1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
// © 2019 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
// localeprioritylist.cpp
// created: 2019jul11 Markus W. Scherer
#include "unicode/utypes.h"
#include "unicode/localpointer.h"
#include "unicode/locid.h"
#include "unicode/stringpiece.h"
#include "unicode/uobject.h"
#include "charstr.h"
#include "cmemory.h"
#include "localeprioritylist.h"
#include "uarrsort.h"
#include "uassert.h"
#include "uhash.h"
U_NAMESPACE_BEGIN
namespace {
int32_t hashLocale(const UHashTok token) {
auto *locale = static_cast<const Locale *>(token.pointer);
return locale->hashCode();
}
UBool compareLocales(const UHashTok t1, const UHashTok t2) {
auto *l1 = static_cast<const Locale *>(t1.pointer);
auto *l2 = static_cast<const Locale *>(t2.pointer);
return *l1 == *l2;
}
constexpr int32_t WEIGHT_ONE = 1000;
struct LocaleAndWeight {
Locale *locale;
int32_t weight; // 0..1000 = 0.0..1.0
int32_t index; // force stable sort
int32_t compare(const LocaleAndWeight &other) const {
int32_t diff = other.weight - weight; // descending: other-this
if (diff != 0) { return diff; }
return index - other.index;
}
};
int32_t U_CALLCONV
compareLocaleAndWeight(const void * /*context*/, const void *left, const void *right) {
return static_cast<const LocaleAndWeight *>(left)->
compare(*static_cast<const LocaleAndWeight *>(right));
}
const char *skipSpaces(const char *p, const char *limit) {
while (p < limit && *p == ' ') { ++p; }
return p;
}
int32_t findTagLength(const char *p, const char *limit) {
// Look for accept-language delimiters.
// Leave other validation up to the Locale constructor.
const char *q;
for (q = p; q < limit; ++q) {
char c = *q;
if (c == ' ' || c == ',' || c == ';') { break; }
}
return static_cast<int32_t>(q - p);
}
/**
* Parses and returns a qvalue weight in millis.
* Advances p to after the parsed substring.
* Returns a negative value if parsing fails.
*/
int32_t parseWeight(const char *&p, const char *limit) {
p = skipSpaces(p, limit);
char c;
if (p == limit || ((c = *p) != '0' && c != '1')) { return -1; }
int32_t weight = (c - '0') * 1000;
if (++p == limit || *p != '.') { return weight; }
int32_t multiplier = 100;
while (++p != limit && '0' <= (c = *p) && c <= '9') {
c -= '0';
if (multiplier > 0) {
weight += c * multiplier;
multiplier /= 10;
} else if (multiplier == 0) {
// round up
if (c >= 5) { ++weight; }
multiplier = -1;
} // else ignore further fraction digits
}
return weight <= WEIGHT_ONE ? weight : -1; // bad if > 1.0
}
} // namespace
/**
* Nothing but a wrapper over a MaybeStackArray of LocaleAndWeight.
*
* This wrapper exists (and is not in an anonymous namespace)
* so that we can forward-declare it in the header file and
* don't have to expose the MaybeStackArray specialization and
* the LocaleAndWeight to code (like the test) that #includes localeprioritylist.h.
* Also, otherwise we would have to do a platform-specific
* template export declaration of some kind for the MaybeStackArray specialization
* to be properly exported from the common DLL.
