LUCENE-3622: PerDocValues -> PerDocProducer (privately used only by SegmentCoreReaders), simplify IR API and MultiDocValues, remove MultiPerDocValues

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene3622@1212828 13f79535-47bb-0310-9956-ffa450edef68

lucene/contrib/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java

@@ -40,8 +40,8 @@ import org.apache.lucene.index.DocsEnum;
 import org.apache.lucene.index.FieldInvertState;
 import org.apache.lucene.index.Fields;
 import org.apache.lucene.index.FieldsEnum;
-import org.apache.lucene.index.PerDocValues;
 import org.apache.lucene.index.IndexReader.AtomicReaderContext;
+import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.OrdTermState;
 import org.apache.lucene.index.StoredFieldVisitor;
@@ -1159,7 +1159,7 @@ public class MemoryIndex {
     }
 
     @Override
-    public PerDocValues perDocValues() throws IOException {
+    public DocValues docValues(String field) throws IOException {
       return null;
     }
   }

lucene/src/java/org/apache/lucene/index/CheckIndex.java

@@ -27,6 +27,8 @@ import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.index.DocValues.Source;
 import org.apache.lucene.index.codecs.Codec;
+import org.apache.lucene.index.codecs.PerDocProducer;
+
 import java.io.File;
 import java.io.IOException;
 import java.io.PrintStream;
@@ -1130,8 +1132,7 @@ public class CheckIndex {
       for (FieldInfo fieldInfo : fieldInfos) {
         if (fieldInfo.hasDocValues()) {
           status.totalValueFields++;
-          final PerDocValues perDocValues = reader.perDocValues();
+          final DocValues docValues = reader.docValues(fieldInfo.name);
-          final DocValues docValues = perDocValues.docValues(fieldInfo.name);
           if (docValues == null) {
             continue;
           }

lucene/src/java/org/apache/lucene/index/DirectoryReader.java

@@ -31,11 +31,8 @@ import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IOContext;
-import org.apache.lucene.store.Lock;
-import org.apache.lucene.store.LockObtainFailedException;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
-import org.apache.lucene.util.InfoStream;
 import org.apache.lucene.util.MapBackedSet;
 
 /** 
@@ -716,7 +713,7 @@ class DirectoryReader extends IndexReader implements Cloneable {
   }
 
   @Override
-  public PerDocValues perDocValues() throws IOException {
+  public DocValues docValues(String field) throws IOException {
-    throw new UnsupportedOperationException("please use MultiPerDocValues#getPerDocs, or wrap your IndexReader with SlowMultiReaderWrapper, if you really need a top level Fields");
+    throw new UnsupportedOperationException("please use MultiDocValues#getDocValues, or wrap your IndexReader with SlowMultiReaderWrapper, if you really need a top level DocValues");
   }
 }

lucene/src/java/org/apache/lucene/index/FilterIndexReader.java

@@ -421,9 +421,9 @@ public class FilterIndexReader extends IndexReader {
   }
 
   @Override
-  public PerDocValues perDocValues() throws IOException {
+  public DocValues docValues(String field) throws IOException {
     ensureOpen();
-    return in.perDocValues();
+    return in.docValues(field);
   }
 
   @Override

lucene/src/java/org/apache/lucene/index/IndexReader.java

@@ -773,21 +773,6 @@ public abstract class IndexReader implements Cloneable,Closeable {
    * through them yourself. */
   public abstract Fields fields() throws IOException;
   
-  /**
-   * Returns {@link PerDocValues} for this reader.
-   * This method may return null if the reader has no per-document
-   * values stored.
-   *
-   * <p><b>NOTE</b>: if this is a multi reader ({@link
-   * #getSequentialSubReaders} is not null) then this
-   * method will throw UnsupportedOperationException.  If
-   * you really need {@link PerDocValues} for such a reader,
-   * use {@link MultiPerDocValues#getPerDocs(IndexReader)}.  However, for
-   * performance reasons, it's best to get all sub-readers
-   * using {@link ReaderUtil#gatherSubReaders} and iterate
-   * through them yourself. */
-  public abstract PerDocValues perDocValues() throws IOException;
-
   public final int docFreq(Term term) throws IOException {
     return docFreq(term.field(), term.bytes());
   }
@@ -1146,14 +1131,20 @@ public abstract class IndexReader implements Cloneable,Closeable {
     throw new UnsupportedOperationException("This reader does not support this method.");
   }
   
-  public final DocValues docValues(String field) throws IOException {
+  /**
-    ensureOpen();
+   * Returns {@link DocValues} for this field.
-    final PerDocValues perDoc = perDocValues();
+   * This method may return null if the reader has no per-document
-    if (perDoc == null) {
+   * values stored.
-      return null;
+   *
-    }
+   * <p><b>NOTE</b>: if this is a multi reader ({@link
-    return perDoc.docValues(field);
+   * #getSequentialSubReaders} is not null) then this
-  }
+   * method will throw UnsupportedOperationException.  If
+   * you really need {@link DocValues} for such a reader,
+   * use {@link MultiDocValues#getDocValues(IndexReader,String)}.  However, for
+   * performance reasons, it's best to get all sub-readers
+   * using {@link ReaderUtil#gatherSubReaders} and iterate
+   * through them yourself. */
+  public abstract DocValues docValues(String field) throws IOException;
 
   private volatile Fields fields;
 
