Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * trgm_regexp.c
4 : : * Regular expression matching using trigrams.
5 : : *
6 : : * The general idea of trigram index support for a regular expression (regex)
7 : : * search is to transform the regex into a logical expression on trigrams.
8 : : * For example:
9 : : *
10 : : * (ab|cd)efg => ((abe & bef) | (cde & def)) & efg
11 : : *
12 : : * If a string matches the regex, then it must match the logical expression on
13 : : * trigrams. The opposite is not necessarily true, however: a string that
14 : : * matches the logical expression might not match the original regex. Such
15 : : * false positives are removed via recheck, by running the regular regex match
16 : : * operator on the retrieved heap tuple.
17 : : *
18 : : * Since the trigram expression involves both AND and OR operators, we can't
19 : : * expect the core index machinery to evaluate it completely. Instead, the
20 : : * result of regex analysis is a list of trigrams to be sought in the index,
21 : : * plus a simplified graph that is used by trigramsMatchGraph() to determine
22 : : * whether a particular indexed value matches the expression.
23 : : *
24 : : * Converting a regex to a trigram expression is based on analysis of an
25 : : * automaton corresponding to the regex. The algorithm consists of four
26 : : * stages:
27 : : *
28 : : * 1) Compile the regexp to NFA form. This is handled by the PostgreSQL
29 : : * regexp library, which provides accessors for its opaque regex_t struct
30 : : * to expose the NFA state graph and the "colors" (sets of equivalent
31 : : * characters) used as state transition labels.
32 : : *
33 : : * 2) Transform the original NFA into an expanded graph, where arcs
34 : : * are labeled with trigrams that must be present in order to move from
35 : : * one state to another via the arcs. The trigrams used in this stage
36 : : * consist of colors, not characters, as in the original NFA.
37 : : *
38 : : * 3) Expand the color trigrams into regular trigrams consisting of
39 : : * characters. If too many distinct trigrams are produced, trigrams are
40 : : * eliminated and the graph is simplified until it's simple enough.
41 : : *
42 : : * 4) Finally, the resulting graph is packed into a TrgmPackedGraph struct,
43 : : * and returned to the caller.
44 : : *
45 : : * 1) Compile the regexp to NFA form
46 : : * ---------------------------------
47 : : * The automaton returned by the regexp compiler is a graph where vertices
48 : : * are "states" and arcs are labeled with colors. Each color represents
49 : : * a set of characters, so that all characters assigned to the same color
50 : : * are interchangeable, so far as matching the regexp is concerned. There
51 : : * are two special states: "initial" and "final". A state can have multiple
52 : : * outgoing arcs labeled with the same color, which makes the automaton
53 : : * non-deterministic, because it can be in many states simultaneously.
54 : : *
55 : : * Note that this NFA is already lossy compared to the original regexp,
56 : : * since it ignores some regex features such as lookahead constraints and
57 : : * backref matching. This is OK for our purposes since it's still the case
58 : : * that only strings matching the NFA can possibly satisfy the regexp.
59 : : *
60 : : * 2) Transform the original NFA into an expanded graph
61 : : * ----------------------------------------------------
62 : : * In the 2nd stage, the automaton is transformed into a graph based on the
63 : : * original NFA. Each state in the expanded graph represents a state from
64 : : * the original NFA, plus a prefix identifying the last two characters
65 : : * (colors, to be precise) seen before entering the state. There can be
66 : : * multiple states in the expanded graph for each state in the original NFA,
67 : : * depending on what characters can precede it. A prefix position can be
68 : : * "unknown" if it's uncertain what the preceding character was, or "blank"
69 : : * if the character was a non-word character (we don't need to distinguish
70 : : * which non-word character it was, so just think of all of them as blanks).
71 : : *
72 : : * For convenience in description, call an expanded-state identifier
73 : : * (two prefix colors plus a state number from the original NFA) an
74 : : * "enter key".
75 : : *
76 : : * Each arc of the expanded graph is labeled with a trigram that must be
77 : : * present in the string to match. We can construct this from an out-arc of
78 : : * the underlying NFA state by combining the expanded state's prefix with the
79 : : * color label of the underlying out-arc, if neither prefix position is
80 : : * "unknown". But note that some of the colors in the trigram might be
81 : : * "blank". This is OK since we want to generate word-boundary trigrams as
82 : : * the regular trigram machinery would, if we know that some word characters
83 : : * must be adjacent to a word boundary in all strings matching the NFA.
84 : : *
85 : : * The expanded graph can also have fewer states than the original NFA,
86 : : * because we don't bother to make a separate state entry unless the state
87 : : * is reachable by a valid arc. When an enter key is reachable from a state
88 : : * of the expanded graph, but we do not know a complete trigram associated
89 : : * with that transition, we cannot make a valid arc; instead we insert the
90 : : * enter key into the enterKeys list of the source state. This effectively
91 : : * means that the two expanded states are not reliably distinguishable based
92 : : * on examining trigrams.
93 : : *
94 : : * So the expanded graph resembles the original NFA, but the arcs are
95 : : * labeled with trigrams instead of individual characters, and there may be
96 : : * more or fewer states. It is a lossy representation of the original NFA:
97 : : * any string that matches the original regexp must match the expanded graph,
98 : : * but the reverse is not true.
99 : : *
100 : : * We build the expanded graph through a breadth-first traversal of states
101 : : * reachable from the initial state. At each reachable state, we identify the
102 : : * states reachable from it without traversing a predictable trigram, and add
103 : : * those states' enter keys to the current state. Then we generate all
104 : : * out-arcs leading out of this collection of states that have predictable
105 : : * trigrams, adding their target states to the queue of states to examine.
106 : : *
107 : : * When building the graph, if the number of states or arcs exceed pre-defined
108 : : * limits, we give up and simply mark any states not yet processed as final
109 : : * states. Roughly speaking, that means that we make use of some portion from
110 : : * the beginning of the regexp. Also, any colors that have too many member
111 : : * characters are treated as "unknown", so that we can't derive trigrams
112 : : * from them.
113 : : *
114 : : * 3) Expand the color trigrams into regular trigrams
115 : : * --------------------------------------------------
116 : : * The trigrams in the expanded graph are "color trigrams", consisting
117 : : * of three consecutive colors that must be present in the string. But for
118 : : * search, we need regular trigrams consisting of characters. In the 3rd
119 : : * stage, the color trigrams are expanded into regular trigrams. Since each
120 : : * color can represent many characters, the total number of regular trigrams
121 : : * after expansion could be very large. Because searching the index for
122 : : * thousands of trigrams would be slow, and would likely produce so many
123 : : * false positives that we would have to traverse a large fraction of the
124 : : * index, the graph is simplified further in a lossy fashion by removing
125 : : * color trigrams. When a color trigram is removed, the states connected by
126 : : * any arcs labeled with that trigram are merged.
127 : : *
128 : : * Trigrams do not all have equivalent value for searching: some of them are
129 : : * more frequent and some of them are less frequent. Ideally, we would like
130 : : * to know the distribution of trigrams, but we don't. But because of padding
131 : : * we know for sure that the empty character is more frequent than others,
132 : : * so we can penalize trigrams according to presence of whitespace. The
133 : : * penalty assigned to each color trigram is the number of simple trigrams
134 : : * it would produce, times the penalties[] multiplier associated with its
135 : : * whitespace content. (The penalties[] constants were calculated by analysis
136 : : * of some real-life text.) We eliminate color trigrams starting with the
137 : : * highest-penalty one, until we get to a total penalty of no more than
138 : : * WISH_TRGM_PENALTY. However, we cannot remove a color trigram if that would
139 : : * lead to merging the initial and final states, so we may not be able to
140 : : * reach WISH_TRGM_PENALTY. It's still okay so long as we have no more than
141 : : * MAX_TRGM_COUNT simple trigrams in total, otherwise we fail.
142 : : *
143 : : * 4) Pack the graph into a compact representation
144 : : * -----------------------------------------------
145 : : * The 2nd and 3rd stages might have eliminated or merged many of the states
146 : : * and trigrams created earlier, so in this final stage, the graph is
147 : : * compacted and packed into a simpler struct that contains only the
148 : : * information needed to evaluate it.
149 : : *
150 : : * ALGORITHM EXAMPLE:
151 : : *
152 : : * Consider the example regex "ab[cd]". This regex is transformed into the
153 : : * following NFA (for simplicity we show colors as their single members):
154 : : *
155 : : * 4#
156 : : * c/
157 : : * a b /
158 : : * 1* --- 2 ---- 3
159 : : * \
160 : : * d\
161 : : * 5#
162 : : *
163 : : * We use * to mark initial state and # to mark final state. It's not depicted,
164 : : * but states 1, 4, 5 have self-referencing arcs for all possible characters,
165 : : * because this pattern can match to any part of a string.
166 : : *
167 : : * As the result of stage 2 we will have the following graph:
168 : : *
169 : : * abc abd
170 : : * 2# <---- 1* ----> 3#
171 : : *
172 : : * The process for generating this graph is:
173 : : * 1) Create state 1 with enter key (UNKNOWN, UNKNOWN, 1).
174 : : * 2) Add key (UNKNOWN, "a", 2) to state 1.
175 : : * 3) Add key ("a", "b", 3) to state 1.
176 : : * 4) Create new state 2 with enter key ("b", "c", 4). Add an arc
177 : : * from state 1 to state 2 with label trigram "abc".
178 : : * 5) Mark state 2 final because state 4 of source NFA is marked as final.
179 : : * 6) Create new state 3 with enter key ("b", "d", 5). Add an arc
180 : : * from state 1 to state 3 with label trigram "abd".
181 : : * 7) Mark state 3 final because state 5 of source NFA is marked as final.
182 : : *
183 : : *
184 : : * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
185 : : * Portions Copyright (c) 1994, Regents of the University of California
186 : : *
187 : : * IDENTIFICATION
188 : : * contrib/pg_trgm/trgm_regexp.c
189 : : *
190 : : *-------------------------------------------------------------------------
191 : : */
192 : : #include "postgres.h"
193 : :
194 : : #include "regex/regexport.h"
195 : : #include "trgm.h"
196 : : #include "tsearch/ts_locale.h"
197 : : #include "utils/hsearch.h"
198 : : #include "utils/memutils.h"
199 : : #include "varatt.h"
200 : :
201 : : /*
202 : : * Uncomment (or use -DTRGM_REGEXP_DEBUG) to print debug info,
203 : : * for exploring and debugging the algorithm implementation.
