pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / store / IndexInput.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/store/IndexInput.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/store/IndexInput.java
new file mode 100644 (file)
index 0000000..6d1445e
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/store/IndexInput.java
@@ -0,0 +1,119 @@
+package org.apache.lucene.store;
+
+/**
+ * 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.io.Closeable;
+
+/** Abstract base class for input from a file in a {@link Directory}.  A
+ * random-access input stream.  Used for all Lucene index input operations.
+ * @see Directory
+ */
+public abstract class IndexInput extends DataInput implements Cloneable,Closeable {
+
+  /**
+   * Expert
+   * 
+   * Similar to {@link #readChars(char[], int, int)} but does not do any conversion operations on the bytes it is reading in.  It still
+   * has to invoke {@link #readByte()} just as {@link #readChars(char[], int, int)} does, but it does not need a buffer to store anything
+   * and it does not have to do any of the bitwise operations, since we don't actually care what is in the byte except to determine
+   * how many more bytes to read
+   * @param length The number of chars to read
+   * @deprecated this method operates on old "modified utf8" encoded
+   *             strings
+   */
+  @Deprecated
+  public void skipChars(int length) throws IOException{
+    for (int i = 0; i < length; i++) {
+      byte b = readByte();
+      if ((b & 0x80) == 0){
+        //do nothing, we only need one byte
+      } else if ((b & 0xE0) != 0xE0) {
+        readByte();//read an additional byte
+      } else {      
+        //read two additional bytes.
+        readByte();
+        readByte();
+      }
+    }
+  }
+
+  private final String resourceDescription;
+
+  /** @deprecated please pass resourceDescription */
+  @Deprecated
+  protected IndexInput() {
+    this("anonymous IndexInput");
+  }
+
+  /** resourceDescription should be a non-null, opaque string
+   *  describing this resource; it's returned from
+   *  {@link #toString}. */
+  protected IndexInput(String resourceDescription) {
+    if (resourceDescription == null) {
+      throw new IllegalArgumentException("resourceDescription must not be null");
+    }
+    this.resourceDescription = resourceDescription;
+  }
+
+  /** Closes the stream to further operations. */
+  public abstract void close() throws IOException;
+
+  /** Returns the current position in this file, where the next read will
+   * occur.
+   * @see #seek(long)
+   */
+  public abstract long getFilePointer();
+
+  /** Sets current position in this file, where the next read will occur.
+   * @see #getFilePointer()
+   */
+  public abstract void seek(long pos) throws IOException;
+
+  /** The number of bytes in the file. */
+  public abstract long length();
+
+  /**
+   * Copies <code>numBytes</code> bytes to the given {@link IndexOutput}.
+   * <p>
+   * <b>NOTE:</b> this method uses an intermediate buffer to copy the bytes.
+   * Consider overriding it in your implementation, if you can make a better,
+   * optimized copy.
+   * <p>
+   * <b>NOTE</b> ensure that there are enough bytes in the input to copy to
+   * output. Otherwise, different exceptions may be thrown, depending on the
+   * implementation.
+   */
+  public void copyBytes(IndexOutput out, long numBytes) throws IOException {
+    assert numBytes >= 0: "numBytes=" + numBytes;
+
+    byte copyBuf[] = new byte[BufferedIndexInput.BUFFER_SIZE];
+
+    while (numBytes > 0) {
+      final int toCopy = (int) (numBytes > copyBuf.length ? copyBuf.length : numBytes);
+      readBytes(copyBuf, 0, toCopy);
+      out.writeBytes(copyBuf, 0, toCopy);
+      numBytes -= toCopy;
+    }
+  }
+
+  @Override
+  public String toString() {
+    return resourceDescription;
+  }
+}