Convert IOContext, MergeInfo, and FlushInfo to record classes (#13205)

dev-tools/missing-doclet/build.gradle

@@ -23,8 +23,8 @@ version = "1.0.0-SNAPSHOT"
 group = "org.apache.lucene.tools"
 description = 'Doclet-based javadoc validation'
 
-sourceCompatibility = JavaVersion.VERSION_11
+sourceCompatibility = JavaVersion.VERSION_21
-targetCompatibility = JavaVersion.VERSION_11
+targetCompatibility = JavaVersion.VERSION_21
 
 tasks.withType(JavaCompile) {
   options.compilerArgs += ["--release", targetCompatibility.toString()]

dev-tools/missing-doclet/src/main/java/org/apache/lucene/missingdoclet/MissingDoclet.java

@@ -237,6 +237,7 @@ public class MissingDoclet extends StandardDoclet {
       case CLASS:
       case INTERFACE:
       case ENUM:
+      case RECORD:
       case ANNOTATION_TYPE:
         if (level(element) >= CLASS) {
           checkComment(element);

lucene/CHANGES.txt

@@ -87,6 +87,8 @@ API Changes
 * GITHUB#13146, GITHUB#13148: Remove ByteBufferIndexInput and only use MemorySegment APIs
   for MMapDirectory.  (Uwe Schindler)
 
+* GITHUB#13205: Convert IOContext, MergeInfo, and FlushInfo to record classes.  (Uwe Schindler)
+
 New Features
 ---------------------
 

lucene/MIGRATE.md

@@ -151,6 +151,15 @@ may throw `IOException` on index problems, bubbling up unexpectedly to the calle
 `(Reverse)PathHierarchyTokenizer` now produces sequential (instead of overlapping) tokens with accurate
 offsets, making positional queries and highlighters possible for fields tokenized with this tokenizer.
 
+### Some classes converted to records classes (GITHUB#13207)
+
+Some classes with only final fields and no programming logic were converted to `record` classes.
+Those changes are mostly compatible with Lucene 9.x code (constructors, accessor methods), but
+record's fields are only available with accessor methods. Some code may need to be refactored to
+access the members using method calls instead of field accesses. Affected classes:
+
+- `IOContext`, `MergeInfo`, and `FlushInfo` (GITHUB#13205)
+
 ## Migration from Lucene 9.0 to Lucene 9.1
 
 ### Test framework package migration and module (LUCENE-10301)

lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/VariableGapTermsIndexReader.java

@@ -27,7 +27,6 @@ import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.SegmentReadState;
-import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.Accountables;
@@ -54,7 +53,7 @@ public class VariableGapTermsIndexReader extends TermsIndexReaderBase {
             state.segmentInfo.name,
             state.segmentSuffix,
             VariableGapTermsIndexWriter.TERMS_INDEX_EXTENSION);
-    final IndexInput in = state.directory.openInput(fileName, new IOContext(state.context, true));
+    final IndexInput in = state.directory.openInput(fileName, state.context.toReadOnce());
     boolean success = false;
 
     try {

lucene/codecs/src/java/org/apache/lucene/codecs/memory/DirectPostingsFormat.java

@@ -103,7 +103,7 @@ public final class DirectPostingsFormat extends PostingsFormat {
   @Override
   public FieldsProducer fieldsProducer(SegmentReadState state) throws IOException {
     FieldsProducer postings = PostingsFormat.forName("Lucene99").fieldsProducer(state);
-    if (state.context.context != IOContext.Context.MERGE) {
+    if (state.context.context() != IOContext.Context.MERGE) {
       FieldsProducer loadedPostings;
       try {
         postings.checkIntegrity();