204 : : * This produces three graph files in /tmp, in Graphviz .gv format.
205 : : * Some progress information is also printed to postmaster stderr.
206 : : */
207 : : /* #define TRGM_REGEXP_DEBUG */
208 : :
209 : : /*
210 : : * These parameters are used to limit the amount of work done.
211 : : * Otherwise regex processing could be too slow and memory-consuming.
212 : : *
213 : : * MAX_EXPANDED_STATES - How many states we allow in expanded graph
214 : : * MAX_EXPANDED_ARCS - How many arcs we allow in expanded graph
215 : : * MAX_TRGM_COUNT - How many simple trigrams we allow to be extracted
216 : : * WISH_TRGM_PENALTY - Maximum desired sum of color trigram penalties
217 : : * COLOR_COUNT_LIMIT - Maximum number of characters per color
218 : : */
219 : : #define MAX_EXPANDED_STATES 128
220 : : #define MAX_EXPANDED_ARCS 1024
221 : : #define MAX_TRGM_COUNT 256
222 : : #define WISH_TRGM_PENALTY 16
223 : : #define COLOR_COUNT_LIMIT 256
224 : :
225 : : /*
226 : : * Penalty multipliers for trigram counts depending on whitespace contents.
227 : : * Numbers based on analysis of real-life texts.
228 : : */
229 : : static const float4 penalties[8] = {
230 : : 1.0f, /* "aaa" */
231 : : 3.5f, /* "aa " */
232 : : 0.0f, /* "a a" (impossible) */
233 : : 0.0f, /* "a " (impossible) */
234 : : 4.2f, /* " aa" */
235 : : 2.1f, /* " a " */
236 : : 25.0f, /* " a" */
237 : : 0.0f /* " " (impossible) */
238 : : };
239 : :
240 : : /* Struct representing a single pg_wchar, converted back to multibyte form */
241 : : typedef struct
242 : : {
243 : : char bytes[MAX_MULTIBYTE_CHAR_LEN];
244 : : } trgm_mb_char;
245 : :
246 : : /*
247 : : * Attributes of NFA colors:
248 : : *
249 : : * expandable - we know the character expansion of this color
250 : : * containsNonWord - color contains non-word characters
251 : : * (which will not be extracted into trigrams)
252 : : * wordCharsCount - count of word characters in color
253 : : * wordChars - array of this color's word characters
254 : : * (which can be extracted into trigrams)
255 : : *
256 : : * When expandable is false, the other attributes don't matter; we just
257 : : * assume this color represents unknown character(s).
258 : : */
259 : : typedef struct
260 : : {
261 : : bool expandable;
262 : : bool containsNonWord;
263 : : int wordCharsCount;
264 : : trgm_mb_char *wordChars;
265 : : } TrgmColorInfo;
266 : :
267 : : /*
268 : : * A "prefix" is information about the colors of the last two characters read
269 : : * before reaching a specific NFA state. These colors can have special values
270 : : * COLOR_UNKNOWN and COLOR_BLANK. COLOR_UNKNOWN means that we have no
271 : : * information, for example because we read some character of an unexpandable
272 : : * color. COLOR_BLANK means that we read a non-word character.
273 : : *
274 : : * We call a prefix ambiguous if at least one of its colors is unknown. It's
275 : : * fully ambiguous if both are unknown, partially ambiguous if only the first
276 : : * is unknown. (The case of first color known, second unknown is not valid.)
277 : : *
278 : : * Wholly- or partly-blank prefixes are mostly handled the same as regular
279 : : * color prefixes. This allows us to generate appropriate partly-blank
280 : : * trigrams when the NFA requires word character(s) to appear adjacent to
281 : : * non-word character(s).
282 : : */
283 : : typedef int TrgmColor;
284 : :
285 : : /* We assume that colors returned by the regexp engine cannot be these: */
286 : : #define COLOR_UNKNOWN (-3)
287 : : #define COLOR_BLANK (-4)
288 : :
289 : : typedef struct
290 : : {
291 : : TrgmColor colors[2];
292 : : } TrgmPrefix;
293 : :
294 : : /*
295 : : * Color-trigram data type. Note that some elements of the trigram can be
296 : : * COLOR_BLANK, but we don't allow COLOR_UNKNOWN.
297 : : */
298 : : typedef struct
299 : : {
300 : : TrgmColor colors[3];
301 : : } ColorTrgm;
302 : :
303 : : /*
304 : : * Key identifying a state of our expanded graph: color prefix, and number
305 : : * of the corresponding state in the underlying regex NFA. The color prefix
306 : : * shows how we reached the regex state (to the extent that we know it).
307 : : */
308 : : typedef struct
309 : : {
310 : : TrgmPrefix prefix;
311 : : int nstate;
312 : : } TrgmStateKey;
313 : :
314 : : /*
315 : : * One state of the expanded graph.
316 : : *
317 : : * stateKey - ID of this state
318 : : * arcs - outgoing arcs of this state (List of TrgmArc)
319 : : * enterKeys - enter keys reachable from this state without reading any
320 : : * predictable trigram (List of TrgmStateKey)
321 : : * flags - flag bits
322 : : * snumber - number of this state (initially assigned as -1, -2, etc,
323 : : * for debugging purposes only; then at the packaging stage,
324 : : * surviving states are renumbered with positive numbers)
325 : : * parent - parent state, if this state has been merged into another
326 : : * tentFlags - flags this state would acquire via planned merges
327 : : * tentParent - planned parent state, if considering a merge
328 : : */
329 : : #define TSTATE_INIT 0x01 /* flag indicating this state is initial */
330 : : #define TSTATE_FIN 0x02 /* flag indicating this state is final */
331 : :
332 : : typedef struct TrgmState
333 : : {
334 : : TrgmStateKey stateKey; /* hashtable key: must be first field */
335 : : List *arcs;
336 : : List *enterKeys;
337 : : int flags;
338 : : int snumber;
339 : : struct TrgmState *parent;
340 : : int tentFlags;
341 : : struct TrgmState *tentParent;
342 : : } TrgmState;
343 : :
344 : : /*
345 : : * One arc in the expanded graph.
346 : : */
347 : : typedef struct
348 : : {
349 : : ColorTrgm ctrgm; /* trigram needed to traverse arc */
350 : : TrgmState *target; /* next state */
351 : : } TrgmArc;
352 : :
353 : : /*
354 : : * Information about arc of specific color trigram (used in stage 3)
355 : : *
356 : : * Contains pointers to the source and target states.
357 : : */
358 : : typedef struct
359 : : {
360 : : TrgmState *source;
361 : : TrgmState *target;
362 : : } TrgmArcInfo;
363 : :
364 : : /*
365 : : * Information about color trigram (used in stage 3)
366 : : *
367 : : * ctrgm - trigram itself
368 : : * cnumber - number of this trigram (used in the packaging stage)
369 : : * count - number of simple trigrams created from this color trigram
370 : : * expanded - indicates this color trigram is expanded into simple trigrams
371 : : * arcs - list of all arcs labeled with this color trigram.
372 : : */
373 : : typedef struct
374 : : {
375 : : ColorTrgm ctrgm;
376 : : int cnumber;
377 : : int count;
378 : : float4 penalty;
379 : : bool expanded;
380 : : List *arcs;
381 : : } ColorTrgmInfo;
382 : :
383 : : /*
384 : : * Data structure representing all the data we need during regex processing.
385 : : *
386 : : * regex - compiled regex
387 : : * colorInfo - extracted information about regex's colors
388 : : * ncolors - number of colors in colorInfo[]
389 : : * states - hashtable of TrgmStates (states of expanded graph)
390 : : * initState - pointer to initial state of expanded graph
391 : : * queue - queue of to-be-processed TrgmStates
392 : : * keysQueue - queue of to-be-processed TrgmStateKeys
393 : : * arcsCount - total number of arcs of expanded graph (for resource
394 : : * limiting)
395 : : * overflowed - we have exceeded resource limit for transformation
396 : : * colorTrgms - array of all color trigrams present in graph
397 : : * colorTrgmsCount - count of those color trigrams
398 : : * totalTrgmCount - total count of extracted simple trigrams
399 : : */
400 : : typedef struct
401 : : {
402 : : /* Source regexp, and color information extracted from it (stage 1) */
403 : : regex_t *regex;
404 : : TrgmColorInfo *colorInfo;
405 : : int ncolors;
406 : :
407 : : /* Expanded graph (stage 2) */
408 : : HTAB *states;
409 : : TrgmState *initState;
410 : : int nstates;
411 : :
412 : : /* Workspace for stage 2 */
413 : : List *queue;
414 : : List *keysQueue;
415 : : int arcsCount;
416 : : bool overflowed;
417 : :
418 : : /* Information about distinct color trigrams in the graph (stage 3) */
419 : : ColorTrgmInfo *colorTrgms;
420 : : int colorTrgmsCount;
421 : : int totalTrgmCount;
422 : : } TrgmNFA;
423 : :
424 : : /*
425 : : * Final, compact representation of expanded graph.
426 : : */
427 : : typedef struct
428 : : {
429 : : int targetState; /* index of target state (zero-based) */
430 : : int colorTrgm; /* index of color trigram for transition */
431 : : } TrgmPackedArc;
432 : :
433 : : typedef struct
434 : : {
435 : : int arcsCount; /* number of out-arcs for this state */
436 : : TrgmPackedArc *arcs; /* array of arcsCount packed arcs */
437 : : } TrgmPackedState;
438 : :
439 : : /* "typedef struct TrgmPackedGraph TrgmPackedGraph" appears in trgm.h */
440 : : struct TrgmPackedGraph
441 : : {
442 : : /*
443 : : * colorTrigramsCount and colorTrigramGroups contain information about how
444 : : * trigrams are grouped into color trigrams. "colorTrigramsCount" is the
445 : : * count of color trigrams and "colorTrigramGroups" contains number of
446 : : * simple trigrams for each color trigram. The array of simple trigrams
447 : : * (stored separately from this struct) is ordered so that the simple
448 : : * trigrams for each color trigram are consecutive, and they're in order
449 : : * by color trigram number.