@@ -1169,21 +1160,6 @@ public abstract class IndexReader implements Cloneable,Closeable {
     return fields;
   }
   
-  private volatile PerDocValues perDocValues;
-  
-  /** @lucene.internal */
-  void storePerDoc(PerDocValues perDocValues) {
-    ensureOpen();
-    this.perDocValues = perDocValues;
-  }
-
-  /** @lucene.internal */
-  PerDocValues retrievePerDoc() {
-    ensureOpen();
-    return perDocValues;
-  }  
-  
-
   /**
    * A struct like class that represents a hierarchical relationship between
    * {@link IndexReader} instances. 

lucene/src/java/org/apache/lucene/index/MultiDocValues.java

@@ -17,10 +17,13 @@ package org.apache.lucene.index;
  * limitations under the License.
  */
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.ReaderUtil;
+import org.apache.lucene.util.ReaderUtil.Gather;
 
 /**
  * A wrapper for compound IndexReader providing access to per segment
@@ -31,59 +34,92 @@ import org.apache.lucene.util.ReaderUtil;
  */
 public class MultiDocValues extends DocValues {
 
-  public static class DocValuesIndex {
+  public static class DocValuesSlice {
-    public final static DocValuesIndex[] EMPTY_ARRAY = new DocValuesIndex[0];
+    public final static DocValuesSlice[] EMPTY_ARRAY = new DocValuesSlice[0];
     final int start;
     final int length;
-    final DocValues docValues;
+    DocValues docValues;
 
-    public DocValuesIndex(DocValues docValues, int start, int length) {
+    public DocValuesSlice(DocValues docValues, int start, int length) {
       this.docValues = docValues;
       this.start = start;
       this.length = length;
     }
   }
 
-  private DocValuesIndex[] docValuesIdx;
+  private DocValuesSlice[] slices;
   private int[] starts;
   private Type type;
   private int valueSize;
 
-  public MultiDocValues() {
+  private MultiDocValues(DocValuesSlice[] slices, int[] starts, TypePromoter promotedType) {
-    starts = new int[0];
+    this.starts = starts;
-    docValuesIdx = new DocValuesIndex[0];
+    this.slices = slices;
+    this.type = promotedType.type();
+    this.valueSize = promotedType.getValueSize();
   }
-
+  
-  public MultiDocValues(DocValuesIndex[] docValuesIdx) {
+  /**
-    reset(docValuesIdx);
+   * Returns a single {@link DocValues} instance for this field, merging
+   * their values on the fly.
+   * 
+   * <p>
+   * <b>NOTE</b>: this is a slow way to access DocValues. It's better to get the
+   * sub-readers (using {@link Gather}) and iterate through them yourself.
+   */
+  public static DocValues getDocValues(IndexReader r, final String field) throws IOException {
+    final IndexReader[] subs = r.getSequentialSubReaders();
+    if (subs == null) {
+      // already an atomic reader
+      return r.docValues(field);
+    } else if (subs.length == 0) {
+      // no fields
+      return null;
+    } else if (subs.length == 1) {
+      return getDocValues(subs[0], field);
+    } else {      
+      final List<DocValuesSlice> slices = new ArrayList<DocValuesSlice>();
+      
+      final TypePromoter promotedType[] = new TypePromoter[1];
+      promotedType[0] = TypePromoter.getIdentityPromoter();
+      
+      // gather all docvalues fields, accumulating a promoted type across 
+      // potentially incompatible types
+      
+      new ReaderUtil.Gather(r) {
+        @Override
+        protected void add(int base, IndexReader r) throws IOException {
+          final DocValues d = r.docValues(field);
+          if (d != null) {
+            TypePromoter incoming = TypePromoter.create(d.type(), d.getValueSize());
+            promotedType[0] = promotedType[0].promote(incoming);
+          }
+          slices.add(new DocValuesSlice(d, base, r.maxDoc()));
+        }
+      }.run();
+      
+      // return null if no docvalues encountered anywhere
+      if (promotedType[0] == TypePromoter.getIdentityPromoter()) {
+        return null;
+      }
+           
+      // populate starts and fill gaps with empty docvalues 
+      int starts[] = new int[slices.size()];
+      for (int i = 0; i < slices.size(); i++) {
+        DocValuesSlice slice = slices.get(i);
+        starts[i] = slice.start;
+        if (slice.docValues == null) {
+          slice.docValues = new EmptyDocValues(slice.length, promotedType[0].type());
+        }
+      }
+      
+      return new MultiDocValues(slices.toArray(new DocValuesSlice[slices.size()]), starts, promotedType[0]);
+    }
   }
 
