apache · jpountz · Apr 14, 2021 · Apr 12, 2021 · Apr 12, 2021
diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
@@ -101,6 +101,8 @@ API Changes
 * LUCENE-9853: JapaneseAnalyzer should use CJKWidthCharFilter for full-width and half-width character normalization.
   (Tomoko Uchida)
 
+* LUCENE-9387: Removed CodecReader#ramBytesUsed. (Adrien Grand)
+
 Improvements
 
 * LUCENE-9687: Hunspell support improvements: add API for spell-checking and suggestions, support compound words,

diff --git a/lucene/MIGRATE.md b/lucene/MIGRATE.md
@@ -376,3 +376,8 @@ better to use the ordinal alone (integer-based datastructures) for per-document
 call lookupOrd() a few times at the end (e.g. for the hits you want to display). Otherwise, if you
 really don't want per-document ordinals, but instead a per-document `byte[]`, use a BinaryDocValues
 field.
+
+## Removed CodecReader.ramBytesUsed() (LUCENE-9387)
+
+Lucene index readers are now using so little memory with the default codec that
+it was decided to remove the ability to estimate their RAM usage.
diff --git a/...ard-codecs/src/java/org/apache/lucene/backward_codecs/lucene40/blocktree/FieldReader.java b/...ard-codecs/src/java/org/apache/lucene/backward_codecs/lucene40/blocktree/FieldReader.java
@@ -17,18 +17,13 @@
 package org.apache.lucene.backward_codecs.lucene40.blocktree;
 
 import java.io.IOException;
-import java.util.Collection;
-import java.util.Collections;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.IndexInput;
-import org.apache.lucene.util.Accountable;
-import org.apache.lucene.util.Accountables;
 import org.apache.lucene.util.BytesRef;
-import org.apache.lucene.util.RamUsageEstimator;
 import org.apache.lucene.util.automaton.CompiledAutomaton;
 import org.apache.lucene.util.fst.ByteSequenceOutputs;
 import org.apache.lucene.util.fst.FST;
@@ -39,14 +34,10 @@
  *
  * @lucene.internal
  */
-public final class FieldReader extends Terms implements Accountable {
+public final class FieldReader extends Terms {
 
   // private final boolean DEBUG = BlockTreeTermsWriter.DEBUG;
 
-  private static final long BASE_RAM_BYTES_USED =
-      RamUsageEstimator.shallowSizeOfInstance(FieldReader.class)
-          + 3 * RamUsageEstimator.shallowSizeOfInstance(BytesRef.class);
-
   final long numTerms;
   final FieldInfo fieldInfo;
   final long sumTotalTermFreq;
@@ -200,20 +191,6 @@ public TermsEnum intersect(CompiledAutomaton compiled, BytesRef startTerm) throw
         this, compiled.automaton, compiled.runAutomaton, compiled.commonSuffixRef, startTerm);
   }
 
-  @Override
-  public long ramBytesUsed() {
-    return BASE_RAM_BYTES_USED + ((index != null) ? index.ramBytesUsed() : 0);
-  }
-
-  @Override
-  public Collection<Accountable> getChildResources() {
-    if (index == null) {
-      return Collections.emptyList();
-    } else {
-      return Collections.singleton(Accountables.namedAccountable("term index", index));
-    }
-  }
-
   @Override
   public String toString() {
     return "BlockTreeTerms(seg="

diff --git a/...va/org/apache/lucene/backward_codecs/lucene40/blocktree/Lucene40BlockTreeTermsReader.java b/...va/org/apache/lucene/backward_codecs/lucene40/blocktree/Lucene40BlockTreeTermsReader.java
@@ -18,7 +18,6 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -35,8 +34,6 @@
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.store.ChecksumIndexInput;
 import org.apache.lucene.store.IndexInput;
-import org.apache.lucene.util.Accountable;
-import org.apache.lucene.util.Accountables;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.IOUtils;
 import org.apache.lucene.util.fst.ByteSequenceOutputs;
@@ -373,23 +370,6 @@ String brToString(BytesRef b) {
     }
   }
 
-  @Override
-  public long ramBytesUsed() {
-    long sizeInBytes = postingsReader.ramBytesUsed();
-    for (FieldReader reader : fieldMap.values()) {
-      sizeInBytes += reader.ramBytesUsed();
-    }
-    return sizeInBytes;
-  }
-
-  @Override
-  public Collection<Accountable> getChildResources() {
-    List<Accountable> resources =
-        new ArrayList<>(Accountables.namedAccountables("field", fieldMap));
-    resources.add(Accountables.namedAccountable("delegate", postingsReader));
-    return Collections.unmodifiableList(resources);
-  }
-
   @Override
   public void checkIntegrity() throws IOException {
     // terms index

diff --git a/...rd-codecs/src/java/org/apache/lucene/backward_codecs/lucene50/Lucene50PostingsReader.java b/...rd-codecs/src/java/org/apache/lucene/backward_codecs/lucene50/Lucene50PostingsReader.java
@@ -46,7 +46,6 @@
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.IOUtils;
-import org.apache.lucene.util.RamUsageEstimator;
 
