1 files changed, 549 insertions, 0 deletions
diff --git a/src/java/com/healthmarketscience/jackcess/Column.java b/src/java/com/healthmarketscience/jackcess/Column.java
new file mode 100644
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--- /dev/null
+++ b/src/java/com/healthmarketscience/jackcess/Column.java
@@ -0,0 +1,549 @@
+/*
+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.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.CharBuffer;
+import java.sql.SQLException;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.Iterator;
+import java.util.List;
+import java.util.TimeZone;
+
+import com.healthmarketscience.jackcess.scsu.EndOfInputException;
+import com.healthmarketscience.jackcess.scsu.Expand;
+import com.healthmarketscience.jackcess.scsu.IllegalInputException;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * Access database column definition
+ * @author Tim McCune
+ */
+public class Column implements Comparable {
+  
+  private static final Log LOG = LogFactory.getLog(Column.class);
+  
+  /**
+   * Access starts counting dates at Jan 1, 1900.  Java starts counting
+   * at Jan 1, 1970.  This is the # of days between them for conversion.
+   */
+  private static final double DAYS_BETWEEN_EPOCH_AND_1900 = 25569d;
+  /**
+   * Access stores numeric dates in days.  Java stores them in milliseconds.
+   */
+  private static final double MILLISECONDS_PER_DAY = 86400000d;
+  
+  /**
+   * Long value (LVAL) type that indicates that the value is stored on the same page
+   */
+  private static final short LONG_VALUE_TYPE_THIS_PAGE = (short) 0x8000;
+  /**
+   * Long value (LVAL) type that indicates that the value is stored on another page
+   */
+  private static final short LONG_VALUE_TYPE_OTHER_PAGE = (short) 0x4000;
+  /**
+   * Long value (LVAL) type that indicates that the value is stored on multiple other pages
+   */
+  private static final short LONG_VALUE_TYPE_OTHER_PAGES = (short) 0x0;
+  
+  /** For text columns, whether or not they are compressed */ 
+  private boolean _compressedUnicode = false;
+  /** Whether or not the column is of variable length */
+  private boolean _variableLength;
+  /** Numeric precision */
+  private byte _precision;
+  /** Numeric scale */
+  private byte _scale;
+  /** Data type */
+  private byte _type;
+  /** Format that the containing database is in */
+  private JetFormat _format;
+  /** Used to read in LVAL pages */
+  private PageChannel _pageChannel;
+  /** Maximum column length */
+  private short _columnLength;
+  /** 0-based column number */
+  private short _columnNumber;
+  /** Column name */
+  private String _name;
+  
+  public Column() {
+    this(JetFormat.VERSION_4);
+  }
+  
+  public Column(JetFormat format) {
+    _format = format;
+  }
+  
+  /**
+   * Read a column definition in from a buffer
+   * @param buffer Buffer containing column definition
+   * @param offset Offset in the buffer at which the column definition starts
+   * @param format Format that the containing database is in
+   */
+  public Column(ByteBuffer buffer, int offset, PageChannel pageChannel, JetFormat format) {
+    if (LOG.isDebugEnabled()) {
+      LOG.debug("Column def block:\n" + ByteUtil.toHexString(buffer, offset, 25));
+    }
+    _pageChannel = pageChannel;
+    _format = format;
+    setType(buffer.get(offset + format.OFFSET_COLUMN_TYPE));
+    _columnNumber = buffer.getShort(offset + format.OFFSET_COLUMN_NUMBER);
+    _columnLength = buffer.getShort(offset + format.OFFSET_COLUMN_LENGTH);
+    if (_type == DataTypes.NUMERIC) {
+      _precision = buffer.get(offset + format.OFFSET_COLUMN_PRECISION);
+      _scale = buffer.get(offset + format.OFFSET_COLUMN_SCALE);
+    }
+    _variableLength = ((buffer.get(offset + format.OFFSET_COLUMN_VARIABLE)
+        & 1) != 1);
+    _compressedUnicode = ((buffer.get(offset +
+        format.OFFSET_COLUMN_COMPRESSED_UNICODE) & 1) == 1);
+  }
+  
+  public String getName() {
+    return _name;
+  }
+  public void setName(String name) {
+    _name = name;
+  }
+  
+  public boolean isVariableLength() {
+    return _variableLength;
+  }
+  public void setVariableLength(boolean variableLength) {
+    _variableLength = variableLength;
+  }
+  
+  public short getColumnNumber() {
+    return _columnNumber;
+  }
+  
+  /**