lucene/core/src/java/org/apache/lucene/index/ConcurrentMergeScheduler.java

@@ -296,7 +296,7 @@ public class ConcurrentMergeScheduler extends MergeScheduler {
         // This Directory is only supposed to be used during merging,
         // so all writes should have MERGE context, else there is a bug
         // somewhere that is failing to pass down the right IOContext:
-        assert context.context == IOContext.Context.MERGE : "got context=" + context.context;
+        assert context.context() == IOContext.Context.MERGE : "got context=" + context.context();
 
         return new RateLimitedIndexOutput(rateLimiter, in.createOutput(name, context));
       }

lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java

@@ -63,9 +63,9 @@ final class SegmentMerger {
       IOContext context,
       Executor intraMergeTaskExecutor)
       throws IOException {
-    if (context.context != IOContext.Context.MERGE) {
+    if (context.context() != IOContext.Context.MERGE) {
       throw new IllegalArgumentException(
-          "IOContext.context should be MERGE; got: " + context.context);
+          "IOContext.context should be MERGE; got: " + context.context());
     }
     mergeState = new MergeState(readers, segmentInfo, infoStream, intraMergeTaskExecutor);
     directory = dir;

lucene/core/src/java/org/apache/lucene/store/BufferedIndexInput.java

@@ -369,7 +369,7 @@ public abstract class BufferedIndexInput extends IndexInput implements RandomAcc
 
   /** Returns default buffer sizes for the given {@link IOContext} */
   public static int bufferSize(IOContext context) {
-    switch (context.context) {
+    switch (context.context()) {
       case MERGE:
         return MERGE_BUFFER_SIZE;
       case DEFAULT:

lucene/core/src/java/org/apache/lucene/store/FlushInfo.java

@@ -19,46 +19,7 @@ package org.apache.lucene.store;
 /**
  * A FlushInfo provides information required for a FLUSH context. It is used as part of an {@link
  * IOContext} in case of FLUSH context.
+ *
+ * <p>These values are only estimates and are not the actual values.
  */
-public class FlushInfo {
+public record FlushInfo(int numDocs, long estimatedSegmentSize) {}
-
-  public final int numDocs;
-
-  public final long estimatedSegmentSize;
-
-  /**
-   * Creates a new {@link FlushInfo} instance from the values required for a FLUSH {@link IOContext}
-   * context.
-   *
-   * <p>These values are only estimates and are not the actual values.
-   */
-  public FlushInfo(int numDocs, long estimatedSegmentSize) {
-    this.numDocs = numDocs;
-    this.estimatedSegmentSize = estimatedSegmentSize;
-  }
-
-  @Override
-  public int hashCode() {
-    final int prime = 31;
-    int result = 1;
-    result = prime * result + (int) (estimatedSegmentSize ^ (estimatedSegmentSize >>> 32));
-    result = prime * result + numDocs;
-    return result;
-  }
-
-  @Override
-  public boolean equals(Object obj) {
-    if (this == obj) return true;
-    if (obj == null) return false;
-    if (getClass() != obj.getClass()) return false;
-    FlushInfo other = (FlushInfo) obj;
-    if (estimatedSegmentSize != other.estimatedSegmentSize) return false;
-    if (numDocs != other.numDocs) return false;
-    return true;
-  }
-
-  @Override
-  public String toString() {
-    return "FlushInfo [numDocs=" + numDocs + ", estimatedSegmentSize=" + estimatedSegmentSize + "]";
-  }
-}

