Trim down PR apache#2506: Remove configuration and statistics

This commit removes the following components from the comprehensive PR apache#2506:
- CacheConfigurationResolver and related configuration classes
- CacheStatistics and related statistics tracking
- Cache configuration parsing and system property handling
- Factory methods from InputSource and InputLocation (merge methods)
- Complex object pooling configuration (keeping only Dependency pooling)

Remaining work:
- Fix compilation errors for missing interfaces
- Adapt to current master branch API structure
- Ensure all tests pass

This trimmed version keeps the core cache improvements while removing
the configuration complexity that's not needed for the 4.0.x branch.

Author: gnodet

api/maven-api-core/src/main/java/org/apache/maven/api/Constants.java

@@ -638,38 +638,6 @@ public final class Constants {
      */
     public static final String MAVEN_LOGGER_LOG_PREFIX = MAVEN_LOGGER_PREFIX + "log.";
 
-    /**
-     * User property key for cache configuration.
-     *
-     * @since 4.1.0
-     */
-    public static final String MAVEN_CACHE_CONFIG_PROPERTY = "maven.cache.config";
-
-    /**
-     * User property to enable cache statistics display at the end of the build.
-     * When set to true, detailed cache statistics including hit/miss ratios,
-     * request type breakdowns, and retention policy effectiveness will be displayed
-     * when the build completes.
-     *
-     * @since 4.1.0
-     */
-    @Config(type = "java.lang.Boolean", defaultValue = "false")
-    public static final String MAVEN_CACHE_STATS = "maven.cache.stats";
-
-    /**
-     * User property to configure separate reference types for cache keys and values.
-     * Format: "key:value" where key and value can be NONE, SOFT, WEAK, or HARD.
-     * Examples:
-     * - "HARD:SOFT" - Keep keys strongly referenced, allow values to be garbage collected under memory pressure
-     * - "WEAK:WEAK" - Allow both keys and values to be garbage collected aggressively
-     * - "SOFT:HARD" - Allow keys to be GC'd under memory pressure, keep values strongly referenced
-     *
-     * This enables fine-grained analysis of cache misses caused by key vs value evictions.
-     *
-     * @since 4.1.0
-     */
-    public static final String MAVEN_CACHE_KEY_VALUE_REFS = "maven.cache.keyValueRefs";
-
     /**
      * User property key for configuring which object types are pooled by ModelObjectProcessor.
      * Value should be a comma-separated list of simple class names (e.g., "Dependency,Plugin,Build").
@@ -680,24 +648,5 @@ public final class Constants {
     @Config(defaultValue = "Dependency")
     public static final String MAVEN_MODEL_PROCESSOR_POOLED_TYPES = "maven.model.processor.pooledTypes";
 
-    /**
-     * User property key for configuring the default reference type used by ModelObjectProcessor.
-     * Valid values are: "SOFT", "HARD", "WEAK", "NONE".
-     * Default is "HARD" for optimal performance.
-     *
-     * @since 4.1.0
-     */
-    @Config(defaultValue = "HARD")
-    public static final String MAVEN_MODEL_PROCESSOR_REFERENCE_TYPE = "maven.model.processor.referenceType";
-
-    /**
-     * User property key prefix for configuring per-object-type reference types.
-     * Format: maven.model.processor.referenceType.{ClassName} = {ReferenceType}
-     * Example: maven.model.processor.referenceType.Dependency = SOFT
-     *
-     * @since 4.1.0
-     */
-    public static final String MAVEN_MODEL_PROCESSOR_REFERENCE_TYPE_PREFIX = "maven.model.processor.referenceType.";
-
     private Constants() {}
 }

api/maven-api-model/src/main/java/org/apache/maven/api/model/InputLocation.java

@@ -78,75 +78,12 @@ public InputLocation(int lineNumber, int columnNumber, InputSource source, Map<O
         this.importedFrom = null;
     }
 
