diff options
Diffstat (limited to 'src/java/com/healthmarketscience/jackcess/JetFormat.java')
| -rw-r--r-- | src/java/com/healthmarketscience/jackcess/JetFormat.java | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/src/java/com/healthmarketscience/jackcess/JetFormat.java b/src/java/com/healthmarketscience/jackcess/JetFormat.java new file mode 100644 index 0000000..561e417 --- /dev/null +++ b/src/java/com/healthmarketscience/jackcess/JetFormat.java @@ -0,0 +1,302 @@ +/* +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.channels.FileChannel; +import java.nio.charset.Charset; + +/** + * Encapsulates constants describing a specific version of the Access Jet format + * @author Tim McCune + */ +public abstract class JetFormat { + + /** Maximum size of a record minus OLE objects and Memo fields */ + public static final int MAX_RECORD_SIZE = 1900; //2kb minus some overhead + + /** Maximum size of a text field */ + public static final short TEXT_FIELD_MAX_LENGTH = 255 * 2; + + /** Offset in the file that holds the byte describing the Jet format version */ + private static final long OFFSET_VERSION = 20L; + /** Version code for Jet version 3 */ + private static final byte CODE_VERSION_3 = 0x0; + /** Version code for Jet version 4 */ + private static final byte CODE_VERSION_4 = 0x1; + + //These constants are populated by this class's constructor. They can't be + //populated by the subclass's constructor because they are final, and Java + //doesn't allow this; hence all the abstract defineXXX() methods. + + /** Database page size in bytes */ + public final int PAGE_SIZE; + + public final int MAX_ROW_SIZE; + + public final int OFFSET_NEXT_TABLE_DEF_PAGE; + public final int OFFSET_NUM_ROWS; + public final int OFFSET_TABLE_TYPE; + public final int OFFSET_NUM_COLS; + public final int OFFSET_NUM_INDEXES; + public final int OFFSET_OWNED_PAGES; + public final int OFFSET_FREE_SPACE_PAGES; + public final int OFFSET_INDEX_DEF_BLOCK; + + public final int OFFSET_COLUMN_TYPE; + public final int OFFSET_COLUMN_NUMBER; + public final int OFFSET_COLUMN_PRECISION; + public final int OFFSET_COLUMN_SCALE; + public final int OFFSET_COLUMN_VARIABLE; + public final int OFFSET_COLUMN_COMPRESSED_UNICODE; + public final int OFFSET_COLUMN_LENGTH; + + public final int OFFSET_TABLE_DEF_LOCATION; + public final int OFFSET_NUM_ROWS_ON_PAGE; + public final int OFFSET_ROW_LOCATION_BLOCK; + + public final int OFFSET_ROW_START; + public final int OFFSET_MAP_START; + + public final int OFFSET_USAGE_MAP_PAGE_DATA; + + public final int OFFSET_REFERENCE_MAP_PAGE_NUMBERS; + + public final int OFFSET_FREE_SPACE; + public final int OFFSET_DATA_ROW_LOCATION_BLOCK; + public final int OFFSET_NUM_ROWS_ON_DATA_PAGE; + + public final int OFFSET_LVAL_ROW_LOCATION_BLOCK; + + public final int OFFSET_USED_PAGES_USAGE_MAP_DEF; + public final int OFFSET_FREE_PAGES_USAGE_MAP_DEF; + + public final int OFFSET_INDEX_ENTRY_MASK; + + public final int SIZE_INDEX_DEFINITION; + public final int SIZE_COLUMN_HEADER; + public final int SIZE_ROW_LOCATION; + public final int SIZE_LONG_VALUE_DEF; + public final int SIZE_TDEF_BLOCK; + public final int SIZE_COLUMN_DEF_BLOCK; + public final int SIZE_INDEX_ENTRY_MASK; + + public final int PAGES_PER_USAGE_MAP_PAGE; + + public final Charset CHARSET; + + public static final JetFormat VERSION_4 = new Jet4Format(); + + /** + * @return The Jet Format represented in the passed-in file + */ + public static JetFormat getFormat(FileChannel channel) throws IOException { + ByteBuffer buffer = ByteBuffer.allocate(1); + channel.read(buffer, OFFSET_VERSION); + buffer.flip(); + byte version = buffer.get(); + if (version == CODE_VERSION_4) { + return VERSION_4; + } else { + throw new IOException("Unsupported version: " + version); + } + } + + private JetFormat() { + + PAGE_SIZE = definePageSize(); + + MAX_ROW_SIZE = defineMaxRowSize(); + + OFFSET_NEXT_TABLE_DEF_PAGE = defineOffsetNextTableDefPage(); + OFFSET_NUM_ROWS = defineOffsetNumRows(); + OFFSET_TABLE_TYPE = defineOffsetTableType(); + OFFSET_NUM_COLS = defineOffsetNumCols(); + OFFSET_NUM_INDEXES = defineOffsetNumIndexes(); + OFFSET_OWNED_PAGES = defineOffsetOwnedPages(); + OFFSET_FREE_SPACE_PAGES = defineOffsetFreeSpacePages(); + OFFSET_INDEX_DEF_BLOCK = defineOffsetIndexDefBlock(); + + OFFSET_COLUMN_TYPE = defineOffsetColumnType(); + OFFSET_COLUMN_NUMBER = defineOffsetColumnNumber(); + OFFSET_COLUMN_PRECISION = defineOffsetColumnPrecision(); + OFFSET_COLUMN_SCALE = defineOffsetColumnScale(); + OFFSET_COLUMN_VARIABLE = defineOffsetColumnVariable(); + OFFSET_COLUMN_COMPRESSED_UNICODE = defineOffsetColumnCompressedUnicode(); + OFFSET_COLUMN_LENGTH = defineOffsetColumnLength(); + + OFFSET_TABLE_DEF_LOCATION = defineOffsetTableDefLocation(); + OFFSET_NUM_ROWS_ON_PAGE = defineOffsetNumRowsOnPage(); + OFFSET_ROW_LOCATION_BLOCK = defineOffsetRowLocationBlock(); + + OFFSET_ROW_START = defineOffsetRowStart(); + OFFSET_MAP_START = defineOffsetMapStart(); + + OFFSET_USAGE_MAP_PAGE_DATA = defineOffsetUsageMapPageData(); + + OFFSET_REFERENCE_MAP_PAGE_NUMBERS = defineOffsetReferenceMapPageNumbers(); + + OFFSET_FREE_SPACE = defineOffsetFreeSpace(); + OFFSET_DATA_ROW_LOCATION_BLOCK = defineOffsetDataRowLocationBlock(); + OFFSET_NUM_ROWS_ON_DATA_PAGE = defineOffsetNumRowsOnDataPage(); + + OFFSET_LVAL_ROW_LOCATION_BLOCK = defineOffsetLvalRowLocationBlock(); + + OFFSET_USED_PAGES_USAGE_MAP_DEF = defineOffsetUsedPagesUsageMapDef(); + OFFSET_FREE_PAGES_USAGE_MAP_DEF = defineOffsetFreePagesUsageMapDef(); + + OFFSET_INDEX_ENTRY_MASK = defineOffsetIndexEntryMask(); + + SIZE_INDEX_DEFINITION = defineSizeIndexDefinition(); + SIZE_COLUMN_HEADER = defineSizeColumnHeader(); + SIZE_ROW_LOCATION = defineSizeRowLocation(); + SIZE_LONG_VALUE_DEF = defineSizeLongValueDef(); + SIZE_TDEF_BLOCK = defineSizeTdefBlock(); + SIZE_COLUMN_DEF_BLOCK = defineSizeColumnDefBlock(); + SIZE_INDEX_ENTRY_MASK = defineSizeIndexEntryMask(); + + PAGES_PER_USAGE_MAP_PAGE = definePagesPerUsageMapPage(); + + CHARSET = defineCharset(); + } + + protected abstract int definePageSize(); + + protected abstract int defineMaxRowSize(); + + protected abstract int defineOffsetNextTableDefPage(); + protected abstract int defineOffsetNumRows(); + protected abstract int defineOffsetTableType(); + protected abstract int defineOffsetNumCols(); + protected abstract int defineOffsetNumIndexes(); + protected abstract int defineOffsetOwnedPages(); + protected abstract int defineOffsetFreeSpacePages(); + protected abstract int defineOffsetIndexDefBlock(); + + protected abstract int defineOffsetColumnType(); + protected abstract int defineOffsetColumnNumber(); + protected abstract int defineOffsetColumnPrecision(); + protected abstract int defineOffsetColumnScale(); + protected abstract int defineOffsetColumnVariable(); + protected abstract int defineOffsetColumnCompressedUnicode(); + protected abstract int defineOffsetColumnLength(); + + protected abstract int defineOffsetTableDefLocation(); + protected abstract int defineOffsetNumRowsOnPage(); + protected abstract int defineOffsetRowLocationBlock(); + + protected abstract int