lucene/core/src/java/org/apache/lucene/store/IOContext.java

@@ -23,8 +23,26 @@ import java.util.Objects;
  * initialized as null as passed as a parameter to either {@link
  * org.apache.lucene.store.Directory#openInput(String, IOContext)} or {@link
  * org.apache.lucene.store.Directory#createOutput(String, IOContext)}
+ *
+ * @param context An object of a enumerator Context type
+ * @param mergeInfo must be given when {@code context == MERGE}
+ * @param flushInfo must be given when {@code context == FLUSH}
+ * @param readOnce This flag indicates that the file will be opened, then fully read sequentially
+ *     then closed.
+ * @param load This flag is used for files that are a small fraction of the total index size and are
+ *     expected to be heavily accessed in random-access fashion. Some {@link Directory}
+ *     implementations may choose to load such files into physical memory (e.g. Java heap) as a way
+ *     to provide stronger guarantees on query latency.
+ * @param randomAccess This flag indicates that the file will be accessed randomly. If this flag is
+ *     set, then readOnce will be false.
  */
-public class IOContext {
+public record IOContext(
+    Context context,
+    MergeInfo mergeInfo,
+    FlushInfo flushInfo,
+    boolean readOnce,
+    boolean load,
+    boolean randomAccess) {
 
   /**
    * Context is a enumerator which specifies the context in which the Directory is being used for.
@@ -36,30 +54,6 @@ public class IOContext {
     DEFAULT
   };
 
-  /** An object of a enumerator Context type */
-  public final Context context;
-
-  public final MergeInfo mergeInfo;
-
-  public final FlushInfo flushInfo;
-
-  /** This flag indicates that the file will be opened, then fully read sequentially then closed. */
-  public final boolean readOnce;
-
-  /**
-   * This flag indicates that the file will be accessed randomly. If this flag is set, then readOnce
-   * will be false.
-   */
-  public final boolean randomAccess;
-
-  /**
-   * This flag is used for files that are a small fraction of the total index size and are expected
-   * to be heavily accessed in random-access fashion. Some {@link Directory} implementations may
-   * choose to load such files into physical memory (e.g. Java heap) as a way to provide stronger
-   * guarantees on query latency. If this flag is set, then {@link #randomAccess} will be true.
-   */
-  public final boolean load;
-
   public static final IOContext DEFAULT = new IOContext(Context.DEFAULT);
 
   public static final IOContext READONCE = new IOContext(true, false, false);
@@ -70,106 +64,48 @@ public class IOContext {
 
   public static final IOContext RANDOM = new IOContext(false, false, true);
 
-  public IOContext() {
+  @SuppressWarnings("incomplete-switch")
-    this(false, false, false);
+  public IOContext {
-  }
+    switch (context) {
-
+      case MERGE -> Objects.requireNonNull(
-  public IOContext(FlushInfo flushInfo) {
+          mergeInfo, "mergeInfo must not be null if context is MERGE");
-    assert flushInfo != null;
+      case FLUSH -> Objects.requireNonNull(
-    this.context = Context.FLUSH;
+          flushInfo, "flushInfo must not be null if context is FLUSH");
-    this.mergeInfo = null;
+    }
-    this.readOnce = false;
+    if (load && readOnce) {
-    this.load = false;
+      throw new IllegalArgumentException("load and readOnce are mutually exclusive");
-    this.randomAccess = false;
+    }
-    this.flushInfo = flushInfo;
-  }
-
-  public IOContext(Context context) {
-    this(context, null);
-  }
-
-  private IOContext(boolean readOnce, boolean load, boolean randomAccess) {
     if (readOnce && randomAccess) {
-      throw new IllegalArgumentException("cannot be both readOnce and randomAccess");
+      throw new IllegalArgumentException("readOnce and randomAccess are mutually exclusive");
     }
     if (load && randomAccess == false) {
       throw new IllegalArgumentException("cannot be load but not randomAccess");
     }
-    this.context = Context.READ;
-    this.mergeInfo = null;
-    this.readOnce = readOnce;
-    this.load = load;
-    this.randomAccess = randomAccess;
-    this.flushInfo = null;
   }
 
