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- /*
- Copyright (c) 2008 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.BufferedReader;
- import java.io.IOException;
- import java.io.InputStreamReader;
- import java.util.Arrays;
- import java.util.HashMap;
- import java.util.Map;
-
- import static com.healthmarketscience.jackcess.ByteUtil.ByteStream;
-
- /**
- * Various constants used for creating "general legacy" (access 2000-2007)
- * sort order text index entries.
- *
- * @author James Ahlborn
- */
- public class GeneralLegacyIndexCodes {
-
- static final int MAX_TEXT_INDEX_CHAR_LENGTH =
- (JetFormat.TEXT_FIELD_MAX_LENGTH / JetFormat.TEXT_FIELD_UNIT_SIZE);
-
- static final byte END_TEXT = (byte)0x01;
- static final byte END_EXTRA_TEXT = (byte)0x00;
-
- // unprintable char is removed from normal text.
- // pattern for unprintable chars in the extra bytes:
- // 01 01 01 <pos> 06 <code> )
- // <pos> = 7 + (4 * char_pos) | 0x8000 (as short)
- // <code> = char code
- static final int UNPRINTABLE_COUNT_START = 7;
- static final int UNPRINTABLE_COUNT_MULTIPLIER = 4;
- static final int UNPRINTABLE_OFFSET_FLAGS = 0x8000;
- static final byte UNPRINTABLE_MIDFIX = (byte)0x06;
-
- // international char is replaced with ascii char.
- // pattern for international chars in the extra bytes:
- // [ 02 (for each normal char) ] [ <symbol_code> (for each inat char) ]
- static final byte INTERNATIONAL_EXTRA_PLACEHOLDER = (byte)0x02;
-
- // see Index.writeCrazyCodes for details on writing crazy codes
- static final byte CRAZY_CODE_START = (byte)0x80;
- static final byte CRAZY_CODE_1 = (byte)0x02;
- static final byte CRAZY_CODE_2 = (byte)0x03;
- static final byte[] CRAZY_CODES_SUFFIX =
- new byte[]{(byte)0xFF, (byte)0x02, (byte)0x80, (byte)0xFF, (byte)0x80};
- static final byte CRAZY_CODES_UNPRINT_SUFFIX = (byte)0xFF;
-
- // stash the codes in some resource files
- private static final String CODES_FILE =
- Database.RESOURCE_PATH + "index_codes_genleg.txt";
- private static final String EXT_CODES_FILE =
- Database.RESOURCE_PATH + "index_codes_ext_genleg.txt";
-
- /**
- * Enum which classifies the types of char encoding strategies used when
- * creating text index entries.
- */
- enum Type {
- SIMPLE("S") {
- @Override public CharHandler parseCodes(String[] codeStrings) {
- return parseSimpleCodes(codeStrings);
- }
- },
- INTERNATIONAL("I") {
- @Override public CharHandler parseCodes(String[] codeStrings) {
- return parseInternationalCodes(codeStrings);
- }
- },
- UNPRINTABLE("U") {
- @Override public CharHandler parseCodes(String[] codeStrings) {
- return parseUnprintableCodes(codeStrings);
- }
- },
- UNPRINTABLE_EXT("P") {
- @Override public CharHandler parseCodes(String[] codeStrings) {
- return parseUnprintableExtCodes(codeStrings);
- }
- },
- INTERNATIONAL_EXT("Z") {
- @Override public CharHandler parseCodes(String[] codeStrings) {
- return parseInternationalExtCodes(codeStrings);
- }
- },
- IGNORED("X") {
- @Override public CharHandler parseCodes(String[] codeStrings) {
- return IGNORED_CHAR_HANDLER;
- }
- };
-
- private final String _prefixCode;
-
- private Type(String prefixCode) {
- _prefixCode = prefixCode;
- }
-
- public String getPrefixCode() {
- return _prefixCode;
- }
-
- public abstract CharHandler parseCodes(String[] codeStrings);
- }
-
- /**
- * Base class for the handlers which hold the text index character encoding
- * information.
