net.sf.mpxj.mpp.FixedData Maven / Gradle / Ivy
/*
* file: FixedData.java
* author: Jon Iles
* copyright: (c) Packwood Software 2002-2003
* date: 03/01/2003
*/
/*
* 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.
*/
package net.sf.mpxj.mpp;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
/**
* This class is used to represent the "FixedData" file entries that are
* found in a Microsoft Project MPP file. The name "Fixed Data" appears to
* refer to the fact that the items held in these blocks have a known maximum
* size, rather than all of the items being identically sized records.
*
* Note that this class has package level access only, and is not intended
* for use outside of this context.
*/
final class FixedData extends MPPComponent
{
/**
* This constructor retrieves the data from the input stream. It
* makes use of the meta data regarding this data block that has
* already been read in from the MPP file.
*
* Note that we actually read in the entire data block in one go.
* This is due to the fact that MS Project sometimes describes data
* using offsets that are out of sequence, and items that may overlap.
* Ideally this data would be read directly from the input stream, but
* this was problematic, so this less than ideal solution has been
* adopted.
*
* @param meta meta data about the contents of this fixed data block
* @param is input stream from which the data is read
* @throws IOException on file read failure
*/
FixedData(FixedMeta meta, InputStream is)
throws IOException
{
this(meta, is, 0);
}
/**
* This version of the above constructor allows us to limit the
* size of blocks we copy where we have an idea of the maximum expected
* block size. This prevents us from reading ridiculously large amounts
* of unnecessary data, causing OutOfMemory exceptions.
*
* @param meta meta data about the contents of this fixed data block
* @param is input stream from which the data is read
* @param maxExpectedSize maximum expected block size
* @throws IOException on file read failure
*/
FixedData(FixedMeta meta, InputStream is, int maxExpectedSize)
throws IOException
{
this(meta, is, maxExpectedSize, 0);
}
/**
* This version of the above constructor allows us to limit the
* size of blocks we copy where we have an idea of the maximum expected
* block size. This prevents us from reading ridiculously large amounts
* of unnecessary data, causing OutOfMemory exceptions.
*
* This constructor will also use the given minimum size in the case that the
* meta data block reports a size of 0
*
* @param meta meta data about the contents of this fixed data block
* @param maxExpectedSize maximum expected block size
* @param minSize minimum size that will be read if size of block is reported as 0.
* @param is input stream from which the data is read
* @throws IOException on file read failure
*/
FixedData(FixedMeta meta, InputStream is, int maxExpectedSize, int minSize)
throws IOException
{
byte[] buffer = new byte[is.available()];
is.read(buffer);
int itemCount = meta.getAdjustedItemCount();
m_array = new Object[itemCount];
m_offset = new int[itemCount];
int available;
for (int loop = 0; loop < itemCount; loop++)
{
byte[] metaData = meta.getByteArrayValue(loop);
int itemOffset = MPPUtility.getInt(metaData, 4);
if (itemOffset < 0 || itemOffset > buffer.length)
{
continue;
}
int itemSize;
if (loop + 1 == itemCount)
{
itemSize = buffer.length - itemOffset;
}
else
{
byte[] nextMetaData = meta.getByteArrayValue(loop + 1);
int nextItemOffset = MPPUtility.getInt(nextMetaData, 4);
itemSize = nextItemOffset - itemOffset;
}
if (itemSize == 0)
{
itemSize = minSize;
}
available = buffer.length - itemOffset;
if (itemSize < 0 || itemSize > available)
{
if (maxExpectedSize == 0)
{
itemSize = available;
}
else
{
if (maxExpectedSize < available)
{
itemSize = maxExpectedSize;
}
else
{
itemSize = available;
}
}
}
if (maxExpectedSize != 0 && itemSize > maxExpectedSize)
{
itemSize = maxExpectedSize;
}
if (itemSize > 0)
{
m_array[loop] = MPPUtility.cloneSubArray(buffer, itemOffset, itemSize);
m_offset[loop] = itemOffset;
}
}
}
/**
* This constructor does the same job as the one above, but assumes that
* the item size reported in the meta information is wrong, and
* instead uses the supplied item size.
