pylucene 3.5.0-3

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

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/store/ByteArrayDataInput.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/store/ByteArrayDataInput.java
new file mode 100644 (file)
index 0000000..59dbb81
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/store/ByteArrayDataInput.java
@@ -0,0 +1,132 @@
+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 org.apache.lucene.util.BytesRef;
+
+/** @lucene.experimental */
+public final class ByteArrayDataInput extends DataInput {
+
+  private byte[] bytes;
+
+  private int pos;
+  private int limit;
+
+  public ByteArrayDataInput(byte[] bytes) {
+    reset(bytes);
+  }
+
+  public ByteArrayDataInput(byte[] bytes, int offset, int len) {
+    reset(bytes, offset, len);
+  }
+
+  public ByteArrayDataInput() {
+    reset(BytesRef.EMPTY_BYTES);
+  }
+
+  public void reset(byte[] bytes) {
+    reset(bytes, 0, bytes.length);
+  }
+
+  public int getPosition() {
+    return pos;
+  }
+  
+  public void reset(byte[] bytes, int offset, int len) {
+    this.bytes = bytes;
+    pos = offset;
+    limit = offset + len;
+  }
+
+  public boolean eof() {
+    return pos == limit;
+  }
+
+  public void skipBytes(int count) {
+    pos += count;
+    assert pos <= limit;
+  }
+
+  @Override
+  public short readShort() {
+    return (short) (((bytes[pos++] & 0xFF) <<  8) |  (bytes[pos++] & 0xFF));
+  }
+ 
+  @Override
+  public int readInt() {
+    assert pos+4 <= limit;
+    return ((bytes[pos++] & 0xFF) << 24) | ((bytes[pos++] & 0xFF) << 16)
+      | ((bytes[pos++] & 0xFF) <<  8) |  (bytes[pos++] & 0xFF);
+  }
+ 
+  @Override
+  public long readLong() {
+    assert pos+8 <= limit;
+    final int i1 = ((bytes[pos++] & 0xff) << 24) | ((bytes[pos++] & 0xff) << 16) |
+      ((bytes[pos++] & 0xff) << 8) | (bytes[pos++] & 0xff);
+    final int i2 = ((bytes[pos++] & 0xff) << 24) | ((bytes[pos++] & 0xff) << 16) |
+      ((bytes[pos++] & 0xff) << 8) | (bytes[pos++] & 0xff);
+    return (((long)i1) << 32) | (i2 & 0xFFFFFFFFL);
+  }
+
+  @Override
+  public int readVInt() {
+    checkBounds();
+    byte b = bytes[pos++];
+    int i = b & 0x7F;
+    for (int shift = 7; (b & 0x80) != 0; shift += 7) {
+      checkBounds();
+      b = bytes[pos++];
+      i |= (b & 0x7F) << shift;
+    }
+    return i;
+  }
+ 
+  @Override
+  public long readVLong() {
+    checkBounds();
+    byte b = bytes[pos++];
+    long i = b & 0x7F;
+    for (int shift = 7; (b & 0x80) != 0; shift += 7) {
+      checkBounds();
+      b = bytes[pos++];
+      i |= (b & 0x7FL) << shift;
+    }
+    return i;
+  }
+
+  // NOTE: AIOOBE not EOF if you read too much
+  @Override
+  public byte readByte() {
+    checkBounds();
+    return bytes[pos++];
+  }
+
+  // NOTE: AIOOBE not EOF if you read too much
+  @Override
+  public void readBytes(byte[] b, int offset, int len) {
+    assert pos + len <= limit;
+    System.arraycopy(bytes, pos, b, offset, len);
+    pos += len;
+  }
+
+  private boolean checkBounds() {
+    assert pos < limit;
+    return true;
+  }
+}