- */
- abstract static class CharHandler {
- public abstract Type getType();
- public byte[] getInlineBytes() {
- return null;
- }
- public byte[] getExtraBytes() {
- return null;
- }
- public byte[] getUnprintableBytes() {
- return null;
- }
- public byte getExtraByteModifier() {
- return 0;
- }
- public byte getCrazyFlag() {
- return 0;
- }
- }
-
- /**
- * CharHandler for Type.SIMPLE
- */
- private static final class SimpleCharHandler extends CharHandler {
- private byte[] _bytes;
- private SimpleCharHandler(byte[] bytes) {
- _bytes = bytes;
- }
- @Override public Type getType() {
- return Type.SIMPLE;
- }
- @Override public byte[] getInlineBytes() {
- return _bytes;
- }
- }
-
- /**
- * CharHandler for Type.INTERNATIONAL
- */
- private static final class InternationalCharHandler extends CharHandler {
- private byte[] _bytes;
- private byte[] _extraBytes;
- private InternationalCharHandler(byte[] bytes, byte[] extraBytes) {
- _bytes = bytes;
- _extraBytes = extraBytes;
- }
- @Override public Type getType() {
- return Type.INTERNATIONAL;
- }
- @Override public byte[] getInlineBytes() {
- return _bytes;
- }
- @Override public byte[] getExtraBytes() {
- return _extraBytes;
- }
- }
-
- /**
- * CharHandler for Type.UNPRINTABLE
- */
- private static final class UnprintableCharHandler extends CharHandler {
- private byte[] _unprintBytes;
- private UnprintableCharHandler(byte[] unprintBytes) {
- _unprintBytes = unprintBytes;
- }
- @Override public Type getType() {
- return Type.UNPRINTABLE;
- }
- @Override public byte[] getUnprintableBytes() {
- return _unprintBytes;
- }
- }
-
- /**
- * CharHandler for Type.UNPRINTABLE_EXT
- */
- private static final class UnprintableExtCharHandler extends CharHandler {
- private byte _extraByteMod;
- private UnprintableExtCharHandler(Byte extraByteMod) {
- _extraByteMod = extraByteMod;
- }
- @Override public Type getType() {
- return Type.UNPRINTABLE_EXT;
- }
- @Override public byte getExtraByteModifier() {
- return _extraByteMod;
- }
- }
-
- /**
- * CharHandler for Type.INTERNATIONAL_EXT
- */
- private static final class InternationalExtCharHandler extends CharHandler {
- private byte[] _bytes;
- private byte[] _extraBytes;
- private byte _crazyFlag;
- private InternationalExtCharHandler(byte[] bytes, byte[] extraBytes,
- byte crazyFlag) {
- _bytes = bytes;
- _extraBytes = extraBytes;
- _crazyFlag = crazyFlag;
- }
- @Override public Type getType() {
- return Type.INTERNATIONAL_EXT;
- }
- @Override public byte[] getInlineBytes() {
- return _bytes;
- }
- @Override public byte[] getExtraBytes() {
- return _extraBytes;
- }
- @Override public byte getCrazyFlag() {
- return _crazyFlag;
- }
- }
-
- /** shared CharHandler instance for Type.IGNORED */
- static final CharHandler IGNORED_CHAR_HANDLER = new CharHandler() {
- @Override public Type getType() {
- return Type.IGNORED;
- }
- };
-
- /** alternate shared CharHandler instance for "surrogate" chars (which we do
- not handle) */
- static final CharHandler SURROGATE_CHAR_HANDLER = new CharHandler() {
- @Override public Type getType() {
- return Type.IGNORED;
- }
- @Override public byte[] getInlineBytes() {
- throw new IllegalStateException(
- "Surrogate pair chars are not handled");
- }
- };
-
- static final char FIRST_CHAR = (char)0x0000;
- static final char LAST_CHAR = (char)0x00FF;
- static final char FIRST_EXT_CHAR = LAST_CHAR + 1;
- static final char LAST_EXT_CHAR = (char)0xFFFF;
-
- private static final class Codes
- {
- /** handlers for the first 256 chars. use nested class to lazy load the
- handlers */
- private static final CharHandler[] _values = loadCodes(
- CODES_FILE, FIRST_CHAR, LAST_CHAR);
- }
-
- private static final class ExtCodes
- {
- /** handlers for the rest of the chars in BMP 0. use nested class to
- lazy load the handlers */
- private static final CharHandler[] _values = loadCodes(
- EXT_CODES_FILE, FIRST_EXT_CHAR, LAST_EXT_CHAR);
- }
-
- static final GeneralLegacyIndexCodes GEN_LEG_INSTANCE =
- new GeneralLegacyIndexCodes();
-
- GeneralLegacyIndexCodes() {
- }
-
- /**
- * Returns the CharHandler for the given character.
