pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / util / packed / GrowableWriter.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/util/packed/GrowableWriter.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/util/packed/GrowableWriter.java
new file mode 100644 (file)
index 0000000..23e27ba
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/util/packed/GrowableWriter.java
@@ -0,0 +1,103 @@
+package org.apache.lucene.util.packed;
+
+/**
+ * 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.
+ */
+
+/**     
+ * Implements {@link PackedInts.Mutable}, but grows the
+ * bit count of the underlying packed ints on-demand.
+ *
+ * <p>@lucene.internal</p>
+ */
+
+public class GrowableWriter implements PackedInts.Mutable {
+
+  private long currentMaxValue;
+  private PackedInts.Mutable current;
+  private final boolean roundFixedSize;
+
+  public GrowableWriter(int startBitsPerValue, int valueCount, boolean roundFixedSize) {
+    this.roundFixedSize = roundFixedSize;
+    current = PackedInts.getMutable(valueCount, getSize(startBitsPerValue));
+    currentMaxValue = PackedInts.maxValue(current.getBitsPerValue());
+  }
+
+  private final int getSize(int bpv) {
+    if (roundFixedSize) {
+      return PackedInts.getNextFixedSize(bpv);
+    } else {
+      return bpv;
+    }
+  }
+
+  public long get(int index) {
+    return current.get(index);
+  }
+
+  public int size() {
+    return current.size();
+  }
+
+  public int getBitsPerValue() {
+    return current.getBitsPerValue();
+  }
+
+  public PackedInts.Mutable getMutable() {
+    return current;
+  }
+
+  // @Override
+  public Object getArray() {
+    return current.getArray();
+  }
+
+  // @Override
+  public boolean hasArray() {
+    return current.hasArray();
+  }
+
+  public void set(int index, long value) {
+    if (value >= currentMaxValue) {
+      int bpv = getBitsPerValue();
+      while(currentMaxValue <= value && currentMaxValue != Long.MAX_VALUE) {
+        bpv++;
+        currentMaxValue *= 2;
+      }
+      final int valueCount = size();
+      PackedInts.Mutable next = PackedInts.getMutable(valueCount, getSize(bpv));
+      for(int i=0;i<valueCount;i++) {
+        next.set(i, current.get(i));
+      }
+      current = next;
+      currentMaxValue = PackedInts.maxValue(current.getBitsPerValue());
+    }
+    current.set(index, value);
+  }
+
+  public void clear() {
+    current.clear();
+  }
+
+  public GrowableWriter resize(int newSize) {
+    GrowableWriter next = new GrowableWriter(getBitsPerValue(), newSize, roundFixedSize);
+    final int limit = Math.min(size(), newSize);
+    for(int i=0;i<limit;i++) {
+      next.set(i, get(i));
+    }
+    return next;
+  }
+}