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/*
*******************************************************************************
* (C) Copyright IBM Corp. 1996-2005 - All Rights Reserved *
* *
* The original version of this source code and documentation is copyrighted *
* and owned by IBM, These materials are provided under terms of a License *
* Agreement between IBM and Sun. This technology is protected by multiple *
* US and International patents. This notice and attribution to IBM may not *
* to removed. *
*******************************************************************************
*/
package sun.text.normalizer;
import java.io.DataInputStream;
import java.io.InputStream;
import java.io.IOException;
/**
* @author Ram Viswanadha
*/
/*
* Description of the format of unorm.icu version 2.1.
*
* Main change from version 1 to version 2:
* Use of new, common Trie instead of normalization-specific tries.
* Change to version 2.1: add third/auxiliary trie with associated data.
*
* For more details of how to use the data structures see the code
* in unorm.cpp (runtime normalization code) and
* in gennorm.c and gennorm/store.c (build-time data generation).
*
* For the serialized format of Trie see Trie.c/TrieHeader.
*
* - Overall partition
*
* unorm.icu customarily begins with a UDataInfo structure, see udata.h and .c.
* After that there are the following structures:
*
* char indexes[INDEX_TOP]; -- INDEX_TOP=32, see enum in this file
*
* Trie normTrie; -- size in bytes=indexes[INDEX_TRIE_SIZE]
*
* char extraData[extraDataTop]; -- extraDataTop=indexes[INDEX_UCHAR_COUNT]
* extraData[0] contains the number of units for
* FC_NFKC_Closure (formatVersion>=2.1)
*
* char combiningTable[combiningTableTop]; -- combiningTableTop=indexes[INDEX_COMBINE_DATA_COUNT]
* combiningTableTop may include one 16-bit padding unit
* to make sure that fcdTrie is 32-bit-aligned
*
* Trie fcdTrie; -- size in bytes=indexes[INDEX_FCD_TRIE_SIZE]
*
* Trie auxTrie; -- size in bytes=indexes[INDEX_AUX_TRIE_SIZE]
*
*
* The indexes array contains lengths and sizes of the following arrays and structures
* as well as the following values:
* indexes[INDEX_COMBINE_FWD_COUNT]=combineFwdTop
* -- one more than the highest combining index computed for forward-only-combining characters
* indexes[INDEX_COMBINE_BOTH_COUNT]=combineBothTop-combineFwdTop
* -- number of combining indexes computed for both-ways-combining characters
* indexes[INDEX_COMBINE_BACK_COUNT]=combineBackTop-combineBothTop
* -- number of combining indexes computed for backward-only-combining characters
*
* indexes[INDEX_MIN_NF*_NO_MAYBE] (where *={ C, D, KC, KD })
* -- first code point with a quick check NF* value of NO/MAYBE
*
*
* - Tries
*
* The main structures are two Trie tables ("compact arrays"),
* each with one index array and one data array.
* See Trie.h and Trie.c.
*
*
* - Tries in unorm.icu
*
* The first trie (normTrie above)
* provides data for the NF* quick checks and normalization.
* The second trie (fcdTrie above) provides data just for FCD checks.
*
*
* - norm32 data words from the first trie
*
* The norm32Table contains one 32-bit word "norm32" per code point.
* It contains the following bit fields:
* 31..16 extra data index, EXTRA_SHIFT is used to shift this field down
* if this index is <EXTRA_INDEX_TOP then it is an index into
* extraData[] where variable-length normalization data for this
* code point is found
* if this index is <EXTRA_INDEX_TOP+EXTRA_SURROGATE_TOP
* then this is a norm32 for a leading surrogate, and the index
* value is used together with the following trailing surrogate
* code unit in the second trie access
* if this index is >=EXTRA_INDEX_TOP+EXTRA_SURROGATE_TOP
* then this is a norm32 for a "special" character,
* i.e., the character is a Hangul syllable or a Jamo
* see EXTRA_HANGUL etc.
* generally, instead of extracting this index from the norm32 and
* comparing it with the above constants,
* the normalization code compares the entire norm32 value
* with MIN_SPECIAL, SURROGATES_TOP, MIN_HANGUL etc.