-    // Factory methods
-
-    public static InputLocation of() {
-        return EMPTY;
-    }
-
-    /**
-     * Creates a new InputLocation with the specified source.
-     * The created instance is processed through ModelObjectProcessor for optimization.
-     *
-     * @param source the input source
-     * @return a new InputLocation instance
-     */
-    public static InputLocation of(InputSource source) {
-        return ModelObjectProcessor.processObject(new InputLocation(source));
-    }
-
-    /**
-     * Creates a new InputLocation with the specified line and column numbers.
-     * The created instance is processed through ModelObjectProcessor for optimization.
-     *
-     * @param lineNumber the line number
-     * @param columnNumber the column number
-     * @return a new InputLocation instance
-     */
-    public static InputLocation of(int lineNumber, int columnNumber) {
-        return ModelObjectProcessor.processObject(new InputLocation(lineNumber, columnNumber));
-    }
-
-    /**
-     * Creates a new InputLocation with the specified line number, column number, and source.
-     * The created instance is processed through ModelObjectProcessor for optimization.
-     *
-     * @param lineNumber the line number
-     * @param columnNumber the column number
-     * @param source the input source
-     * @return a new InputLocation instance
-     */
-    public static InputLocation of(int lineNumber, int columnNumber, InputSource source) {
-        return ModelObjectProcessor.processObject(new InputLocation(lineNumber, columnNumber, source));
-    }
-
-    /**
-     * Creates a new InputLocation with the specified line number, column number, source, and self location key.
-     * The created instance is processed through ModelObjectProcessor for optimization.
-     *
-     * @param lineNumber the line number
-     * @param columnNumber the column number
-     * @param source the input source
-     * @param selfLocationKey the self location key
-     * @return a new InputLocation instance
-     */
-    public static InputLocation of(int lineNumber, int columnNumber, InputSource source, Object selfLocationKey) {
-        return ModelObjectProcessor.processObject(new InputLocation(lineNumber, columnNumber, source, selfLocationKey));
-    }
-
-    /**
-     * Creates a new InputLocation with the specified line number, column number, source, and locations map.
-     * The created instance is processed through ModelObjectProcessor for optimization.
-     *
-     * @param lineNumber the line number
-     * @param columnNumber the column number
-     * @param source the input source
-     * @param locations the locations map
-     * @return a new InputLocation instance
-     */
-    public static InputLocation of(
-            int lineNumber, int columnNumber, InputSource source, Map<Object, InputLocation> locations) {
-        return ModelObjectProcessor.processObject(new InputLocation(lineNumber, columnNumber, source, locations));
+    public InputLocation(InputLocation original) {
+        this.lineNumber = original.lineNumber;
+        this.columnNumber = original.columnNumber;
+        this.source = original.source;
+        this.locations = original.locations;
+        this.importedFrom = original.importedFrom;
     }
 
     public int getLineNumber() {
@@ -211,7 +148,7 @@ public static InputLocation merge(InputLocation target, InputLocation source, bo
         }
 
         return new InputLocation(-1, -1, InputSource.merge(source.getSource(), target.getSource()), locations);
-    } // -- InputLocation merge( InputLocation, InputLocation, boolean )
+    }
 
     /**
      * Merges the {@code source} location into the {@code target} location.
@@ -250,7 +187,7 @@ public static InputLocation merge(InputLocation target, InputLocation source, Co
         }
 
         return new InputLocation(-1, -1, InputSource.merge(source.getSource(), target.getSource()), locations);
-    } // -- InputLocation merge( InputLocation, InputLocation, java.util.Collection )
+    }
 
     @Override
     public boolean equals(Object o) {
@@ -331,6 +268,23 @@ public int safeHash(Map<Object, InputLocation> locations) {
         return result;
     }
 
+    /**
+     * Class StringFormatter.
+     *
+     * @version $Revision$ $Date$
+     */
+    public interface StringFormatter {
+
+        // -----------/
+        // - Methods -/
+        // -----------/
+
+        /**
+         * Method toString.
+         */
+        String toString(InputLocation location);
+    }
+
     @Override
     public String toString() {
         return String.format("%s @ %d:%d", source != null ? source.getLocation() : "n/a", lineNumber, columnNumber);

api/maven-api-model/src/main/java/org/apache/maven/api/model/InputSource.java

@@ -61,44 +61,6 @@ public InputSource(Collection<InputSource> inputs) {
         this.importedFrom = null;
     }
 
-    // Factory methods
-
-    /**
-     * Creates a new InputSource with the specified model ID and location.
-     * The created instance is processed through ModelObjectProcessor for optimization.
-     *
-     * @param modelId the model ID
-     * @param location the location
-     * @return a new InputSource instance
-     */
-    public static InputSource of(String modelId, String location) {
-        return ModelObjectProcessor.processObject(new InputSource(modelId, location));
-    }
-
-    /**
-     * Creates a new InputSource with the specified model ID, location, and imported from location.
-     * The created instance is processed through ModelObjectProcessor for optimization.
-     *
-     * @param modelId the model ID
-     * @param location the location
-     * @param importedFrom the imported from location
-     * @return a new InputSource instance
-     */
-    public static InputSource of(String modelId, String location, InputLocation importedFrom) {
-        return ModelObjectProcessor.processObject(new InputSource(modelId, location, importedFrom));
-    }
-
-    /**
-     * Creates a new InputSource from a collection of input sources.
-     * The created instance is processed through ModelObjectProcessor for optimization.
-     *
-     * @param inputs the collection of input sources
-     * @return a new InputSource instance
-     */
-    public static InputSource of(Collection<InputSource> inputs) {
-        return ModelObjectProcessor.processObject(new InputSource(inputs));
-    }
-
     /**
      * Get the path/URL of the POM or {@code null} if unknown.
      *
@@ -165,6 +127,13 @@ public String toString() {
         return getModelId() + " " + getLocation();
     }
 