- */
- CharHandler getCharHandler(char c)
- {
- if(c <= LAST_CHAR) {
- return Codes._values[c];
- }
-
- int extOffset = asUnsignedChar(c) - asUnsignedChar(FIRST_EXT_CHAR);
- return ExtCodes._values[extOffset];
- }
-
- /**
- * Loads the CharHandlers for the given range of characters from the
- * resource file with the given name.
- */
- static CharHandler[] loadCodes(String codesFilePath,
- char firstChar, char lastChar)
- {
- int numCodes = (asUnsignedChar(lastChar) - asUnsignedChar(firstChar)) + 1;
- CharHandler[] values = new CharHandler[numCodes];
-
- Map<String,Type> prefixMap = new HashMap<String,Type>();
- for(Type type : Type.values()) {
- prefixMap.put(type.getPrefixCode(), type);
- }
-
- BufferedReader reader = null;
- try {
-
- reader = new BufferedReader(
- new InputStreamReader(
- Database.getResourceAsStream(codesFilePath), "US-ASCII"));
-
- int start = asUnsignedChar(firstChar);
- int end = asUnsignedChar(lastChar);
- for(int i = start; i <= end; ++i) {
- char c = (char)i;
- CharHandler ch = null;
- if(Character.isHighSurrogate(c) || Character.isLowSurrogate(c)) {
- // surrogate chars are not included in the codes files
- ch = SURROGATE_CHAR_HANDLER;
- } else {
- String codeLine = reader.readLine();
- ch = parseCodes(prefixMap, codeLine);
- }
- values[(i - start)] = ch;
- }
-
- } catch(IOException e) {
- throw new RuntimeException("failed loading index codes file " +
- codesFilePath, e);
- } finally {
- if (reader != null) {
- try {
- reader.close();
- } catch (IOException ex) {
- // ignored
- }
- }
- }
-
- return values;
- }
-
- /**
- * Returns a CharHandler parsed from the given line from an index codes
- * file.
- */
- private static CharHandler parseCodes(Map<String,Type> prefixMap,
- String codeLine)
- {
- String prefix = codeLine.substring(0, 1);
- String suffix = ((codeLine.length() > 1) ? codeLine.substring(1) : "");
- return prefixMap.get(prefix).parseCodes(suffix.split(",", -1));
- }
-
- /**
- * Returns a SimpleCharHandler parsed from the given index code strings.
- */
- private static CharHandler parseSimpleCodes(String[] codeStrings)
- {
- if(codeStrings.length != 1) {
- throw new IllegalStateException("Unexpected code strings " +
- Arrays.asList(codeStrings));
- }
- return new SimpleCharHandler(codesToBytes(codeStrings[0], true));
- }
-
- /**
- * Returns an InternationalCharHandler parsed from the given index code
- * strings.
- */
- private static CharHandler parseInternationalCodes(String[] codeStrings)
- {
- if(codeStrings.length != 2) {
- throw new IllegalStateException("Unexpected code strings " +
- Arrays.asList(codeStrings));
- }
- return new InternationalCharHandler(codesToBytes(codeStrings[0], true),
- codesToBytes(codeStrings[1], true));
- }
-
- /**
- * Returns a UnprintableCharHandler parsed from the given index code
- * strings.
