839 lines
20 KiB
C++
839 lines
20 KiB
C++
/*----------------------------------------------------------------------------
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%%File: fechauto.c
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%%Unit: fechmap
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%%Contact: jpick
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Module that attempts to auto-detect encoding for a given stream.
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----------------------------------------------------------------------------*/
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#include <stdio.h>
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#include <stddef.h>
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#include "private.h"
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#include "fechmap_.h"
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#include "lexint_.h"
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// Code marked by these #defines will be deleted eventually ...
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// (It prints out useful information and statistics about how
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// auto-detect is doing and what it's finding in the input).
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//
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#define JPDEBUG 0
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#define JPDEBUG2 0
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#define JPDEBUG3 0
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#define NEED_NAMES 0
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#if JPDEBUG || JPDEBUG2 || JPDEBUG3
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#undef NEED_NAMES
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#define NEED_NAMES 1
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#endif
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#if NEED_NAMES
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static char *rgszIcetNames[icetCount] =
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{
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"icetEucCn",
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"icetEucJp",
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"icetEucKr",
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"icetEucTw",
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"icetIso2022Cn",
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"icetIso2022Jp",
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"icetIso2022Kr",
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"icetIso2022Tw",
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"icetBig5",
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"icetGbk",
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"icetHz",
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"icetShiftJis",
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"icetWansung",
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"icetUtf7",
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"icetUtf8",
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};
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#endif
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// Characters we care about
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//
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#define chSo (UCHAR) 0x0e
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#define chSi (UCHAR) 0x0f
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#define chEsc (UCHAR) 0x1b
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// Minimum Sample Size
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//
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#define cchMinSample 64
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// High-ASCII character threshold. If this routine is unable
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// to absolutely determine the encoding of this file, it will
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// need to guess. Files that are ASCII, but contain high-ASCII
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// characters (e.g., a file with some Cyrillic characters) may
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// confuse us. If the number of high-ASCII characters falls
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// below this threshold, return the encoding we guessed but
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// also return a special rc that says the file "might be ASCII."
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//
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// 5%, for now.
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//
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// 40%, for now, of the high-ascii characters must be in high-
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// ascii pairs. (Pulled down because of Big5 and the other
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// DBCS encodings that can have trail bytes in the low range).
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//
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#define nHighCharThreshold 5 // %
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#define nHighPairThreshold 40 // %
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// Used by CceDetermineInputTypeReturnAll() to determine whether any icet has
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// high enough count to rule out all other icets.
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//
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#define CchCountThreshold(icet) (((icet) == icetHz || (icet) == icetUtf7) ? 5 : 10)
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// Tokens
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//
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// Stop tokens (negative) imply special handling and will cause
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// the processing loop to stop (eof, err, si, so and esc are
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// stop tokens).
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//
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#define xmn 0
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#define esc (-1)
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#define so (-2)
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#define si (-3)
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#define eof (-4)
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#define err (-5)
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#define _FStopToken(tk) ((tk) < 0)
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// Masks used in _CBitsOnFromUlong()
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//
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#define lMaskBitCount1 (LONG) 0x55555555
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#define lMaskBitCount2 (LONG) 0x33333333
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#define lMaskBitCount3 (LONG) 0x0F0F0F0F
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#define lMaskBitCount4 (LONG) 0x00FF00FF
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#define lMaskBitCount5 (LONG) 0x0000FFFF
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/* _ C B I T S O N F R O M U L O N G */
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/*----------------------------------------------------------------------------
