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_CAPI int32_t U_EXPORT2
41ustr_hashUCharsN(const UChar *str, int32_t length);
42
43U_CAPI int32_t U_EXPORT2
44ustr_hashCharsN(const char *str, int32_t length);
45
46U_CAPI int32_t U_EXPORT2
47ustr_hashICharsN(const char *str, int32_t length);
48
49/**
50 * NUL-terminate a UChar * string if possible.
51 * If length < destCapacity then NUL-terminate.
52 * If length == destCapacity then do not terminate but set U_STRING_NOT_TERMINATED_WARNING.
53 * If length > destCapacity then do not terminate but set U_BUFFER_OVERFLOW_ERROR.
54 *
55 * @param dest Destination buffer, can be NULL if destCapacity==0.
56 * @param destCapacity Number of UChars available at dest.
57 * @param length Number of UChars that were (to be) written to dest.
58 * @param pErrorCode ICU error code.
59 * @return length
60 */
61U_CAPI int32_t U_EXPORT2
62u_terminateUChars(UChar *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
63
64/**
65 * NUL-terminate a char * string if possible.
66 * Same as u_terminateUChars() but for a different string type.
67 */
68U_CAPI int32_t U_EXPORT2
69u_terminateChars(char *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
70
71/**
72 * NUL-terminate a UChar32 * string if possible.
73 * Same as u_terminateUChars() but for a different string type.
74 */
75U_CAPI int32_t U_EXPORT2
76u_terminateUChar32s(UChar32 *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
77
78/**
79 * NUL-terminate a wchar_t * string if possible.
80 * Same as u_terminateUChars() but for a different string type.
81 */
82U_CAPI int32_t U_EXPORT2
83u_terminateWChars(wchar_t *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
84
85/**
86 * Counts the bytes of any whole valid sequence for a UTF-8 lead byte.
87 * Returns 1 for ASCII 0..0x7f.
88 * Returns 0 for 0x80..0xc1 as well as for 0xf5..0xff.
89 * leadByte might be evaluated multiple times.
90 *
91 * @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff.
92 * @return 0..4
93 */
94#define U8_COUNT_BYTES(leadByte) \
95 (U8_IS_SINGLE(leadByte) ? 1 : U8_COUNT_BYTES_NON_ASCII(leadByte))
96
97/**
98 * Counts the bytes of any whole valid sequence for a UTF-8 lead byte.
99 * Returns 0 for 0x00..0xc1 as well as for 0xf5..0xff.
100 * leadByte might be evaluated multiple times.
101 *
102 * @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff.
103 * @return 0 or 2..4
104 */
105#define U8_COUNT_BYTES_NON_ASCII(leadByte) \
106 (U8_IS_LEAD(leadByte) ? ((uint8_t)(leadByte)>=0xe0)+((uint8_t)(leadByte)>=0xf0)+2 : 0)
107
108#ifdef __cplusplus
109
110U_NAMESPACE_BEGIN
111
112class UTF8 {
113public:
114 UTF8() = delete; // all static
115
116 /**
117 * Is t a valid UTF-8 trail byte?
118 *
119 * @param prev Must be the preceding lead byte if i==1 and length>=3;
120 * otherwise ignored.
121 * @param t The i-th byte following the lead byte.
122 * @param i The index (1..3) of byte t in the byte sequence. 0<i<length
123 * @param length The length (2..4) of the byte sequence according to the lead byte.
124 * @return TRUE if t is a valid trail byte in this context.
125 */
126 static inline UBool isValidTrail(int32_t prev, uint8_t t, int32_t i, int32_t length) {
127 // The first trail byte after a 3- or 4-byte lead byte
128 // needs to be validated together with its lead byte.
129 if (length <= 2 || i > 1) {
130 return U8_IS_TRAIL(t);
131 } else if (length == 3) {
132 return U8_IS_VALID_LEAD3_AND_T1(prev, t);
133 } else { // length == 4
134 return U8_IS_VALID_LEAD4_AND_T1(prev, t);
135 }
136 }
137};
138
139U_NAMESPACE_END
140
141#endif // __cplusplus
142
143#endif
144