- */
- private static CharHandler parseUnprintableCodes(String[] codeStrings)
- {
- if(codeStrings.length != 1) {
- throw new IllegalStateException("Unexpected code strings " +
- Arrays.asList(codeStrings));
- }
- return new UnprintableCharHandler(codesToBytes(codeStrings[0], true));
- }
-
- /**
- * Returns a UnprintableExtCharHandler parsed from the given index code
- * strings.
- */
- private static CharHandler parseUnprintableExtCodes(String[] codeStrings)
- {
- if(codeStrings.length != 1) {
- throw new IllegalStateException("Unexpected code strings " +
- Arrays.asList(codeStrings));
- }
- byte[] bytes = codesToBytes(codeStrings[0], true);
- if(bytes.length != 1) {
- throw new IllegalStateException("Unexpected code strings " +
- Arrays.asList(codeStrings));
- }
- return new UnprintableExtCharHandler(bytes[0]);
- }
-
- /**
- * Returns a InternationalExtCharHandler parsed from the given index code
- * strings.
- */
- private static CharHandler parseInternationalExtCodes(String[] codeStrings)
- {
- if(codeStrings.length != 3) {
- throw new IllegalStateException("Unexpected code strings " +
- Arrays.asList(codeStrings));
- }
-
- byte crazyFlag = ("1".equals(codeStrings[2]) ?
- CRAZY_CODE_1 : CRAZY_CODE_2);
- return new InternationalExtCharHandler(codesToBytes(codeStrings[0], true),
- codesToBytes(codeStrings[1], false),
- crazyFlag);
- }
-
- /**
- * Converts a string of hex encoded bytes to a byte[], optionally throwing
- * an exception if no codes are given.
- */
- private static byte[] codesToBytes(String codes, boolean required)
- {
- if(codes.length() == 0) {
- if(required) {
- throw new IllegalStateException("empty code bytes");
- }
- return null;
- }
- if((codes.length() % 2) != 0) {
- // stripped a leading 0
- codes = "0" + codes;
- }
- byte[] bytes = new byte[codes.length() / 2];
- for(int i = 0; i < bytes.length; ++i) {
- int charIdx = i*2;
- bytes[i] = (byte)(Integer.parseInt(codes.substring(charIdx, charIdx + 2),
- 16));
- }
- return bytes;
- }
-
- /**
- * Returns an the char value converted to an unsigned char value. Note, I
- * think this is unnecessary (I think java treats chars as unsigned), but I
- * did this just to be on the safe side.
- */
- static int asUnsignedChar(char c)
- {
- return c & 0xFFFF;
- }
-
- /**
- * Converts an index value for a text column into the entry value (which
- * is based on a variety of nifty codes).
- */
- void writeNonNullIndexTextValue(
- Object value, ByteStream bout, boolean isAscending)
- throws IOException
- {
- // first, convert to string
- String str = Column.toCharSequence(value).toString();
-
- // all text columns (including memos) are only indexed up to the max
- // number of chars in a VARCHAR column
- if(str.length() > MAX_TEXT_INDEX_CHAR_LENGTH) {
- str = str.substring(0, MAX_TEXT_INDEX_CHAR_LENGTH);
- }
-
- // record pprevious entry length so we can do any post-processing
- // necessary for this entry (handling descending)
- int prevLength = bout.getLength();
-
- // now, convert each character to a "code" of one or more bytes
- ExtraCodesStream extraCodes = null;
- ByteStream unprintableCodes = null;
- ByteStream crazyCodes = null;
- int charOffset = 0;
- for(int i = 0; i < str.length(); ++i) {
-
- char c = str.charAt(i);
- CharHandler ch = getCharHandler(c);
-
- int curCharOffset = charOffset;
- byte[] bytes = ch.getInlineBytes();
- if(bytes != null) {
- // write the "inline" codes immediately
- bout.write(bytes);
-
- // only increment the charOffset for chars with inline codes
- ++charOffset;
- }
-
- if(ch.getType() == Type.SIMPLE) {
- // common case, skip further code handling
- continue;
- }
-
- bytes = ch.getExtraBytes();