 /**
  * Concrete class that reads docId(maybe frq,pos,offset,payloads) list with postings format.
@@ -55,9 +54,6 @@
  */
 public final class Lucene50PostingsReader extends PostingsReaderBase {
 
-  private static final long BASE_RAM_BYTES_USED =
-      RamUsageEstimator.shallowSizeOfInstance(Lucene50PostingsReader.class);
-
   private final IndexInput docIn;
   private final IndexInput posIn;
   private final IndexInput payIn;
@@ -1844,11 +1840,6 @@ public long cost() {
     }
   }
 
-  @Override
-  public long ramBytesUsed() {
-    return BASE_RAM_BYTES_USED;
-  }
-
   @Override
   public void checkIntegrity() throws IOException {
     if (docIn != null) {

diff --git a/...d-codecs/src/java/org/apache/lucene/backward_codecs/lucene50/compressing/FieldsIndex.java b/...d-codecs/src/java/org/apache/lucene/backward_codecs/lucene50/compressing/FieldsIndex.java
@@ -18,9 +18,8 @@
 
 import java.io.Closeable;
 import java.io.IOException;
-import org.apache.lucene.util.Accountable;
 
-abstract class FieldsIndex implements Accountable, Cloneable, Closeable {
+abstract class FieldsIndex implements Cloneable, Closeable {
 
   /** Get the start pointer for the block that contains the given docID. */
   abstract long getStartPointer(int docID);

diff --git a/...cs/src/java/org/apache/lucene/backward_codecs/lucene50/compressing/FieldsIndexReader.java b/...cs/src/java/org/apache/lucene/backward_codecs/lucene50/compressing/FieldsIndexReader.java
@@ -25,17 +25,13 @@
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.RandomAccessInput;
-import org.apache.lucene.util.RamUsageEstimator;
 import org.apache.lucene.util.packed.DirectMonotonicReader;
 
 final class FieldsIndexReader extends FieldsIndex {
 
   static final int VERSION_START = 0;
   static final int VERSION_CURRENT = 0;
 
-  private static final long BASE_RAM_BYTES_USED =
-      RamUsageEstimator.shallowSizeOfInstance(FieldsIndexReader.class);
-
   private final int maxDoc;
   private final int blockShift;
   private final int numChunks;
@@ -111,15 +107,6 @@ private FieldsIndexReader(FieldsIndexReader other) throws IOException {
     startPointers = DirectMonotonicReader.getInstance(startPointersMeta, startPointersSlice);
   }
 
-  @Override
-  public long ramBytesUsed() {
-    return BASE_RAM_BYTES_USED
-        + docsMeta.ramBytesUsed()
-        + startPointersMeta.ramBytesUsed()
-        + docs.ramBytesUsed()
-        + startPointers.ramBytesUsed();
-  }
-
   @Override
   public void close() throws IOException {
     indexInput.close();

diff --git a/.../java/org/apache/lucene/backward_codecs/lucene50/compressing/LegacyFieldsIndexReader.java b/.../java/org/apache/lucene/backward_codecs/lucene50/compressing/LegacyFieldsIndexReader.java
@@ -19,24 +19,14 @@
 import static org.apache.lucene.util.BitUtil.zigZagDecode;
 
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
 import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.store.IndexInput;
-import org.apache.lucene.util.Accountable;
-import org.apache.lucene.util.Accountables;
 import org.apache.lucene.util.ArrayUtil;
-import org.apache.lucene.util.RamUsageEstimator;
 import org.apache.lucene.util.packed.PackedInts;
 
 final class LegacyFieldsIndexReader extends FieldsIndex {
 
-  private static final long BASE_RAM_BYTES_USED =
-      RamUsageEstimator.shallowSizeOfInstance(LegacyFieldsIndexReader.class);
-
   final int maxDoc;
   final int[] docBases;
   final long[] startPointers;
@@ -177,46 +167,6 @@ public LegacyFieldsIndexReader clone() {
     return this;
   }
 
