1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3/*
4**********************************************************************
5* Copyright (C) 1999-2015, International Business Machines
6* Corporation and others. All Rights Reserved.
7**********************************************************************
8* file name: ustr_imp.h
9* encoding: UTF-8
10* tab size: 8 (not used)
11* indentation:4
12*
13* created on: 2001jan30
14* created by: Markus W. Scherer
15*/
16
17#ifndef __USTR_IMP_H__
18#define __USTR_IMP_H__
19
20#include "unicode/utypes.h"
21#include "unicode/utf8.h"
22
23/**
24 * Internal option for unorm_cmpEquivFold() for strncmp style.
25 * If set, checks for both string length and terminating NUL.
26 */
27#define _STRNCMP_STYLE 0x1000
28
29/**
30 * Compare two strings in code point order or code unit order.
31 * Works in strcmp style (both lengths -1),
32 * strncmp style (lengths equal and >=0, flag TRUE),
33 * and memcmp/UnicodeString style (at least one length >=0).
34 */
35U_CFUNC int32_t U_EXPORT2
36uprv_strCompare(const UChar *s1, int32_t length1,
37 const UChar *s2, int32_t length2,
38 UBool strncmpStyle, UBool codePointOrder);
39
40U_INTERNAL int32_t U_EXPORT2
41ustr_hashUCharsN(const UChar *str, int32_t length);
42
43U_INTERNAL int32_t U_EXPORT2
44ustr_hashCharsN(const char *str, int32_t length);
45
46U_INTERNAL int32_t U_EXPORT2
47ustr_hashICharsN(const char *str, int32_t length);
48
49/**
50 * Convert an ASCII-range lowercase character to uppercase.
51 *
52 * @param c A UChar.
53 * @return If UChar is a lowercase ASCII character, returns the uppercase version.
54 * Otherwise, returns the input character.
55 */
56U_INTERNAL UChar U_EXPORT2
57u_asciiToUpper(UChar c);
58
59// TODO: Add u_asciiToLower if/when there is a need for it.
60
61/**
62 * NUL-terminate a UChar * string if possible.
63 * If length < destCapacity then NUL-terminate.
64 * If length == destCapacity then do not terminate but set U_STRING_NOT_TERMINATED_WARNING.
65 * If length > destCapacity then do not terminate but set U_BUFFER_OVERFLOW_ERROR.
66 *
67 * @param dest Destination buffer, can be NULL if destCapacity==0.
68 * @param destCapacity Number of UChars available at dest.
69 * @param length Number of UChars that were (to be) written to dest.
70 * @param pErrorCode ICU error code.
71 * @return length
72 */
73U_INTERNAL int32_t U_EXPORT2
74u_terminateUChars(UChar *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
75
76/**
77 * NUL-terminate a char * string if possible.
78 * Same as u_terminateUChars() but for a different string type.
79 */
80U_INTERNAL int32_t U_EXPORT2
81u_terminateChars(char *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
82
83/**
84 * NUL-terminate a UChar32 * string if possible.
85 * Same as u_terminateUChars() but for a different string type.
86 */
87U_INTERNAL int32_t U_EXPORT2
88u_terminateUChar32s(UChar32 *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
89
90/**
91 * NUL-terminate a wchar_t * string if possible.
92 * Same as u_terminateUChars() but for a different string type.
93 */
94U_INTERNAL int32_t U_EXPORT2
95u_terminateWChars(wchar_t *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
96
97/**
98 * Counts the bytes of any whole valid sequence for a UTF-8 lead byte.
99 * Returns 1 for ASCII 0..0x7f.
100 * Returns 0 for 0x80..0xc1 as well as for 0xf5..0xff.
101 * leadByte might be evaluated multiple times.
102 *
103 * @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff.
104 * @return 0..4
105 */
106#define U8_COUNT_BYTES(leadByte) \
107 (U8_IS_SINGLE(leadByte) ? 1 : U8_COUNT_BYTES_NON_ASCII(leadByte))
108
109/**
110 * Counts the bytes of any whole valid sequence for a UTF-8 lead byte.
111 * Returns 0 for 0x00..0xc1 as well as for 0xf5..0xff.
112 * leadByte might be evaluated multiple times.
113 *
114 * @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff.
115 * @return 0 or 2..4
116 */
117#define U8_COUNT_BYTES_NON_ASCII(leadByte) \
118 (U8_IS_LEAD(leadByte) ? ((uint8_t)(leadByte)>=0xe0)+((uint8_t)(leadByte)>=0xf0)+2 : 0)
119
120#ifdef __cplusplus
121
122U_NAMESPACE_BEGIN
123
124class UTF8 {
125public:
126 UTF8() = delete; // all static
127
128 /**
129 * Is t a valid UTF-8 trail byte?
130 *
131 * @param prev Must be the preceding lead byte if i==1 and length>=3;
132 * otherwise ignored.
133 * @param t The i-th byte following the lead byte.
134 * @param i The index (1..3) of byte t in the byte sequence. 0<i<length
135 * @param length The length (2..4) of the byte sequence according to the lead byte.
136 * @return TRUE if t is a valid trail byte in this context.
137 */
138 static inline UBool isValidTrail(int32_t prev, uint8_t t, int32_t i, int32_t length) {
139 // The first trail byte after a 3- or 4-byte lead byte
140 // needs to be validated together with its lead byte.
141 if (length <= 2 || i > 1) {
142 return U8_IS_TRAIL(t);
143 } else if (length == 3) {
144 return U8_IS_VALID_LEAD3_AND_T1(prev, t);
145 } else { // length == 4
146 return U8_IS_VALID_LEAD4_AND_T1(prev, t);
147 }
148 }
149};
150
151U_NAMESPACE_END
152
153#endif // __cplusplus
154
155#endif
156