   @Override
   public Source load() throws IOException {
-    return new MultiSource(docValuesIdx, starts, false);
+    return new MultiSource(slices, starts, false, type);
-  }
-
-  public DocValues reset(DocValuesIndex[] docValuesIdx) {
-    final int[] start = new int[docValuesIdx.length];
-    TypePromoter promoter = TypePromoter.getIdentityPromoter();
-    for (int i = 0; i < docValuesIdx.length; i++) {
-      start[i] = docValuesIdx[i].start;
-      if (!(docValuesIdx[i].docValues instanceof EmptyDocValues)) {
-        // only promote if not a dummy
-        final TypePromoter incomingPromoter = TypePromoter.create(
-            docValuesIdx[i].docValues.type(),
-            docValuesIdx[i].docValues.getValueSize());
-        promoter = promoter.promote(incomingPromoter);
-        if (promoter == null) {
-          throw new IllegalStateException("Can not promote " + incomingPromoter);
-        }
-      }
-    }
-    this.type = promoter.type();
-    this.valueSize = promoter.getValueSize();
-    this.starts = start;
-    this.docValuesIdx = docValuesIdx;
-    return this;
   }
 
   public static class EmptyDocValues extends DocValues {
@@ -117,14 +153,14 @@ public class MultiDocValues extends DocValues {
     private int start = 0;
     private Source current;
     private final int[] starts;
-    private final DocValuesIndex[] docValuesIdx;
+    private final DocValuesSlice[] slices;
     private boolean direct;
 
-    public MultiSource(DocValuesIndex[] docValuesIdx, int[] starts, boolean direct) {
+    public MultiSource(DocValuesSlice[] slices, int[] starts, boolean direct, Type type) {
-      super(docValuesIdx[0].docValues.type());
+      super(type);
-      this.docValuesIdx = docValuesIdx;
+      this.slices = slices;
       this.starts = starts;
-      assert docValuesIdx.length != 0;
+      assert slices.length != 0;
       this.direct = direct;
     }
 
@@ -138,22 +174,22 @@ public class MultiDocValues extends DocValues {
         return docID - start;
       } else {
         final int idx = ReaderUtil.subIndex(docID, starts);
-        assert idx >= 0 && idx < docValuesIdx.length : "idx was " + idx
+        assert idx >= 0 && idx < slices.length : "idx was " + idx
             + " for doc id: " + docID + " slices : " + Arrays.toString(starts);
-        assert docValuesIdx[idx] != null;
+        assert slices[idx] != null;
         try {
           if (direct) {
-            current = docValuesIdx[idx].docValues.getDirectSource();
+            current = slices[idx].docValues.getDirectSource();
           } else {
-            current = docValuesIdx[idx].docValues.getSource();
+            current = slices[idx].docValues.getSource();
           }
         } catch (IOException e) {
           throw new RuntimeException("load failed", e); // TODO how should we
           // handle this
         }
 
-        start = docValuesIdx[idx].start;
+        start = slices[idx].start;
-        numDocs = docValuesIdx[idx].length;
+        numDocs = slices[idx].length;
         return docID - start;
       }
     }
@@ -206,6 +242,6 @@ public class MultiDocValues extends DocValues {
 
   @Override
   public Source getDirectSource() throws IOException {
-    return new MultiSource(docValuesIdx, starts, true);
+    return new MultiSource(slices, starts, true, type);
   }
 }

lucene/src/java/org/apache/lucene/index/MultiFieldsEnum.java

@@ -38,14 +38,9 @@ public final  class MultiFieldsEnum extends FieldsEnum {
   // Holds sub-readers containing field we are currently
   // on, popped from queue.
   private final FieldsEnumWithSlice[] top;
-  private final FieldsEnumWithSlice[] enumWithSlices;
 
   private int numTop;
 
-  // Re-used TermsEnum
-  private final MultiTermsEnum terms;
-  private final MultiDocValues docValues;
-
   private final Fields fields;
 
   private String currentField;
@@ -54,9 +49,7 @@ public final  class MultiFieldsEnum extends FieldsEnum {
    *  (ie, {@link FieldsEnum#next} has not been called. */
   public MultiFieldsEnum(MultiFields fields, FieldsEnum[] subs, ReaderUtil.Slice[] subSlices) throws IOException {
     this.fields = fields;
-    terms = new MultiTermsEnum(subSlices);
     queue = new FieldMergeQueue(subs.length);
-    docValues = new MultiDocValues();
     top = new FieldsEnumWithSlice[subs.length];
     List<FieldsEnumWithSlice> enumWithSlices = new ArrayList<FieldsEnumWithSlice>();
 
@@ -72,8 +65,6 @@ public final  class MultiFieldsEnum extends FieldsEnum {
         queue.add(sub);
       }
     }
-    this.enumWithSlices = enumWithSlices.toArray(FieldsEnumWithSlice.EMPTY_ARRAY);
-
   }
 