-  @Override
-  public long ramBytesUsed() {
-    long res = BASE_RAM_BYTES_USED;
-
-    res += RamUsageEstimator.shallowSizeOf(docBasesDeltas);
-    for (PackedInts.Reader r : docBasesDeltas) {
-      res += r.ramBytesUsed();
-    }
-    res += RamUsageEstimator.shallowSizeOf(startPointersDeltas);
-    for (PackedInts.Reader r : startPointersDeltas) {
-      res += r.ramBytesUsed();
-    }
-
-    res += RamUsageEstimator.sizeOf(docBases);
-    res += RamUsageEstimator.sizeOf(startPointers);
-    res += RamUsageEstimator.sizeOf(avgChunkDocs);
-    res += RamUsageEstimator.sizeOf(avgChunkSizes);
-
-    return res;
-  }
-
-  @Override
-  public Collection<Accountable> getChildResources() {
-    List<Accountable> resources = new ArrayList<>();
-
-    long docBaseDeltaBytes = RamUsageEstimator.shallowSizeOf(docBasesDeltas);
-    for (PackedInts.Reader r : docBasesDeltas) {
-      docBaseDeltaBytes += r.ramBytesUsed();
-    }
-    resources.add(Accountables.namedAccountable("doc base deltas", docBaseDeltaBytes));
-
-    long startPointerDeltaBytes = RamUsageEstimator.shallowSizeOf(startPointersDeltas);
-    for (PackedInts.Reader r : startPointersDeltas) {
-      startPointerDeltaBytes += r.ramBytesUsed();
-    }
-    resources.add(Accountables.namedAccountable("start pointer deltas", startPointerDeltaBytes));
-
-    return Collections.unmodifiableList(resources);
-  }
-
   @Override
   public String toString() {
     return getClass().getSimpleName() + "(blocks=" + docBases.length + ")";

diff --git a/...he/lucene/backward_codecs/lucene50/compressing/Lucene50CompressingStoredFieldsReader.java b/...he/lucene/backward_codecs/lucene50/compressing/Lucene50CompressingStoredFieldsReader.java
@@ -19,8 +19,6 @@
 import java.io.EOFException;
 import java.io.IOException;
 import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.StoredFieldsReader;
 import org.apache.lucene.codecs.compressing.CompressionMode;
@@ -39,8 +37,6 @@
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
-import org.apache.lucene.util.Accountable;
-import org.apache.lucene.util.Accountables;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BitUtil;
 import org.apache.lucene.util.BytesRef;
@@ -791,16 +787,6 @@ int getPackedIntsVersion() {
     return packedIntsVersion;
   }
 
-  @Override
-  public long ramBytesUsed() {
-    return indexReader.ramBytesUsed();
-  }
-
-  @Override
-  public Collection<Accountable> getChildResources() {
-    return Collections.singleton(Accountables.namedAccountable("stored field index", indexReader));
-  }
-
   @Override
   public void checkIntegrity() throws IOException {
     indexReader.checkIntegrity();

diff --git a/...che/lucene/backward_codecs/lucene50/compressing/Lucene50CompressingTermVectorsReader.java b/...che/lucene/backward_codecs/lucene50/compressing/Lucene50CompressingTermVectorsReader.java
@@ -17,8 +17,6 @@
 package org.apache.lucene.backward_codecs.lucene50.compressing;
 
 import java.io.IOException;
-import java.util.Collection;
-import java.util.Collections;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import org.apache.lucene.codecs.CodecUtil;
@@ -43,8 +41,6 @@
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
-import org.apache.lucene.util.Accountable;
-import org.apache.lucene.util.Accountables;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.IOUtils;
@@ -1337,16 +1333,6 @@ private static int sum(int[] arr) {
     return sum;
   }
 
-  @Override
-  public long ramBytesUsed() {
-    return indexReader.ramBytesUsed();
-  }
-
-  @Override
-  public Collection<Accountable> getChildResources() {
-    return Collections.singleton(Accountables.namedAccountable("term vector index", indexReader));
-  }
-
   @Override
   public void checkIntegrity() throws IOException {
     indexReader.checkIntegrity();

diff --git a/...ward-codecs/src/java/org/apache/lucene/backward_codecs/lucene60/Lucene60PointsReader.java b/...ward-codecs/src/java/org/apache/lucene/backward_codecs/lucene60/Lucene60PointsReader.java
@@ -130,11 +130,6 @@ public PointValues getValues(String fieldName) {
     return readers.get(fieldInfo.number);
   }
 
-  @Override
-  public long ramBytesUsed() {
-    return 0L;
-  }
-
   @Override
   public void checkIntegrity() throws IOException {
     CodecUtil.checksumEntireFile(dataIn);