450 : : */
451 : : int colorTrigramsCount;
452 : : int *colorTrigramGroups; /* array of size colorTrigramsCount */
453 : :
454 : : /*
455 : : * The states of the simplified NFA. State number 0 is always initial
456 : : * state and state number 1 is always final state.
457 : : */
458 : : int statesCount;
459 : : TrgmPackedState *states; /* array of size statesCount */
460 : :
461 : : /* Temporary work space for trigramsMatchGraph() */
462 : : bool *colorTrigramsActive; /* array of size colorTrigramsCount */
463 : : bool *statesActive; /* array of size statesCount */
464 : : int *statesQueue; /* array of size statesCount */
465 : : };
466 : :
467 : : /*
468 : : * Temporary structure for representing an arc during packaging.
469 : : */
470 : : typedef struct
471 : : {
472 : : int sourceState;
473 : : int targetState;
474 : : int colorTrgm;
475 : : } TrgmPackArcInfo;
476 : :
477 : :
478 : : /* prototypes for private functions */
479 : : static TRGM *createTrgmNFAInternal(regex_t *regex, TrgmPackedGraph **graph,
480 : : MemoryContext rcontext);
481 : : static void RE_compile(regex_t *regex, text *text_re,
482 : : int cflags, Oid collation);
483 : : static void getColorInfo(regex_t *regex, TrgmNFA *trgmNFA);
484 : : static bool convertPgWchar(pg_wchar c, trgm_mb_char *result);
485 : : static void transformGraph(TrgmNFA *trgmNFA);
486 : : static void processState(TrgmNFA *trgmNFA, TrgmState *state);
487 : : static void addKey(TrgmNFA *trgmNFA, TrgmState *state, TrgmStateKey *key);
488 : : static void addKeyToQueue(TrgmNFA *trgmNFA, TrgmStateKey *key);
489 : : static void addArcs(TrgmNFA *trgmNFA, TrgmState *state);
490 : : static void addArc(TrgmNFA *trgmNFA, TrgmState *state, TrgmStateKey *key,
491 : : TrgmColor co, TrgmStateKey *destKey);
492 : : static bool validArcLabel(TrgmStateKey *key, TrgmColor co);
493 : : static TrgmState *getState(TrgmNFA *trgmNFA, TrgmStateKey *key);
494 : : static bool prefixContains(TrgmPrefix *prefix1, TrgmPrefix *prefix2);
495 : : static bool selectColorTrigrams(TrgmNFA *trgmNFA);
496 : : static TRGM *expandColorTrigrams(TrgmNFA *trgmNFA, MemoryContext rcontext);
497 : : static void fillTrgm(trgm *ptrgm, trgm_mb_char s[3]);
498 : : static void mergeStates(TrgmState *state1, TrgmState *state2);
499 : : static int colorTrgmInfoCmp(const void *p1, const void *p2);
500 : : static int colorTrgmInfoPenaltyCmp(const void *p1, const void *p2);
501 : : static TrgmPackedGraph *packGraph(TrgmNFA *trgmNFA, MemoryContext rcontext);
502 : : static int packArcInfoCmp(const void *a1, const void *a2);
503 : :
504 : : #ifdef TRGM_REGEXP_DEBUG
505 : : static void printSourceNFA(regex_t *regex, TrgmColorInfo *colors, int ncolors);
506 : : static void printTrgmNFA(TrgmNFA *trgmNFA);
507 : : static void printTrgmColor(StringInfo buf, TrgmColor co);
508 : : static void printTrgmPackedGraph(TrgmPackedGraph *packedGraph, TRGM *trigrams);
509 : : #endif
510 : :
511 : :
512 : : /*
513 : : * Main entry point to process a regular expression.
514 : : *
515 : : * Returns an array of trigrams required by the regular expression, or NULL if
516 : : * the regular expression was too complex to analyze. In addition, a packed
517 : : * graph representation of the regex is returned into *graph. The results
518 : : * must be allocated in rcontext (which might or might not be the current
519 : : * context).
520 : : */
521 : : TRGM *
4022 tgl@sss.pgh.pa.us 522 :CBC 65 : createTrgmNFA(text *text_re, Oid collation,
523 : : TrgmPackedGraph **graph, MemoryContext rcontext)
524 : : {
525 : : TRGM *trg;
526 : : regex_t regex;
527 : : MemoryContext tmpcontext;
528 : : MemoryContext oldcontext;
529 : :
530 : : /*
531 : : * This processing generates a great deal of cruft, which we'd like to
532 : : * clean up before returning (since this function may be called in a
533 : : * query-lifespan memory context). Make a temp context we can work in so
534 : : * that cleanup is easy.
535 : : */
4023 536 : 65 : tmpcontext = AllocSetContextCreate(CurrentMemoryContext,
537 : : "createTrgmNFA temporary context",
538 : : ALLOCSET_DEFAULT_SIZES);
539 : 65 : oldcontext = MemoryContextSwitchTo(tmpcontext);
540 : :
541 : : /*
542 : : * Stage 1: Compile the regexp into a NFA, using the regexp library.
543 : : */
544 : : #ifdef IGNORECASE
979 545 : 65 : RE_compile(®ex, text_re,
546 : : REG_ADVANCED | REG_NOSUB | REG_ICASE, collation);
547 : : #else
548 : : RE_compile(®ex, text_re,
549 : : REG_ADVANCED | REG_NOSUB, collation);
550 : : #endif
551 : :
372 tmunro@postgresql.or 552 : 65 : trg = createTrgmNFAInternal(®ex, graph, rcontext);
553 : :
554 : : /* Clean up all the cruft we created (including regex) */
4023 tgl@sss.pgh.pa.us 555 : 65 : MemoryContextSwitchTo(oldcontext);
556 : 65 : MemoryContextDelete(tmpcontext);
557 : :
558 : 65 : return trg;
559 : : }
560 : :
561 : : /*
562 : : * Body of createTrgmNFA, exclusive of regex compilation/freeing.
563 : : */
564 : : static TRGM *
565 : 65 : createTrgmNFAInternal(regex_t *regex, TrgmPackedGraph **graph,
566 : : MemoryContext rcontext)
567 : : {
568 : : TRGM *trg;
569 : : TrgmNFA trgmNFA;
570 : :
571 : 65 : trgmNFA.regex = regex;
572 : :
573 : : /* Collect color information from the regex */
574 : 65 : getColorInfo(regex, &trgmNFA);
575 : :
576 : : #ifdef TRGM_REGEXP_DEBUG
577 : : printSourceNFA(regex, trgmNFA.colorInfo, trgmNFA.ncolors);
578 : : #endif
579 : :
580 : : /*
581 : : * Stage 2: Create an expanded graph from the source NFA.
582 : : */
583 : 65 : transformGraph(&trgmNFA);
584 : :
585 : : #ifdef TRGM_REGEXP_DEBUG
586 : : printTrgmNFA(&trgmNFA);
587 : : #endif
588 : :
589 : : /*
590 : : * Fail if we were unable to make a nontrivial graph, ie it is possible to
591 : : * get from the initial state to the final state without reading any
592 : : * predictable trigram.
593 : : */
2608 594 [ + + ]: 65 : if (trgmNFA.initState->flags & TSTATE_FIN)
4023 595 : 9 : return NULL;
596 : :
597 : : /*
598 : : * Stage 3: Select color trigrams to expand. Fail if too many trigrams.
599 : : */
600 [ + + ]: 56 : if (!selectColorTrigrams(&trgmNFA))
601 : 3 : return NULL;
602 : :
603 : : /*
604 : : * Stage 4: Expand color trigrams and pack graph into final
605 : : * representation.
606 : : */
607 : 53 : trg = expandColorTrigrams(&trgmNFA, rcontext);
608 : :
609 : 53 : *graph = packGraph(&trgmNFA, rcontext);
610 : :
611 : : #ifdef TRGM_REGEXP_DEBUG
612 : : printTrgmPackedGraph(*graph, trg);
613 : : #endif
614 : :
615 : 53 : return trg;
616 : : }
617 : :
618 : : /*
619 : : * Main entry point for evaluating a graph during index scanning.
620 : : *
621 : : * The check[] array is indexed by trigram number (in the array of simple
622 : : * trigrams returned by createTrgmNFA), and holds true for those trigrams
623 : : * that are present in the index entry being checked.
624 : : */
625 : : bool
626 : 3560 : trigramsMatchGraph(TrgmPackedGraph *graph, bool *check)
627 : : {
628 : : int i,
629 : : j,
630 : : k,
631 : : queueIn,
632 : : queueOut;
633 : :
634 : : /*
635 : : * Reset temporary working areas.
636 : : */
637 : 3560 : memset(graph->colorTrigramsActive, 0,
638 : 3560 : sizeof(bool) * graph->colorTrigramsCount);
639 : 3560 : memset(graph->statesActive, 0, sizeof(bool) * graph->statesCount);
640 : :
641 : : /*
642 : : * Check which color trigrams were matched. A match for any simple
643 : : * trigram associated with a color trigram counts as a match of the color
644 : : * trigram.
645 : : */
646 : 3560 : j = 0;
647 [ + + ]: 11048 : for (i = 0; i < graph->colorTrigramsCount; i++)
648 : : {
649 : 7488 : int cnt = graph->colorTrigramGroups[i];
650 : :
651 [ + + ]: 166815 : for (k = j; k < j + cnt; k++)
652 : : {
653 [ + + ]: 163185 : if (check[k])
654 : : {
655 : : /*
656 : : * Found one matched trigram in the group. Can skip the rest
657 : : * of them and go to the next group.
658 : : */
659 : 3858 : graph->colorTrigramsActive[i] = true;
660 : 3858 : break;
661 : : }
662 : : }
663 : 7488 : j = j + cnt;
664 : : }
665 : :
666 : : /*
667 : : * Initialize the statesQueue to hold just the initial state. Note:
668 : : * statesQueue has room for statesCount entries, which is certainly enough
669 : : * since no state will be put in the queue more than once. The
670 : : * statesActive array marks which states have been queued.
