Refactoring of Module Loading API (#211)

* Refactored the module loading and data binding layers of the library. The result is a much cleaner API that should perform better overall, due to shorter code paths. This version is much more expansible and enabled dynamic compilation of module classes to be disabled by default. 
* Added a builder pattern to use in creating an IBindingContext with common options.
* Reformatted code.

cli-processor/pom.xml

@@ -3,7 +3,7 @@
 	<parent>
 		<groupId>dev.metaschema.java</groupId>
 		<artifactId>metaschema-framework</artifactId>
-		<version>1.3.0-SNAPSHOT</version>
+		<version>2.0.0-SNAPSHOT</version>
 	</parent>
 
 	<artifactId>cli-processor</artifactId>

core/pom.xml

@@ -4,7 +4,7 @@
     <parent>
 		<groupId>dev.metaschema.java</groupId>
         <artifactId>metaschema-framework</artifactId>
-        <version>1.3.0-SNAPSHOT</version>
+        <version>2.0.0-SNAPSHOT</version>
     </parent>
 
     <artifactId>metaschema-core</artifactId>
@@ -109,6 +109,10 @@
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-text</artifactId>
         </dependency>
+        <dependency>
+		    <groupId>com.github.ben-manes.caffeine</groupId>
+		    <artifactId>caffeine</artifactId>
+		</dependency>
         <dependency>
             <groupId>org.apache.logging.log4j</groupId>
             <artifactId>log4j-api</artifactId>

core/src/main/java/gov/nist/secauto/metaschema/core/datatype/AbstractDataTypeProvider.java

@@ -8,6 +8,7 @@
 import gov.nist.secauto.metaschema.core.datatype.adapter.MetaschemaDataTypeProvider;
 import gov.nist.secauto.metaschema.core.util.CollectionUtil;
 
+import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.concurrent.locks.Lock;
@@ -32,9 +33,10 @@ public abstract class AbstractDataTypeProvider implements IDataTypeProvider {
   @Override
   public List<? extends IDataTypeAdapter<?>> getJavaTypeAdapters() {
     Lock readLock = libraryLock.readLock();
+    readLock.lock();
     try {
-      readLock.lock();
-      return CollectionUtil.unmodifiableList(library);
+      // make a defensive copy to protect callers from potential modifications
+      return CollectionUtil.unmodifiableList(new ArrayList<>(library));
     } finally {
       readLock.unlock();
     }
@@ -53,8 +55,8 @@ protected void registerDatatype(@NonNull IDataTypeAdapter<?> adapter) {
       throw new IllegalArgumentException("The adapter has no name: " + adapter.getClass().getName());
     }
     Lock writeLock = libraryLock.writeLock();
+    writeLock.lock();
     try {
-      writeLock.lock();
       library.add(adapter);
     } finally {
       writeLock.unlock();

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/DynamicContext.java

@@ -5,6 +5,8 @@
 
 package gov.nist.secauto.metaschema.core.metapath;
 
+import com.github.benmanes.caffeine.cache.Caffeine;
+
 import gov.nist.secauto.metaschema.core.configuration.DefaultConfiguration;
 import gov.nist.secauto.metaschema.core.configuration.IConfiguration;
 import gov.nist.secauto.metaschema.core.configuration.IMutableConfiguration;
@@ -23,6 +25,7 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
 
 import javax.xml.namespace.QName;
 
@@ -87,7 +90,10 @@ public SharedState(@NonNull StaticContext staticContext) {
       this.implicitTimeZone = ObjectUtils.notNull(clock.getZone());
       this.currentDateTime = ObjectUtils.notNull(ZonedDateTime.now(clock));
       this.availableDocuments = new HashMap<>();
-      this.functionResultCache = new HashMap<>();
+      this.functionResultCache = ObjectUtils.notNull(Caffeine.newBuilder()
+          .maximumSize(5000)
+          .expireAfterAccess(10, TimeUnit.MINUTES)
+          .<CallingContext, ISequence<?>>build().asMap());
       this.configuration = new DefaultConfiguration<>();
       this.configuration.enableFeature(MetapathEvaluationFeature.METAPATH_EVALUATE_PREDICATES);
     }

