Imported sourceshms

git-svn-id: https://svn.code.sf.net/p/jackcess/code/jackcess/branches/hms@2 f203690c-595d-4dc9-a70b-905162fa7fd2

1 files changed, 114 insertions, 0 deletions

diff --git a/src/java/com/healthmarketscience/jackcess/ByteUtil.java b/src/java/com/healthmarketscience/jackcess/ByteUtil.java
new file mode 100644
index 0000000..5e8d276
--- /dev/null
+++ b/src/java/com/healthmarketscience/jackcess/ByteUtil.java
@@ -0,0 +1,114 @@
+/*
+Copyright (c) 2005 Health Market Science, Inc.
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+USA
+
+You can contact Health Market Science at info@healthmarketscience.com
+or at the following address:
+
+Health Market Science
+2700 Horizon Drive
+Suite 200
+King of Prussia, PA 19406
+*/
+
+package com.healthmarketscience.jackcess;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Byte manipulation and display utilities
+ * @author Tim McCune
+ */
+public final class ByteUtil {
+  
+  private static final String[] HEX_CHARS = new String[] {
+      "0", "1", "2", "3", "4", "5", "6", "7",
+      "8", "9", "A", "B", "C", "D", "E", "F"};
+      
+  private ByteUtil() {}
+  
+  /**
+   * Convert an int from 4 bytes to 3
+   * @param i Int to convert
+   * @return Array of 3 bytes in little-endian order
+   */    
+  public static byte[] to3ByteInt(int i) {
+    byte[] rtn = new byte[3];
+    rtn[0] = (byte) (i & 0xFF);
+    rtn[1] = (byte) ((i >>> 8) & 0xFF);
+    rtn[2] = (byte) ((i >>> 16) & 0xFF);
+    return rtn;
+  }
+  
+  /**
+   * Read a 3 byte int from a buffer in little-endian order
+   * @param buffer Buffer containing the bytes
+   * @param offset Offset at which to start reading the int
+   * @return The int
+   */
+  public static int get3ByteInt(ByteBuffer buffer, int offset) {
+    int rtn = buffer.get(offset) & 0xff;
+    rtn += ((((int) buffer.get(offset + 1)) & 0xFF) << 8);
+    rtn += ((((int) buffer.get(offset + 2)) & 0xFF) << 16);
+    rtn &= 16777215;  //2 ^ (8 * 3) - 1
+    return rtn;
+  }
+  
+  /**
+   * Convert a byte buffer to a hexadecimal string for display
+   * @param buffer Buffer to display, starting at offset 0
+   * @param size Number of bytes to read from the buffer
+   * @return The display String
+   */
+  public static String toHexString(ByteBuffer buffer, int size) {
+    return toHexString(buffer, 0, size);
+  }
+  
+  /**
+   * Convert a byte buffer to a hexadecimal string for display
+   * @param buffer Buffer to display, starting at offset 0
+   * @param offset Offset at which to start reading the buffer
+   * @param size Number of bytes to read from the buffer
+   * @return The display String
+   */
+  public static String toHexString(ByteBuffer buffer, int offset, int size) {
+    
+    StringBuffer rtn = new StringBuffer();
+    int position = buffer.position();
+    buffer.position(offset);
+       
+    for (int i = 0; i < size; i++) {
+      byte b = buffer.get();
+      byte h = (byte) (b & 0xF0);
+      h = (byte) (h >>> 4);
+      h = (byte) (h & 0x0F);    
+      rtn.append(HEX_CHARS[(int) h]);
+      h = (byte) (b & 0x0F);  
+      rtn.append(HEX_CHARS[(int) h] + " ");
+      if ((i + 1) % 4 == 0) {
+        rtn.append(" ");
+      }
+      if ((i + 1) % 24 == 0) {
+        rtn.append("\n");
+      }
+    }
+    
+    buffer.position(position);
+    return rtn.toString();
+  }    
+  
+}