LUCENE-5675: add docs/AndPositionsEnums

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene5675@1594985 13f79535-47bb-0310-9956-ffa450edef68

lucene/codecs/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsReader.java

@@ -61,14 +61,31 @@ public final class IDVersionPostingsReader extends PostingsReaderBase {
 
   @Override
   public DocsEnum docs(FieldInfo fieldInfo, BlockTermState termState, Bits liveDocs, DocsEnum reuse, int flags) throws IOException {
-    // nocommit todo -- need a SingleDocDocsEnum
-    return null;
+    SingleDocsEnum docsEnum;
+
+    if (reuse instanceof SingleDocsEnum) {
+      docsEnum = (SingleDocsEnum) reuse;
+    } else {
+      docsEnum = new SingleDocsEnum();
+    }
+    docsEnum.reset(((IDVersionTermState) termState).docID, liveDocs);
+
+    return docsEnum;
   }
 
   @Override
-  public DocsAndPositionsEnum docsAndPositions(FieldInfo fieldInfo, BlockTermState termState, Bits liveDocs,
+  public DocsAndPositionsEnum docsAndPositions(FieldInfo fieldInfo, BlockTermState _termState, Bits liveDocs,
                                                DocsAndPositionsEnum reuse, int flags) {
-    return null;
+    SingleDocsAndPositionsEnum posEnum;
+
+    if (reuse instanceof SingleDocsAndPositionsEnum) {
+      posEnum = (SingleDocsAndPositionsEnum) reuse;
+    } else {
+      posEnum = new SingleDocsAndPositionsEnum();
+    }
+    IDVersionTermState termState = (IDVersionTermState) _termState;
+    posEnum.reset(termState.docID, termState.idVersion, liveDocs);
+    return posEnum;
   }
 
   @Override

lucene/codecs/src/java/org/apache/lucene/codecs/idversion/SingleDocsAndPositionsEnum.java

@@ -0,0 +1,100 @@
+package org.apache.lucene.codecs.idversion;
+
+/*
+ * 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 org.apache.lucene.index.DocsAndPositionsEnum;
+import org.apache.lucene.util.Bits;
+import org.apache.lucene.util.BytesRef;
+
+class SingleDocsAndPositionsEnum extends DocsAndPositionsEnum {
+  private int doc;
+  private int pos;
+  private int singleDocID;
+  private Bits liveDocs;
+  private long version;
+  private final BytesRef payload = new BytesRef();
+
+  /** For reuse */
+  public void reset(int singleDocID, long version, Bits liveDocs) {
+    doc = -1;
+    this.liveDocs = liveDocs;
+    this.singleDocID = singleDocID;
+    this.version = version;
+    pos = -1;
+  }
+
+  @Override
+  public int nextDoc() {
+    if (doc == -1 && (liveDocs == null || liveDocs.get(singleDocID))) {
+      doc = singleDocID;
+    } else {
+      doc = NO_MORE_DOCS;
+    }
+    pos = 0;
+    
+    return doc;
+  }
+
+  @Override
+  public int docID() {
+    return doc;
+  }
+
+  @Override
+  public int advance(int target) {
+    if (doc == -1 && target <= singleDocID && (liveDocs == null || liveDocs.get(singleDocID))) {
+      doc = singleDocID;
+    } else {
+      doc = NO_MORE_DOCS;
+    }
+    return doc;
+  }
+
+  @Override
+  public long cost() {
+    return 1;
+  }
+
+  @Override
+  public int freq() {
+    return 1;
+  }
+
+  @Override
+  public int nextPosition() {
+    assert pos == -1;
+    pos = 0;
+    // nocommit re-encode version back into payload here:
+    return pos;
+  }
+
+  @Override
+  public BytesRef getPayload() {
+    return payload;
+  }
+
+  @Override
+  public int startOffset() {
+    return -1;
+  }
+
+  @Override
+  public int endOffset() {
+    return -1;
+  }
+}

lucene/codecs/src/java/org/apache/lucene/codecs/idversion/SingleDocsEnum.java

@@ -0,0 +1,71 @@
+package org.apache.lucene.codecs.idversion;
+
+/*
+ * 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 org.apache.lucene.index.DocsEnum;
+import org.apache.lucene.util.Bits;
+
+class SingleDocsEnum extends DocsEnum {
+
+  private int doc;
+  private int singleDocID;
+  private Bits liveDocs;
+
+  /** For reuse */
+  public void reset(int singleDocID, Bits liveDocs) {
+    doc = -1;
+    this.liveDocs = liveDocs;
+    this.singleDocID = singleDocID;
+  }
+
+  @Override
+  public int nextDoc() {
+    if (doc == -1 && (liveDocs == null || liveDocs.get(singleDocID))) {
+      doc = singleDocID;
+    } else {
+      doc = NO_MORE_DOCS;
+    }
+    
+    return doc;
+  }
+
+  @Override
+  public int docID() {
+    return doc;
+  }
+
+  @Override
+  public int advance(int target) {
+    if (doc == -1 && target <= singleDocID && (liveDocs == null || liveDocs.get(singleDocID))) {
+      doc = singleDocID;
+    } else {
+      doc = NO_MORE_DOCS;
+    }
+    return doc;
+  }
+
+  @Override
+  public long cost() {
+    return 1;
+  }
+
+  @Override
+  public int freq() {
+    return 1;
+  }
+}

lucene/codecs/src/resources/META-INF/services/org.apache.lucene.codecs.PostingsFormat

@@ -22,3 +22,4 @@ org.apache.lucene.codecs.memory.FSTPulsing41PostingsFormat
 org.apache.lucene.codecs.memory.FSTOrdPulsing41PostingsFormat
 org.apache.lucene.codecs.memory.FSTPostingsFormat
 org.apache.lucene.codecs.memory.FSTOrdPostingsFormat
+org.apache.lucene.codecs.idversion.IDVersionPostingsFormat

lucene/core/src/java/org/apache/lucene/codecs/BlockTreeTermsReader.java

@@ -1318,6 +1318,8 @@ public class BlockTreeTermsReader extends FieldsProducer {
       private Frame currentFrame;
       private boolean termExists;
 
+      // nocommit make this public "for casting" and add a getVersion method?
+
       private int targetBeforeCurrentLength;
 
       private final ByteArrayDataInput scratchReader = new ByteArrayDataInput();
@@ -1560,6 +1562,8 @@ public class BlockTreeTermsReader extends FieldsProducer {
         return true;
       }
 
+      // nocommit we need a seekExact(BytesRef target, long minVersion) API?
+
       @Override
       public boolean seekExact(final BytesRef target) throws IOException {