javajs.util.CompoundDocHeader Maven / Gradle / Ivy
/* $RCSfile$
* $Author$
* $Date$
* $Revision$
*
* Copyright (C) 2011 The Jmol Development Team
*
* Contact: [email protected]
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
package javajs.util;
class CompoundDocHeader {
/**
*
*/
private final CompoundDocument cd;
/**
* @param compoundDocument
*/
CompoundDocHeader(CompoundDocument compoundDocument) {
cd = compoundDocument;
}
//512 bytes
//offset 0:
byte[] magicNumbers = new byte[8]; // D0CF11E0A1B11AE1
byte[] uniqueID16 = new byte[16];
byte revNumber; // 3E = 62
//byte unusedb1;
byte verNumber; // 3
//byte unusedb2;
//short byteOrder; // -2 littleEndian
short sectorPower; // 2^sectorPower = sector size; 512 = 2^9
short shortSectorPower; // 2^shortSectorPower = short sector size; 64 = 2^6
byte[] unused = new byte[10];
int nSATsectors; // number of sectors for sector allocation table
int SID_DIR_start; // sector identifier of start of directory sector
//offset 56:
int minBytesStandardStream; // less than this (and not DIR) will be "short"
int SID_SSAT_start; // start of short sector allocation table (SSAT)
int nSSATsectors; // number of sectors allocated to SSAT
int SID_MSAT_next; // pointer to next master sector allocation table sector
int nAdditionalMATsectors; // number of sectors allocated to more MSAT sectors
//offset 76; 436 bytes:
int[] MSAT0 = new int[109]; // beginning of master allocation table
/*
* Sector 0 is first sector AFTER this header
*
* If sectorPower = 9, then this allows for 109 PAGES
* of sector allocation tables, with 127 pointers per
* page (plus 1 pointer to the next SAT page), each
* pointing to a sector of 512 bytes. Thus, with no additional
* MSAT pages, the header allows for 109*128*512 = 7.1 Mb file
*
*/
final boolean readData() {
try {
cd.readByteArray(magicNumbers, 0, 8);
if ((magicNumbers[0] & 0xFF) != 0xD0 || (magicNumbers[1] & 0xFF) != 0xCF
|| (magicNumbers[2] & 0xFF) != 0x11 || (magicNumbers[3] & 0xFF) != 0xE0
|| (magicNumbers[4] & 0xFF) != 0xA1 || (magicNumbers[5] & 0xFF) != 0xB1
|| (magicNumbers[6] & 0xFF) != 0x1A || (magicNumbers[7] & 0xFF) != 0xE1)
return false;
cd.readByteArray(uniqueID16, 0, 16);
revNumber = cd.readByte();
cd.readByte();
verNumber = cd.readByte();
cd.readByte();
byte b1 = cd.readByte();
byte b2 = cd.readByte();
cd.isBigEndian = (b1 == -1 && b2 == -2);
sectorPower = cd.readShort();
shortSectorPower = cd.readShort();
cd.readByteArray(unused, 0, 10);
nSATsectors = cd.readInt();
SID_DIR_start = cd.readInt();
cd.readByteArray(unused, 0, 4);
minBytesStandardStream = cd.readInt();
SID_SSAT_start = cd.readInt();
nSSATsectors = cd.readInt();
SID_MSAT_next = cd.readInt();
nAdditionalMATsectors = cd.readInt();
for (int i = 0; i < 109; i++)
MSAT0[i] = cd.readInt();
} catch (Exception e) {
System.out.println(e.toString());
return false;
}
return true;
}
}