+  private IOContext(boolean readOnce, boolean load, boolean randomAccess) {
+    this(Context.READ, null, null, readOnce, load, randomAccess);
+  }
+
+  private IOContext(Context context) {
+    this(context, null, null, false, false, false);
+  }
+
+  /** Creates an IOContext for flushing. */
+  public IOContext(FlushInfo flushInfo) {
+    this(Context.FLUSH, null, flushInfo, false, false, false);
+  }
+
+  /** Creates an IOContext for merging. */
   public IOContext(MergeInfo mergeInfo) {
-    this(Context.MERGE, mergeInfo);
+    this(Context.MERGE, mergeInfo, null, false, false, false);
-  }
-
-  private IOContext(Context context, MergeInfo mergeInfo) {
-    assert context != Context.MERGE || mergeInfo != null
-        : "MergeInfo must not be null if context is MERGE";
-    assert context != Context.FLUSH : "Use IOContext(FlushInfo) to create a FLUSH IOContext";
-    this.context = context;
-    this.readOnce = false;
-    this.load = false;
-    this.randomAccess = false;
-    this.mergeInfo = mergeInfo;
-    this.flushInfo = null;
   }
 
   /**
-   * This constructor is used to initialize a {@link IOContext} instance with a new value for the
+   * Return a copy of this IOContext with {@link #readOnce} set to {@code true}. The {@link #load}
-   * readOnce variable.
+   * flag is set to {@code false}.
-   *
-   * @param ctxt {@link IOContext} object whose information is used to create the new instance
-   *     except the readOnce variable.
-   * @param readOnce The new {@link IOContext} object will use this value for readOnce.
    */
-  public IOContext(IOContext ctxt, boolean readOnce) {
+  public IOContext toReadOnce() {
-    this.context = ctxt.context;
+    return new IOContext(context, mergeInfo, flushInfo, true, false, randomAccess);
-    this.mergeInfo = ctxt.mergeInfo;
-    this.flushInfo = ctxt.flushInfo;
-    this.readOnce = readOnce;
-    this.randomAccess = ctxt.randomAccess;
-    this.load = false;
-  }
-
-  @Override
-  public int hashCode() {
-    return Objects.hash(context, flushInfo, mergeInfo, readOnce, load, randomAccess);
-  }
-
-  @Override
-  public boolean equals(Object obj) {
-    if (this == obj) return true;
-    if (obj == null) return false;
-    if (getClass() != obj.getClass()) return false;
-    IOContext other = (IOContext) obj;
-    if (context != other.context) return false;
-    if (!Objects.equals(flushInfo, other.flushInfo)) return false;
-    if (!Objects.equals(mergeInfo, other.mergeInfo)) return false;
-    if (readOnce != other.readOnce) return false;
-    if (load != other.load) return false;
-    if (randomAccess != other.randomAccess) return false;
-    return true;
-  }
-
-  @Override
-  public String toString() {
-    return "IOContext [context="
-        + context
-        + ", mergeInfo="
-        + mergeInfo
-        + ", flushInfo="
-        + flushInfo
-        + ", readOnce="
-        + readOnce
-        + ", load="
-        + load
-        + ", randomAccess="
-        + randomAccess
-        + "]";
   }
 }

lucene/core/src/java/org/apache/lucene/store/MMapDirectory.java

@@ -88,7 +88,7 @@ public class MMapDirectory extends FSDirectory {
    * opening them if they use the {@link IOContext#LOAD} I/O context.
    */
   public static final BiPredicate<String, IOContext> BASED_ON_LOAD_IO_CONTEXT =
-      (filename, context) -> context.load;
+      (filename, context) -> context.load();
 
   private BiPredicate<String, IOContext> preload = NO_FILES;
 