671 : : */
672 : 3560 : graph->statesActive[0] = true;
673 : 3560 : graph->statesQueue[0] = 0;
674 : 3560 : queueIn = 0;
675 : 3560 : queueOut = 1;
676 : :
677 : : /* Process queued states as long as there are any. */
678 [ + + ]: 7660 : while (queueIn < queueOut)
679 : : {
680 : 7524 : int stateno = graph->statesQueue[queueIn++];
681 : 7524 : TrgmPackedState *state = &graph->states[stateno];
682 : 7524 : int cnt = state->arcsCount;
683 : :
684 : : /* Loop over state's out-arcs */
685 [ + + ]: 15162 : for (i = 0; i < cnt; i++)
686 : : {
687 : 11062 : TrgmPackedArc *arc = &state->arcs[i];
688 : :
689 : : /*
690 : : * If corresponding color trigram is present then activate the
691 : : * corresponding state. We're done if that's the final state,
692 : : * otherwise queue the state if it's not been queued already.
693 : : */
694 [ + + ]: 11062 : if (graph->colorTrigramsActive[arc->colorTrgm])
695 : : {
696 : 7730 : int nextstate = arc->targetState;
697 : :
698 [ + + ]: 7730 : if (nextstate == 1)
699 : 3424 : return true; /* success: final state is reachable */
700 : :
701 [ + + ]: 4306 : if (!graph->statesActive[nextstate])
702 : : {
703 : 4249 : graph->statesActive[nextstate] = true;
704 : 4249 : graph->statesQueue[queueOut++] = nextstate;
705 : : }
706 : : }
707 : : }
708 : : }
709 : :
710 : : /* Queue is empty, so match fails. */
711 : 136 : return false;
712 : : }
713 : :
714 : : /*
715 : : * Compile regex string into struct at *regex.
716 : : * NB: pg_regfree must be applied to regex if this completes successfully.
717 : : */
718 : : static void
719 : 65 : RE_compile(regex_t *regex, text *text_re, int cflags, Oid collation)
720 : : {
721 [ - + - - : 65 : int text_re_len = VARSIZE_ANY_EXHDR(text_re);
- - - - -
+ ]
722 [ - + ]: 65 : char *text_re_val = VARDATA_ANY(text_re);
723 : : pg_wchar *pattern;
724 : : int pattern_len;
725 : : int regcomp_result;
726 : : char errMsg[100];
727 : :
728 : : /* Convert pattern string to wide characters */
729 : 65 : pattern = (pg_wchar *) palloc((text_re_len + 1) * sizeof(pg_wchar));
730 : 65 : pattern_len = pg_mb2wchar_with_len(text_re_val,
731 : : pattern,
732 : : text_re_len);
733 : :
734 : : /* Compile regex */
735 : 65 : regcomp_result = pg_regcomp(regex,
736 : : pattern,
737 : : pattern_len,
738 : : cflags,
739 : : collation);
740 : :
741 : 65 : pfree(pattern);
742 : :
743 [ - + ]: 65 : if (regcomp_result != REG_OKAY)
744 : : {
745 : : /* re didn't compile (no need for pg_regfree, if so) */
4023 tgl@sss.pgh.pa.us 746 :UBC 0 : pg_regerror(regcomp_result, regex, errMsg, sizeof(errMsg));
747 [ # # ]: 0 : ereport(ERROR,
748 : : (errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
749 : : errmsg("invalid regular expression: %s", errMsg)));
750 : : }
4023 tgl@sss.pgh.pa.us 751 :CBC 65 : }
752 : :
753 : :
754 : : /*---------------------
755 : : * Subroutines for pre-processing the color map (stage 1).
756 : : *---------------------
757 : : */
758 : :
759 : : /*
760 : : * Fill TrgmColorInfo structure for each color using regex export functions.
761 : : */
762 : : static void
763 : 65 : getColorInfo(regex_t *regex, TrgmNFA *trgmNFA)
764 : : {
765 : 65 : int colorsCount = pg_reg_getnumcolors(regex);
766 : : int i;
767 : :
768 : 65 : trgmNFA->ncolors = colorsCount;
769 : 65 : trgmNFA->colorInfo = (TrgmColorInfo *)
770 : 65 : palloc0(colorsCount * sizeof(TrgmColorInfo));
771 : :
772 : : /*
773 : : * Loop over colors, filling TrgmColorInfo about each. Note we include
774 : : * WHITE (0) even though we know it'll be reported as non-expandable.
775 : : */
776 [ + + ]: 596 : for (i = 0; i < colorsCount; i++)
777 : : {
778 : 531 : TrgmColorInfo *colorInfo = &trgmNFA->colorInfo[i];
779 : 531 : int charsCount = pg_reg_getnumcharacters(regex, i);
780 : : pg_wchar *chars;
781 : : int j;
782 : :
783 [ + + - + ]: 531 : if (charsCount < 0 || charsCount > COLOR_COUNT_LIMIT)
784 : : {
785 : : /* Non expandable, or too large to work with */
786 : 325 : colorInfo->expandable = false;
787 : 325 : continue;
788 : : }
789 : :
790 : 206 : colorInfo->expandable = true;
791 : 206 : colorInfo->containsNonWord = false;
792 : 206 : colorInfo->wordChars = (trgm_mb_char *)
793 : 206 : palloc(sizeof(trgm_mb_char) * charsCount);
794 : 206 : colorInfo->wordCharsCount = 0;
795 : :
796 : : /* Extract all the chars in this color */
797 : 206 : chars = (pg_wchar *) palloc(sizeof(pg_wchar) * charsCount);
798 : 206 : pg_reg_getcharacters(regex, i, chars, charsCount);
799 : :
800 : : /*
801 : : * Convert characters back to multibyte form, and save only those that
802 : : * are word characters. Set "containsNonWord" if any non-word
803 : : * character. (Note: it'd probably be nicer to keep the chars in
804 : : * pg_wchar format for now, but ISWORDCHR wants to see multibyte.)
805 : : */
806 [ + + ]: 991 : for (j = 0; j < charsCount; j++)
807 : : {
808 : : trgm_mb_char c;
809 : :
810 [ + + ]: 785 : if (!convertPgWchar(chars[j], &c))
811 : 365 : continue; /* ok to ignore it altogether */
812 [ + + ]: 420 : if (ISWORDCHR(c.bytes))
813 : 395 : colorInfo->wordChars[colorInfo->wordCharsCount++] = c;
814 : : else
815 : 25 : colorInfo->containsNonWord = true;
816 : : }
817 : :
818 : 206 : pfree(chars);
819 : : }
820 : 65 : }
821 : :
822 : : /*
823 : : * Convert pg_wchar to multibyte format.
824 : : * Returns false if the character should be ignored completely.
825 : : */
826 : : static bool
827 : 785 : convertPgWchar(pg_wchar c, trgm_mb_char *result)
828 : : {
829 : : /* "s" has enough space for a multibyte character and a trailing NUL */
830 : : char s[MAX_MULTIBYTE_CHAR_LEN + 1];
831 : :
832 : : /*
833 : : * We can ignore the NUL character, since it can never appear in a PG text
834 : : * string. This avoids the need for various special cases when
835 : : * reconstructing trigrams.
836 : : */
837 [ - + ]: 785 : if (c == 0)
4023 tgl@sss.pgh.pa.us 838 :UBC 0 : return false;
839 : :
840 : : /* Do the conversion, making sure the result is NUL-terminated */
4023 tgl@sss.pgh.pa.us 841 :CBC 785 : memset(s, 0, sizeof(s));
842 : 785 : pg_wchar2mb_with_len(&c, s, 1);
843 : :
844 : : /*
845 : : * In IGNORECASE mode, we can ignore uppercase characters. We assume that
846 : : * the regex engine generated both uppercase and lowercase equivalents
847 : : * within each color, since we used the REG_ICASE option; so there's no
848 : : * need to process the uppercase version.
849 : : *
850 : : * XXX this code is dependent on the assumption that lowerstr() works the
851 : : * same as the regex engine's internal case folding machinery. Might be
852 : : * wiser to expose pg_wc_tolower and test whether c == pg_wc_tolower(c).
853 : : * On the other hand, the trigrams in the index were created using
854 : : * lowerstr(), so we're probably screwed if there's any incompatibility
855 : : * anyway.
856 : : */
857 : : #ifdef IGNORECASE
858 : : {
859 : 785 : char *lowerCased = lowerstr(s);
860 : :
861 [ + + ]: 785 : if (strcmp(lowerCased, s) != 0)
862 : : {
863 : 365 : pfree(lowerCased);
864 : 365 : return false;
865 : : }
866 : 420 : pfree(lowerCased);
867 : : }
868 : : #endif
869 : :
870 : : /* Fill result with exactly MAX_MULTIBYTE_CHAR_LEN bytes */
3368 871 : 420 : memcpy(result->bytes, s, MAX_MULTIBYTE_CHAR_LEN);
4023 872 : 420 : return true;
873 : : }
874 : :
875 : :
876 : : /*---------------------
877 : : * Subroutines for expanding original NFA graph into a trigram graph (stage 2).
878 : : *---------------------
879 : : */
880 : :
881 : : /*
882 : : * Transform the graph, given a regex and extracted color information.
883 : : *
884 : : * We create and process a queue of expanded-graph states until all the states
885 : : * are processed.
886 : : *
887 : : * This algorithm may be stopped due to resource limitation. In this case we
888 : : * force every unprocessed branch to immediately finish with matching (this
889 : : * can give us false positives but no false negatives) by marking all
890 : : * unprocessed states as final.