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%%Function: _CBitsOnFromUlong
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%%Contact: jpick
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(adapted from code in convio.c)
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----------------------------------------------------------------------------*/
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int __inline _CBitsOnFromUlong(ULONG ulBits)
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{
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ulBits = (ulBits & lMaskBitCount1) + ((ulBits & ~lMaskBitCount1) >> 1);
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ulBits = (ulBits & lMaskBitCount2) + ((ulBits & ~lMaskBitCount2) >> 2);
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ulBits = (ulBits & lMaskBitCount3) + ((ulBits & ~lMaskBitCount3) >> 4);
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ulBits = (ulBits & lMaskBitCount4) + ((ulBits & ~lMaskBitCount4) >> 8);
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ulBits = (ulBits & lMaskBitCount5) + ((ulBits & ~lMaskBitCount5) >> 16);
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return (int)ulBits;
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}
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// Masks for the encodings
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//
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#define grfEucCn (ULONG) 0x0001
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#define grfEucJp (ULONG) 0x0002
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#define grfEucKr (ULONG) 0x0004
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#define grfEucTw (ULONG) 0x0008
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#define grfIso2022Cn (ULONG) 0x0010
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#define grfIso2022Jp (ULONG) 0x0020
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#define grfIso2022Kr (ULONG) 0x0040
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#define grfIso2022Tw (ULONG) 0x0080
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#define grfBig5 (ULONG) 0x0100
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#define grfGbk (ULONG) 0x0200
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#define grfHz (ULONG) 0x0400
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#define grfShiftJis (ULONG) 0x0800
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#define grfWansung (ULONG) 0x1000
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#define grfUtf7 (ULONG) 0x2000
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#define grfUtf8 (ULONG) 0x4000
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// grfAll assumes that the tests for Euc-Kr fall within those
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// for Wansung (as far as I can tell from reading, Euc-Kr is a
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// strict subset of Wansung). The same for Euc-Cn and Gbk. No
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// need to test for both the subset and the whole.
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//
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#define grfAll (ULONG) 0x7FFA
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#define grfAllButIso2022 (ULONG) 0x7F0A
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#define cAll 13 // == number bits set in grfAll
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#define cAllButIso2022 9 // == number bits set in grfAllButIso2022
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// Array that maps an encoding to its mask
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//
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static ULONG _mpicetgrf[icetCount] =
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{
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grfEucCn,
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grfEucJp,
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grfEucKr,
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grfEucTw,
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grfIso2022Cn,
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grfIso2022Jp,
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grfIso2022Kr,
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grfIso2022Tw,
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grfBig5,
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grfGbk,
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grfHz,
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grfShiftJis,
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grfWansung,
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grfUtf7,
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grfUtf8,
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};
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// Prototypes
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//
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static int _NGetNextUch(IStream *pstmIn, unsigned char *c, BOOL *lpfIsHigh);
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static ICET _IcetFromIcetMask(ULONG ulMask);
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static ICET _IcetDefaultFromIcetMask(ULONG ulMask);
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static CCE _CceResolveAmbiguity(ULONG grfIcet, ICET *lpicet, int nPrefCp, EFam efPref);
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static CCE _CceReadEscSeq(IStream *pstmIn, int nPrefCp, ICET *lpicet, BOOL *lpfGuess);
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/* C C E D E T E R M I N E I N P U T T Y P E */
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/*----------------------------------------------------------------------------
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%%Function: CceDetermineInputType
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%%Contact: jpick
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Attempt to determine the appropriate ICET type for the given
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stream. Caller-supplied get/unget routines used for data access.
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----------------------------------------------------------------------------*/
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CCE CceDetermineInputType(
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IStream *pstmIn, // input stream
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DWORD dwFlags, // configuration flags
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EFam efPref, // optional: preferred encoding family
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int nPrefCp, // optional: preferred code page
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ICET *lpicet, // set to detected encoding
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BOOL *lpfGuess // set to fTrue if function "guessed"
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)
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{
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unsigned char uch;
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int nToken;
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CCE cceRet;
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BOOL fGuess;
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ICET icet;
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int cIcetActive;
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ULONG grfIcetActive; // Bitarray tracks which encodings are still active candidates.
