/src/icu/icu4c/source/common/bytestrie.cpp
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1  |  | // © 2016 and later: Unicode, Inc. and others.  | 
2  |  | // License & terms of use: http://www.unicode.org/copyright.html  | 
3  |  | /*  | 
4  |  | *******************************************************************************  | 
5  |  | *   Copyright (C) 2010-2011, International Business Machines  | 
6  |  | *   Corporation and others.  All Rights Reserved.  | 
7  |  | *******************************************************************************  | 
8  |  | *   file name:  bytestrie.cpp  | 
9  |  | *   encoding:   UTF-8  | 
10  |  | *   tab size:   8 (not used)  | 
11  |  | *   indentation:4  | 
12  |  | *  | 
13  |  | *   created on: 2010sep25  | 
14  |  | *   created by: Markus W. Scherer  | 
15  |  | */  | 
16  |  |  | 
17  |  | #include "unicode/utypes.h"  | 
18  |  | #include "unicode/bytestream.h"  | 
19  |  | #include "unicode/bytestrie.h"  | 
20  |  | #include "unicode/uobject.h"  | 
21  |  | #include "cmemory.h"  | 
22  |  | #include "uassert.h"  | 
23  |  |  | 
24  |  | U_NAMESPACE_BEGIN  | 
25  |  |  | 
26  | 13.3k  | BytesTrie::~BytesTrie() { | 
27  | 13.3k  |     uprv_free(ownedArray_);  | 
28  | 13.3k  | }  | 
29  |  |  | 
30  |  | // lead byte already shifted right by 1.  | 
31  |  | int32_t  | 
32  | 13.3k  | BytesTrie::readValue(const uint8_t *pos, int32_t leadByte) { | 
33  | 13.3k  |     int32_t value;  | 
34  | 13.3k  |     if(leadByte<kMinTwoByteValueLead) { | 
35  | 0  |         value=leadByte-kMinOneByteValueLead;  | 
36  | 13.3k  |     } else if(leadByte<kMinThreeByteValueLead) { | 
37  | 13.1k  |         value=((leadByte-kMinTwoByteValueLead)<<8)|*pos;  | 
38  | 13.1k  |     } else if(leadByte<kFourByteValueLead) { | 
39  | 236  |         value=((leadByte-kMinThreeByteValueLead)<<16)|(pos[0]<<8)|pos[1];  | 
40  | 236  |     } else if(leadByte==kFourByteValueLead) { | 
41  | 0  |         value=(pos[0]<<16)|(pos[1]<<8)|pos[2];  | 
42  | 0  |     } else { | 
43  | 0  |         value=(pos[0]<<24)|(pos[1]<<16)|(pos[2]<<8)|pos[3];  | 
44  | 0  |     }  | 
45  | 13.3k  |     return value;  | 
46  | 13.3k  | }  | 
47  |  |  | 
48  |  | const uint8_t *  | 
49  | 52.5k  | BytesTrie::jumpByDelta(const uint8_t *pos) { | 
50  | 52.5k  |     int32_t delta=*pos++;  | 
51  | 52.5k  |     if(delta<kMinTwoByteDeltaLead) { | 
52  |  |         // nothing to do  | 
53  | 39.9k  |     } else if(delta<kMinThreeByteDeltaLead) { | 
54  | 35.1k  |         delta=((delta-kMinTwoByteDeltaLead)<<8)|*pos++;  | 
55  | 35.1k  |     } else if(delta<kFourByteDeltaLead) { | 
56  | 4.71k  |         delta=((delta-kMinThreeByteDeltaLead)<<16)|(pos[0]<<8)|pos[1];  | 
57  | 4.71k  |         pos+=2;  | 
58  | 4.71k  |     } else if(delta==kFourByteDeltaLead) { | 
59  | 0  |         delta=(pos[0]<<16)|(pos[1]<<8)|pos[2];  | 
60  | 0  |         pos+=3;  | 
61  | 0  |     } else { | 
62  | 0  |         delta=(pos[0]<<24)|(pos[1]<<16)|(pos[2]<<8)|pos[3];  | 
63  | 0  |         pos+=4;  | 
64  | 0  |     }  | 
65  | 52.5k  |     return pos+delta;  | 
66  | 52.5k  | }  | 
67  |  |  | 
68  |  | UStringTrieResult  | 
69  | 0  | BytesTrie::current() const { | 
70  | 0  |     const uint8_t *pos=pos_;  | 
71  | 0  |     if(pos==nullptr) { | 
72  | 0  |         return USTRINGTRIE_NO_MATCH;  | 
73  | 0  |     } else { | 
74  | 0  |         int32_t node;  | 
75  | 0  |         return (remainingMatchLength_<0 && (node=*pos)>=kMinValueLead) ?  | 