891 : : */
892 : : static void
893 : 65 : transformGraph(TrgmNFA *trgmNFA)
894 : : {
895 : : HASHCTL hashCtl;
896 : : TrgmStateKey initkey;
897 : : TrgmState *initstate;
898 : : ListCell *lc;
899 : :
900 : : /* Initialize this stage's workspace in trgmNFA struct */
901 : 65 : trgmNFA->queue = NIL;
902 : 65 : trgmNFA->keysQueue = NIL;
903 : 65 : trgmNFA->arcsCount = 0;
904 : 65 : trgmNFA->overflowed = false;
905 : :
906 : : /* Create hashtable for states */
907 : 65 : hashCtl.keysize = sizeof(TrgmStateKey);
908 : 65 : hashCtl.entrysize = sizeof(TrgmState);
909 : 65 : hashCtl.hcxt = CurrentMemoryContext;
910 : 65 : trgmNFA->states = hash_create("Trigram NFA",
911 : : 1024,
912 : : &hashCtl,
913 : : HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
2557 914 : 65 : trgmNFA->nstates = 0;
915 : :
916 : : /* Create initial state: ambiguous prefix, NFA's initial state */
4023 917 [ - + - - : 65 : MemSet(&initkey, 0, sizeof(initkey));
- - - - -
- ]
918 : 65 : initkey.prefix.colors[0] = COLOR_UNKNOWN;
919 : 65 : initkey.prefix.colors[1] = COLOR_UNKNOWN;
920 : 65 : initkey.nstate = pg_reg_getinitialstate(trgmNFA->regex);
921 : :
922 : 65 : initstate = getState(trgmNFA, &initkey);
2608 923 : 65 : initstate->flags |= TSTATE_INIT;
4023 924 : 65 : trgmNFA->initState = initstate;
925 : :
926 : : /*
927 : : * Recursively build the expanded graph by processing queue of states
928 : : * (breadth-first search). getState already put initstate in the queue.
929 : : * Note that getState will append new states to the queue within the loop,
930 : : * too; this works as long as we don't do repeat fetches using the "lc"
931 : : * pointer.
932 : : */
895 933 [ + - + + : 729 : foreach(lc, trgmNFA->queue)
+ + ]
934 : : {
935 : 664 : TrgmState *state = (TrgmState *) lfirst(lc);
936 : :
937 : : /*
938 : : * If we overflowed then just mark state as final. Otherwise do
939 : : * actual processing.
940 : : */
4023 941 [ + + ]: 664 : if (trgmNFA->overflowed)
2608 942 : 9 : state->flags |= TSTATE_FIN;
943 : : else
4023 944 : 655 : processState(trgmNFA, state);
945 : :
946 : : /* Did we overflow? */
947 [ + - + + ]: 1328 : if (trgmNFA->arcsCount > MAX_EXPANDED_ARCS ||
948 : 664 : hash_get_num_entries(trgmNFA->states) > MAX_EXPANDED_STATES)
949 : 12 : trgmNFA->overflowed = true;
950 : : }
951 : 65 : }
952 : :
953 : : /*
954 : : * Process one state: add enter keys and then add outgoing arcs.
955 : : */
956 : : static void
957 : 655 : processState(TrgmNFA *trgmNFA, TrgmState *state)
958 : : {
959 : : ListCell *lc;
960 : :
961 : : /* keysQueue should be NIL already, but make sure */
962 : 655 : trgmNFA->keysQueue = NIL;
963 : :
964 : : /*
965 : : * Add state's own key, and then process all keys added to keysQueue until
966 : : * queue is finished. But we can quit if the state gets marked final.
967 : : */
968 : 655 : addKey(trgmNFA, state, &state->stateKey);
895 969 [ + + + + : 1266 : foreach(lc, trgmNFA->keysQueue)
+ + ]
970 : : {
971 : 692 : TrgmStateKey *key = (TrgmStateKey *) lfirst(lc);
972 : :
973 [ + + ]: 692 : if (state->flags & TSTATE_FIN)
974 : 81 : break;
4023 975 : 611 : addKey(trgmNFA, state, key);
976 : : }
977 : :
978 : : /* Release keysQueue to clean up for next cycle */
895 979 : 655 : list_free(trgmNFA->keysQueue);
980 : 655 : trgmNFA->keysQueue = NIL;
981 : :
982 : : /*
983 : : * Add outgoing arcs only if state isn't final (we have no interest in
984 : : * outgoing arcs if we already match)
985 : : */
2608 986 [ + + ]: 655 : if (!(state->flags & TSTATE_FIN))
4023 987 : 571 : addArcs(trgmNFA, state);
988 : 655 : }
989 : :
990 : : /*
991 : : * Add the given enter key into the state's enterKeys list, and determine
992 : : * whether this should result in any further enter keys being added.
993 : : * If so, add those keys to keysQueue so that processState will handle them.
994 : : *
995 : : * If the enter key is for the NFA's final state, mark state as TSTATE_FIN.
996 : : * This situation means that we can reach the final state from this expanded
997 : : * state without reading any predictable trigram, so we must consider this
998 : : * state as an accepting one.
999 : : *
1000 : : * The given key could be a duplicate of one already in enterKeys, or be
1001 : : * redundant with some enterKeys. So we check that before doing anything.
1002 : : *
1003 : : * Note that we don't generate any actual arcs here. addArcs will do that
1004 : : * later, after we have identified all the enter keys for this state.
1005 : : */
1006 : : static void
1007 : 1266 : addKey(TrgmNFA *trgmNFA, TrgmState *state, TrgmStateKey *key)
1008 : : {
1009 : : regex_arc_t *arcs;
1010 : : TrgmStateKey destKey;
1011 : : ListCell *cell;
1012 : : int i,
1013 : : arcsCount;
1014 : :
1015 : : /*
1016 : : * Ensure any pad bytes in destKey are zero, since it may get used as a
1017 : : * hashtable key by getState.
1018 : : */
1019 [ - + - - : 1266 : MemSet(&destKey, 0, sizeof(destKey));
- - - - -
- ]
1020 : :
1021 : : /*
1022 : : * Compare key to each existing enter key of the state to check for
1023 : : * redundancy. We can drop either old key(s) or the new key if we find
1024 : : * redundancy.
1025 : : */
1735 1026 [ + + + + : 1979 : foreach(cell, state->enterKeys)
+ + ]
1027 : : {
4023 1028 : 1016 : TrgmStateKey *existingKey = (TrgmStateKey *) lfirst(cell);
1029 : :
1030 [ + + ]: 1016 : if (existingKey->nstate == key->nstate)
1031 : : {
1032 [ + + ]: 312 : if (prefixContains(&existingKey->prefix, &key->prefix))
1033 : : {
1034 : : /* This old key already covers the new key. Nothing to do */
1035 : 303 : return;
1036 : : }
1037 [ + + ]: 9 : if (prefixContains(&key->prefix, &existingKey->prefix))
1038 : : {
1039 : : /*
1040 : : * The new key covers this old key. Remove the old key, it's
1041 : : * no longer needed once we add this key to the list.
1042 : : */
1735 1043 : 6 : state->enterKeys = foreach_delete_current(state->enterKeys,
1044 : : cell);
1045 : : }
1046 : : }
1047 : : }
1048 : :
1049 : : /* No redundancy, so add this key to the state's list */
4023 1050 : 963 : state->enterKeys = lappend(state->enterKeys, key);
1051 : :
1052 : : /* If state is now known final, mark it and we're done */
1053 [ + + ]: 963 : if (key->nstate == pg_reg_getfinalstate(trgmNFA->regex))
1054 : : {
2608 1055 : 84 : state->flags |= TSTATE_FIN;
4023 1056 : 84 : return;
1057 : : }
1058 : :
1059 : : /*
1060 : : * Loop through all outgoing arcs of the corresponding state in the
1061 : : * original NFA.
1062 : : */
1063 : 879 : arcsCount = pg_reg_getnumoutarcs(trgmNFA->regex, key->nstate);
1064 : 879 : arcs = (regex_arc_t *) palloc(sizeof(regex_arc_t) * arcsCount);
1065 : 879 : pg_reg_getoutarcs(trgmNFA->regex, key->nstate, arcs, arcsCount);
1066 : :
1067 [ + + ]: 2384 : for (i = 0; i < arcsCount; i++)
1068 : : {
1069 : 1505 : regex_arc_t *arc = &arcs[i];
1070 : :
1071 [ + + ]: 1505 : if (pg_reg_colorisbegin(trgmNFA->regex, arc->co))
1072 : : {
1073 : : /*
1074 : : * Start of line/string (^). Trigram extraction treats start of
1075 : : * line same as start of word: double space prefix is added.
1076 : : * Hence, make an enter key showing we can reach the arc
1077 : : * destination with all-blank prefix.
1078 : : */
1079 : 246 : destKey.prefix.colors[0] = COLOR_BLANK;
1080 : 246 : destKey.prefix.colors[1] = COLOR_BLANK;
1081 : 246 : destKey.nstate = arc->to;
1082 : :
1083 : : /* Add enter key to this state */
1084 : 246 : addKeyToQueue(trgmNFA, &destKey);
1085 : : }
1086 [ + + ]: 1259 : else if (pg_reg_colorisend(trgmNFA->regex, arc->co))
1087 : : {
1088 : : /*
1089 : : * End of line/string ($). We must consider this arc as a
1090 : : * transition that doesn't read anything. The reason for adding
1091 : : * this enter key to the state is that if the arc leads to the
1092 : : * NFA's final state, we must mark this expanded state as final.
1093 : : */
1094 : 162 : destKey.prefix.colors[0] = COLOR_UNKNOWN;
1095 : 162 : destKey.prefix.colors[1] = COLOR_UNKNOWN;
1096 : 162 : destKey.nstate = arc->to;
1097 : :
1098 : : /* Add enter key to this state */
1099 : 162 : addKeyToQueue(trgmNFA, &destKey);
1100 : : }
1149 1101 [ + + ]: 1097 : else if (arc->co >= 0)
1102 : : {
1103 : : /* Regular color (including WHITE) */
4023 1104 : 893 : TrgmColorInfo *colorInfo = &trgmNFA->colorInfo[arc->co];
1105 : :
1106 [ + - ]: 893 : if (colorInfo->expandable)
1107 : : {
1108 [ + + ]: 893 : if (colorInfo->containsNonWord &&
1109 [ + + ]: 55 : !validArcLabel(key, COLOR_BLANK))
1110 : : {
1111 : : /*
1112 : : * We can reach the arc destination after reading a
1113 : : * non-word character, but the prefix is not something
1114 : : * that addArc will accept with COLOR_BLANK, so no trigram
1115 : : * arc can get made for this transition. We must make an
1116 : : * enter key to show that the arc destination is
1117 : : * reachable. Set it up with an all-blank prefix, since
1118 : : * that corresponds to what the trigram extraction code
1119 : : * will do at a word starting boundary.