+   * Also sets the length and the variable length flag, inferred from the type
+   */
+  public void setType(byte type) {
+    _type = type;
+    setLength((short) size());
+    switch (type) {
+      case DataTypes.BOOLEAN:
+      case DataTypes.BYTE:
+      case DataTypes.INT:
+      case DataTypes.LONG:
+      case DataTypes.DOUBLE:
+      case DataTypes.FLOAT:
+      case DataTypes.SHORT_DATE_TIME:
+        setVariableLength(false);
+        break;
+      case DataTypes.BINARY:
+      case DataTypes.TEXT:
+        setVariableLength(true);
+        break;
+    }
+  }
+  public byte getType() {
+    return _type;
+  }
+  
+  public int getSQLType() throws SQLException {
+    return DataTypes.toSQLType(_type);      
+  }
+  
+  public void setSQLType(int type) throws SQLException {
+    setType(DataTypes.fromSQLType(type));
+  }
+  
+  public boolean isCompressedUnicode() {
+    return _compressedUnicode;
+  }
+  
+  public byte getPrecision() {
+    return _precision;
+  }
+  
+  public byte getScale() {
+    return _scale;
+  }
+  
+  public void setLength(short length) {
+    _columnLength = length;
+  }
+  public short getLength() {
+    return _columnLength;
+  }
+  
+  /**
+   * Deserialize a raw byte value for this column into an Object
+   * @param data The raw byte value
+   * @return The deserialized Object
+   */
+  public Object read(byte[] data) throws IOException {
+    return read(data, ByteOrder.LITTLE_ENDIAN);
+  }
+  
+  /**
+   * Deserialize a raw byte value for this column into an Object
+   * @param data The raw byte value
+   * @param order Byte order in which the raw value is stored
+   * @return The deserialized Object
+   */  
+  public Object read(byte[] data, ByteOrder order) throws IOException {
+    ByteBuffer buffer = ByteBuffer.wrap(data);
+    buffer.order(order);
+    switch (_type) {
+      case DataTypes.BOOLEAN:
+        throw new IOException("Tried to read a boolean from data instead of null mask.");
+      case DataTypes.BYTE:
+        return new Byte(buffer.get());
+      case DataTypes.INT:
+        return new Short(buffer.getShort());
+      case DataTypes.LONG:
+        return new Integer(buffer.getInt());
+      case DataTypes.DOUBLE:
+        return new Double(buffer.getDouble());
+      case DataTypes.FLOAT:
+        return new Float(buffer.getFloat());
+      case DataTypes.SHORT_DATE_TIME:
+        long time = (long) ((buffer.getDouble() - DAYS_BETWEEN_EPOCH_AND_1900) *
+            MILLISECONDS_PER_DAY);
+        Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
+        cal.setTimeInMillis(time);
+        //Not sure why we're off by 1...
+        cal.add(Calendar.DATE, 1);
+        return cal.getTime();
+      case DataTypes.BINARY:
+        return data;
+      case DataTypes.TEXT:
+        if (_compressedUnicode) {
+          try {
+            String rtn = new Expand().expand(data);
+            //SCSU expander isn't handling the UTF-8-looking 2-byte combo that
+            //prepends some of these strings.  Rather than dig into that code,
+            //I'm just stripping them off here.  However, this is probably not
+            //a great idea.
+            if (rtn.length() > 2 && (int) rtn.charAt(0) == 255 &&
+                (int) rtn.charAt(1) == 254)
+            {
+              rtn = rtn.substring(2);
+            }
+            //It also isn't handling short strings.
+            if (rtn.length() > 1 && (int) rtn.charAt(1) == 0) {
+              char[] fixed = new char[rtn.length() / 2];
+              for (int i = 0; i < fixed.length; i ++) {
+                fixed[i] = rtn.charAt(i * 2);
+              }
+              rtn = new String(fixed);
+            }
+            return rtn;
+          } catch (IllegalInputException e) {
+            throw new IOException("Can't expand text column");
+          } catch (EndOfInputException e) {
+            throw new IOException("Can't expand text column");
+          }
+        } else {
+          return _format.CHARSET.decode(ByteBuffer.wrap(data)).toString();
+        }
+      case DataTypes.MONEY:
+        //XXX
+        return null;
+      case DataTypes.OLE:
+        if (data.length > 0) {
+          return getLongValue(data);
+        } else {
+          return null;
+        }
+      case DataTypes.MEMO:
+        if (data.length > 0) {