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/FunctionLibrary.java

@@ -46,8 +46,8 @@ private void registerFunctionByQName(@NonNull IFunction function) {
     QName qname = function.getQName();
     IFunction duplicate;
     Lock writeLock = instanceLock.writeLock();
+    writeLock.lock();
     try {
-      writeLock.lock();
       NamedFunctionSet functions = libraryByQName.get(qname);
       if (functions == null) {
         functions = new NamedFunctionSet();
@@ -66,8 +66,8 @@ private void registerFunctionByQName(@NonNull IFunction function) {
   private void registerFunctionByName(@NonNull IFunction function) {
     String name = function.getName();
     Lock writeLock = instanceLock.writeLock();
+    writeLock.lock();
     try {
-      writeLock.lock();
       NamedFunctionSet functions = libraryByName.get(name);
       if (functions == null) {
         functions = new NamedFunctionSet();
@@ -83,8 +83,8 @@ private void registerFunctionByName(@NonNull IFunction function) {
   @Override
   public Stream<IFunction> stream() {
     Lock readLock = instanceLock.readLock();
+    readLock.lock();
     try {
-      readLock.lock();
       return ObjectUtils.notNull(libraryByQName.values().stream().flatMap(NamedFunctionSet::getFunctionsAsStream));
     } finally {
       readLock.unlock();
@@ -95,8 +95,8 @@ public Stream<IFunction> stream() {
   public IFunction getFunction(@NonNull String name, int arity) {
     IFunction retval = null;
     Lock readLock = instanceLock.readLock();
+    readLock.lock();
     try {
-      readLock.lock();
       NamedFunctionSet functions = libraryByName.get(name);
       if (functions != null) {
         retval = functions.getFunctionWithArity(arity);
@@ -111,8 +111,8 @@ public IFunction getFunction(@NonNull String name, int arity) {
   public IFunction getFunction(@NonNull QName name, int arity) {
     IFunction retval = null;
     Lock readLock = instanceLock.readLock();
+    readLock.lock();
     try {
-      readLock.lock();
       NamedFunctionSet functions = libraryByQName.get(name);
       if (functions != null) {
         retval = functions.getFunctionWithArity(arity);

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/DefaultFunctionLibrary.java

@@ -22,12 +22,15 @@
 import gov.nist.secauto.metaschema.core.metapath.item.atomic.IPositiveIntegerItem;
 import gov.nist.secauto.metaschema.core.metapath.item.atomic.IStringItem;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
 /**
  * Provides built-in Metapath functions based on the XPath 3.1
  * <a href= "https://www.w3.org/TR/xpath-functions-31/">function
  * specification</a>.
  */
 @SuppressWarnings({ "removal" })
+@SuppressFBWarnings("UWF_UNWRITTEN_FIELD")
 @AutoService(IFunctionLibrary.class)
 public class DefaultFunctionLibrary
     extends FunctionLibrary {

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/FnLowerCase.java

@@ -11,14 +11,12 @@
 import gov.nist.secauto.metaschema.core.metapath.function.FunctionUtils;
 import gov.nist.secauto.metaschema.core.metapath.function.IArgument;
 import gov.nist.secauto.metaschema.core.metapath.function.IFunction;
-import gov.nist.secauto.metaschema.core.metapath.function.InvalidTypeFunctionException;
 import gov.nist.secauto.metaschema.core.metapath.item.IItem;
-import gov.nist.secauto.metaschema.core.metapath.item.atomic.IAnyAtomicItem;
-import gov.nist.secauto.metaschema.core.metapath.item.atomic.IIntegerItem;
 import gov.nist.secauto.metaschema.core.metapath.item.atomic.IStringItem;
-import gov.nist.secauto.metaschema.core.metapath.item.node.INodeItem;
+import gov.nist.secauto.metaschema.core.util.ObjectUtils;
 
 import java.util.List;
+import java.util.Locale;
 
 import edu.umd.cs.findbugs.annotations.NonNull;
 
@@ -57,13 +55,11 @@ private static ISequence<IStringItem> executeOneArg(@NonNull IFunction function,
       @NonNull List<ISequence<?>> arguments, @NonNull DynamicContext dynamicContext, IItem focus) {
 
     // From the XPath 3.1 specification:
-    // If the value of $arg is the empty sequence, the zero-length string is returned.
-    if (arguments.get(0).size() == 0) {
-      return ISequence.of(IStringItem.valueOf(""));
-    }
-
-    IStringItem arg = FunctionUtils.asTypeOrNull(arguments.get(0).getFirstItem(true));
-    return ISequence.of(fnLowerCase(arg));
+    // If the value of $arg is the empty sequence, the zero-length string is
+    // returned.
+    return ISequence.of(arguments.get(0).isEmpty()
+        ? IStringItem.valueOf("")
+        : fnLowerCase(FunctionUtils.asType(ObjectUtils.notNull(arguments.get(0).getFirstItem(true)))));
   }
 
