chromium/third_party/icu/source/common/utrie2_impl.h

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
******************************************************************************
*
*   Copyright (C) 2001-2008, International Business Machines
*   Corporation and others.  All Rights Reserved.
*
******************************************************************************
*   file name:  utrie2_impl.h
*   encoding:   UTF-8
*   tab size:   8 (not used)
*   indentation:4
*
*   created on: 2008sep26 (split off from utrie2.c)
*   created by: Markus W. Scherer
*
*   Definitions needed for both runtime and builder code for UTrie2,
*   used by utrie2.c and utrie2_builder.c.
*/

#ifndef __UTRIE2_IMPL_H__
#define __UTRIE2_IMPL_H__

#ifdef UCPTRIE_DEBUG
#include "unicode/umutablecptrie.h"
#endif
#include "utrie2.h"

/* Public UTrie2 API implementation ----------------------------------------- */

/*
 * These definitions are mostly needed by utrie2.cpp,
 * but also by utrie2_serialize() and utrie2_swap().
 */

// UTrie2 signature values, in platform endianness and opposite endianness.
// The UTrie2 signature ASCII byte values spell "Tri2".
#define UTRIE2_SIG …
#define UTRIE2_OE_SIG …

/**
 * Trie data structure in serialized form:
 *
 * UTrie2Header header;
 * uint16_t index[header.index2Length];
 * uint16_t data[header.shiftedDataLength<<2];  -- or uint32_t data[...]
 * @internal
 */
UTrie2Header;

/**
 * Constants for use with UTrie2Header.options.
 * @internal
 */
enum { … };

/* Building a trie ---------------------------------------------------------- */

/*
 * These definitions are mostly needed by utrie2_builder.c, but also by
 * utrie2_get32() and utrie2_enum().
 */

enum { … };

/**
 * Maximum length of the build-time data array.
 * One entry per 0x110000 code points, plus the illegal-UTF-8 block and the null block,
 * plus values for the 0x400 surrogate code units.
 */
#define UNEWTRIE2_MAX_DATA_LENGTH …

/*
 * Build-time trie structure.
 *
 * Just using a boolean flag for "repeat use" could lead to data array overflow
 * because we would not be able to detect when a data block becomes unused.
 * It also leads to orphan data blocks that are kept through serialization.
 *
 * Need to use reference counting for data blocks,
 * and allocDataBlock() needs to look for a free block before increasing dataLength.
 *
 * This scheme seems like overkill for index-2 blocks since the whole index array is
 * preallocated anyway (unlike the growable data array).
 * Just allocating multiple index-2 blocks as needed.
 */
struct UNewTrie2 { … };

#endif