pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / facet / src / java / org / apache / lucene / facet / taxonomy / writercache / cl2o / CharBlockArray.java

diff --git a/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/taxonomy/writercache/cl2o/CharBlockArray.java b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/taxonomy/writercache/cl2o/CharBlockArray.java
new file mode 100644 (file)
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--- /dev/null
+++ b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/taxonomy/writercache/cl2o/CharBlockArray.java
@@ -0,0 +1,195 @@
+package org.apache.lucene.facet.taxonomy.writercache.cl2o;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.OutputStream;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 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.
+ */
+
+/**
+ * Similar to {@link StringBuilder}, but with a more efficient growing strategy.
+ * This class uses char array blocks to grow.
+ * 
+ * @lucene.experimental
+ */
+class CharBlockArray implements Appendable, Serializable, CharSequence {
+
+  private static final long serialVersionUID = 1L;
+
+  private final static int DefaultBlockSize = 32 * 1024;  // 32 KB default size
+
+  final static class Block implements Serializable, Cloneable {
+    private static final long serialVersionUID = 1L;
+
+    char[] chars;
+    int length;
+
+    Block(int size) {
+      this.chars = new char[size];
+      this.length = 0;
+    }
+  }
+
+  List<Block> blocks;
+  Block current;
+  int blockSize;
+  int length;
+
+  CharBlockArray() {
+    this(DefaultBlockSize);
+  }
+
+  CharBlockArray(int blockSize) {
+    this.blocks = new ArrayList<Block>();
+    this.blockSize = blockSize;
+    addBlock();
+  }
+
+  private void addBlock() {
+    this.current = new Block(this.blockSize);
+    this.blocks.add(this.current);
+  }
+
+  int blockIndex(int index) {
+    return index / blockSize;
+  }
+
+  int indexInBlock(int index) {
+    return index % blockSize;
+  }
+
+  public CharBlockArray append(CharSequence chars) {
+    return append(chars, 0, chars.length());
+  }
+
+  public CharBlockArray append(char c) {
+    if (this.current.length == this.blockSize) {
+      addBlock();
+    }
+    this.current.chars[this.current.length++] = c;
+    this.length++;
+
+    return this;
+  }
+
+  public CharBlockArray append(CharSequence chars, int start, int length) {
+    int end = start + length;
+    for (int i = start; i < end; i++) {
+      append(chars.charAt(i));
+    }
+    return this;
+  }
+
+  public CharBlockArray append(char[] chars, int start, int length) {
+    int offset = start;
+    int remain = length;
+    while (remain > 0) {
+      if (this.current.length == this.blockSize) {
+        addBlock();
+      }
+      int toCopy = remain;
+      int remainingInBlock = this.blockSize - this.current.length;
+      if (remainingInBlock < toCopy) {
+        toCopy = remainingInBlock;
+      }
+      System.arraycopy(chars, offset, this.current.chars, this.current.length, toCopy);
+      offset += toCopy;
+      remain -= toCopy;
+      this.current.length += toCopy;
+    }
+
+    this.length += length;
+    return this;
+  }
+
+  public CharBlockArray append(String s) {
+    int remain = s.length();
+    int offset = 0;
+    while (remain > 0) {
+      if (this.current.length == this.blockSize) {
+        addBlock();
+      }
+      int toCopy = remain;
+      int remainingInBlock = this.blockSize - this.current.length;
+      if (remainingInBlock < toCopy) {
+        toCopy = remainingInBlock;
+      }
+      s.getChars(offset, offset + toCopy, this.current.chars, this.current.length);
+      offset += toCopy;
+      remain -= toCopy;
+      this.current.length += toCopy;
+    }
+
+    this.length += s.length();
+    return this;
+  }
+
+  public char charAt(int index) {
+    Block b = this.blocks.get(blockIndex(index));
+    return b.chars[indexInBlock(index)];
+  }
+
+  public int length() {
+    return this.length;
+  }
+
+  public CharSequence subSequence(int start, int end) {
+    throw new UnsupportedOperationException("subsequence not implemented yet");
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder b = new StringBuilder(blockSize * this.blocks.size());
+    for (int i = 0; i < this.blocks.size(); i++) {
+      b.append(this.blocks.get(i).chars);
+    }
+    return b.toString();
+  }
+
+  void flush(OutputStream out) throws IOException {
+    ObjectOutputStream oos = null;
+    try {
+      oos = new ObjectOutputStream(out);
+      oos.writeObject(this);
+      oos.flush();
+    } finally {
+      if (oos != null) {
+        oos.close();
+      }
+    }
+  }
+
+  public static CharBlockArray open(InputStream in) throws IOException, ClassNotFoundException {
+    ObjectInputStream ois = null;
+    try {
+      ois = new ObjectInputStream(in);
+      CharBlockArray a = (CharBlockArray) ois.readObject();
+      return a;
+    } finally {
+      if (ois != null) {
+        ois.close();
+      }
+    }
+  }
+
+}