*
* @param meta meta data about the contents of this fixed data block
* @param itemSize expected item size
* @param is input stream from which the data is read
* @throws IOException
*/
FixedData(FixedMeta meta, int itemSize, InputStream is)
throws IOException
{
byte[] buffer = new byte[is.available()];
is.read(buffer);
int itemCount = meta.getAdjustedItemCount();
m_array = new Object[itemCount];
m_offset = new int[itemCount];
byte[] metaData;
int itemOffset;
int available;
for (int loop = 0; loop < itemCount; loop++)
{
metaData = meta.getByteArrayValue(loop);
itemOffset = MPPUtility.getInt(metaData, 4);
if (itemOffset > buffer.length)
{
continue;
}
available = buffer.length - itemOffset;
if (itemSize < 0)
{
itemSize = available;
}
else
{
if (itemSize > available)
{
itemSize = available;
}
}
m_array[loop] = MPPUtility.cloneSubArray(buffer, itemOffset, itemSize);
m_offset[loop] = itemOffset;
}
}
/**
* This constructor is provided to allow the contents of a fixed data
* block to be read when the size of the items in the data block is
* fixed and known in advance. This is used in one particular instance
* where the contents of the meta data block do not appear to be
* consistent.
*
* @param itemSize the size of the data items in the block
* @param is input stream from which the data is read
* @throws IOException on file read failure
*/
FixedData(int itemSize, InputStream is)
throws IOException
{
this(itemSize, is, false);
}
/**
* This constructor is provided to allow the contents of a fixed data
* block to be read when the size of the items in the data block is
* fixed and known in advance. This is used in one particular instance
* where the contents of the meta data block do not appear to be
* consistent.
*
* @param itemSize the size of the data items in the block
* @param is input stream from which the data is read
* @param readRemainderBlock read the final block even if it is not full size
* @throws IOException on file read failure
*/
FixedData(int itemSize, InputStream is, boolean readRemainderBlock)
throws IOException
{
int offset = 0;
int itemCount = is.available() / itemSize;
if (readRemainderBlock == true && is.available() % itemSize != 0)
{
++itemCount;
}
m_array = new Object[itemCount];
m_offset = new int[itemCount];
for (int loop = 0; loop < itemCount; loop++)
{
m_offset[loop] = offset;
int currentItemSize = itemSize;
if (readRemainderBlock == true && is.available() < itemSize)
{
currentItemSize = is.available();
}
m_array[loop] = readByteArray(is, currentItemSize);
offset += itemSize;
}
}
/**
* This method retrieves a byte array containing the data at the
* given index in the block. If no data is found at the given index
* this method returns null.
*
* @param index index of the data item to be retrieved
* @return byte array containing the requested data
*/
public byte[] getByteArrayValue(int index)
{
byte[] result = null;
if (index >= 0 && index < m_array.length && m_array[index] != null)
{
result = (byte[]) m_array[index];
}
return (result);
}
/**
* Accessor method used to retrieve the number of items held in
* this fixed data block. Note that this item count is made without
* reference to the meta data associated with this block.
*
* @return number of items in the block
*/
public int getItemCount()
{
return (m_array.length);
}
/**
* Returns a flag indicating if the supplied offset is valid for
* the data in this fixed data block.
*
* @param offset offset value
* @return boolean flag
*/
public boolean isValidOffset(Integer offset)
{
return (offset == null ? false : isValidOffset(offset.intValue()));
}
/**
* Returns a flag indicating if the supplied offset is valid for
* the data in this fixed data block.
*
* @param offset offset value
* @return boolean flag
*/
public boolean isValidOffset(int offset)
{
return (offset >= 0 && offset < m_array.length);
}
/**
* This method converts an offset value into an array index, which in
* turn allows the data present in the fixed block to be retrieved. Note
* that if the requested offset is not found, then this method returns -1.
*
* @param offset Offset of the data in the fixed block
* @return Index of data item within the fixed data block
*/
public int getIndexFromOffset(int offset)
{
int result = -1;
for (int loop = 0; loop < m_offset.length; loop++)
{
if (m_offset[loop] == offset)
{
result = loop;
break;
}
}
return (result);
}
/**
* This method dumps the contents of this FixedData block as a String.
* Note that this facility is provided as a debugging aid.
*
* @return formatted contents of this block
*/
@Override public String toString()
{
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
pw.println("BEGIN FixedData");
for (int loop = 0; loop < m_array.length; loop++)
{
pw.println(" Data at index: " + loop + " offset: " + m_offset[loop]);
pw.println(" " + MPPUtility.hexdump((byte[]) m_array[loop], true));
}
pw.println("END FixedData");
pw.println();
pw.close();
return (sw.toString());
}
/**
* An array containing all of the items of data held in this block.
*/
private Object[] m_array;
/**
* Array containing offset values for each item in the array.
*/
private int[] m_offset;
}
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