1120 : : */
1121 : 27 : destKey.prefix.colors[0] = COLOR_BLANK;
1122 : 27 : destKey.prefix.colors[1] = COLOR_BLANK;
1123 : 27 : destKey.nstate = arc->to;
1124 : 27 : addKeyToQueue(trgmNFA, &destKey);
1125 : : }
1126 : :
1127 [ + + ]: 893 : if (colorInfo->wordCharsCount > 0 &&
1128 [ + + ]: 838 : !validArcLabel(key, arc->co))
1129 : : {
1130 : : /*
1131 : : * We can reach the arc destination after reading a word
1132 : : * character, but the prefix is not something that addArc
1133 : : * will accept, so no trigram arc can get made for this
1134 : : * transition. We must make an enter key to show that the
1135 : : * arc destination is reachable. The prefix for the enter
1136 : : * key should reflect the info we have for this arc.
1137 : : */
1138 : 131 : destKey.prefix.colors[0] = key->prefix.colors[1];
1139 : 131 : destKey.prefix.colors[1] = arc->co;
1140 : 131 : destKey.nstate = arc->to;
1141 : 131 : addKeyToQueue(trgmNFA, &destKey);
1142 : : }
1143 : : }
1144 : : else
1145 : : {
1146 : : /*
1147 : : * Unexpandable color. Add enter key with ambiguous prefix,
1148 : : * showing we can reach the destination from this state, but
1149 : : * the preceding colors will be uncertain. (We do not set the
1150 : : * first prefix color to key->prefix.colors[1], because a
1151 : : * prefix of known followed by unknown is invalid.)
1152 : : */
4023 tgl@sss.pgh.pa.us 1153 :UBC 0 : destKey.prefix.colors[0] = COLOR_UNKNOWN;
1154 : 0 : destKey.prefix.colors[1] = COLOR_UNKNOWN;
1155 : 0 : destKey.nstate = arc->to;
1156 : 0 : addKeyToQueue(trgmNFA, &destKey);
1157 : : }
1158 : : }
1159 : : else
1160 : : {
1161 : : /* RAINBOW: treat as unexpandable color */
1149 tgl@sss.pgh.pa.us 1162 :CBC 204 : destKey.prefix.colors[0] = COLOR_UNKNOWN;
1163 : 204 : destKey.prefix.colors[1] = COLOR_UNKNOWN;
1164 : 204 : destKey.nstate = arc->to;
1165 : 204 : addKeyToQueue(trgmNFA, &destKey);
1166 : : }
1167 : : }
1168 : :
4023 1169 : 879 : pfree(arcs);
1170 : : }
1171 : :
1172 : : /*
1173 : : * Add copy of given key to keysQueue for later processing.
1174 : : */
1175 : : static void
1176 : 770 : addKeyToQueue(TrgmNFA *trgmNFA, TrgmStateKey *key)
1177 : : {
1178 : 770 : TrgmStateKey *keyCopy = (TrgmStateKey *) palloc(sizeof(TrgmStateKey));
1179 : :
1180 : 770 : memcpy(keyCopy, key, sizeof(TrgmStateKey));
1181 : 770 : trgmNFA->keysQueue = lappend(trgmNFA->keysQueue, keyCopy);
1182 : 770 : }
1183 : :
1184 : : /*
1185 : : * Add outgoing arcs from given state, whose enter keys are all now known.
1186 : : */
1187 : : static void
1188 : 571 : addArcs(TrgmNFA *trgmNFA, TrgmState *state)
1189 : : {
1190 : : TrgmStateKey destKey;
1191 : : ListCell *cell;
1192 : : regex_arc_t *arcs;
1193 : : int arcsCount,
1194 : : i;
1195 : :
1196 : : /*
1197 : : * Ensure any pad bytes in destKey are zero, since it may get used as a
1198 : : * hashtable key by getState.
1199 : : */
1200 [ - + - - : 571 : MemSet(&destKey, 0, sizeof(destKey));
- - - - -
- ]
1201 : :
1202 : : /*
1203 : : * Iterate over enter keys associated with this expanded-graph state. This
1204 : : * includes both the state's own stateKey, and any enter keys we added to
1205 : : * it during addKey (which represent expanded-graph states that are not
1206 : : * distinguishable from this one by means of trigrams). For each such
1207 : : * enter key, examine all the out-arcs of the key's underlying NFA state,
1208 : : * and try to make a trigram arc leading to where the out-arc leads.
1209 : : * (addArc will deal with whether the arc is valid or not.)
1210 : : */
1211 [ + - + + : 1336 : foreach(cell, state->enterKeys)
+ + ]
1212 : : {
1213 : 765 : TrgmStateKey *key = (TrgmStateKey *) lfirst(cell);
1214 : :
1215 : 765 : arcsCount = pg_reg_getnumoutarcs(trgmNFA->regex, key->nstate);
1216 : 765 : arcs = (regex_arc_t *) palloc(sizeof(regex_arc_t) * arcsCount);
1217 : 765 : pg_reg_getoutarcs(trgmNFA->regex, key->nstate, arcs, arcsCount);
1218 : :
1219 [ + + ]: 1946 : for (i = 0; i < arcsCount; i++)
1220 : : {
1221 : 1181 : regex_arc_t *arc = &arcs[i];
1222 : : TrgmColorInfo *colorInfo;
1223 : :
1224 : : /*
1225 : : * Ignore non-expandable colors; addKey already handled the case.
1226 : : *
1227 : : * We need no special check for WHITE or begin/end pseudocolors
1228 : : * here. We don't need to do any processing for them, and they
1229 : : * will be marked non-expandable since the regex engine will have
1230 : : * reported them that way. We do have to watch out for RAINBOW,
1231 : : * which has a negative color number.
1232 : : */
1148 1233 [ + + ]: 1181 : if (arc->co < 0)
1234 : 102 : continue;
1235 [ - + ]: 1079 : Assert(arc->co < trgmNFA->ncolors);
1236 : :
1237 : 1079 : colorInfo = &trgmNFA->colorInfo[arc->co];
4023 1238 [ + + ]: 1079 : if (!colorInfo->expandable)
1239 : 210 : continue;
1240 : :
1241 [ + + ]: 869 : if (colorInfo->containsNonWord)
1242 : : {
1243 : : /*
1244 : : * Color includes non-word character(s).
1245 : : *
1246 : : * Generate an arc, treating this transition as occurring on
1247 : : * BLANK. This allows word-ending trigrams to be manufactured
1248 : : * if possible.
1249 : : */
1250 : 55 : destKey.prefix.colors[0] = key->prefix.colors[1];
1251 : 55 : destKey.prefix.colors[1] = COLOR_BLANK;
1252 : 55 : destKey.nstate = arc->to;
1253 : :
1254 : 55 : addArc(trgmNFA, state, key, COLOR_BLANK, &destKey);
1255 : : }
1256 : :
1257 [ + + ]: 869 : if (colorInfo->wordCharsCount > 0)
1258 : : {
1259 : : /*
1260 : : * Color includes word character(s).
1261 : : *
1262 : : * Generate an arc. Color is pushed into prefix of target
1263 : : * state.
1264 : : */
1265 : 814 : destKey.prefix.colors[0] = key->prefix.colors[1];
1266 : 814 : destKey.prefix.colors[1] = arc->co;
1267 : 814 : destKey.nstate = arc->to;
1268 : :
1269 : 814 : addArc(trgmNFA, state, key, arc->co, &destKey);
1270 : : }
1271 : : }
1272 : :
1273 : 765 : pfree(arcs);
1274 : : }
1275 : 571 : }
1276 : :
1277 : : /*
1278 : : * Generate an out-arc of the expanded graph, if it's valid and not redundant.
1279 : : *
1280 : : * state: expanded-graph state we want to add an out-arc to
1281 : : * key: provides prefix colors (key->nstate is not used)
1282 : : * co: transition color
1283 : : * destKey: identifier for destination state of expanded graph
1284 : : */
1285 : : static void
1286 : 869 : addArc(TrgmNFA *trgmNFA, TrgmState *state, TrgmStateKey *key,
1287 : : TrgmColor co, TrgmStateKey *destKey)
1288 : : {
1289 : : TrgmArc *arc;
1290 : : ListCell *cell;
1291 : :
1292 : : /* Do nothing if this wouldn't be a valid arc label trigram */
1293 [ + + ]: 869 : if (!validArcLabel(key, co))
1294 : 137 : return;
1295 : :
1296 : : /*
1297 : : * Check if we are going to reach key which is covered by a key which is
1298 : : * already listed in this state. If so arc is useless: the NFA can bypass
1299 : : * it through a path that doesn't require any predictable trigram, so
1300 : : * whether the arc's trigram is present or not doesn't really matter.
1301 : : */
1302 [ + - + + : 1767 : foreach(cell, state->enterKeys)
+ + ]
1303 : : {
1304 : 1041 : TrgmStateKey *existingKey = (TrgmStateKey *) lfirst(cell);
1305 : :
1306 [ + + + + ]: 1066 : if (existingKey->nstate == destKey->nstate &&
1307 : 25 : prefixContains(&existingKey->prefix, &destKey->prefix))
1308 : 6 : return;
1309 : : }
1310 : :
1311 : : /* Checks were successful, add new arc */
1312 : 726 : arc = (TrgmArc *) palloc(sizeof(TrgmArc));
1313 : 726 : arc->target = getState(trgmNFA, destKey);
1314 : 726 : arc->ctrgm.colors[0] = key->prefix.colors[0];
1315 : 726 : arc->ctrgm.colors[1] = key->prefix.colors[1];
1316 : 726 : arc->ctrgm.colors[2] = co;
1317 : :
1318 : 726 : state->arcs = lappend(state->arcs, arc);
1319 : 726 : trgmNFA->arcsCount++;
1320 : : }
1321 : :
1322 : : /*
1323 : : * Can we make a valid trigram arc label from the given prefix and arc color?