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ICET icetSeq;
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int i, nCount, nCountCurr;
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DWORD dwValFlags;
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BOOL fIsHigh;
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int cchHigh = 0;
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int cchHighPairs = 0;
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int cchTotal = 0;
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BOOL fLastHigh = fFalse;
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#if JPDEBUG3
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ULONG grfIcetNoCommonChars;
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#endif
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#if JPDEBUG
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printf("flags: %d\n", dwFlags);
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#endif
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// Initialize parsers
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//
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dwValFlags = grfCountCommonChars;
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if (dwFlags & grfDetectUseCharMapping)
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dwValFlags |= grfValidateCharMapping;
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ValidateInitAll(dwValFlags);
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// Initialize locals -- be optimistic
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//
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cceRet = cceSuccess;
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fGuess = fFalse;
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grfIcetActive = grfAllButIso2022;
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cIcetActive = cAllButIso2022;
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#if JPDEBUG3
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grfIcetNoCommonChars = grfAllButIso2022;
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#endif
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while (fTrue)
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{
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nToken = _NGetNextUch(pstmIn, &uch, &fIsHigh);
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if (_FStopToken(nToken))
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break;
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// Update (admittedly dumb) statistics -- really counts high
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// ascii characters in runs (not really pairs). But threshold
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// constants (defined, above) were determined by calculating
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// exactly these numbers for ~25 files, so it should be ok (?).
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//
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++cchTotal;
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if (fIsHigh)
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{
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++cchHigh;
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if (fLastHigh)
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++cchHighPairs;
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}
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fLastHigh = fIsHigh;
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for (i = 0; i < icetCount; i++)
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{
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if (!(grfIcetActive & _mpicetgrf[i]) || (NValidateUch((ICET)i, uch, fFalse) != 0))
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continue;
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grfIcetActive &= ~_mpicetgrf[i];
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--cIcetActive;
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#if JPDEBUG
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printf("Log: Lost %s at offset 0x%.4x (%d), char 0x%.2x\n", rgszIcetNames[i], (cchTotal-1), (cchTotal-1), uch);
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#endif
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}
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#if JPDEBUG3
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for (i = 0; i < icetCount; i++)
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{
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if (!(grfIcetActive & _mpicetgrf[i]) || !(grfIcetNoCommonChars & _mpicetgrf[i]))
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continue;
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if (!FValidateCharCount(i, &nCount) || (nCount == 0))
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continue;
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grfIcetNoCommonChars &= ~_mpicetgrf[i];
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printf("Log: Found first common seq for %s at offset 0x%.4x (%d)\n", rgszIcetNames[i], (cchTotal-1), (cchTotal-1));
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}
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#endif
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if ((cIcetActive == 0) || ((cIcetActive == 1) && (cchTotal > cchMinSample)))
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break;
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}
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// Figure out why we exited the loop.
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//
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if (nToken == err)
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{
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cceRet = cceRead;
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goto _LRet;
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}
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// Process escapes separately. Interpret the escape sequence
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// to determine for real which ISO7 flavor we have found.
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//
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if ((nToken == esc) || (nToken == so) || (nToken == si))
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{
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LARGE_INTEGER li;
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HRESULT hr;
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LISet32(li, -1 );
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hr = pstmIn->Seek(li,STREAM_SEEK_CUR, NULL);
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// if (!pfnUnget(uch, lpvPrivate))
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// {
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// cceRet = cceUnget;
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// goto _LRet;
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// }
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cceRet = _CceReadEscSeq(pstmIn, nPrefCp, &icet, &fGuess);
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#if JPDEBUG
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if (cceRet == cceSuccess)
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printf("Log: Found encoding %s at offset 0x%.4x (%d)\n", rgszIcetNames[icet], cchTotal, cchTotal);
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#endif
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// ISO is a special case -- no need to check statistics.
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//
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goto _LRet;
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}
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#if JPDEBUG2
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printf("Counts: %d total chars, %d high chars, %d high pairs\n", cchTotal, cchHigh, cchHighPairs);
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#endif
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// If the token was eof, and we're not ignoring eof, transition
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// the remaining active sets on eof.
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//
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if ((nToken == eof) && !(dwFlags & grfDetectIgnoreEof))
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{
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for (i = 0; i < icetCount; i++)
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{
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if (!(grfIcetActive & _mpicetgrf[i]) || (NValidateUch((ICET)i, 0, fTrue) != 0))
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continue;
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#if JPDEBUG
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printf("Log: Lost %s at EOF\n", rgszIcetNames[i]);
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#endif
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grfIcetActive &= ~_mpicetgrf[i];
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--cIcetActive;
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}
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}
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Assert(cIcetActive >= 0); // better *not* be less than 0
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// See how we've narrowed our field of choices and set the
|
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// return status accordingly.