+          return _format.CHARSET.decode(ByteBuffer.wrap(getLongValue(data))).toString();
+        } else {
+          return null;
+        }
+      case DataTypes.NUMERIC:
+        //XXX
+        return null;
+      case DataTypes.UNKNOWN_0D:
+      case DataTypes.GUID:
+        return null;
+      default:
+        throw new IOException("Unrecognized data type: " + _type);
+    }
+  }
+  
+  /**
+   * @param lvalDefinition Column value that points to an LVAL record
+   * @return The LVAL data
+   */
+  private byte[] getLongValue(byte[] lvalDefinition) throws IOException {
+    ByteBuffer def = ByteBuffer.wrap(lvalDefinition);
+    def.order(ByteOrder.LITTLE_ENDIAN);
+    short length = def.getShort();
+    byte[] rtn = new byte[length];
+    short type = def.getShort();
+    switch (type) {
+      case LONG_VALUE_TYPE_OTHER_PAGE:
+        if (lvalDefinition.length != _format.SIZE_LONG_VALUE_DEF) {
+          throw new IOException("Expected " + _format.SIZE_LONG_VALUE_DEF +
+              " bytes in long value definition, but found " + lvalDefinition.length);
+        }
+        byte rowNum = def.get();
+        int pageNum = ByteUtil.get3ByteInt(def, def.position());
+        ByteBuffer lvalPage = _pageChannel.createPageBuffer();
+        _pageChannel.readPage(lvalPage, pageNum);
+        short offset = lvalPage.getShort(14 +
+            rowNum * _format.SIZE_ROW_LOCATION);
+        lvalPage.position(offset);
+        lvalPage.get(rtn);
+        break;
+      case LONG_VALUE_TYPE_THIS_PAGE:
+        def.getLong();  //Skip over lval_dp and unknown
+        def.get(rtn);
+      case LONG_VALUE_TYPE_OTHER_PAGES:
+        //XXX
+        return null;
+      default:
+        throw new IOException("Unrecognized long value type: " + type);
+    }
+    return rtn;
+  }
+  
+  /**
+   * Write an LVAL column into a ByteBuffer inline (LONG_VALUE_TYPE_THIS_PAGE)
+   * @param value Value of the LVAL column
+   * @return A buffer containing the LVAL definition and the column value
+   */
+  public ByteBuffer writeLongValue(byte[] value) throws IOException {
+    ByteBuffer def = ByteBuffer.allocate(_format.SIZE_LONG_VALUE_DEF + value.length);
+    def.order(ByteOrder.LITTLE_ENDIAN);
+    def.putShort((short) value.length);
+    def.putShort(LONG_VALUE_TYPE_THIS_PAGE);
+    def.putInt(0);
+    def.putInt(0);  //Unknown
+    def.put(value);
+    def.flip();
+    return def;    
+  }
+  
+  /**
+   * Write an LVAL column into a ByteBuffer on another page
+   *    (LONG_VALUE_TYPE_OTHER_PAGE)
+   * @param value Value of the LVAL column
+   * @return A buffer containing the LVAL definition
+   */
+  public ByteBuffer writeLongValueInNewPage(byte[] value) throws IOException {
+    ByteBuffer lvalPage = _pageChannel.createPageBuffer();
+    lvalPage.put(PageTypes.DATA); //Page type
+    lvalPage.put((byte) 1); //Unknown
+    lvalPage.putShort((short) (_format.PAGE_SIZE -
+        _format.OFFSET_LVAL_ROW_LOCATION_BLOCK - _format.SIZE_ROW_LOCATION -
+        value.length)); //Free space
+    lvalPage.put((byte) 'L');
+    lvalPage.put((byte) 'V');
+    lvalPage.put((byte) 'A');
+    lvalPage.put((byte) 'L');
+    int offset = _format.PAGE_SIZE - value.length;
+    lvalPage.position(14);
+    lvalPage.putShort((short) offset);
+    lvalPage.position(offset);
+    lvalPage.put(value);
+    ByteBuffer def = ByteBuffer.allocate(_format.SIZE_LONG_VALUE_DEF);
+    def.order(ByteOrder.LITTLE_ENDIAN);
+    def.putShort((short) value.length);
+    def.putShort(LONG_VALUE_TYPE_OTHER_PAGE);
+    def.put((byte) 0); //Row number
+    def.put(ByteUtil.to3ByteInt(_pageChannel.writeNewPage(lvalPage)));  //Page #
+    def.putInt(0);  //Unknown
+    def.flip();
+    return def;    
+  }
+  
+  /**
+   * Serialize an Object into a raw byte value for this column in little endian order
+   * @param obj Object to serialize
+   * @return A buffer containing the bytes
+   */
+  public ByteBuffer write(Object obj) throws IOException {
+    return write(obj, ByteOrder.LITTLE_ENDIAN);
+  }
+  
+  /**
+   * Serialize an Object into a raw byte value for this column
+   * @param obj Object to serialize
+   * @param order Order in which to serialize
+   * @return A buffer containing the bytes
+   */
+  public ByteBuffer write(Object obj, ByteOrder order) throws IOException {
+    int size = size();