+    /**
+     * Merges two InputSource instances.
+     *
+     * @param src1 the first input source
+     * @param src2 the second input source
+     * @return a new merged InputSource
+     */
     public static InputSource merge(InputSource src1, InputSource src2) {
         return new InputSource(
                 Stream.concat(src1.sources(), src2.sources()).distinct().toList());

compat/maven-compat/src/test/java/org/apache/maven/project/interpolation/StringSearchModelInterpolatorTest.java

@@ -32,7 +32,7 @@ class StringSearchModelInterpolatorTest {
     void interpolate() throws ModelInterpolationException, InitializationException {
         Model model = Model.newBuilder()
                 .groupId("group")
-                .location("groupId", InputLocation.of(InputSource.of("model", null)))
+                .location("groupId", new InputLocation(new InputSource("model", null)))
                 .build();
         StringSearchModelInterpolator interpolator = new StringSearchModelInterpolator();
         interpolator.initialize();

compat/maven-embedder/src/main/java/org/apache/maven/cli/MavenCli.java

@@ -860,7 +860,7 @@ private List<CoreExtension> readCoreExtensionsDescriptor(String extensionsFile)
             if (Files.exists(extensionsPath)) {
                 try (InputStream is = Files.newInputStream(extensionsPath)) {
                     return new CoreExtensionsStaxReader()
-                            .read(is, true, InputSource.of(extensionsFile))
+                            .read(is, true, new InputSource(extensionsFile))
                             .getExtensions();
                 }
             }

compat/maven-model/src/main/java/org/apache/maven/model/InputSource.java

@@ -181,6 +181,6 @@ public String toString() {
     }
 
     public org.apache.maven.api.model.InputSource toApiSource() {
-        return org.apache.maven.api.model.InputSource.of(modelId, location);
+        return new org.apache.maven.api.model.InputSource(modelId, location);
     }
 }

compat/maven-settings-builder/src/main/java/org/apache/maven/settings/io/DefaultSettingsReader.java

@@ -49,7 +49,7 @@ public Settings read(File input, Map<String, ?> options) throws IOException {
         Objects.requireNonNull(input, "input cannot be null");
 
         try (InputStream in = Files.newInputStream(input.toPath())) {
-            InputSource source = InputSource.of(input.toString());
+            InputSource source = new InputSource(input.toString());
             return new Settings(new SettingsStaxReader().read(in, isStrict(options), source));
         } catch (XMLStreamException e) {
             throw new SettingsParseException(

compat/maven-toolchain-builder/src/main/java/org/apache/maven/toolchain/io/DefaultToolchainsReader.java

@@ -50,7 +50,7 @@ public PersistedToolchains read(File input, Map<String, ?> options) throws IOExc
         Objects.requireNonNull(input, "input cannot be null");
 
         try (InputStream in = Files.newInputStream(input.toPath())) {
-            InputSource source = InputSource.of(input.toString());
+            InputSource source = new InputSource(input.toString());
             return new PersistedToolchains(new MavenToolchainsStaxReader().read(in, isStrict(options), source));
         } catch (XMLStreamException e) {
             throw new ToolchainsParseException(

impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/BaseParser.java

@@ -518,7 +518,7 @@ protected List<CoreExtension> readCoreExtensionsDescriptorFromFile(Path extensio
                     return validateCoreExtensionsDescriptorFromFile(
                             extensionsFile,
                             List.copyOf(new CoreExtensionsStaxReader()
-                                    .read(is, true, InputSource.of(extensionsFile.toString()))
+                                    .read(is, true, new InputSource(extensionsFile.toString()))
                                     .getExtensions()));
                 }
             }

impl/maven-core/src/main/java/org/apache/maven/internal/impl/DefaultLifecycleRegistry.java

@@ -92,7 +92,7 @@ public class DefaultLifecycleRegistry implements LifecycleRegistry {
             + ":default-lifecycle-bindings";
 
     public static final InputLocation DEFAULT_LIFECYCLE_INPUT_LOCATION =
-            InputLocation.of(InputSource.of(DEFAULT_LIFECYCLE_MODELID, null));
+            new InputLocation(new InputSource(DEFAULT_LIFECYCLE_MODELID, null));
 
     public static final String SCOPE_COMPILE = DependencyScope.COMPILE.id();
     public static final String SCOPE_RUNTIME = DependencyScope.RUNTIME.id();