*
* 15..8 combining class (cc) according to UnicodeData.txt
*
* 7..6 COMBINES_ANY flags, used in composition to see if a character
* combines with any following or preceding character(s)
* at all
* 7 COMBINES_BACK
* 6 COMBINES_FWD
*
* 5..0 quick check flags, set for "no" or "maybe", with separate flags for
* each normalization form
* the higher bits are "maybe" flags; for NF*D there are no such flags
* the lower bits are "no" flags for all forms, in the same order
* as the "maybe" flags,
* which is (MSB to LSB): NFKD NFD NFKC NFC
* 5..4 QC_ANY_MAYBE
* 3..0 QC_ANY_NO
* see further related constants
*
*
* - Extra data per code point
*
* "Extra data" is referenced by the index in norm32.
* It is variable-length data. It is only present, and only those parts
* of it are, as needed for a given character.
* The norm32 extra data index is added to the beginning of extraData[]
* to get to a vector of 16-bit words with data at the following offsets:
*
* [-1] Combining index for composition.
* Stored only if norm32&COMBINES_ANY .
* [0] Lengths of the canonical and compatibility decomposition strings.
* Stored only if there are decompositions, i.e.,
* if norm32&(QC_NFD|QC_NFKD)
* High byte: length of NFKD, or 0 if none
* Low byte: length of NFD, or 0 if none
* Each length byte also has another flag:
* Bit 7 of a length byte is set if there are non-zero
* combining classes (cc's) associated with the respective
* decomposition. If this flag is set, then the decomposition
* is preceded by a 16-bit word that contains the
* leading and trailing cc's.
* Bits 6..0 of a length byte are the length of the
* decomposition string, not counting the cc word.
* [1..n] NFD
* [n+1..] NFKD
*
* Each of the two decompositions consists of up to two parts:
* - The 16-bit words with the leading and trailing cc's.
* This is only stored if bit 7 of the corresponding length byte
* is set. In this case, at least one of the cc's is not zero.
* High byte: leading cc==cc of the first code point in the decomposition string
* Low byte: trailing cc==cc of the last code point in the decomposition string
* - The decomposition string in UTF-16, with length code units.
*
*
* - Combining indexes and combiningTable[]
*
* Combining indexes are stored at the [-1] offset of the extra data
* if the character combines forward or backward with any other characters.
* They are used for (re)composition in NF*C.
* Values of combining indexes are arranged according to whether a character
* combines forward, backward, or both ways:
* forward-only < both ways < backward-only
*
* The index values for forward-only and both-ways combining characters
* are indexes into the combiningTable[].
* The index values for backward-only combining characters are simply
* incremented from the preceding index values to be unique.
*
* In the combiningTable[], a variable-length list
* of variable-length (back-index, code point) pair entries is stored
* for each forward-combining character.
*
* These back-indexes are the combining indexes of both-ways or backward-only
* combining characters that the forward-combining character combines with.
*
* Each list is sorted in ascending order of back-indexes.
* Each list is terminated with the last back-index having bit 15 set.
*
* Each pair (back-index, code point) takes up either 2 or 3
* 16-bit words.
* The first word of a list entry is the back-index, with its bit 15 set if
* this is the last pair in the list.
*
* The second word contains flags in bits 15..13 that determine
* if there is a third word and how the combined character is encoded:
* 15 set if there is a third word in this list entry
* 14 set if the result is a supplementary character
* 13 set if the result itself combines forward
*
* According to these bits 15..14 of the second word,
* the result character is encoded as follows:
* 00 or 01 The result is <=0x1fff and stored in bits 12..0 of
* the second word.
* 10 The result is 0x2000..0xffff and stored in the third word.
* Bits 12..0 of the second word are not used.
* 11 The result is a supplementary character.
* Bits 9..0 of the leading surrogate are in bits 9..0 of
* the second word.
* Add 0xd800 to these bits to get the complete surrogate.
* Bits 12..10 of the second word are not used.
* The trailing surrogate is stored in the third word.
*
*
* - FCD trie
*
* The FCD trie is very simple.
* It is a folded trie with 16-bit data words.
* In each word, the high byte contains the leading cc of the character,
* and the low byte contains the trailing cc of the character.
* These cc's are the cc's of the first and last code points in the
* canonical decomposition of the character.
*
* Since all 16 bits are used for cc's, lead surrogates must be tested
* by checking the code unit instead of the trie data.
* This is done only if the 16-bit data word is not zero.
* If the code unit is a leading surrogate and the data word is not zero,
* then instead of cc's it contains the offset for the second trie lookup.