*/
struct LocaleAndWeightArray : public UMemory {
MaybeStackArray<LocaleAndWeight, 20> array;
};
LocalePriorityList::LocalePriorityList(StringPiece s, UErrorCode &errorCode) {
if (U_FAILURE(errorCode)) { return; }
list = new LocaleAndWeightArray();
if (list == nullptr) {
errorCode = U_MEMORY_ALLOCATION_ERROR;
return;
}
const char *p = s.data();
const char *limit = p + s.length();
while ((p = skipSpaces(p, limit)) != limit) {
if (*p == ',') { // empty range field
++p;
continue;
}
int32_t tagLength = findTagLength(p, limit);
if (tagLength == 0) {
errorCode = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
CharString tag(p, tagLength, errorCode);
if (U_FAILURE(errorCode)) { return; }
Locale locale = Locale(tag.data());
if (locale.isBogus()) {
errorCode = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
int32_t weight = WEIGHT_ONE;
if ((p = skipSpaces(p + tagLength, limit)) != limit && *p == ';') {
if ((p = skipSpaces(p + 1, limit)) == limit || *p != 'q' ||
(p = skipSpaces(p + 1, limit)) == limit || *p != '=' ||
(++p, (weight = parseWeight(p, limit)) < 0)) {
errorCode = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
p = skipSpaces(p, limit);
}
if (p != limit && *p != ',') { // trailing junk
errorCode = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
add(locale, weight, errorCode);
if (p == limit) { break; }
++p;
}
sort(errorCode);
}
LocalePriorityList::~LocalePriorityList() {
if (list != nullptr) {
for (int32_t i = 0; i < listLength; ++i) {
delete list->array[i].locale;
}
delete list;
}
uhash_close(map);
}
const Locale *LocalePriorityList::localeAt(int32_t i) const {
return list->array[i].locale;
}
Locale *LocalePriorityList::orphanLocaleAt(int32_t i) {
if (list == nullptr) { return nullptr; }
LocaleAndWeight &lw = list->array[i];
Locale *l = lw.locale;
lw.locale = nullptr;
return l;
}
bool LocalePriorityList::add(const Locale &locale, int32_t weight, UErrorCode &errorCode) {
if (U_FAILURE(errorCode)) { return false; }
if (map == nullptr) {
if (weight <= 0) { return true; } // do not add q=0
map = uhash_open(hashLocale, compareLocales, uhash_compareLong, &errorCode);
if (U_FAILURE(errorCode)) { return false; }
}
LocalPointer<Locale> clone;
int32_t index = uhash_geti(map, &locale);
if (index != 0) {
// Duplicate: Remove the old item and append it anew.
LocaleAndWeight &lw = list->array[index - 1];
clone.adoptInstead(lw.locale);
lw.locale = nullptr;
lw.weight = 0;
++numRemoved;
}
if (weight <= 0) { // do not add q=0
if (index != 0) {
// Not strictly necessary but cleaner.
uhash_removei(map, &locale);
}
return true;
}
if (clone.isNull()) {
clone.adoptInstead(locale.clone());
if (clone.isNull() || (clone->isBogus() && !locale.isBogus())) {
errorCode = U_MEMORY_ALLOCATION_ERROR;
return false;
}
}
if (listLength == list->array.getCapacity()) {
int32_t newCapacity = listLength < 50 ? 100 : 4 * listLength;
if (list->array.resize(newCapacity, listLength) == nullptr) {
errorCode = U_MEMORY_ALLOCATION_ERROR;
return false;
}
}
uhash_puti(map, clone.getAlias(), listLength + 1, &errorCode);
if (U_FAILURE(errorCode)) { return false; }
LocaleAndWeight &lw = list->array[listLength];
lw.locale = clone.orphan();
lw.weight = weight;
lw.index = listLength++;
if (weight < WEIGHT_ONE) { hasWeights = true; }
U_ASSERT(uhash_count(map) == getLength());
return true;
}
void LocalePriorityList::sort(UErrorCode &errorCode) {
// Sort by descending weights if there is a mix of weights.
// The comparator forces a stable sort via the item index.
if (U_FAILURE(errorCode) || getLength() <= 1 || !hasWeights) { return; }
uprv_sortArray(list->array.getAlias(), listLength, sizeof(LocaleAndWeight),
compareLocaleAndWeight, nullptr, FALSE, &errorCode);
}
U_NAMESPACE_END
|