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//
|
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if (cIcetActive <= 0)
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{
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#if JPDEBUG
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printf("Log: Bailed out entirely at offset 0x%.4x (%d)\n", cchTotal, cchTotal);
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#endif
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cceRet = cceUnknownInput;
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goto _LRet;
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}
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else if (cIcetActive == 1)
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{
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icet = _IcetFromIcetMask(grfIcetActive);
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#if JPDEBUG
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printf("Log: Found encoding %s at offset 0x%.4x (%d)\n", rgszIcetNames[icet], cchTotal, cchTotal);
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#endif
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// If we matched an encoding type and also found matching
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// common character runs, skip statistics (see comment,
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// below).
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//
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if (FValidateCharCount(icet, &nCount) && (nCount > 0))
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{
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#if JPDEBUG3
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printf("Log: %d common sequences for %s\n", nCount, rgszIcetNames[icet]);
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#endif
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goto _LRet;
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}
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else
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{
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goto _LStats;
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}
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}
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|
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// Did we learn anything from counting characters?
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//
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icetSeq = (ICET)-1;
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nCountCurr = 0;
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for (i = 0; i < icetCount; i++)
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{
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if (!(grfIcetActive & _mpicetgrf[i]) || !FValidateCharCount((ICET)i, &nCount))
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continue;
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if (nCount > nCountCurr)
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{
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icetSeq = (ICET)i;
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nCountCurr = nCount;
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}
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|
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#if JPDEBUG3
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printf("Log: %d common sequences for %s\n", nCount, rgszIcetNames[i]);
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#endif
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}
|
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|
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// Any luck? If so, return. Don't bother checking statistics.
|
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// We just proved that we found at least one common run of
|
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// characters in this input. The odds against this for just a
|
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// plain ASCII file with some high characters seem pretty high.
|
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// Ignore the statistics and just return the encoding type we
|
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// found.
|
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//
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if (icetSeq != -1)
|
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{
|
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icet = icetSeq;
|
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goto _LRet;
|
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}
|
|
|
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#if JPDEBUG
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printf("Log: Active Icet Mask 0x%.8x, %d left\n", grfIcetActive, cIcetActive);
|
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printf("Log: Icet's left -- ");
|
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for (i = 0; i < icetCount; i++)
|
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{
|
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if (grfIcetActive & _mpicetgrf[i])
|
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printf("%s, ", rgszIcetNames[i]);
|
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}
|
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printf("\n");
|
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#endif
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|
|
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// If caller did not want us to try to guess at the encoding
|
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// in the absence of definitive data, bail out.
|
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//
|
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if (!(dwFlags & grfDetectResolveAmbiguity))
|
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{
|
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cceRet = cceAmbiguousInput;
|
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goto _LRet;
|
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}
|
|
|
|
// We're guessing -- note it.
|
|
//
|
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fGuess = fTrue;
|
|
|
|
// More than one active encoding. Attempt to resolve ambiguity.
|
|
//
|
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cceRet = _CceResolveAmbiguity(grfIcetActive, &icet, nPrefCp, efPref);
|
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if (cceRet != cceSuccess)
|
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return cceRet;
|
|
|
|
_LStats:
|
|
|
|
// Adjust the return code based on the "statistics" we gathered,
|
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// above.
|
|
//
|
|
if (cchHigh > 0)
|
|
{
|
|
if ((cchTotal < cchMinSample) ||
|
|
(((cchHigh * 100) / cchTotal) < nHighCharThreshold) ||
|
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(((cchHighPairs * 100) / cchHigh) < nHighPairThreshold))
|
|
{
|
|
cceRet = cceMayBeAscii;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
cceRet = cceMayBeAscii; // no high-ascii characters? definitely maybe!
|
|
}
|
|
|
|
#if JPDEBUG2
|
|
if (cchHigh > 0)
|
|
{
|
|
int nPercent1 = ((cchHigh * 100) / cchTotal);
|
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int nPercent2 = ((cchHighPairs * 100) / cchHigh);
|
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printf("Ratios -- high/total: %d%%, runs/high: %d%%\n", nPercent1, nPercent2);
|
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}
|
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#endif
|
|
|
|
_LRet:
|
|
|
|
// Set the return variables, if successful.