   @Override

lucene/src/java/org/apache/lucene/index/MultiPerDocValues.java

@@ -1,147 +0,0 @@
-package org.apache.lucene.index;
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
-
-import org.apache.lucene.index.MultiDocValues.DocValuesIndex;
-import org.apache.lucene.index.DocValues;
-import org.apache.lucene.util.IOUtils;
-import org.apache.lucene.util.ReaderUtil;
-import org.apache.lucene.util.ReaderUtil.Gather;
-
-/**
- * Exposes per-document values, merged from per-document values API of
- * sub-segments. This is useful when you're interacting with an {@link IndexReader}
- * implementation that consists of sequential sub-readers (eg DirectoryReader
- * or {@link MultiReader}). 
- * 
- * <p>
- * <b>NOTE</b>: for multi readers, you'll get better performance by gathering
- * the sub readers using {@link ReaderUtil#gatherSubReaders} and then operate
- * per-reader, instead of using this class.
- * 
- * @lucene.experimental
- */
-public class MultiPerDocValues extends PerDocValues {
-  private final PerDocValues[] subs;
-  private final ReaderUtil.Slice[] subSlices;
-  private final Map<String, DocValues> docValues = new ConcurrentHashMap<String, DocValues>();
-
-  public MultiPerDocValues(PerDocValues[] subs, ReaderUtil.Slice[] subSlices) {
-    this.subs = subs;
-    this.subSlices = subSlices;
-  }
-
-  /**
-   * Returns a single {@link PerDocValues} instance for this reader, merging
-   * their values on the fly. This method will not return <code>null</code>.
-   * 
-   * <p>
-   * <b>NOTE</b>: this is a slow way to access postings. It's better to get the
-   * sub-readers (using {@link Gather}) and iterate through them yourself.
-   */
-  public static PerDocValues getPerDocs(IndexReader r) throws IOException {
-    final IndexReader[] subs = r.getSequentialSubReaders();
-    if (subs == null) {
-      // already an atomic reader
-      return r.perDocValues();
-    } else if (subs.length == 0) {
-      // no fields
-      return null;
-    } else if (subs.length == 1) {
-      return getPerDocs(subs[0]);
-    }
-    PerDocValues perDocValues = r.retrievePerDoc();
-    if (perDocValues == null) {
-
-      final List<PerDocValues> producer = new ArrayList<PerDocValues>();
-      final List<ReaderUtil.Slice> slices = new ArrayList<ReaderUtil.Slice>();
-
-      new ReaderUtil.Gather(r) {
-        @Override
-        protected void add(int base, IndexReader r) throws IOException {
-          final PerDocValues f = r.perDocValues();
-          if (f != null) {
-            producer.add(f);
-            slices
-                .add(new ReaderUtil.Slice(base, r.maxDoc(), producer.size() - 1));
-          }
-        }
-      }.run();
-
-      if (producer.size() == 0) {
-        return null;
-      } else if (producer.size() == 1) {
-        perDocValues = producer.get(0);
-      } else {
-        perDocValues = new MultiPerDocValues(
-            producer.toArray(PerDocValues.EMPTY_ARRAY),
-            slices.toArray(ReaderUtil.Slice.EMPTY_ARRAY));
-      }
-      r.storePerDoc(perDocValues);
-    }
-    return perDocValues;
-  }
-
-  public DocValues docValues(String field) throws IOException {
-    DocValues result = docValues.get(field);
-    if (result == null) {
-      // Lazy init: first time this field is requested, we
-      // create & add to docValues:
-      final List<MultiDocValues.DocValuesIndex> docValuesIndex = new ArrayList<MultiDocValues.DocValuesIndex>();
-      int docsUpto = 0;
-      DocValues.Type type = null;
-      // Gather all sub-readers that share this field
-      for (int i = 0; i < subs.length; i++) {
-        DocValues values = subs[i].docValues(field);
-        final int start = subSlices[i].start;
-        final int length = subSlices[i].length;
-        if (values != null) {
-          if (docsUpto != start) {
-            type = values.type();
-            docValuesIndex.add(new MultiDocValues.DocValuesIndex(
-                new MultiDocValues.EmptyDocValues(start, type), docsUpto, start
-                    - docsUpto));
-          }
-          docValuesIndex.add(new MultiDocValues.DocValuesIndex(values, start,
-              length));
-          docsUpto = start + length;
-
-        } else if (i + 1 == subs.length && !docValuesIndex.isEmpty()) {
-          docValuesIndex.add(new MultiDocValues.DocValuesIndex(
-              new MultiDocValues.EmptyDocValues(start, type), docsUpto, start
-                  - docsUpto));
-        }
-      }
-      if (docValuesIndex.isEmpty()) {
-        return null;
-      }
-      result = new MultiDocValues(
-          docValuesIndex.toArray(DocValuesIndex.EMPTY_ARRAY));
-      docValues.put(field, result);
-    }
-    return result;
-  }
-
-  public void close() throws IOException {
-    IOUtils.close(this.subs);
-  }
-}

lucene/src/java/org/apache/lucene/index/MultiReader.java

@@ -22,6 +22,7 @@ import java.util.Collection;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.apache.lucene.index.codecs.PerDocProducer;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.ReaderUtil;
@@ -330,7 +331,7 @@ public class MultiReader extends IndexReader implements Cloneable {
   }
 
   @Override
-  public PerDocValues perDocValues() throws IOException {
+  public DocValues docValues(String field) throws IOException {
-    throw new UnsupportedOperationException("please use MultiPerDocValues#getPerDocs, or wrap your IndexReader with SlowMultiReaderWrapper, if you really need a top level Fields");
+    throw new UnsupportedOperationException("please use MultiDocValues#getDocValues, or wrap your IndexReader with SlowMultiReaderWrapper, if you really need a top level DocValues");
   }
 }

lucene/src/java/org/apache/lucene/index/ParallelReader.java

@@ -57,7 +57,6 @@ public class ParallelReader extends IndexReader {
   private boolean hasDeletions;
 
   private final ParallelFields fields = new ParallelFields();
-  private final ParallelPerDocs perDocs = new ParallelPerDocs();
 