- byte extraCodeModifier = ch.getExtraByteModifier();
- if((bytes != null) || (extraCodeModifier != 0)) {
- if(extraCodes == null) {
- extraCodes = new ExtraCodesStream(str.length());
- }
-
- // keep track of the extra codes for later
- writeExtraCodes(curCharOffset, bytes, extraCodeModifier, extraCodes);
- }
-
- bytes = ch.getUnprintableBytes();
- if(bytes != null) {
- if(unprintableCodes == null) {
- unprintableCodes = new ByteStream();
- }
-
- // keep track of the unprintable codes for later
- writeUnprintableCodes(curCharOffset, bytes, unprintableCodes,
- extraCodes);
- }
-
- byte crazyFlag = ch.getCrazyFlag();
- if(crazyFlag != 0) {
- if(crazyCodes == null) {
- crazyCodes = new ByteStream();
- }
-
- // keep track of the crazy flags for later
- crazyCodes.write(crazyFlag);
- }
- }
-
- // write end text flag
- bout.write(END_TEXT);
-
- boolean hasExtraCodes = trimExtraCodes(
- extraCodes, (byte)0, INTERNATIONAL_EXTRA_PLACEHOLDER);
- boolean hasUnprintableCodes = (unprintableCodes != null);
- boolean hasCrazyCodes = (crazyCodes != null);
- if(hasExtraCodes || hasUnprintableCodes || hasCrazyCodes) {
-
- // we write all the international extra bytes first
- if(hasExtraCodes) {
- extraCodes.writeTo(bout);
- }
-
- if(hasCrazyCodes || hasUnprintableCodes) {
-
- // write 2 more end flags
- bout.write(END_TEXT);
- bout.write(END_TEXT);
-
- // next come the crazy flags
- if(hasCrazyCodes) {
-
- writeCrazyCodes(crazyCodes, bout);
-
- // if we are writing unprintable codes after this, tack on another
- // code
- if(hasUnprintableCodes) {
- bout.write(CRAZY_CODES_UNPRINT_SUFFIX);
- }
- }
-
- // then we write all the unprintable extra bytes
- if(hasUnprintableCodes) {
-
- // write another end flag
- bout.write(END_TEXT);
-
- unprintableCodes.writeTo(bout);
- }
- }
- }
-
- // handle descending order by inverting the bytes
- if(!isAscending) {
-
- // we actually write the end byte before flipping the bytes, and write
- // another one after flipping
- bout.write(END_EXTRA_TEXT);
-
- // flip the bytes that we have written thus far for this text value
- IndexData.flipBytes(bout.getBytes(), prevLength,
- (bout.getLength() - prevLength));
- }
-
- // write end extra text
- bout.write(END_EXTRA_TEXT);
- }
-
- /**
- * Encodes the given extra code info in the given stream.
- */
- private static void writeExtraCodes(
- int charOffset, byte[] bytes, byte extraCodeModifier,
- ExtraCodesStream extraCodes)
- throws IOException
- {
- // we fill in a placeholder value for any chars w/out extra codes
- int numChars = extraCodes.getNumChars();
- if(numChars < charOffset) {
- int fillChars = charOffset - numChars;
- extraCodes.writeFill(fillChars, INTERNATIONAL_EXTRA_PLACEHOLDER);
- extraCodes.incrementNumChars(fillChars);
- }
-
- if(bytes != null) {
-
- // write the actual extra codes and update the number of chars
- extraCodes.write(bytes);
- extraCodes.incrementNumChars(1);
-
- } else {
-
- // extra code modifiers modify the existing extra code bytes and do not
- // count as additional extra code chars
- int lastIdx = extraCodes.getLength() - 1;
- if(lastIdx >= 0) {
-
- // the extra code modifier is added to the last extra code written
- byte lastByte = extraCodes.get(lastIdx);
- lastByte += extraCodeModifier;
- extraCodes.set(lastIdx, lastByte);
-
- } else {
-
- // there is no previous extra code, add a new code (but keep track of
- // this "unprintable code" prefix)
- extraCodes.write(extraCodeModifier);
- extraCodes.setUnprintablePrefixLen(1);
- }
- }
- }
-
- /**
- * Trims any bytes in the given range off of the end of the given stream,
- * returning whether or not there are any bytes left in the given stream
- * after trimming.