76  | 0  |                 valueResult(node) : USTRINGTRIE_NO_VALUE;  | 
77  | 0  |     }  | 
78  | 0  | }  | 
79  |  |  | 
80  |  | UStringTrieResult  | 
81  | 28.3k  | BytesTrie::branchNext(const uint8_t *pos, int32_t length, int32_t inByte) { | 
82  |  |     // Branch according to the current byte.  | 
83  | 28.3k  |     if(length==0) { | 
84  | 24.2k  |         length=*pos++;  | 
85  | 24.2k  |     }  | 
86  | 28.3k  |     ++length;  | 
87  |  |     // The length of the branch is the number of bytes to select from.  | 
88  |  |     // The data structure encodes a binary search.  | 
89  | 101k  |     while(length>kMaxBranchLinearSubNodeLength) { | 
90  | 73.5k  |         if(inByte<*pos++) { | 
91  | 52.5k  |             length>>=1;  | 
92  | 52.5k  |             pos=jumpByDelta(pos);  | 
93  | 52.5k  |         } else { | 
94  | 20.9k  |             length=length-(length>>1);  | 
95  | 20.9k  |             pos=skipDelta(pos);  | 
96  | 20.9k  |         }  | 
97  | 73.5k  |     }  | 
98  |  |     // Drop down to linear search for the last few bytes.  | 
99  |  |     // length>=2 because the loop body above sees length>kMaxBranchLinearSubNodeLength>=3  | 
100  |  |     // and divides length by 2.  | 
101  | 43.8k  |     do { | 
102  | 43.8k  |         if(inByte==*pos++) { | 
103  | 23.6k  |             UStringTrieResult result;  | 
104  | 23.6k  |             int32_t node=*pos;  | 
105  | 23.6k  |             U_ASSERT(node>=kMinValueLead);  | 
106  | 23.6k  |             if(node&kValueIsFinal) { | 
107  |  |                 // Leave the final value for getValue() to read.  | 
108  | 11.4k  |                 result=USTRINGTRIE_FINAL_VALUE;  | 
109  | 12.1k  |             } else { | 
110  |  |                 // Use the non-final value as the jump delta.  | 
111  | 12.1k  |                 ++pos;  | 
112  |  |                 // int32_t delta=readValue(pos, node>>1);  | 
113  | 12.1k  |                 node>>=1;  | 
114  | 12.1k  |                 int32_t delta;  | 
115  | 12.1k  |                 if(node<kMinTwoByteValueLead) { | 
116  | 1.14k  |                     delta=node-kMinOneByteValueLead;  | 
117  | 10.9k  |                 } else if(node<kMinThreeByteValueLead) { | 
118  | 10.9k  |                     delta=((node-kMinTwoByteValueLead)<<8)|*pos++;  | 
119  | 10.9k  |                 } else if(node<kFourByteValueLead) { | 
120  | 86  |                     delta=((node-kMinThreeByteValueLead)<<16)|(pos[0]<<8)|pos[1];  | 
121  | 86  |                     pos+=2;  | 
122  | 86  |                 } else if(node==kFourByteValueLead) { | 
123  | 0  |                     delta=(pos[0]<<16)|(pos[1]<<8)|pos[2];  | 
124  | 0  |                     pos+=3;  | 
125  | 0  |                 } else { | 
126  | 0  |                     delta=(pos[0]<<24)|(pos[1]<<16)|(pos[2]<<8)|pos[3];  | 
127  | 0  |                     pos+=4;  | 
128  | 0  |                 }  | 
129  |  |                 // end readValue()  | 
130  | 12.1k  |                 pos+=delta;  | 
131  | 12.1k  |                 node=*pos;  | 
132  | 12.1k  |                 result= node>=kMinValueLead ? valueResult(node) : USTRINGTRIE_NO_VALUE;  | 
133  | 12.1k  |             }  | 
134  | 23.6k  |             pos_=pos;  | 
135  | 23.6k  |             return result;  | 
136  | 23.6k  |         }  | 
137  | 20.2k  |         --length;  | 
138  | 20.2k  |         pos=skipValue(pos);  | 
139  | 20.2k  |     } while(length>1);  | 
140  | 4.75k  |     if(inByte==*pos++) { | 
141  | 4.46k  |         pos_=pos;  | 