  /** Construct a ParallelReader. 
   * <p>Note that all subreaders are closed if this ParallelReader is closed.</p>
@@ -130,7 +129,6 @@ public class ParallelReader extends IndexReader {
       if (fieldToReader.get(field) == null) {
         fieldToReader.put(field, reader);
         this.fields.addField(field, MultiFields.getFields(reader).terms(field));
-        this.perDocs.addField(field, reader);
       }
     }
 
@@ -463,35 +461,8 @@ public class ParallelReader extends IndexReader {
   }
 
   @Override
-  public PerDocValues perDocValues() throws IOException {
+  public DocValues docValues(String field) throws IOException {
-    ensureOpen();
+    IndexReader reader = fieldToReader.get(field);
-    return perDocs;
+    return reader == null ? null : reader.docValues(field);
-  }
-  
-  // Single instance of this, per ParallelReader instance
-  private static final class ParallelPerDocs extends PerDocValues {
-    final TreeMap<String,DocValues> fields = new TreeMap<String,DocValues>();
-
-    void addField(String field, IndexReader r) throws IOException {
-      PerDocValues perDocs = MultiPerDocValues.getPerDocs(r);
-      if (perDocs != null) {
-        fields.put(field, perDocs.docValues(field));
-      }
-    }
-
-    @Override
-    public void close() throws IOException {
-      // nothing to do here
-    }
-
-    @Override
-    public DocValues docValues(String field) throws IOException {
-      return fields.get(field);
-    }
   }
 }
-
-
-
-
-

lucene/src/java/org/apache/lucene/index/SegmentCoreReaders.java

@@ -22,6 +22,7 @@ import java.util.concurrent.atomic.AtomicInteger;
 
 import org.apache.lucene.index.codecs.Codec;
 import org.apache.lucene.index.codecs.NormsReader;
+import org.apache.lucene.index.codecs.PerDocProducer;
 import org.apache.lucene.index.codecs.PostingsFormat;
 import org.apache.lucene.index.codecs.FieldsProducer;
 import org.apache.lucene.index.codecs.StoredFieldsReader;
@@ -47,7 +48,7 @@ final class SegmentCoreReaders {
   final FieldInfos fieldInfos;
   
   final FieldsProducer fields;
-  final PerDocValues perDocProducer;
+  final PerDocProducer perDocProducer;
   final NormsReader norms;
 
   final Directory dir;

lucene/src/java/org/apache/lucene/index/SegmentReader.java

@@ -27,6 +27,7 @@ import java.util.concurrent.atomic.AtomicInteger;
 
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.index.FieldInfo.IndexOptions;
+import org.apache.lucene.index.codecs.PerDocProducer;
 import org.apache.lucene.index.codecs.StoredFieldsReader;
 import org.apache.lucene.index.codecs.TermVectorsReader;
 import org.apache.lucene.store.IOContext;
@@ -424,9 +425,13 @@ public final class SegmentReader extends IndexReader implements Cloneable {
   }
   
   @Override
-  public PerDocValues perDocValues() throws IOException {
+  public DocValues docValues(String field) throws IOException {
     ensureOpen();
-    return core.perDocProducer;
+    final PerDocProducer perDoc = core.perDocProducer;
+    if (perDoc == null) {
+      return null;
+    }
+    return perDoc.docValues(field);
   }
 
   /**

lucene/src/java/org/apache/lucene/index/SlowMultiReaderWrapper.java

@@ -34,11 +34,12 @@ import org.apache.lucene.index.MultiReader; // javadoc
  * IndexReader#getSequentialSubReaders}) to emulate an
  * atomic reader.  This requires implementing the postings
  * APIs on-the-fly, using the static methods in {@link
- * MultiFields}, by stepping through the sub-readers to
+ * MultiFields}, {@link MultiNorms}, {@link MultiDocValues}, 
- * merge fields/terms, appending docs, etc.
+ * by stepping through the sub-readers to merge fields/terms, 
+ * appending docs, etc.
  *
  * <p>If you ever hit an UnsupportedOperationException saying
- * "please use MultiFields.XXX instead", the simple
+ * "please use MultiXXX.YYY instead", the simple
  * but non-performant workaround is to wrap your reader
  * using this class.</p>
  *
@@ -71,9 +72,9 @@ public final class SlowMultiReaderWrapper extends FilterIndexReader {
   }
 
   @Override
-  public PerDocValues perDocValues() throws IOException {
+  public DocValues docValues(String field) throws IOException {
     ensureOpen();
-    return MultiPerDocValues.getPerDocs(in);
+    return MultiDocValues.getDocValues(in, field);
   }
 
   @Override

lucene/src/java/org/apache/lucene/index/codecs/DocValuesFormat.java

@@ -20,7 +20,6 @@ package org.apache.lucene.index.codecs;
 import java.io.IOException;
 import java.util.Set;
 