- */
- private static boolean trimExtraCodes(ByteStream extraCodes,
- byte minTrimCode, byte maxTrimCode)
- throws IOException
- {
- if(extraCodes == null) {
- return false;
- }
-
- extraCodes.trimTrailing(minTrimCode, maxTrimCode);
-
- // anything left?
- return (extraCodes.getLength() > 0);
- }
-
- /**
- * Encodes the given unprintable char codes in the given stream.
- */
- private static void writeUnprintableCodes(
- int charOffset, byte[] bytes, ByteStream unprintableCodes,
- ExtraCodesStream extraCodes)
- throws IOException
- {
- // the offset seems to be calculated based on the number of bytes in the
- // "extra codes" part of the entry (even if there are no extra codes bytes
- // actually written in the final entry).
- int unprintCharOffset = charOffset;
- if(extraCodes != null) {
- // we need to account for some extra codes which have not been written
- // yet. additionally, any unprintable bytes added to the beginning of
- // the extra codes are ignored.
- unprintCharOffset = extraCodes.getLength() +
- (charOffset - extraCodes.getNumChars()) -
- extraCodes.getUnprintablePrefixLen();
- }
-
- // we write a whacky combo of bytes for each unprintable char which
- // includes a funky offset and extra char itself
- int offset =
- (UNPRINTABLE_COUNT_START +
- (UNPRINTABLE_COUNT_MULTIPLIER * unprintCharOffset))
- | UNPRINTABLE_OFFSET_FLAGS;
-
- // write offset as big-endian short
- unprintableCodes.write((offset >> 8) & 0xFF);
- unprintableCodes.write(offset & 0xFF);
-
- unprintableCodes.write(UNPRINTABLE_MIDFIX);
- unprintableCodes.write(bytes);
- }
-
- /**
- * Encode the given crazy code bytes into the given byte stream.
- */
- private static void writeCrazyCodes(ByteStream crazyCodes, ByteStream bout)
- throws IOException
- {
- // CRAZY_CODE_2 flags at the end are ignored, so ditch them
- trimExtraCodes(crazyCodes, CRAZY_CODE_2, CRAZY_CODE_2);
-
- if(crazyCodes.getLength() > 0) {
-
- // the crazy codes get encoded into 6 bit sequences where each code is 2
- // bits (where the first 2 bits in the byte are a common prefix).
- byte curByte = CRAZY_CODE_START;
- int idx = 0;
- for(int i = 0; i < crazyCodes.getLength(); ++i) {
- byte nextByte = crazyCodes.get(i);
- nextByte <<= ((2 - idx) * 2);
- curByte |= nextByte;
-
- ++idx;
- if(idx == 3) {
- // write current byte and reset
- bout.write(curByte);
- curByte = CRAZY_CODE_START;
- idx = 0;
- }
- }
-
- // write last byte
- if(idx > 0) {
- bout.write(curByte);
- }
- }
-
- // write crazy code suffix (note, we write this even if all the codes are
- // trimmed
- bout.write(CRAZY_CODES_SUFFIX);
- }
-
- /**
- * Extension of ByteStream which keeps track of an additional char count and
- * the length of any "unprintable" code prefix.
- */
- private static final class ExtraCodesStream extends ByteStream
- {
- private int _numChars;
- private int _unprintablePrefixLen;
-
- private ExtraCodesStream(int length) {
- super(length);
- }
-
- public int getNumChars() {
- return _numChars;
- }
-
- public void incrementNumChars(int inc) {
- _numChars += inc;
- }
-
- public int getUnprintablePrefixLen() {
- return _unprintablePrefixLen;
- }
-
- public void setUnprintablePrefixLen(int len) {
- _unprintablePrefixLen = len;
- }
- }
-
- }
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