142  | 4.46k  |         int32_t node=*pos;  | 
143  | 4.46k  |         return node>=kMinValueLead ? valueResult(node) : USTRINGTRIE_NO_VALUE;  | 
144  | 4.46k  |     } else { | 
145  | 286  |         stop();  | 
146  | 286  |         return USTRINGTRIE_NO_MATCH;  | 
147  | 286  |     }  | 
148  | 4.75k  | }  | 
149  |  |  | 
150  |  | UStringTrieResult  | 
151  | 28.6k  | BytesTrie::nextImpl(const uint8_t *pos, int32_t inByte) { | 
152  | 28.8k  |     for(;;) { | 
153  | 28.8k  |         int32_t node=*pos++;  | 
154  | 28.8k  |         if(node<kMinLinearMatch) { | 
155  | 28.3k  |             return branchNext(pos, node, inByte);  | 
156  | 28.3k  |         } else if(node<kMinValueLead) { | 
157  |  |             // Match the first of length+1 bytes.  | 
158  | 280  |             int32_t length=node-kMinLinearMatch;  // Actual match length minus 1.  | 
159  | 280  |             if(inByte==*pos++) { | 
160  | 263  |                 remainingMatchLength_=--length;  | 
161  | 263  |                 pos_=pos;  | 
162  | 263  |                 return (length<0 && (node=*pos)>=kMinValueLead) ?  | 
163  | 186  |                         valueResult(node) : USTRINGTRIE_NO_VALUE;  | 
164  | 263  |             } else { | 
165  |  |                 // No match.  | 
166  | 17  |                 break;  | 
167  | 17  |             }  | 
168  | 280  |         } else if(node&kValueIsFinal) { | 
169  |  |             // No further matching bytes.  | 
170  | 0  |             break;  | 
171  | 212  |         } else { | 
172  |  |             // Skip intermediate value.  | 
173  | 212  |             pos=skipValue(pos, node);  | 
174  |  |             // The next node must not also be a value node.  | 
175  | 212  |             U_ASSERT(*pos<kMinValueLead);  | 
176  | 212  |         }  | 
177  | 28.8k  |     }  | 
178  | 17  |     stop();  | 
179  | 17  |     return USTRINGTRIE_NO_MATCH;  | 
180  | 28.6k  | }  | 
181  |  |  | 
182  |  | UStringTrieResult  | 
183  | 28.9k  | BytesTrie::next(int32_t inByte) { | 
184  | 28.9k  |     const uint8_t *pos=pos_;  | 
185  | 28.9k  |     if(pos==nullptr) { | 
186  | 0  |         return USTRINGTRIE_NO_MATCH;  | 
187  | 0  |     }  | 
188  | 28.9k  |     if(inByte<0) { | 
189  | 0  |         inByte+=0x100;  | 
190  | 0  |     }  | 
191  | 28.9k  |     int32_t length=remainingMatchLength_;  // Actual remaining match length minus 1.  | 
192  | 28.9k  |     if(length>=0) { | 
193  |  |         // Remaining part of a linear-match node.  | 
194  | 334  |         if(inByte==*pos++) { | 
195  | 325  |             remainingMatchLength_=--length;  | 
196  | 325  |             pos_=pos;  | 
197  | 325  |             int32_t node;  | 
198  | 325  |             return (length<0 && (node=*pos)>=kMinValueLead) ?  | 
199  | 186  |                     valueResult(node) : USTRINGTRIE_NO_VALUE;  | 
200  | 325  |         } else { | 
201  | 9  |             stop();  | 
202  | 9  |             return USTRINGTRIE_NO_MATCH;  | 
203  | 9  |         }  | 
204  | 334  |     }  | 
205  | 28.6k  |     return nextImpl(pos, inByte);  | 
206  | 28.9k  | }  | 
207  |  |  | 
208  |  | UStringTrieResult  | 
209  | 0  | BytesTrie::next(const char *s, int32_t sLength) { | 
210  | 0  |     if(sLength<0 ? *s==0 : sLength==0) { | 
211  |  |         // Empty input.  | 
212  | 0  |         return current();  | 
213  | 0  |     }  | 
214  | 0  |     const uint8_t *pos=pos_;  | 
215  | 0  |     if(pos==nullptr) { | 
216  | 0  |         return USTRINGTRIE_NO_MATCH;  | 
217  | 0  |     }  | 