-import org.apache.lucene.index.PerDocValues;
 import org.apache.lucene.index.PerDocWriteState;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentReadState;
@@ -28,6 +27,6 @@ import org.apache.lucene.store.Directory;
 
 public abstract class DocValuesFormat {
   public abstract PerDocConsumer docsConsumer(PerDocWriteState state) throws IOException;
-  public abstract PerDocValues docsProducer(SegmentReadState state) throws IOException;
+  public abstract PerDocProducer docsProducer(SegmentReadState state) throws IOException;
   public abstract void files(Directory dir, SegmentInfo info, Set<String> files) throws IOException;
 }

lucene/src/java/org/apache/lucene/index/codecs/DocValuesReaderBase.java

@@ -28,7 +28,6 @@ import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
 import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.DocValues.Type; // javadocs
-import org.apache.lucene.index.PerDocValues;
 import org.apache.lucene.index.codecs.lucene40.values.Bytes;
 import org.apache.lucene.index.codecs.lucene40.values.Floats;
 import org.apache.lucene.index.codecs.lucene40.values.Ints;
@@ -37,11 +36,11 @@ import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.BytesRef;
 
 /**
- * Abstract base class for PerDocValues implementations
+ * Abstract base class for PerDocProducer implementations
  * @lucene.experimental
  */
 // TODO: this needs to go under lucene40 codec (its specific to its impl)
-public abstract class DocValuesReaderBase extends PerDocValues {
+public abstract class DocValuesReaderBase extends PerDocProducer {
   
   protected abstract void closeInternal(Collection<? extends Closeable> closeables) throws IOException;
   protected abstract Map<String, DocValues> docValues();

lucene/src/java/org/apache/lucene/index/codecs/PerDocConsumer.java

@@ -21,7 +21,6 @@ import java.io.IOException;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.MergeState;
-import org.apache.lucene.index.PerDocValues;
 
 /**
  * Abstract API that consumes per document values. Concrete implementations of
@@ -39,30 +38,22 @@ public abstract class PerDocConsumer implements Closeable{
       throws IOException;
 
   /**
-   * Consumes and merges the given {@link PerDocValues} producer
+   * Consumes and merges the given {@link PerDocProducer} producer
    * into this consumers format.   
    */
   public void merge(MergeState mergeState) throws IOException {
     final DocValues[] docValues = new DocValues[mergeState.readers.size()];
-    final PerDocValues[] perDocValues = new PerDocValues[mergeState.readers.size()];
+
-    // pull all PerDocValues 
-    for (int i = 0; i < perDocValues.length; i++) {
-      perDocValues[i] = mergeState.readers.get(i).reader.perDocValues();
-    }
     for (FieldInfo fieldInfo : mergeState.fieldInfos) {
       mergeState.fieldInfo = fieldInfo; // set the field we are merging
       if (fieldInfo.hasDocValues()) {
-        for (int i = 0; i < perDocValues.length; i++) {
+        for (int i = 0; i < docValues.length; i++) {
-          if (perDocValues[i] != null) { // get all IDV to merge
+          docValues[i] = mergeState.readers.get(i).reader.docValues(fieldInfo.name);
-            docValues[i] = perDocValues[i].docValues(fieldInfo.name);
-          }
         }
         final DocValuesConsumer docValuesConsumer = addValuesField(fieldInfo.getDocValuesType(), fieldInfo);
         assert docValuesConsumer != null;
         docValuesConsumer.merge(mergeState, docValues);
       }
     }
-    /* NOTE: don't close the perDocProducers here since they are private segment producers
-     * and will be closed once the SegmentReader goes out of scope */ 
   }  
 }

lucene/src/java/org/apache/lucene/index/codecs/PerDocProducer.java

@@ -1,4 +1,4 @@
-package org.apache.lucene.index;
+package org.apache.lucene.index.codecs;
 /**
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
@@ -18,8 +18,7 @@ package org.apache.lucene.index;
 import java.io.Closeable;
 import java.io.IOException;
 
-import org.apache.lucene.index.codecs.PerDocConsumer;
+import org.apache.lucene.index.DocValues;
-import org.apache.lucene.index.codecs.PostingsFormat;
 
 /**
  * Abstract API that provides access to one or more per-document storage
@@ -27,13 +26,13 @@ import org.apache.lucene.index.codecs.PostingsFormat;
  * storage on a per-document basis corresponding to their actual
  * {@link PerDocConsumer} counterpart.
  * <p>
- * The {@link PerDocValues} API is accessible through the
+ * The {@link PerDocProducer} API is accessible through the
  * {@link PostingsFormat} - API providing per field consumers and producers for inverted
  * data (terms, postings) as well as per-document data.
  * 
  * @lucene.experimental
  */
-public abstract class PerDocValues implements Closeable {
+public abstract class PerDocProducer implements Closeable {
   /**
    * Returns {@link DocValues} for the current field.
    * 
@@ -45,5 +44,5 @@ public abstract class PerDocValues implements Closeable {
    */
   public abstract DocValues docValues(String field) throws IOException;
 
-  public static final PerDocValues[] EMPTY_ARRAY = new PerDocValues[0];
+  public static final PerDocProducer[] EMPTY_ARRAY = new PerDocProducer[0];
 }

lucene/src/java/org/apache/lucene/index/codecs/lucene3x/Lucene3xCodec.java

@@ -20,7 +20,6 @@ package org.apache.lucene.index.codecs.lucene3x;
 import java.io.IOException;
 import java.util.Set;
 