1324 : : *
1325 : : * This is split out so that tests in addKey and addArc will stay in sync.
1326 : : */
1327 : : static bool
1328 : 1762 : validArcLabel(TrgmStateKey *key, TrgmColor co)
1329 : : {
1330 : : /*
1331 : : * We have to know full trigram in order to add outgoing arc. So we can't
1332 : : * do it if prefix is ambiguous.
1333 : : */
1334 [ + + ]: 1762 : if (key->prefix.colors[0] == COLOR_UNKNOWN)
1335 : 233 : return false;
1336 : :
1337 : : /* If key->prefix.colors[0] isn't unknown, its second color isn't either */
1338 [ - + ]: 1529 : Assert(key->prefix.colors[1] != COLOR_UNKNOWN);
1339 : : /* And we should not be called with an unknown arc color anytime */
1340 [ - + ]: 1529 : Assert(co != COLOR_UNKNOWN);
1341 : :
1342 : : /*
1343 : : * We don't bother with making arcs representing three non-word
1344 : : * characters, since that's useless for trigram extraction.
1345 : : */
1346 [ + + ]: 1529 : if (key->prefix.colors[0] == COLOR_BLANK &&
1347 [ + + + + ]: 164 : key->prefix.colors[1] == COLOR_BLANK &&
1348 : : co == COLOR_BLANK)
1349 : 12 : return false;
1350 : :
1351 : : /*
1352 : : * We also reject nonblank-blank-anything. The nonblank-blank-nonblank
1353 : : * case doesn't correspond to any trigram the trigram extraction code
1354 : : * would make. The nonblank-blank-blank case is also not possible with
1355 : : * RPADDING = 1. (Note that in many cases we'd fail to generate such a
1356 : : * trigram even if it were valid, for example processing "foo bar" will
1357 : : * not result in considering the trigram "o ". So if you want to support
1358 : : * RPADDING = 2, there's more to do than just twiddle this test.)
1359 : : */
1360 [ + + ]: 1517 : if (key->prefix.colors[0] != COLOR_BLANK &&
1361 [ + + ]: 1365 : key->prefix.colors[1] == COLOR_BLANK)
1362 : 50 : return false;
1363 : :
1364 : : /*
1365 : : * Other combinations involving blank are valid, in particular we assume
1366 : : * blank-blank-nonblank is valid, which presumes that LPADDING is 2.
1367 : : *
1368 : : * Note: Using again the example "foo bar", we will not consider the
1369 : : * trigram " b", though this trigram would be found by the trigram
1370 : : * extraction code. Since we will find " ba", it doesn't seem worth
1371 : : * trying to hack the algorithm to generate the additional trigram.
1372 : : */
1373 : :
1374 : : /* arc label is valid */
1375 : 1467 : return true;
1376 : : }
1377 : :
1378 : : /*
1379 : : * Get state of expanded graph for given state key,
1380 : : * and queue the state for processing if it didn't already exist.
1381 : : */
1382 : : static TrgmState *
1383 : 791 : getState(TrgmNFA *trgmNFA, TrgmStateKey *key)
1384 : : {
1385 : : TrgmState *state;
1386 : : bool found;
1387 : :
1388 : 791 : state = (TrgmState *) hash_search(trgmNFA->states, key, HASH_ENTER,
1389 : : &found);
1390 [ + + ]: 791 : if (!found)
1391 : : {
1392 : : /* New state: initialize and queue it */
1393 : 664 : state->arcs = NIL;
1394 : 664 : state->enterKeys = NIL;
2608 1395 : 664 : state->flags = 0;
1396 : : /* states are initially given negative numbers */
2557 1397 : 664 : state->snumber = -(++trgmNFA->nstates);
4023 1398 : 664 : state->parent = NULL;
2557 1399 : 664 : state->tentFlags = 0;
2608 1400 : 664 : state->tentParent = NULL;
1401 : :
4023 1402 : 664 : trgmNFA->queue = lappend(trgmNFA->queue, state);
1403 : : }
1404 : 791 : return state;
1405 : : }
1406 : :
1407 : : /*
1408 : : * Check if prefix1 "contains" prefix2.
1409 : : *
1410 : : * "contains" means that any exact prefix (with no ambiguity) that satisfies
1411 : : * prefix2 also satisfies prefix1.
1412 : : */
1413 : : static bool
1414 : 346 : prefixContains(TrgmPrefix *prefix1, TrgmPrefix *prefix2)
1415 : : {
1416 [ + + ]: 346 : if (prefix1->colors[1] == COLOR_UNKNOWN)
1417 : : {
1418 : : /* Fully ambiguous prefix contains everything */
1419 : 306 : return true;
1420 : : }
1421 [ + + ]: 40 : else if (prefix1->colors[0] == COLOR_UNKNOWN)
1422 : : {
1423 : : /*
1424 : : * Prefix with only first unknown color contains every prefix with
1425 : : * same second color.
1426 : : */
1427 [ + + ]: 12 : if (prefix1->colors[1] == prefix2->colors[1])
1428 : 3 : return true;
1429 : : else
1430 : 9 : return false;
1431 : : }
1432 : : else
1433 : : {
1434 : : /* Exact prefix contains only the exact same prefix */
1435 [ + + ]: 28 : if (prefix1->colors[0] == prefix2->colors[0] &&
1436 [ + + ]: 13 : prefix1->colors[1] == prefix2->colors[1])
1437 : 6 : return true;
1438 : : else
1439 : 22 : return false;
1440 : : }
1441 : : }
1442 : :
1443 : :
1444 : : /*---------------------
1445 : : * Subroutines for expanding color trigrams into regular trigrams (stage 3).
1446 : : *---------------------
1447 : : */
1448 : :
1449 : : /*
1450 : : * Get vector of all color trigrams in graph and select which of them
1451 : : * to expand into simple trigrams.
1452 : : *
1453 : : * Returns true if OK, false if exhausted resource limits.
1454 : : */
1455 : : static bool
1456 : 56 : selectColorTrigrams(TrgmNFA *trgmNFA)
1457 : : {
1458 : : HASH_SEQ_STATUS scan_status;
1459 : 56 : int arcsCount = trgmNFA->arcsCount,
1460 : : i;
1461 : : TrgmState *state;
1462 : : ColorTrgmInfo *colorTrgms;
1463 : : int64 totalTrgmCount;
1464 : : float4 totalTrgmPenalty;
1465 : : int cnumber;
1466 : :
1467 : : /* Collect color trigrams from all arcs */
2557 1468 : 56 : colorTrgms = (ColorTrgmInfo *) palloc0(sizeof(ColorTrgmInfo) * arcsCount);
4023 1469 : 56 : trgmNFA->colorTrgms = colorTrgms;
1470 : :
1471 : 56 : i = 0;
1472 : 56 : hash_seq_init(&scan_status, trgmNFA->states);
1473 [ + + ]: 711 : while ((state = (TrgmState *) hash_seq_search(&scan_status)) != NULL)
1474 : : {
1475 : : ListCell *cell;
1476 : :
1477 [ + + + + : 1381 : foreach(cell, state->arcs)
+ + ]
1478 : : {
1479 : 726 : TrgmArc *arc = (TrgmArc *) lfirst(cell);
1480 : 726 : TrgmArcInfo *arcInfo = (TrgmArcInfo *) palloc(sizeof(TrgmArcInfo));
2557 1481 : 726 : ColorTrgmInfo *trgmInfo = &colorTrgms[i];
1482 : :
4023 1483 : 726 : arcInfo->source = state;
1484 : 726 : arcInfo->target = arc->target;
2557 1485 : 726 : trgmInfo->ctrgm = arc->ctrgm;
1486 : 726 : trgmInfo->cnumber = -1;
1487 : : /* count and penalty will be set below */
1488 : 726 : trgmInfo->expanded = true;
1489 : 726 : trgmInfo->arcs = list_make1(arcInfo);
4023 1490 : 726 : i++;
1491 : : }
1492 : : }
1493 [ - + ]: 56 : Assert(i == arcsCount);
1494 : :
1495 : : /* Remove duplicates, merging their arcs lists */
1496 [ + + ]: 56 : if (arcsCount >= 2)
1497 : : {
1498 : : ColorTrgmInfo *p1,
1499 : : *p2;
1500 : :
1501 : : /* Sort trigrams to ease duplicate detection */
1502 : 34 : qsort(colorTrgms, arcsCount, sizeof(ColorTrgmInfo), colorTrgmInfoCmp);
1503 : :
1504 : : /* p1 is probe point, p2 is last known non-duplicate. */
1505 : 34 : p2 = colorTrgms;
1506 [ + + ]: 706 : for (p1 = colorTrgms + 1; p1 < colorTrgms + arcsCount; p1++)
1507 : : {
1508 [ + + ]: 672 : if (colorTrgmInfoCmp(p1, p2) > 0)
1509 : : {
1510 : 224 : p2++;
1511 : 224 : *p2 = *p1;
1512 : : }
1513 : : else
1514 : : {
1515 : 448 : p2->arcs = list_concat(p2->arcs, p1->arcs);
1516 : : }
1517 : : }
1518 : 34 : trgmNFA->colorTrgmsCount = (p2 - colorTrgms) + 1;
1519 : : }
1520 : : else
1521 : : {
1522 : 22 : trgmNFA->colorTrgmsCount = arcsCount;
1523 : : }
1524 : :
1525 : : /*
1526 : : * Count number of simple trigrams generated by each color trigram, and
1527 : : * also compute a penalty value, which is the number of simple trigrams
1528 : : * times a multiplier that depends on its whitespace content.
1529 : : *
1530 : : * Note: per-color-trigram counts cannot overflow an int so long as
1531 : : * COLOR_COUNT_LIMIT is not more than the cube root of INT_MAX, ie about
1532 : : * 1290. However, the grand total totalTrgmCount might conceivably
1533 : : * overflow an int, so we use int64 for that within this routine. Also,
1534 : : * penalties are calculated in float4 arithmetic to avoid any overflow
1535 : : * worries.
