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
|
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2010-2012, International Business Machines
* Corporation and others. All Rights Reserved.
*******************************************************************************
* file name: bytestrieiterator.cpp
* encoding: UTF-8
* tab size: 8 (not used)
* indentation:4
*
* created on: 2010nov03
* created by: Markus W. Scherer
*/
#include "unicode/utypes.h"
#include "unicode/bytestrie.h"
#include "unicode/stringpiece.h"
#include "charstr.h"
#include "uvectr32.h"
U_NAMESPACE_BEGIN
BytesTrie::Iterator::Iterator(const void *trieBytes, int32_t maxStringLength,
UErrorCode &errorCode)
: bytes_(static_cast<const uint8_t *>(trieBytes)),
pos_(bytes_), initialPos_(bytes_),
remainingMatchLength_(-1), initialRemainingMatchLength_(-1),
str_(nullptr), maxLength_(maxStringLength), value_(0), stack_(nullptr) {
if(U_FAILURE(errorCode)) {
return;
}
// str_ and stack_ are pointers so that it's easy to turn bytestrie.h into
// a public API header for which we would want it to depend only on
// other public headers.
// Unlike BytesTrie itself, its Iterator performs memory allocations anyway
// via the CharString and UVector32 implementations, so this additional
// cost is minimal.
str_=new CharString();
stack_=new UVector32(errorCode);
if(U_SUCCESS(errorCode) && (str_==nullptr || stack_==nullptr)) {
errorCode=U_MEMORY_ALLOCATION_ERROR;
}
}
BytesTrie::Iterator::Iterator(const BytesTrie &trie, int32_t maxStringLength,
UErrorCode &errorCode)
: bytes_(trie.bytes_), pos_(trie.pos_), initialPos_(trie.pos_),
remainingMatchLength_(trie.remainingMatchLength_),
initialRemainingMatchLength_(trie.remainingMatchLength_),
str_(nullptr), maxLength_(maxStringLength), value_(0), stack_(nullptr) {
if(U_FAILURE(errorCode)) {
return;
}
str_=new CharString();
stack_=new UVector32(errorCode);
if(U_FAILURE(errorCode)) {
return;
}
if(str_==nullptr || stack_==nullptr) {
errorCode=U_MEMORY_ALLOCATION_ERROR;
return;
}
int32_t length=remainingMatchLength_; // Actual remaining match length minus 1.
if(length>=0) {
// Pending linear-match node, append remaining bytes to str_.
++length;
if(maxLength_>0 && length>maxLength_) {
length=maxLength_; // This will leave remainingMatchLength>=0 as a signal.
}
str_->append(reinterpret_cast<const char *>(pos_), length, errorCode);
pos_+=length;
remainingMatchLength_-=length;
}
}
BytesTrie::Iterator::~Iterator() {
delete str_;
delete stack_;
}
BytesTrie::Iterator &
BytesTrie::Iterator::reset() {
pos_=initialPos_;
remainingMatchLength_=initialRemainingMatchLength_;
int32_t length=remainingMatchLength_+1; // Remaining match length.
if(maxLength_>0 && length>maxLength_) {
length=maxLength_;
}
str_->truncate(length);
pos_+=length;
remainingMatchLength_-=length;
stack_->setSize(0);
return *this;
}
UBool
BytesTrie::Iterator::hasNext() const { return pos_!=nullptr || !stack_->isEmpty(); }
UBool
BytesTrie::Iterator::next(UErrorCode &errorCode) {
if(U_FAILURE(errorCode)) {
return false;
}
const uint8_t *pos=pos_;
if(pos==nullptr) {
if(stack_->isEmpty()) {
return false;
}
// Pop the state off the stack and continue with the next outbound edge of
// the branch node.
int32_t stackSize=stack_->size();
int32_t length=stack_->elementAti(stackSize-1);
pos=bytes_+stack_->elementAti(stackSize-2);
stack_->setSize(stackSize-2);
str_->truncate(length&0xffff);
length = static_cast<int32_t>(static_cast<uint32_t>(length) >> 16);
if(length>1) {
pos=branchNext(pos, length, errorCode);
if(pos==nullptr) {
return true; // Reached a final value.
}
} else {
str_->append(static_cast<char>(*pos++), errorCode);
}
}
if(remainingMatchLength_>=0) {
// We only get here if we started in a pending linear-match node
// with more than maxLength remaining bytes.
return truncateAndStop();
}
for(;;) {
int32_t node=*pos++;
if(node>=kMinValueLead) {
// Deliver value for the byte sequence so far.
UBool isFinal = static_cast<UBool>(node & kValueIsFinal);
value_=readValue(pos, node>>1);
if(isFinal || (maxLength_>0 && str_->length()==maxLength_)) {
pos_=nullptr;
} else {
pos_=skipValue(pos, node);
}
return true;
}
if(maxLength_>0 && str_->length()==maxLength_) {
return truncateAndStop();
}
if(node<kMinLinearMatch) {
if(node==0) {
node=*pos++;
}
pos=branchNext(pos, node+1, errorCode);
if(pos==nullptr) {
return true; // Reached a final value.
}
} else {
// Linear-match node, append length bytes to str_.
int32_t length=node-kMinLinearMatch+1;
if(maxLength_>0 && str_->length()+length>maxLength_) {
str_->append(reinterpret_cast<const char *>(pos),
maxLength_-str_->length(), errorCode);
return truncateAndStop();
}
str_->append(reinterpret_cast<const char *>(pos), length, errorCode);
pos+=length;
}
}
}
StringPiece
BytesTrie::Iterator::getString() const {
return str_ == nullptr ? StringPiece() : str_->toStringPiece();
}
UBool
BytesTrie::Iterator::truncateAndStop() {
pos_=nullptr;
value_=-1; // no real value for str
return true;
}
// Branch node, needs to take the first outbound edge and push state for the rest.
const uint8_t *
BytesTrie::Iterator::branchNext(const uint8_t *pos, int32_t length, UErrorCode &errorCode) {
while(length>kMaxBranchLinearSubNodeLength) {
++pos; // ignore the comparison byte
// Push state for the greater-or-equal edge.
stack_->addElement(static_cast<int32_t>(skipDelta(pos) - bytes_), errorCode);
stack_->addElement(((length-(length>>1))<<16)|str_->length(), errorCode);
// Follow the less-than edge.
length>>=1;
pos=jumpByDelta(pos);
}
// List of key-value pairs where values are either final values or jump deltas.
// Read the first (key, value) pair.
uint8_t trieByte=*pos++;
int32_t node=*pos++;
UBool isFinal = static_cast<UBool>(node & kValueIsFinal);
int32_t value=readValue(pos, node>>1);
pos=skipValue(pos, node);
stack_->addElement(static_cast<int32_t>(pos - bytes_), errorCode);
stack_->addElement(((length-1)<<16)|str_->length(), errorCode);
str_->append(static_cast<char>(trieByte), errorCode);
if(isFinal) {
pos_=nullptr;
value_=value;
return nullptr;
} else {
return pos+value;
}
}
U_NAMESPACE_END
|