218  | 0  |     int32_t length=remainingMatchLength_;  // Actual remaining match length minus 1.  | 
219  | 0  |     for(;;) { | 
220  |  |         // Fetch the next input byte, if there is one.  | 
221  |  |         // Continue a linear-match node without rechecking sLength<0.  | 
222  | 0  |         int32_t inByte;  | 
223  | 0  |         if(sLength<0) { | 
224  | 0  |             for(;;) { | 
225  | 0  |                 if((inByte=*s++)==0) { | 
226  | 0  |                     remainingMatchLength_=length;  | 
227  | 0  |                     pos_=pos;  | 
228  | 0  |                     int32_t node;  | 
229  | 0  |                     return (length<0 && (node=*pos)>=kMinValueLead) ?  | 
230  | 0  |                             valueResult(node) : USTRINGTRIE_NO_VALUE;  | 
231  | 0  |                 }  | 
232  | 0  |                 if(length<0) { | 
233  | 0  |                     remainingMatchLength_=length;  | 
234  | 0  |                     break;  | 
235  | 0  |                 }  | 
236  | 0  |                 if(inByte!=*pos) { | 
237  | 0  |                     stop();  | 
238  | 0  |                     return USTRINGTRIE_NO_MATCH;  | 
239  | 0  |                 }  | 
240  | 0  |                 ++pos;  | 
241  | 0  |                 --length;  | 
242  | 0  |             }  | 
243  | 0  |         } else { | 
244  | 0  |             for(;;) { | 
245  | 0  |                 if(sLength==0) { | 
246  | 0  |                     remainingMatchLength_=length;  | 
247  | 0  |                     pos_=pos;  | 
248  | 0  |                     int32_t node;  | 
249  | 0  |                     return (length<0 && (node=*pos)>=kMinValueLead) ?  | 
250  | 0  |                             valueResult(node) : USTRINGTRIE_NO_VALUE;  | 
251  | 0  |                 }  | 
252  | 0  |                 inByte=*s++;  | 
253  | 0  |                 --sLength;  | 
254  | 0  |                 if(length<0) { | 
255  | 0  |                     remainingMatchLength_=length;  | 
256  | 0  |                     break;  | 
257  | 0  |                 }  | 
258  | 0  |                 if(inByte!=*pos) { | 
259  | 0  |                     stop();  | 
260  | 0  |                     return USTRINGTRIE_NO_MATCH;  | 
261  | 0  |                 }  | 
262  | 0  |                 ++pos;  | 
263  | 0  |                 --length;  | 
264  | 0  |             }  | 
265  | 0  |         }  | 
266  | 0  |         for(;;) { | 
267  | 0  |             int32_t node=*pos++;  | 
268  | 0  |             if(node<kMinLinearMatch) { | 
269  | 0  |                 UStringTrieResult result=branchNext(pos, node, inByte);  | 
270  | 0  |                 if(result==USTRINGTRIE_NO_MATCH) { | 
271  | 0  |                     return USTRINGTRIE_NO_MATCH;  | 
272  | 0  |                 }  | 
273  |  |                 // Fetch the next input byte, if there is one.  | 
274  | 0  |                 if(sLength<0) { | 
275  | 0  |                     if((inByte=*s++)==0) { | 
276  | 0  |                         return result;  | 
277  | 0  |                     }  | 
278  | 0  |                 } else { | 
279  | 0  |                     if(sLength==0) { | 
280  | 0  |                         return result;  | 
281  | 0  |                     }  | 
282  | 0  |                     inByte=*s++;  | 
283  | 0  |                     --sLength;  | 
284  | 0  |                 }  | 
285  | 0  |                 if(result==USTRINGTRIE_FINAL_VALUE) { | 
286  |  |                     // No further matching bytes.  | 