+    if (_type == DataTypes.OLE || _type == DataTypes.MEMO) {
+      size += ((byte[]) obj).length;
+    }
+    if (_type == DataTypes.TEXT) {
+      size = getLength();
+    }
+    ByteBuffer buffer = ByteBuffer.allocate(size);
+    buffer.order(order);
+    switch (_type) {
+      case DataTypes.BOOLEAN:
+        break;
+      case DataTypes.BYTE:
+        buffer.put(((Byte) obj).byteValue());
+        break;
+      case DataTypes.INT:
+        buffer.putShort(((Short) obj).shortValue());
+        break;
+      case DataTypes.LONG:
+        buffer.putInt(((Integer) obj).intValue());
+        break;
+      case DataTypes.DOUBLE:
+        buffer.putDouble(((Double) obj).doubleValue());
+        break;
+      case DataTypes.FLOAT:
+        buffer.putFloat(((Float) obj).floatValue());
+        break;
+      case DataTypes.SHORT_DATE_TIME:
+        Calendar cal = Calendar.getInstance();
+        cal.setTime((Date) obj);
+        long ms = cal.getTimeInMillis();
+        ms += (long) TimeZone.getDefault().getOffset(ms);
+        buffer.putDouble((double) ms / MILLISECONDS_PER_DAY +
+            DAYS_BETWEEN_EPOCH_AND_1900);
+        break;
+      case DataTypes.BINARY:
+        buffer.put((byte[]) obj);
+        break;
+      case DataTypes.TEXT:
+        CharSequence text = (CharSequence) obj;
+        int maxChars = size / 2;
+        if (text.length() > maxChars) {
+          text = text.subSequence(0, maxChars);
+        }
+        buffer.put(encodeText(text));
+        break;
+      case DataTypes.OLE:
+        buffer.put(writeLongValue((byte[]) obj));
+        break;
+      case DataTypes.MEMO:
+        buffer.put(writeLongValue(encodeText((CharSequence) obj).array()));
+        break;
+      default:
+        throw new IOException("Unsupported data type: " + _type);
+    }
+    buffer.flip();
+    return buffer;
+  }
+  
+  /**
+   * @param text Text to encode
+   * @return A buffer with the text encoded
+   */
+  private ByteBuffer encodeText(CharSequence text) {
+    return _format.CHARSET.encode(CharBuffer.wrap(text));
+  }
+  
+  /**
+   * @return Number of bytes that should be read for this column
+   *    (applies to fixed-width columns)
+   */
+  public int size() {
+    switch (_type) {
+      case DataTypes.BOOLEAN:
+        return 0;
+      case DataTypes.BYTE:
+        return 1;
+      case DataTypes.INT:
+        return 2;
+      case DataTypes.LONG:
+        return 4;
+      case DataTypes.MONEY:
+      case DataTypes.DOUBLE:
+        return 8;
+      case DataTypes.FLOAT:
+        return 4;
+      case DataTypes.SHORT_DATE_TIME:
+        return 8;
+      case DataTypes.BINARY:
+        return 255;
+      case DataTypes.TEXT:
+        return 50 * 2;
+      case DataTypes.OLE:
+        return _format.SIZE_LONG_VALUE_DEF;
+      case DataTypes.MEMO:
+        return _format.SIZE_LONG_VALUE_DEF;
+      case DataTypes.NUMERIC:
+        throw new IllegalArgumentException("FIX ME");
+      case DataTypes.UNKNOWN_0D:
+      case DataTypes.GUID:
+        throw new IllegalArgumentException("FIX ME");
+      default:
+        throw new IllegalArgumentException("Unrecognized data type: " + _type);
+    }
+  }
+  
+  public String toString() {
+    StringBuffer rtn = new StringBuffer();
+    rtn.append("\tName: " + _name);
+    rtn.append("\n\tType: 0x" + Integer.toHexString((int)_type));
+    rtn.append("\n\tNumber: " + _columnNumber);
+    rtn.append("\n\tLength: " + _columnLength);
+    rtn.append("\n\tVariable length: " + _variableLength);
+    rtn.append("\n\tCompressed Unicode: " + _compressedUnicode);
+    rtn.append("\n\n");
+    return rtn.toString();
+  }
+  
+  public int compareTo(Object obj) {
+    Column other = (Column) obj;
+    if (_columnNumber > other.getColumnNumber()) {
+      return 1;
+    } else if (_columnNumber < other.getColumnNumber()) {
+      return -1;
+    } else {
+      return 0;
+    }
+  }
+  
+  /**
+   * @param columns A list of columns in a table definition
+   * @return The number of variable length columns found in the list
+   */
+  public static short countVariableLength(List columns) {
+    short rtn = 0;
+    Iterator iter = columns.iterator();
+    while (iter.hasNext()) {
+      Column col = (Column) iter.next();
+      if (col.isVariableLength()) {
+        rtn++;
+      }
+    }
+    return rtn;
+  }
+  
+}