|
|
//
|
|
if ((cceRet == cceSuccess) || (cceRet == cceMayBeAscii))
|
|
{
|
|
*lpicet = icet;
|
|
*lpfGuess = fGuess;
|
|
}
|
|
|
|
#if JPDEBUG
|
|
if (cceRet == cceSuccess)
|
|
{
|
|
printf("Log: Returning %s, fGuess = %s\n", rgszIcetNames[icet], (fGuess ? "fTrue" : "fFalse"));
|
|
}
|
|
else if (cceRet == cceMayBeAscii)
|
|
{
|
|
printf("Log: Returning %s, fGuess = %s, may-be-ASCII\n", rgszIcetNames[icet], (fGuess ? "fTrue" : "fFalse"));
|
|
}
|
|
#endif
|
|
|
|
return cceRet;
|
|
}
|
|
|
|
|
|
/* _ N G E T N E X T U C H */
|
|
/*----------------------------------------------------------------------------
|
|
%%Function: _NGetNextUch
|
|
%%Contact: jpick
|
|
|
|
Get the next character from the input stream. Classify the character.
|
|
----------------------------------------------------------------------------*/
|
|
static int _NGetNextUch(IStream *pstmIn, unsigned char *c, BOOL *lpfIsHigh)
|
|
{
|
|
ULONG rc;
|
|
unsigned char uch;
|
|
HRESULT hr;
|
|
|
|
hr = pstmIn->Read(&uch, 1, &rc);
|
|
|
|
if (rc == 0)
|
|
return eof;
|
|
else if (hr != S_OK )
|
|
return err;
|
|
|
|
*lpfIsHigh = (uch >= 0x80);
|
|
*c = uch;
|
|
|
|
switch (uch)
|
|
{
|
|
case chEsc:
|
|
return esc;
|
|
case chSo:
|
|
return so;
|
|
case chSi:
|
|
return si;
|
|
default:
|
|
return xmn;
|
|
}
|
|
}
|
|
|
|
|
|
// Masks for _CceResolveAmbiguity() -- only externally supported character
|
|
// sets are used in ambiguity resolution. Don't include Euc-Tw here.
|
|
//
|
|
#define grfJapan (ULONG) (grfShiftJis | grfEucJp)
|
|
#define grfChina (ULONG) (grfEucCn | grfGbk)
|
|
#define grfKorea (ULONG) (grfEucKr | grfWansung)
|
|
#define grfTaiwan (ULONG) (grfBig5)
|
|
#define grfDbcs (ULONG) (grfShiftJis | grfGbk | grfWansung | grfBig5)
|
|
#define grfEuc (ULONG) (grfEucJp | grfEucKr | grfEucCn)
|
|
|
|
|
|
/* _ C E F R O M C E M A S K */
|
|
/*----------------------------------------------------------------------------
|
|
%%Function: _IcetFromIcetMask
|
|
%%Contact: jpick
|
|
----------------------------------------------------------------------------*/
|
|
static ICET _IcetFromIcetMask(ULONG ulMask)
|
|
{
|
|
switch (ulMask)
|
|
{
|
|
case grfEucCn:
|
|
return icetEucCn;
|
|
case grfEucJp:
|
|
return icetEucJp;
|
|
case grfEucKr:
|
|
return icetEucKr;
|
|
case grfEucTw:
|
|
return icetEucTw;
|
|
case grfIso2022Cn:
|
|
return icetIso2022Cn;
|
|
case grfIso2022Jp:
|
|
return icetIso2022Jp;
|
|
case grfIso2022Kr:
|
|
return icetIso2022Kr;
|
|
case grfIso2022Tw:
|
|
return icetIso2022Tw;
|
|
case grfBig5:
|
|
return icetBig5;
|
|
case grfGbk:
|
|
return icetGbk;
|
|
case grfHz:
|
|
return icetHz;
|
|
case grfShiftJis:
|
|
return icetShiftJis;
|
|
case grfWansung:
|
|
return icetWansung;
|
|
case grfUtf7:
|
|
return icetUtf7;
|
|
case grfUtf8:
|
|
return icetUtf8;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
// Should never get here ...
|
|
//
|
|
// NotReached();
|
|
|
|
// Can't return a bogus value, here.