-import org.apache.lucene.index.PerDocValues;
 import org.apache.lucene.index.PerDocWriteState;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentReadState;
@@ -28,6 +27,7 @@ import org.apache.lucene.index.codecs.Codec;
 import org.apache.lucene.index.codecs.DocValuesFormat;
 import org.apache.lucene.index.codecs.FieldInfosFormat;
 import org.apache.lucene.index.codecs.NormsFormat;
+import org.apache.lucene.index.codecs.PerDocProducer;
 import org.apache.lucene.index.codecs.StoredFieldsFormat;
 import org.apache.lucene.index.codecs.PerDocConsumer;
 import org.apache.lucene.index.codecs.PostingsFormat;
@@ -75,7 +75,7 @@ public class Lucene3xCodec extends Codec {
     }
 
     @Override
-    public PerDocValues docsProducer(SegmentReadState state) throws IOException {
+    public PerDocProducer docsProducer(SegmentReadState state) throws IOException {
       return null;
     }
 

lucene/src/java/org/apache/lucene/index/codecs/lucene40/Lucene40DocValuesFormat.java

@@ -20,12 +20,12 @@ package org.apache.lucene.index.codecs.lucene40;
 import java.io.IOException;
 import java.util.Set;
 
-import org.apache.lucene.index.PerDocValues;
 import org.apache.lucene.index.PerDocWriteState;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentReadState;
 import org.apache.lucene.index.codecs.DocValuesFormat;
 import org.apache.lucene.index.codecs.PerDocConsumer;
+import org.apache.lucene.index.codecs.PerDocProducer;
 import org.apache.lucene.store.Directory;
 
 public class Lucene40DocValuesFormat extends DocValuesFormat {
@@ -36,7 +36,7 @@ public class Lucene40DocValuesFormat extends DocValuesFormat {
   }
 
   @Override
-  public PerDocValues docsProducer(SegmentReadState state) throws IOException {
+  public PerDocProducer docsProducer(SegmentReadState state) throws IOException {
     return new Lucene40DocValuesProducer(state);
   }
 

lucene/src/java/org/apache/lucene/index/codecs/lucene40/Lucene40DocValuesProducer.java

@@ -33,7 +33,7 @@ import org.apache.lucene.store.Directory;
 import org.apache.lucene.util.IOUtils;
 
 /**
- * Default PerDocValues implementation that uses compound file.
+ * Default PerDocProducer implementation that uses compound file.
  * @lucene.experimental
  */
 public class Lucene40DocValuesProducer extends DocValuesReaderBase {

lucene/src/java/org/apache/lucene/index/codecs/sep/SepDocValuesProducer.java

@@ -28,7 +28,7 @@ import org.apache.lucene.index.codecs.DocValuesReaderBase;
 import org.apache.lucene.util.IOUtils;
 
 /**
- * Implementation of PerDocValues that uses separate files.
+ * Implementation of PerDocProducer that uses separate files.
  * @lucene.experimental
  */
 public class SepDocValuesProducer extends DocValuesReaderBase {

lucene/src/test-framework/java/org/apache/lucene/index/codecs/mocksep/MockSepDocValuesFormat.java

@@ -20,12 +20,12 @@ package org.apache.lucene.index.codecs.mocksep;
 import java.io.IOException;
 import java.util.Set;
 
-import org.apache.lucene.index.PerDocValues;
 import org.apache.lucene.index.PerDocWriteState;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentReadState;
 import org.apache.lucene.index.codecs.DocValuesFormat;
 import org.apache.lucene.index.codecs.PerDocConsumer;
+import org.apache.lucene.index.codecs.PerDocProducer;
 import org.apache.lucene.index.codecs.sep.SepDocValuesConsumer;
 import org.apache.lucene.index.codecs.sep.SepDocValuesProducer;
 import org.apache.lucene.store.Directory;
@@ -43,7 +43,7 @@ public class MockSepDocValuesFormat extends DocValuesFormat {
   }
 
   @Override
-  public PerDocValues docsProducer(SegmentReadState state) throws IOException {
+  public PerDocProducer docsProducer(SegmentReadState state) throws IOException {
     return new SepDocValuesProducer(state);
   }
 

lucene/src/test/org/apache/lucene/index/TestAddIndexes.java

@@ -1284,7 +1284,7 @@ public class TestAddIndexes extends LuceneTestCase {
     w.close();
     IndexReader sr = getOnlySegmentReader(r3);
     assertEquals(2, sr.numDocs());
-    DocValues docValues = sr.perDocValues().docValues("dv");
+    DocValues docValues = sr.docValues("dv");
     assertNotNull(docValues);
     r3.close();
     d3.close();

lucene/src/test/org/apache/lucene/index/TestDuelingCodecs.java

@@ -18,12 +18,15 @@ package org.apache.lucene.index;
  */
 
 import java.io.IOException;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Random;
+import java.util.Set;
 