287  | 0  |                     stop();  | 
288  | 0  |                     return USTRINGTRIE_NO_MATCH;  | 
289  | 0  |                 }  | 
290  | 0  |                 pos=pos_;  // branchNext() advanced pos and wrote it to pos_ .  | 
291  | 0  |             } else if(node<kMinValueLead) { | 
292  |  |                 // Match length+1 bytes.  | 
293  | 0  |                 length=node-kMinLinearMatch;  // Actual match length minus 1.  | 
294  | 0  |                 if(inByte!=*pos) { | 
295  | 0  |                     stop();  | 
296  | 0  |                     return USTRINGTRIE_NO_MATCH;  | 
297  | 0  |                 }  | 
298  | 0  |                 ++pos;  | 
299  | 0  |                 --length;  | 
300  | 0  |                 break;  | 
301  | 0  |             } else if(node&kValueIsFinal) { | 
302  |  |                 // No further matching bytes.  | 
303  | 0  |                 stop();  | 
304  | 0  |                 return USTRINGTRIE_NO_MATCH;  | 
305  | 0  |             } else { | 
306  |  |                 // Skip intermediate value.  | 
307  | 0  |                 pos=skipValue(pos, node);  | 
308  |  |                 // The next node must not also be a value node.  | 
309  | 0  |                 U_ASSERT(*pos<kMinValueLead);  | 
310  | 0  |             }  | 
311  | 0  |         }  | 
312  | 0  |     }  | 
313  | 0  | }  | 
314  |  |  | 
315  |  | const uint8_t *  | 
316  |  | BytesTrie::findUniqueValueFromBranch(const uint8_t *pos, int32_t length,  | 
317  | 0  |                                      UBool haveUniqueValue, int32_t &uniqueValue) { | 
318  | 0  |     while(length>kMaxBranchLinearSubNodeLength) { | 
319  | 0  |         ++pos;  // ignore the comparison byte  | 
320  | 0  |         if(nullptr==findUniqueValueFromBranch(jumpByDelta(pos), length>>1, haveUniqueValue, uniqueValue)) { | 
321  | 0  |             return nullptr;  | 
322  | 0  |         }  | 
323  | 0  |         length=length-(length>>1);  | 
324  | 0  |         pos=skipDelta(pos);  | 
325  | 0  |     }  | 
326  | 0  |     do { | 
327  | 0  |         ++pos;  // ignore a comparison byte  | 
328  |  |         // handle its value  | 
329  | 0  |         int32_t node=*pos++;  | 
330  | 0  |         UBool isFinal = static_cast<UBool>(node & kValueIsFinal);  | 
331  | 0  |         int32_t value=readValue(pos, node>>1);  | 
332  | 0  |         pos=skipValue(pos, node);  | 
333  | 0  |         if(isFinal) { | 
334  | 0  |             if(haveUniqueValue) { | 
335  | 0  |                 if(value!=uniqueValue) { | 
336  | 0  |                     return nullptr;  | 
337  | 0  |                 }  | 
338  | 0  |             } else { | 
339  | 0  |                 uniqueValue=value;  | 
340  | 0  |                 haveUniqueValue=true;  | 
341  | 0  |             }  | 
342  | 0  |         } else { | 
343  | 0  |             if(!findUniqueValue(pos+value, haveUniqueValue, uniqueValue)) { | 
344  | 0  |                 return nullptr;  | 
345  | 0  |             }  | 
346  | 0  |             haveUniqueValue=true;  | 
347  | 0  |         }  | 
348  | 0  |     } while(--length>1);  | 
349  | 0  |     return pos+1;  // ignore the last comparison byte  | 
350  | 0  | }  | 
351  |  |  | 
352  |  | UBool  | 
353  | 0  | BytesTrie::findUniqueValue(const uint8_t *pos, UBool haveUniqueValue, int32_t &uniqueValue) { | 
354  | 0  |     for(;;) { | 
355  | 0  |         int32_t node=*pos++;  | 
356  | 0  |         if(node<kMinLinearMatch) { | 
357  | 0  |             if(node==0) { | 
