries, to the
008 * extent that NIST may hold copyright, to use, copy, modify, create derivative
009 * works, and distribute this software and its documentation without fee is hereby
010 * granted on a non-exclusive basis, provided that this notice and disclaimer
011 * of warranty appears in all copies.
012 *
013 * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
014 * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
015 * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
016 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
017 * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
018 * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
019 * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
020 * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
021 * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
022 * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
023 * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
024 * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
025 */
026
027package gov.nist.secauto.metaschema.core.metapath.function;
028
029import gov.nist.secauto.metaschema.core.metapath.IExpression;
030import gov.nist.secauto.metaschema.core.util.ObjectUtils;
031
032import java.util.HashMap;
033import java.util.List;
034import java.util.Map;
035import java.util.stream.Stream;
036
037import javax.xml.namespace.QName;
038
039import edu.umd.cs.findbugs.annotations.NonNull;
040import edu.umd.cs.findbugs.annotations.Nullable;
041
042public class FunctionLibrary implements IFunctionLibrary {
043
044  @NonNull
045  private final Map<QName, NamedFunctionSet> libraryByQName = new HashMap<>(); // NOPMD - intentional
046  @NonNull
047  private final Map<String, NamedFunctionSet> libraryByName = new HashMap<>(); // NOPMD - intentional
048
049  /**
050   * Register the provided function signature.
051   *
052   * @param function
053   *          the function signature to register
054   * @throws IllegalArgumentException
055   *           if the provided function has the same arity as a previously
056   *           registered function with the same name
057   */
058  public void registerFunction(@NonNull IFunction function) {
059    registerFunctionByQName(function);
060    registerFunctionByName(function);
061  }
062
063  protected void registerFunctionByQName(@NonNull IFunction function) {
064    QName qname = function.getQName();
065    IFunction duplicate;
066    synchronized (this) {
067      NamedFunctionSet functions = libraryByQName.get(qname);
068      if (functions == null) {
069        functions = new NamedFunctionSet();
070        libraryByQName.put(qname, functions);
071      }
072      duplicate = functions.addFunction(function);
073    }
074    if (duplicate != null) {
075      throw new IllegalArgumentException(String.format("Duplicate functions with same arity: %s shadows %s",
076          duplicate.toSignature(), function.toSignature()));
077    }
078  }
079
080  protected void registerFunctionByName(@NonNull IFunction function) {
081    String name = function.getName();
082    synchronized (this) {
083      NamedFunctionSet functions = libraryByName.get(name);
084      if (functions == null) {
085        functions = new NamedFunctionSet();
086        libraryByName.put(name, functions);
087      }
088      // replace duplicates
089      functions.addFunction(function);
090    }
091  }
092
093  @Override
094  public Stream<IFunction> getFunctionsAsStream() {
095    synchronized (this) {
096      return ObjectUtils.notNull(
097          libraryByQName.values().stream().flatMap(set -> {
098            return set.getFunctionsAsStream();
099          }));
100    }
101  }
102
103  @Override
104  public IFunction getFunction(@NonNull String name, @NonNull List<IExpression> args) {
105    IFunction retval;
106    synchronized (this) {
107      NamedFunctionSet functions = libraryByName.get(name);
108      retval = functions == null ? null : functions.getFunctionWithArity(args.size());
109    }
110    return retval;
111  }
112
113  @Override
114  public IFunction getFunction(@NonNull QName name, @NonNull List<IExpression> args) {
115    IFunction retval;
116    synchronized (this) {
117      NamedFunctionSet functions = libraryByQName.get(name);
118      retval = functions == null ? null : functions.getFunctionWithArity(args.size());
119    }
120    return retval;
121  }
122
123  private static class NamedFunctionSet {
124    private final Map<Integer, IFunction> arityToFunctionMap;
125
126    public NamedFunctionSet() {
127      this.arityToFunctionMap = new HashMap<>();
128    }
129
130    @SuppressWarnings("null")
131    @NonNull
132    public Stream<IFunction> getFunctionsAsStream() {
133      return arityToFunctionMap.values().stream();
134    }
135
136    @Nullable
137    public IFunction getFunctionWithArity(int arity) {
138      return arityToFunctionMap.get(arity);
139    }
140
141    @Nullable
142    public IFunction addFunction(@NonNull IFunction function) {
143      return arityToFunctionMap.put(function.arity(), function);
144    }
145  }
146}