|
|
//
|
|
return icetShiftJis;
|
|
}
|
|
|
|
/* _ C E D E F A U L T F R O M C E M A S K */
|
|
/*----------------------------------------------------------------------------
|
|
%%Function: _IcetDefaultFromIcetMask
|
|
%%Contact: jpick
|
|
----------------------------------------------------------------------------*/
|
|
static ICET _IcetDefaultFromIcetMask(ULONG ulMask)
|
|
{
|
|
// Priorities -- DBCS, EUC, Japan, Taiwan, China and Korea (???).
|
|
//
|
|
if (ulMask & grfDbcs)
|
|
{
|
|
if (ulMask & grfJapan)
|
|
return icetShiftJis;
|
|
if (ulMask & grfChina)
|
|
return icetGbk;
|
|
if (ulMask & grfTaiwan)
|
|
return icetBig5;
|
|
if (ulMask & grfKorea)
|
|
return icetWansung;
|
|
}
|
|
else // EUC
|
|
{
|
|
if (ulMask & grfJapan)
|
|
return icetEucJp;
|
|
if (ulMask & grfChina)
|
|
return icetEucCn;
|
|
if (ulMask & grfKorea)
|
|
return icetEucKr; // may be able to return icetWansung, here
|
|
}
|
|
|
|
// (Assert);
|
|
return icetShiftJis; // ???
|
|
}
|
|
|
|
/* _ U L C E M A S K F R O M C P E T P */
|
|
/*----------------------------------------------------------------------------
|
|
%%Function: _UlIcetMaskFromCpEf
|
|
%%Contact: jpick
|
|
----------------------------------------------------------------------------*/
|
|
static ULONG _UlIcetMaskFromCpEf(int nCp, EFam ef)
|
|
{
|
|
ULONG grf = grfAll;
|
|
|
|
switch (nCp)
|
|
{
|
|
case nCpJapan:
|
|
grf &= grfJapan;
|
|
break;
|
|
case nCpChina:
|
|
grf &= grfChina;
|
|
break;
|
|
case nCpKorea:
|
|
grf &= grfKorea;
|
|
break;
|
|
case nCpTaiwan:
|
|
grf &= grfTaiwan;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
switch (ef)
|
|
{
|
|
case efDbcs:
|
|
grf &= grfDbcs;
|
|
break;
|
|
case efEuc:
|
|
grf &= grfEuc;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return grf;
|
|
}
|
|
|
|
|
|
/* _ C C E R E S O L V E A M B I G U I T Y */
|
|
/*----------------------------------------------------------------------------
|
|
%%Function: _CceResolveAmbiguity
|
|
%%Contact: jpick
|
|
|
|
Attempt to resolve ambiguous input encoding based on user
|
|
preferences, if set, and system code page. grfIcet contains a
|
|
bitmask representing the encodings that are still possible after
|
|
examining the input sample.
|
|
----------------------------------------------------------------------------*/
|
|
static CCE _CceResolveAmbiguity(ULONG grfIcet, ICET *lpicet, int nPrefCp, EFam efPref)
|
|
{
|
|
ULONG grfIcetOrig = grfIcet;
|
|
ULONG grfPref;
|
|
ULONG grfSys;
|
|
ULONG grfResult;
|
|
int cIcet;
|
|
|
|
// Build "list" of encodings based on user-prefs.
|
|
//
|
|
grfPref = _UlIcetMaskFromCpEf(nPrefCp, efPref);
|
|
|
|
// See if the user's preferences make any difference.
|
|
//
|
|
grfResult = grfIcet & grfPref;
|
|
|
|
if (grfResult)
|
|
{
|
|
cIcet = _CBitsOnFromUlong(grfResult);
|
|
if (cIcet == 1)
|
|
{
|
|
*lpicet = _IcetFromIcetMask(grfResult);
|
|
return cceSuccess;
|
|
}
|
|
else
|
|
grfIcet = grfResult; // see comment, below
|
|
}
|
|
|
|
// Now look to the system code page for help. Look at
|
|
// the set of encodings as modified by the user
|
|
// preferences (??? do we want to do this ???).