*
*
* - Auxiliary trie and data
*
*
* The auxiliary 16-bit trie contains data for additional properties.
* Bits
* 15..13 reserved
* 12 not NFC_Skippable (f) (formatVersion>=2.2)
* 11 flag: not a safe starter for canonical closure
* 10 composition exclusion
* 9.. 0 index into extraData[] to FC_NFKC_Closure string
* (not for lead surrogate),
* or lead surrogate offset (for lead surrogate, if 9..0 not zero)
*
* Conditions for "NF* Skippable" from Mark Davis' com.ibm.text.UCD.NFSkippable:
* (used in NormalizerTransliterator)
*
* A skippable character is
* a) unassigned, or ALL of the following:
* b) of combining class 0.
* c) not decomposed by this normalization form.
* AND if NFC or NFKC,
* d) can never compose with a previous character.
* e) can never compose with a following character.
* f) can never change if another character is added.
* Example: a-breve might satisfy all but f, but if you
* add an ogonek it changes to a-ogonek + breve
*
* a)..e) must be tested from norm32.
* Since f) is more complicated, the (not-)NFC_Skippable flag (f) is built
* into the auxiliary trie.
* The same bit is used for NFC and NFKC; (c) differs for them.
* As usual, we build the "not skippable" flags so that unassigned
* code points get a 0 bit.
* This bit is only valid after (a)..(e) test FALSE; test NFD_NO before (f) as well.
* Test Hangul LV syllables entirely in code.
*
*
* - FC_NFKC_Closure strings in extraData[]
*
* Strings are either stored as a single code unit or as the length
* followed by that many units.
*
*/
final class NormalizerDataReader implements ICUBinary.Authenticate {
/**
* <p>Protected constructor.</p>
* @param inputStream ICU uprop.dat file input stream
* @exception IOException throw if data file fails authentication
* @draft 2.1
*/
protected NormalizerDataReader(InputStream inputStream)
throws IOException{
unicodeVersion = ICUBinary.readHeader(inputStream, DATA_FORMAT_ID, this);
dataInputStream = new DataInputStream(inputStream);
}
// protected methods -------------------------------------------------
protected int[] readIndexes(int length)throws IOException{
int[] indexes = new int[length];
//Read the indexes
for (int i = 0; i <length ; i++) {
indexes[i] = dataInputStream.readInt();
}
return indexes;
}
/**
* <p>Reads unorm.icu, parse it into blocks of data to be stored in
* NormalizerImpl.</P
* @param normBytes
* @param fcdBytes
* @param auxBytes
* @param extraData
* @param combiningTable
* @exception thrown when data reading fails
* @draft 2.1
*/
protected void read(byte[] normBytes, byte[] fcdBytes, byte[] auxBytes,
char[] extraData, char[] combiningTable)
throws IOException{
//Read the bytes that make up the normTrie
dataInputStream.read(normBytes);
//normTrieStream= new ByteArrayInputStream(normBytes);
//Read the extra data
for(int i=0;i<extraData.length;i++){
extraData[i]=dataInputStream.readChar();
}
//Read the combining class table
for(int i=0; i<combiningTable.length; i++){
combiningTable[i]=dataInputStream.readChar();
}
//Read the fcdTrie
dataInputStream.read(fcdBytes);
//Read the AuxTrie
dataInputStream.read(auxBytes);
}
public byte[] getDataFormatVersion(){
return DATA_FORMAT_VERSION;
}
public boolean isDataVersionAcceptable(byte version[])
{
return version[0] == DATA_FORMAT_VERSION[0]
&& version[2] == DATA_FORMAT_VERSION[2]
&& version[3] == DATA_FORMAT_VERSION[3];
}
public byte[] getUnicodeVersion(){
return unicodeVersion;
}
// private data members -------------------------------------------------
/**
* ICU data file input stream
*/
private DataInputStream dataInputStream;
private byte[] unicodeVersion;
/**
* File format version that this class understands.
* No guarantees are made if a older version is used
* see store.c of gennorm for more information and values
*/
private static final byte DATA_FORMAT_ID[] = {(byte)0x4E, (byte)0x6F,
(byte)0x72, (byte)0x6D};
private static final byte DATA_FORMAT_VERSION[] = {(byte)0x2, (byte)0x2,
(byte)0x5, (byte)0x2};
}