lucene/core/src/java/org/apache/lucene/store/MergeInfo.java

@@ -19,65 +19,8 @@ package org.apache.lucene.store;
 /**
  * A MergeInfo provides information required for a MERGE context. It is used as part of an {@link
  * IOContext} in case of MERGE context.
+ *
+ * <p>These values are only estimates and are not the actual values.
  */
-public class MergeInfo {
+public record MergeInfo(
-
+    int totalMaxDoc, long estimatedMergeBytes, boolean isExternal, int mergeMaxNumSegments) {}
-  public final int totalMaxDoc;
-
-  public final long estimatedMergeBytes;
-
-  public final boolean isExternal;
-
-  public final int mergeMaxNumSegments;
-
-  /**
-   * Creates a new {@link MergeInfo} instance from the values required for a MERGE {@link IOContext}
-   * context.
-   *
-   * <p>These values are only estimates and are not the actual values.
-   */
-  public MergeInfo(
-      int totalMaxDoc, long estimatedMergeBytes, boolean isExternal, int mergeMaxNumSegments) {
-    this.totalMaxDoc = totalMaxDoc;
-    this.estimatedMergeBytes = estimatedMergeBytes;
-    this.isExternal = isExternal;
-    this.mergeMaxNumSegments = mergeMaxNumSegments;
-  }
-
-  @Override
-  public int hashCode() {
-    final int prime = 31;
-    int result = 1;
-    result = prime * result + (int) (estimatedMergeBytes ^ (estimatedMergeBytes >>> 32));
-    result = prime * result + (isExternal ? 1231 : 1237);
-    result = prime * result + mergeMaxNumSegments;
-    result = prime * result + totalMaxDoc;
-    return result;
-  }
-
-  @Override
-  public boolean equals(Object obj) {
-    if (this == obj) return true;
-    if (obj == null) return false;
-    if (getClass() != obj.getClass()) return false;
-    MergeInfo other = (MergeInfo) obj;
-    if (estimatedMergeBytes != other.estimatedMergeBytes) return false;
-    if (isExternal != other.isExternal) return false;
-    if (mergeMaxNumSegments != other.mergeMaxNumSegments) return false;
-    if (totalMaxDoc != other.totalMaxDoc) return false;
-    return true;
-  }
-
-  @Override
-  public String toString() {
-    return "MergeInfo [totalMaxDoc="
-        + totalMaxDoc
-        + ", estimatedMergeBytes="
-        + estimatedMergeBytes
-        + ", isExternal="
-        + isExternal
-        + ", mergeMaxNumSegments="
-        + mergeMaxNumSegments
-        + "]";
-  }
-}

lucene/core/src/java/org/apache/lucene/store/NRTCachingDirectory.java

@@ -223,10 +223,10 @@ public class NRTCachingDirectory extends FilterDirectory implements Accountable
     // size=" + (merge==null ? 0 : merge.estimatedMergeBytes));
 
     long bytes = 0;
-    if (context.mergeInfo != null) {
+    if (context.mergeInfo() != null) {
-      bytes = context.mergeInfo.estimatedMergeBytes;
+      bytes = context.mergeInfo().estimatedMergeBytes();
-    } else if (context.flushInfo != null) {
+    } else if (context.flushInfo() != null) {
-      bytes = context.flushInfo.estimatedSegmentSize;
+      bytes = context.flushInfo().estimatedSegmentSize();
     } else {
       return false;
     }

lucene/core/src/java21/org/apache/lucene/store/PosixNativeAccess.java

@@ -139,13 +139,13 @@ final class PosixNativeAccess extends NativeAccess {
   private Integer mapIOContext(IOContext ctx) {
     // Merging always wins and implies sequential access, because kernel is advised to free pages
     // after use:
-    if (ctx.context == Context.MERGE) {
+    if (ctx.context() == Context.MERGE) {
       return POSIX_MADV_SEQUENTIAL;
     }
-    if (ctx.randomAccess) {
+    if (ctx.randomAccess()) {
       return POSIX_MADV_RANDOM;
     }
-    if (ctx.readOnce) {
+    if (ctx.readOnce()) {
       return POSIX_MADV_SEQUENTIAL;
     }
     return null;

lucene/misc/src/java/org/apache/lucene/misc/store/ByteWritesTrackingDirectoryWrapper.java

