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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
*
* Copyright (C) 2000-2008, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* file name: genmbcs.h
* encoding: UTF-8
* tab size: 8 (not used)
* indentation:4
*
* created on: 2000jul10
* created by: Markus W. Scherer
*/
#ifndef __GENMBCS_H__
#define __GENMBCS_H__
#include "makeconv.h"
enum {
/*
* TODO: Consider using ucnvmbcs.h constants.
* However, not all values need to be exactly the same, for example
* the xxx_UTF8_MAX values may be different. (Especially SBCS_UTF8_MAX
* may be higher in makeconv than in the runtime code because that
* affects only a small number of .cnv files [if any] but all
* runtime UConverterSharedData objects.
*/
MBCS_STAGE_2_SHIFT=4,
MBCS_STAGE_2_BLOCK_SIZE=0x40, /* =64=1<<6 for 6 bits in stage 2 */
MBCS_STAGE_2_BLOCK_SIZE_SHIFT=6, /* log2(MBCS_STAGE_2_BLOCK_SIZE) */
MBCS_STAGE_2_BLOCK_MASK=0x3f, /* for after shifting by MBCS_STAGE_2_SHIFT */
MBCS_STAGE_1_SHIFT=10,
MBCS_STAGE_1_BMP_SIZE=0x40, /* 0x10000>>MBCS_STAGE_1_SHIFT, or 16 for one entry per 1k code points on the BMP */
MBCS_STAGE_1_SIZE=0x440, /* 0x110000>>MBCS_STAGE_1_SHIFT, or 17*64 for one entry per 1k code points */
MBCS_STAGE_2_SIZE=0xfbc0, /* 0x10000-MBCS_STAGE_1_SIZE: stages 1 & 2 share a 16-bit-indexed array */
MBCS_MAX_STAGE_2_TOP=MBCS_STAGE_2_SIZE,
MBCS_STAGE_2_MAX_BLOCKS=MBCS_STAGE_2_SIZE>>MBCS_STAGE_2_BLOCK_SIZE_SHIFT,
MBCS_STAGE_2_ALL_UNASSIGNED_INDEX=0, /* stage 1 entry for the all-unassigned stage 2 block */
MBCS_STAGE_2_FIRST_ASSIGNED=MBCS_STAGE_2_BLOCK_SIZE, /* start of the first stage 2 block after the all-unassigned one */
MBCS_STAGE_3_BLOCK_SIZE=16, /* =16=1<<4 for 4 bits in stage 3 */
MBCS_STAGE_3_BLOCK_MASK=0xf,
MBCS_STAGE_3_FIRST_ASSIGNED=MBCS_STAGE_3_BLOCK_SIZE, /* start of the first stage 3 block after the all-unassigned one */
MBCS_STAGE_3_GRANULARITY=16, /* =1<<4: MBCS stage 2 indexes are shifted left 4 */
MBCS_STAGE_3_SBCS_SIZE=0x10000, /* max 64k mappings for SBCS */
MBCS_STAGE_3_MBCS_SIZE=0x10000*MBCS_STAGE_3_GRANULARITY, /* max mappings for MBCS */
/*
* SBCS_UTF8_MAX: Maximum code point with UTF-8-friendly SBCS data structures.
* Possible values are 0x01ff..0xffff, in steps of 0x100.
*
* Unlike for MBCS, this constant only affects the stage 3 block allocation size;
* there is no additional stage 1/2 table stored in the .cnv file.
* The max value should be at least 0x7ff to cover 2-byte UTF-8.
* 0xfff also covers a number other small scripts which have legacy charsets
* (like Thai).
* Higher values up to 0x1fff are harmless and potentially useful because
* that covers small-script blocks which usually have either dense mappings
* or no mappings at all.
* Starting at U+2000, there are mostly symbols and format characters
* with a low density of SBCS mappings, which would result in more wasted
* stage 3 entries with the larger block size.
*/
SBCS_UTF8_MAX=0x1fff,
/*
* MBCS_UTF8_MAX: Maximum code point with UTF-8-friendly MBCS data structures.
* Possible values are 0x01ff..0xffff, in steps of 0x100.
*
* Note that with 0xffff, MBCSAddFromUnicode() may overflow the additional UTF-8 stage table
* with extreme input data. The function checks for this overflow.
*
* 0xd7ff is chosen for the majority of common characters including Unihan and Hangul.
* At U+d800 there are mostly surrogates, private use codes, compatibility characters, etc.
* Larger values cause slightly larger MBCS .cnv files.
*/
MBCS_UTF8_MAX=0xd7ff,
MBCS_UTF8_LIMIT=MBCS_UTF8_MAX+1, /* =0xd800 */
MBCS_UTF8_STAGE_SHIFT=6,
MBCS_UTF8_STAGE_3_BLOCK_SIZE=0x40, /* =64=1<<6 for 6 bits from last trail byte */
MBCS_UTF8_STAGE_3_BLOCK_MASK=0x3f,
/* size of the single-stage table for up to U+d7ff (used instead of stage1/2) */
MBCS_UTF8_STAGE_SIZE=MBCS_UTF8_LIMIT>>MBCS_UTF8_STAGE_SHIFT, /* =0x360 */
MBCS_FROM_U_EXT_FLAG=0x10, /* UCMapping.f bit for base table mappings that fit into the base toU table */
MBCS_FROM_U_EXT_MASK=0x0f, /* but need to go into the extension fromU table */
/* =4 number of regular stage 3 blocks for final UTF-8 trail byte */
MBCS_UTF8_STAGE_3_BLOCKS=MBCS_UTF8_STAGE_3_BLOCK_SIZE/MBCS_STAGE_3_BLOCK_SIZE,
MBCS_MAX_FALLBACK_COUNT=8192
};
U_CFUNC NewConverter *
MBCSOpen(UCMFile *ucm);
struct MBCSData;
typedef struct MBCSData MBCSData;
/*
* Get a dummy MBCSData for use with MBCSOkForBaseFromUnicode()
* for creating an extension-only file.
* Assume maxCharLength>1.
*/
U_CFUNC const MBCSData *
MBCSGetDummy(void);
/* Test if a 1:1 mapping fits into the MBCS base table's fromUnicode structure. */
U_CFUNC UBool
MBCSOkForBaseFromUnicode(const MBCSData *mbcsData,
const uint8_t *bytes, int32_t length,
UChar32 c, int8_t flag);
U_CFUNC NewConverter *
CnvExtOpen(UCMFile *ucm);
#endif /* __GENMBCS_H__ */
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