   /**
@@ -76,6 +72,6 @@ private static ISequence<IStringItem> executeOneArg(@NonNull IFunction function,
    */
   @NonNull
   public static IStringItem fnLowerCase(@NonNull IStringItem arg) {
-    return IStringItem.valueOf(arg.toString().toLowerCase());
+    return IStringItem.valueOf(ObjectUtils.notNull(arg.toString().toLowerCase(Locale.ROOT)));
   }
 }

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/FnStringLength.java

@@ -83,9 +83,9 @@ private static ISequence<IIntegerItem> executeOneArg(
     // If the value of $arg is the empty sequence, the function returns the
     // xs:integer value zero (0).
     IStringItem arg = FunctionUtils.asTypeOrNull(arguments.get(0).getFirstItem(true));
-    return arg == null
-        ? ISequence.of(IIntegerItem.ZERO)
-        : ISequence.of(fnStringLength(arg));
+    return ISequence.of(arg == null
+        ? IIntegerItem.ZERO
+        : fnStringLength(arg));
   }
 
   /**

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/FnSubstringAfter.java

@@ -20,8 +20,8 @@
 import java.util.List;
 
 import edu.umd.cs.findbugs.annotations.NonNull;
-// CPD-OFF
 
+// CPD-OFF
 /**
  * Implements the XPath 3.1 <a href=
  * "https://www.w3.org/TR/xpath-functions-31/#func-substring-after">fn:substring-after</a>

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/FnSubstringBefore.java

@@ -20,8 +20,8 @@
 import java.util.List;
 
 import edu.umd.cs.findbugs.annotations.NonNull;
-// CPD-OFF
 
+// CPD-OFF
 /**
  * Implements the XPath 3.1 <a href=
  * "https://www.w3.org/TR/xpath-functions-31/#func-substring-before">fn:substring-before</a>

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/FnUpperCase.java

@@ -11,14 +11,12 @@
 import gov.nist.secauto.metaschema.core.metapath.function.FunctionUtils;
 import gov.nist.secauto.metaschema.core.metapath.function.IArgument;
 import gov.nist.secauto.metaschema.core.metapath.function.IFunction;
-import gov.nist.secauto.metaschema.core.metapath.function.InvalidTypeFunctionException;
 import gov.nist.secauto.metaschema.core.metapath.item.IItem;
-import gov.nist.secauto.metaschema.core.metapath.item.atomic.IAnyAtomicItem;
-import gov.nist.secauto.metaschema.core.metapath.item.atomic.IIntegerItem;
 import gov.nist.secauto.metaschema.core.metapath.item.atomic.IStringItem;
-import gov.nist.secauto.metaschema.core.metapath.item.node.INodeItem;
+import gov.nist.secauto.metaschema.core.util.ObjectUtils;
 
 import java.util.List;
+import java.util.Locale;
 
 import edu.umd.cs.findbugs.annotations.NonNull;
 
@@ -57,13 +55,12 @@ private static ISequence<IStringItem> executeOneArg(@NonNull IFunction function,
       @NonNull List<ISequence<?>> arguments, @NonNull DynamicContext dynamicContext, IItem focus) {
 
     // From the XPath 3.1 specification:
-    // If the value of $arg is the empty sequence, the zero-length string is returned.
-    if (arguments.get(0).size() == 0) {
-      return ISequence.of(IStringItem.valueOf(""));
-    }
+    // If the value of $arg is the empty sequence, the zero-length string is
+    // returned.
+    return ISequence.of(arguments.get(0).isEmpty()
+        ? IStringItem.valueOf("")
+        : fnUpperCase(FunctionUtils.asType(ObjectUtils.notNull(arguments.get(0).getFirstItem(true)))));
 
-    IStringItem arg = FunctionUtils.asTypeOrNull(arguments.get(0).getFirstItem(true));
-    return ISequence.of(fnUpperCase(arg));
   }
 
   /**
@@ -76,6 +73,6 @@ private static ISequence<IStringItem> executeOneArg(@NonNull IFunction function,
    */
   @NonNull
   public static IStringItem fnUpperCase(@NonNull IStringItem arg) {
-    return IStringItem.valueOf(arg.toString().toUpperCase());
+    return IStringItem.valueOf(ObjectUtils.notNull(arg.toString().toUpperCase(Locale.ROOT)));
   }
 }