@@ -48,14 +48,14 @@ public final class ByteWritesTrackingDirectoryWrapper extends FilterDirectory {
   @Override
   public IndexOutput createOutput(String name, IOContext ioContext) throws IOException {
     IndexOutput output = in.createOutput(name, ioContext);
-    return createByteTrackingOutput(output, ioContext.context);
+    return createByteTrackingOutput(output, ioContext.context());
   }
 
   @Override
   public IndexOutput createTempOutput(String prefix, String suffix, IOContext ioContext)
       throws IOException {
     IndexOutput output = in.createTempOutput(prefix, suffix, ioContext);
-    return trackTempOutput ? createByteTrackingOutput(output, ioContext.context) : output;
+    return trackTempOutput ? createByteTrackingOutput(output, ioContext.context()) : output;
   }
 
   private IndexOutput createByteTrackingOutput(IndexOutput output, IOContext.Context context) {

lucene/misc/src/java/org/apache/lucene/misc/store/DirectIODirectory.java

@@ -158,8 +158,8 @@ public class DirectIODirectory extends FilterDirectory {
    *     requested from delegate directory.
    */
   protected boolean useDirectIO(String name, IOContext context, OptionalLong fileLength) {
-    return context.context == Context.MERGE
+    return context.context() == Context.MERGE
-        && context.mergeInfo.estimatedMergeBytes >= minBytesDirect
+        && context.mergeInfo().estimatedMergeBytes() >= minBytesDirect
         && fileLength.orElse(minBytesDirect) >= minBytesDirect;
   }
 

lucene/test-framework/src/java/org/apache/lucene/tests/index/BaseCompoundFormatTestCase.java

@@ -146,7 +146,7 @@ public abstract class BaseCompoundFormatTestCase extends BaseIndexFileFormatTest
   // LUCENE-5724: things like NRTCachingDir rely upon IOContext being properly passed down
   public void testPassIOContext() throws IOException {
     final String testfile = "_123.test";
-    final IOContext myContext = new IOContext();
+    final IOContext myContext = IOContext.DEFAULT;
 
     Directory dir =
         new FilterDirectory(newDirectory()) {

lucene/test-framework/src/java/org/apache/lucene/tests/index/BasePostingsFormatTestCase.java

@@ -465,7 +465,7 @@ public abstract class BasePostingsFormatTestCase extends BaseIndexFileFormatTest
                   public void write(Fields fields, NormsProducer norms) throws IOException {
                     fieldsConsumer.write(fields, norms);
 
-                    boolean isMerge = state.context.context == IOContext.Context.MERGE;
+                    boolean isMerge = state.context.context() == IOContext.Context.MERGE;
 
                     // We only use one thread for flushing
                     // in this test:

lucene/test-framework/src/java/org/apache/lucene/tests/util/LuceneTestCase.java

@@ -1778,18 +1778,19 @@ public abstract class LuceneTestCase extends Assert {
   public static IOContext newIOContext(Random random, IOContext oldContext) {
     final int randomNumDocs = random.nextInt(4192);
     final int size = random.nextInt(512) * randomNumDocs;
-    if (oldContext.flushInfo != null) {
+    if (oldContext.flushInfo() != null) {
       // Always return at least the estimatedSegmentSize of
       // the incoming IOContext:
       return new IOContext(
-          new FlushInfo(randomNumDocs, Math.max(oldContext.flushInfo.estimatedSegmentSize, size)));
+          new FlushInfo(
-    } else if (oldContext.mergeInfo != null) {
+              randomNumDocs, Math.max(oldContext.flushInfo().estimatedSegmentSize(), size)));
+    } else if (oldContext.mergeInfo() != null) {
       // Always return at least the estimatedMergeBytes of
       // the incoming IOContext:
       return new IOContext(
           new MergeInfo(
               randomNumDocs,
-              Math.max(oldContext.mergeInfo.estimatedMergeBytes, size),
+              Math.max(oldContext.mergeInfo().estimatedMergeBytes(), size),
               random.nextBoolean(),
               TestUtil.nextInt(random, 1, 100)));
     } else {