358  | 0  |                 node=*pos++;  | 
359  | 0  |             }  | 
360  | 0  |             pos=findUniqueValueFromBranch(pos, node+1, haveUniqueValue, uniqueValue);  | 
361  | 0  |             if(pos==nullptr) { | 
362  | 0  |                 return false;  | 
363  | 0  |             }  | 
364  | 0  |             haveUniqueValue=true;  | 
365  | 0  |         } else if(node<kMinValueLead) { | 
366  |  |             // linear-match node  | 
367  | 0  |             pos+=node-kMinLinearMatch+1;  // Ignore the match bytes.  | 
368  | 0  |         } else { | 
369  | 0  |             UBool isFinal = static_cast<UBool>(node & kValueIsFinal);  | 
370  | 0  |             int32_t value=readValue(pos, node>>1);  | 
371  | 0  |             if(haveUniqueValue) { | 
372  | 0  |                 if(value!=uniqueValue) { | 
373  | 0  |                     return false;  | 
374  | 0  |                 }  | 
375  | 0  |             } else { | 
376  | 0  |                 uniqueValue=value;  | 
377  | 0  |                 haveUniqueValue=true;  | 
378  | 0  |             }  | 
379  | 0  |             if(isFinal) { | 
380  | 0  |                 return true;  | 
381  | 0  |             }  | 
382  | 0  |             pos=skipValue(pos, node);  | 
383  | 0  |         }  | 
384  | 0  |     }  | 
385  | 0  | }  | 
386  |  |  | 
387  |  | int32_t  | 
388  | 0  | BytesTrie::getNextBytes(ByteSink &out) const { | 
389  | 0  |     const uint8_t *pos=pos_;  | 
390  | 0  |     if(pos==nullptr) { | 
391  | 0  |         return 0;  | 
392  | 0  |     }  | 
393  | 0  |     if(remainingMatchLength_>=0) { | 
394  | 0  |         append(out, *pos);  // Next byte of a pending linear-match node.  | 
395  | 0  |         return 1;  | 
396  | 0  |     }  | 
397  | 0  |     int32_t node=*pos++;  | 
398  | 0  |     if(node>=kMinValueLead) { | 
399  | 0  |         if(node&kValueIsFinal) { | 
400  | 0  |             return 0;  | 
401  | 0  |         } else { | 
402  | 0  |             pos=skipValue(pos, node);  | 
403  | 0  |             node=*pos++;  | 
404  | 0  |             U_ASSERT(node<kMinValueLead);  | 
405  | 0  |         }  | 
406  | 0  |     }  | 
407  | 0  |     if(node<kMinLinearMatch) { | 
408  | 0  |         if(node==0) { | 
409  | 0  |             node=*pos++;  | 
410  | 0  |         }  | 
411  | 0  |         getNextBranchBytes(pos, ++node, out);  | 
412  | 0  |         return node;  | 
413  | 0  |     } else { | 
414  |  |         // First byte of the linear-match node.  | 
415  | 0  |         append(out, *pos);  | 
416  | 0  |         return 1;  | 
417  | 0  |     }  | 
418  | 0  | }  | 
419  |  |  | 
420  |  | void  | 
421  | 0  | BytesTrie::getNextBranchBytes(const uint8_t *pos, int32_t length, ByteSink &out) { | 
422  | 0  |     while(length>kMaxBranchLinearSubNodeLength) { | 
423  | 0  |         ++pos;  // ignore the comparison byte  | 
424  | 0  |         getNextBranchBytes(jumpByDelta(pos), length>>1, out);  | 
425  | 0  |         length=length-(length>>1);  | 
426  | 0  |         pos=skipDelta(pos);  | 
427  | 0  |     }  | 
428  | 0  |     do { | 
429  | 0  |         append(out, *pos++);  | 
430  | 0  |         pos=skipValue(pos);  | 
431  | 0  |     } while(--length>1);  | 
432  | 0  |     append(out, *pos);  | 
433  | 0  | }  | 
434  |  |  | 
435  |  | void  | 
436  | 0  | BytesTrie::append(ByteSink &out, int c) { | 
437  | 0  |     char ch = static_cast<char>(c);  | 
438  | 0  |     out.Append(&ch, 1);  | 
439  | 0  | }  | 
440  |  |  | 
441  |  | U_NAMESPACE_END  |