defineOffsetRowStart(); + protected abstract int defineOffsetMapStart(); + + protected abstract int defineOffsetUsageMapPageData(); + + protected abstract int defineOffsetReferenceMapPageNumbers(); + + protected abstract int defineOffsetFreeSpace(); + protected abstract int defineOffsetDataRowLocationBlock(); + protected abstract int defineOffsetNumRowsOnDataPage(); + + protected abstract int defineOffsetLvalRowLocationBlock(); + + protected abstract int defineOffsetUsedPagesUsageMapDef(); + protected abstract int defineOffsetFreePagesUsageMapDef(); + + protected abstract int defineOffsetIndexEntryMask(); + + protected abstract int defineSizeIndexDefinition(); + protected abstract int defineSizeColumnHeader(); + protected abstract int defineSizeRowLocation(); + protected abstract int defineSizeLongValueDef(); + protected abstract int defineSizeTdefBlock(); + protected abstract int defineSizeColumnDefBlock(); + protected abstract int defineSizeIndexEntryMask(); + + protected abstract int definePagesPerUsageMapPage(); + + protected abstract Charset defineCharset(); + + private static final class Jet4Format extends JetFormat { + + protected int definePageSize() { return 4096; } + + protected int defineMaxRowSize() { return PAGE_SIZE - 18; } + + protected int defineOffsetNextTableDefPage() { return 4; } + protected int defineOffsetNumRows() { return 16; } + protected int defineOffsetTableType() { return 40; } + protected int defineOffsetNumCols() { return 45; } + protected int defineOffsetNumIndexes() { return 47; } + protected int defineOffsetOwnedPages() { return 55; } + protected int defineOffsetFreeSpacePages() { return 59; } + protected int defineOffsetIndexDefBlock() { return 63; } + + protected int defineOffsetColumnType() { return 0; } + protected int defineOffsetColumnNumber() { return 5; } + protected int defineOffsetColumnPrecision() { return 11; } + protected int defineOffsetColumnScale() { return 12; } + protected int defineOffsetColumnVariable() { return 15; } + protected int defineOffsetColumnCompressedUnicode() { return 16; } + protected int defineOffsetColumnLength() { return 23; } + + protected int defineOffsetTableDefLocation() { return 4; } + protected int defineOffsetNumRowsOnPage() { return 12; } + protected int defineOffsetRowLocationBlock() { return 16; } + + protected int defineOffsetRowStart() { return 14; } + protected int defineOffsetMapStart() { return 5; } + + protected int defineOffsetUsageMapPageData() { return 4; } + + protected int defineOffsetReferenceMapPageNumbers() { return 1; } + + protected int defineOffsetFreeSpace() { return 2; } + protected int defineOffsetDataRowLocationBlock() { return 14; } + protected int defineOffsetNumRowsOnDataPage() { return 12; } + + protected int defineOffsetLvalRowLocationBlock() { return 10; } + + protected int defineOffsetUsedPagesUsageMapDef() { return 4027; } + protected int defineOffsetFreePagesUsageMapDef() { return 3958; } + + protected int defineOffsetIndexEntryMask() { return 27; } + + protected int defineSizeIndexDefinition() { return 12; } + protected int defineSizeColumnHeader() { return 25; } + protected int defineSizeRowLocation() { return 2; } + protected int defineSizeLongValueDef() { return 12; } + protected int defineSizeTdefBlock() { return 63; } + protected int defineSizeColumnDefBlock() { return 25; } + protected int defineSizeIndexEntryMask() { return 453; } + + protected int definePagesPerUsageMapPage() { return 4092 * 8; } + + protected Charset defineCharset() { return Charset.forName("UTF-16LE"); } + } + +} |