|
|
//
|
|
if (!FIsFeCp(g_uACP) || (grfIcetOrig & grfUtf8))
|
|
goto _LDefault;
|
|
|
|
// Build "list" of encodings based on system cp.
|
|
//
|
|
grfSys = _UlIcetMaskFromCpEf(g_uACP, (EFam) 0);
|
|
|
|
// See if the system cp makes any difference.
|
|
//
|
|
grfResult = grfIcet & grfSys;
|
|
|
|
if (grfResult)
|
|
{
|
|
cIcet = _CBitsOnFromUlong(grfResult);
|
|
if (cIcet == 1)
|
|
{
|
|
*lpicet = _IcetFromIcetMask(grfResult);
|
|
return cceSuccess;
|
|
}
|
|
}
|
|
|
|
_LDefault:
|
|
|
|
// Special case -- pick UTF-8 if it's legal and the prefs
|
|
// don't help us.
|
|
//
|
|
*lpicet =
|
|
(grfIcetOrig & grfUtf8) ? icetUtf8 : _IcetDefaultFromIcetMask(grfIcet);
|
|
return cceSuccess;
|
|
}
|
|
|
|
|
|
/* _ C C E R E A D E S C S E Q */
|
|
/*----------------------------------------------------------------------------
|
|
%%Function: _CceReadEscSeq
|
|
%%Contact: jpick
|
|
|
|
We've read (and put back) an escape character. Call the ISO-2022
|
|
escape sequence converter to have it map the escape sequence to the
|
|
appropriate character set. We may be looking at the escape sequence
|
|
for ASCII, so be prepared to read ahead to the next one.
|
|
----------------------------------------------------------------------------*/
|
|
static CCE _CceReadEscSeq(
|
|
IStream *pstmIn, // input stream
|
|
int nPrefCp,
|
|
ICET *lpicet,
|
|
BOOL *lpfGuess
|
|
)
|
|
{
|
|
unsigned char uch;
|
|
CCE cceRet;
|
|
int nToken;
|
|
BOOL fDummy;
|
|
|
|
do
|
|
{
|
|
cceRet = CceReadEscSeq(pstmIn, lpicet);
|
|
|
|
if ((cceRet == cceSuccess) || (cceRet != cceMayBeAscii))
|
|
break;
|
|
|
|
while (fTrue)
|
|
{
|
|
nToken = _NGetNextUch(pstmIn, &uch, &fDummy);
|
|
if (_FStopToken(nToken))
|
|
break;
|
|
}
|
|
|
|
// Why did we stop?
|
|
//
|
|
if (nToken == err)
|
|
{
|
|
cceRet = cceRead;
|
|
break;
|
|
}
|
|
else if (nToken == eof)
|
|
{
|
|
// Means this is legal ISO-2022 input, but we've seen nothing
|
|
// but non-flavor-specific escape sequences (e.g., only ASCII
|
|
// or shift sequences). Choose the encoding type based on
|
|
// preferences (only pick from those currently supported
|
|
// externally).
|
|
//
|
|
switch (nPrefCp)
|
|
{
|
|
case nCpKorea:
|
|
*lpicet = icetIso2022Kr;
|
|
break;
|
|
case nCpJapan:
|
|
default: // Right ??? (gotta pick something ...)
|
|
*lpicet = icetIso2022Jp;
|
|
break;
|
|
}
|
|
*lpfGuess = fTrue; // not *really* guessing, but ... (???)
|
|
cceRet = cceSuccess;
|
|
break;
|
|
}
|
|
|
|
Assert((nToken == esc) || (nToken == so) || (nToken == si));
|
|
{
|
|
LARGE_INTEGER li;
|
|
HRESULT hr;
|
|
|
|
LISet32(li, -1 );
|
|
|
|
hr = pstmIn->Seek(li,STREAM_SEEK_CUR, NULL);
|
|
}
|
|
// Put it back for CceReadEscSeq() to process.
|
|
//
|
|
// if (!pfnUnget(uch, lpvPrivate))
|
|
// {
|
|
// cceRet = cceUnget;
|
|
// break;
|
|
// }
|
|
|
|
} while (fTrue);
|
|
|
|
return cceRet;
|
|
}
|