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/MapEntry.java

@@ -61,8 +61,7 @@ private static <T extends ICollectionValue> ISequence<IMapItem<T>> execute(@NonN
       @NonNull DynamicContext dynamicContext,
       IItem focus) {
     IAnyAtomicItem key = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(0).getFirstItem(true)));
-    @SuppressWarnings("unchecked")
-    T value = (T) arguments.get(1).toCollectionValue();
+    @SuppressWarnings("unchecked") T value = (T) arguments.get(1).toCollectionValue();
 
     return entry(key, value).asSequence();
   }

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/MapMerge.java

@@ -106,8 +106,7 @@ private enum Duplicates {
     private final CustomCollectors.DuplicateHandler<IMapKey, ICollectionValue> duplicateHander;
 
     static {
-      @SuppressWarnings("PMD.UseConcurrentHashMap")
-      Map<String, Duplicates> map = new HashMap<>();
+      @SuppressWarnings("PMD.UseConcurrentHashMap") Map<String, Duplicates> map = new HashMap<>();
       for (Duplicates value : values()) {
         map.put(value.getName(), value);
       }

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/MapPut.java

@@ -70,8 +70,7 @@ private static <V extends ICollectionValue> ISequence<?> execute(@NonNull IFunct
       IItem focus) {
     IMapItem<V> map = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(0).getFirstItem(true)));
     IAnyAtomicItem key = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(1).getFirstItem(true)));
-    @SuppressWarnings("unchecked")
-    V value = (V) ObjectUtils.requireNonNull(arguments.get(2)).toCollectionValue();
+    @SuppressWarnings("unchecked") V value = (V) ObjectUtils.requireNonNull(arguments.get(2)).toCollectionValue();
 
     return put(map, key, value).asSequence();
   }
@@ -95,8 +94,7 @@ public static <V extends ICollectionValue> IMapItem<V> put(
       @NonNull IMapItem<V> map,
       @NonNull IAnyAtomicItem key,
       @NonNull V value) {
-    @SuppressWarnings("PMD.UseConcurrentHashMap")
-    Map<IMapKey, V> copy = new HashMap<>(map);
+    @SuppressWarnings("PMD.UseConcurrentHashMap") Map<IMapKey, V> copy = new HashMap<>(map);
     copy.put(key.asMapKey(), value);
 
     return IMapItem.ofCollection(copy);

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/MpRecurseDepth.java

@@ -143,8 +143,7 @@ public static ISequence<INodeItem> recurseDepth(
 
     return ISequence.of(ObjectUtils.notNull(initialContext.stream()
         .flatMap(item -> {
-          @NonNull
-          ISequence<INodeItem> metapathResult = recursionMetapath.evaluate(item, dynamicContext);
+          @NonNull ISequence<INodeItem> metapathResult = recursionMetapath.evaluate(item, dynamicContext);
           // ensure this is list backed
           metapathResult.getValue();
 

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/package-info.java

@@ -8,8 +8,9 @@
  * functions that operate on an underlying XML document model (XDM) have been
  * adapted to work with an underlying Metaschema module-base model instead.
  * <p>
- * The {@link MpRecurseDepth} functions are new Metapath functions that are not
- * present in XPath 3.1.
+ * The
+ * {@link gov.nist.secauto.metaschema.core.metapath.function.library.MpRecurseDepth}
+ * functions are new Metapath functions that are not present in XPath 3.1.
  */
 
 package gov.nist.secauto.metaschema.core.metapath.function.library;

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/impl/StreamSequence.java

@@ -46,8 +46,8 @@ public StreamSequence(@NonNull Stream<ITEM> stream) {
 
   @Override
   public List<ITEM> getValue() {
+    instanceLock.lock();
     try {
-      instanceLock.lock();
       if (list == null) {
         list = stream().collect(Collectors.toUnmodifiableList());
       }
@@ -62,8 +62,8 @@ public List<ITEM> getValue() {
   public Stream<ITEM> stream() {
     @NonNull Stream<ITEM> retval;
     // Ensure thread safety and prevent multiple consumptions of the stream
+    instanceLock.lock();
     try {
-      instanceLock.lock();
       if (list == null) {
         if (stream == null) {
           throw new IllegalStateException("stream is already consumed");