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
+import org.apache.lucene.index.IndexReader.FieldOption;
 import org.apache.lucene.index.codecs.Codec;
 import org.apache.lucene.search.DocIdSetIterator;
 import org.apache.lucene.store.Directory;
@@ -516,29 +519,15 @@ public class TestDuelingCodecs extends LuceneTestCase {
    * checks that docvalues across all fields are equivalent
    */
   public void assertDocValues(IndexReader leftReader, IndexReader rightReader) throws Exception {
-    PerDocValues leftPerDoc = MultiPerDocValues.getPerDocs(leftReader);
+    Set<String> leftValues = new HashSet<String>(leftReader.getFieldNames(FieldOption.DOC_VALUES));
-    PerDocValues rightPerDoc = MultiPerDocValues.getPerDocs(rightReader);
+    Set<String> rightValues = new HashSet<String>(rightReader.getFieldNames(FieldOption.DOC_VALUES));
-    
+    assertEquals(info, leftValues, rightValues);
-    Fields leftFields = MultiFields.getFields(leftReader);
+
-    Fields rightFields = MultiFields.getFields(rightReader);
+    for (String field : leftValues) {
-    // Fields could be null if there are no postings,
+      DocValues leftDocValues = MultiDocValues.getDocValues(leftReader, field);
-    // but then it must be null for both
+      DocValues rightDocValues = MultiDocValues.getDocValues(rightReader, field);
-    if (leftFields == null || rightFields == null) {
+      assertNotNull(info, leftDocValues);
-      assertNull(info, leftFields);
+      assertNotNull(info, rightDocValues);
-      assertNull(info, rightFields);
-      return;
-    }
-    
-    FieldsEnum fieldsEnum = leftFields.iterator();
-    String field;
-    while ((field = fieldsEnum.next()) != null) {
-      DocValues leftDocValues = leftPerDoc.docValues(field);
-      DocValues rightDocValues = rightPerDoc.docValues(field);
-      if (leftDocValues == null || rightDocValues == null) {
-        assertNull(info, leftDocValues);
-        assertNull(info, rightDocValues);
-        continue;
-      }
       assertDocValuesSource(leftDocValues.getDirectSource(), rightDocValues.getDirectSource());
       assertDocValuesSource(leftDocValues.getSource(), rightDocValues.getSource());
     }

lucene/src/test/org/apache/lucene/index/values/TestDocValuesIndexing.java

@@ -37,13 +37,13 @@ import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriterConfig;
 import org.apache.lucene.index.LogDocMergePolicy;
 import org.apache.lucene.index.LogMergePolicy;
-import org.apache.lucene.index.MultiPerDocValues;
+import org.apache.lucene.index.MultiDocValues;
-import org.apache.lucene.index.PerDocValues;
 import org.apache.lucene.index.RandomIndexWriter;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.index.DocValues.Source;
 import org.apache.lucene.index.DocValues.Type;
 import org.apache.lucene.index.codecs.Codec;
+import org.apache.lucene.index.codecs.PerDocProducer;
 import org.apache.lucene.search.*;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.LockObtainFailedException;
@@ -104,7 +104,7 @@ public class TestDocValuesIndexing extends LuceneTestCase {
     TopDocs search = searcher.search(query, 10);
     assertEquals(5, search.totalHits);
     ScoreDoc[] scoreDocs = search.scoreDocs;
-    DocValues docValues = MultiPerDocValues.getPerDocs(reader).docValues("docId");
+    DocValues docValues = MultiDocValues.getDocValues(reader, "docId");
     Source source = docValues.getSource();
     for (int i = 0; i < scoreDocs.length; i++) {
       assertEquals(i, scoreDocs[i].doc);
@@ -418,24 +418,8 @@ public class TestDocValuesIndexing extends LuceneTestCase {
     d.close();
   }
 
-  private DocValues getDocValues(IndexReader reader, String field)
+  private DocValues getDocValues(IndexReader reader, String field) throws IOException {
-      throws IOException {
+    return MultiDocValues.getDocValues(reader, field);
-    boolean singleSeg = reader.getSequentialSubReaders().length == 1;
-    PerDocValues perDoc = singleSeg ? reader.getSequentialSubReaders()[0].perDocValues()
-        : MultiPerDocValues.getPerDocs(reader);
-    switch (random.nextInt(singleSeg ? 3 : 2)) { // case 2 only if single seg
-    case 0:
-      return perDoc.docValues(field);
-    case 1:
-      DocValues docValues = perDoc.docValues(field);
-      if (docValues != null) {
-        return docValues;
-      }
-      throw new RuntimeException("no such field " + field);
-    case 2:// this only works if we are on a single seg index!
-      return reader.getSequentialSubReaders()[0].docValues(field);
-    }
-    throw new RuntimeException();
   }
 
   private Source getSource(DocValues values) throws IOException {
@@ -570,7 +554,7 @@ public class TestDocValuesIndexing extends LuceneTestCase {
     w.forceMerge(1);
     IndexReader r = w.getReader();
     w.close();
-    assertEquals(17, r.getSequentialSubReaders()[0].perDocValues().docValues("field").load().getInt(0));
+    assertEquals(17, r.getSequentialSubReaders()[0].docValues("field").load().getInt(0));
     r.close();
     d.close();
   }
@@ -600,7 +584,7 @@ public class TestDocValuesIndexing extends LuceneTestCase {
     w.forceMerge(1);
     IndexReader r = w.getReader();
     w.close();
-    assertEquals(17, r.getSequentialSubReaders()[0].perDocValues().docValues("field").load().getInt(0));
+    assertEquals(17, r.getSequentialSubReaders()[0].docValues("field").load().getInt(0));
     r.close();
     d.close();
   }