1536 : : */
1537 : 56 : totalTrgmCount = 0;
3662 1538 : 56 : totalTrgmPenalty = 0.0f;
4023 1539 [ + + ]: 334 : for (i = 0; i < trgmNFA->colorTrgmsCount; i++)
1540 : : {
1541 : 278 : ColorTrgmInfo *trgmInfo = &colorTrgms[i];
1542 : : int j,
3662 1543 : 278 : count = 1,
1544 : 278 : typeIndex = 0;
1545 : :
4023 1546 [ + + ]: 1112 : for (j = 0; j < 3; j++)
1547 : : {
1548 : 834 : TrgmColor c = trgmInfo->ctrgm.colors[j];
1549 : :
3662 1550 : 834 : typeIndex *= 2;
1551 [ + + ]: 834 : if (c == COLOR_BLANK)
1552 : 113 : typeIndex++;
1553 : : else
4023 1554 : 721 : count *= trgmNFA->colorInfo[c].wordCharsCount;
1555 : : }
1556 : 278 : trgmInfo->count = count;
1557 : 278 : totalTrgmCount += count;
3662 1558 : 278 : trgmInfo->penalty = penalties[typeIndex] * (float4) count;
1559 : 278 : totalTrgmPenalty += trgmInfo->penalty;
1560 : : }
1561 : :
1562 : : /* Sort color trigrams in descending order of their penalties */
4023 1563 : 56 : qsort(colorTrgms, trgmNFA->colorTrgmsCount, sizeof(ColorTrgmInfo),
1564 : : colorTrgmInfoPenaltyCmp);
1565 : :
1566 : : /*
1567 : : * Remove color trigrams from the graph so long as total penalty of color
1568 : : * trigrams exceeds WISH_TRGM_PENALTY. (If we fail to get down to
1569 : : * WISH_TRGM_PENALTY, it's OK so long as total count is no more than
1570 : : * MAX_TRGM_COUNT.) We prefer to remove color trigrams with higher
1571 : : * penalty, since those are the most promising for reducing the total
1572 : : * penalty. When removing a color trigram we have to merge states
1573 : : * connected by arcs labeled with that trigram. It's necessary to not
1574 : : * merge initial and final states, because our graph becomes useless if
1575 : : * that happens; so we cannot always remove the trigram we'd prefer to.
1576 : : */
3662 1577 [ + + ]: 204 : for (i = 0; i < trgmNFA->colorTrgmsCount; i++)
1578 : : {
4023 1579 : 179 : ColorTrgmInfo *trgmInfo = &colorTrgms[i];
1580 : 179 : bool canRemove = true;
1581 : : ListCell *cell;
1582 : :
1583 : : /* Done if we've reached the target */
3662 1584 [ + + ]: 179 : if (totalTrgmPenalty <= WISH_TRGM_PENALTY)
1585 : 31 : break;
1586 : :
1587 : : #ifdef TRGM_REGEXP_DEBUG
1588 : : fprintf(stderr, "considering ctrgm %d %d %d, penalty %f, %d arcs\n",
1589 : : trgmInfo->ctrgm.colors[0],
1590 : : trgmInfo->ctrgm.colors[1],
1591 : : trgmInfo->ctrgm.colors[2],
1592 : : trgmInfo->penalty,
1593 : : list_length(trgmInfo->arcs));
1594 : : #endif
1595 : :
1596 : : /*
1597 : : * Does any arc of this color trigram connect initial and final
1598 : : * states? If so we can't remove it.
1599 : : */
4023 1600 [ + - + + : 306 : foreach(cell, trgmInfo->arcs)
+ + ]
1601 : : {
1602 : 191 : TrgmArcInfo *arcInfo = (TrgmArcInfo *) lfirst(cell);
1603 : 191 : TrgmState *source = arcInfo->source,
1604 : 191 : *target = arcInfo->target;
1605 : : int source_flags,
1606 : : target_flags;
1607 : :
1608 : : #ifdef TRGM_REGEXP_DEBUG
1609 : : fprintf(stderr, "examining arc to s%d (%x) from s%d (%x)\n",
1610 : : -target->snumber, target->flags,
1611 : : -source->snumber, source->flags);
1612 : : #endif
1613 : :
1614 : : /* examine parent states, if any merging has already happened */
1615 [ + + ]: 341 : while (source->parent)
1616 : 150 : source = source->parent;
1617 [ + + ]: 407 : while (target->parent)
1618 : 216 : target = target->parent;
1619 : :
1620 : : #ifdef TRGM_REGEXP_DEBUG
1621 : : fprintf(stderr, " ... after completed merges: to s%d (%x) from s%d (%x)\n",
1622 : : -target->snumber, target->flags,
1623 : : -source->snumber, source->flags);
1624 : : #endif
1625 : :
1626 : : /* we must also consider merges we are planning right now */
2557 1627 : 191 : source_flags = source->flags | source->tentFlags;
2608 1628 [ + + ]: 195 : while (source->tentParent)
1629 : : {
1630 : 4 : source = source->tentParent;
2557 1631 : 4 : source_flags |= source->flags | source->tentFlags;
1632 : : }
1633 : 191 : target_flags = target->flags | target->tentFlags;
2608 1634 [ + + ]: 206 : while (target->tentParent)
1635 : : {
1636 : 15 : target = target->tentParent;
2557 1637 : 15 : target_flags |= target->flags | target->tentFlags;
1638 : : }
1639 : :
1640 : : #ifdef TRGM_REGEXP_DEBUG
1641 : : fprintf(stderr, " ... after tentative merges: to s%d (%x) from s%d (%x)\n",
1642 : : -target->snumber, target_flags,
1643 : : -source->snumber, source_flags);
1644 : : #endif
1645 : :
1646 : : /* would fully-merged state have both INIT and FIN set? */
2608 1647 [ + + ]: 191 : if (((source_flags | target_flags) & (TSTATE_INIT | TSTATE_FIN)) ==
1648 : : (TSTATE_INIT | TSTATE_FIN))
1649 : : {
4023 1650 : 33 : canRemove = false;
1651 : 33 : break;
1652 : : }
1653 : :
1654 : : /* ok so far, so remember planned merge */
2608 1655 [ + + ]: 158 : if (source != target)
1656 : : {
1657 : : #ifdef TRGM_REGEXP_DEBUG
1658 : : fprintf(stderr, " ... tentatively merging s%d into s%d\n",
1659 : : -target->snumber, -source->snumber);
1660 : : #endif
1661 : 113 : target->tentParent = source;
2557 1662 : 113 : source->tentFlags |= target_flags;
1663 : : }
1664 : : }
1665 : :
1666 : : /*
1667 : : * We must reset all the tentFlags/tentParent fields before
1668 : : * continuing. tentFlags could only have become set in states that
1669 : : * are the source or parent or tentative parent of one of the current
1670 : : * arcs; likewise tentParent could only have become set in states that
1671 : : * are the target or parent or tentative parent of one of the current
1672 : : * arcs. There might be some overlap between those sets, but if we
1673 : : * clear tentFlags in target states as well as source states, we
1674 : : * should be okay even if we visit a state as target before visiting
1675 : : * it as a source.
1676 : : */
2608 1677 [ + - + + : 348 : foreach(cell, trgmInfo->arcs)
+ + ]
1678 : : {
1679 : 200 : TrgmArcInfo *arcInfo = (TrgmArcInfo *) lfirst(cell);
2557 1680 : 200 : TrgmState *source = arcInfo->source,
1681 : 200 : *target = arcInfo->target;
1682 : : TrgmState *ttarget;
1683 : :
1684 : : /* no need to touch previously-merged states */
1685 [ + + ]: 350 : while (source->parent)
1686 : 150 : source = source->parent;
2608 1687 [ + + ]: 440 : while (target->parent)
1688 : 240 : target = target->parent;
1689 : :
2557 1690 [ + + ]: 406 : while (source)
1691 : : {
1692 : 206 : source->tentFlags = 0;
1693 : 206 : source = source->tentParent;
1694 : : }
1695 : :
2608 1696 [ + + ]: 313 : while ((ttarget = target->tentParent) != NULL)
1697 : : {
1698 : 113 : target->tentParent = NULL;
2557 1699 : 113 : target->tentFlags = 0; /* in case it was also a source */
2608 1700 : 113 : target = ttarget;
1701 : : }
1702 : : }
1703 : :
1704 : : /* Now, move on if we can't drop this trigram */
4023 1705 [ + + ]: 148 : if (!canRemove)
1706 : : {
1707 : : #ifdef TRGM_REGEXP_DEBUG
1708 : : fprintf(stderr, " ... not ok to merge\n");
1709 : : #endif
1710 : 33 : continue;
1711 : : }
1712 : :
1713 : : /* OK, merge states linked by each arc labeled by the trigram */
1714 [ + - + + : 263 : foreach(cell, trgmInfo->arcs)
+ + ]
1715 : : {
1716 : 148 : TrgmArcInfo *arcInfo = (TrgmArcInfo *) lfirst(cell);
1717 : 148 : TrgmState *source = arcInfo->source,
1718 : 148 : *target = arcInfo->target;
1719 : :
1720 [ + + ]: 292 : while (source->parent)
1721 : 144 : source = source->parent;
1722 [ + + ]: 346 : while (target->parent)
1723 : 198 : target = target->parent;
1724 [ + + ]: 148 : if (source != target)
1725 : : {
1726 : : #ifdef TRGM_REGEXP_DEBUG
1727 : : fprintf(stderr, "merging s%d into s%d\n",
1728 : : -target->snumber, -source->snumber);
1729 : : #endif
1730 : 103 : mergeStates(source, target);
1731 : : /* Assert we didn't merge initial and final states */
2608 1732 [ - + ]: 103 : Assert((source->flags & (TSTATE_INIT | TSTATE_FIN)) !=
1733 : : (TSTATE_INIT | TSTATE_FIN));
1734 : : }
1735 : : }
1736 : :
1737 : : /* Mark trigram unexpanded, and update totals */
4023 1738 : 115 : trgmInfo->expanded = false;
1739 : 115 : totalTrgmCount -= trgmInfo->count;
3662 1740 : 115 : totalTrgmPenalty -= trgmInfo->penalty;
1741 : : }
1742 : :
1743 : : /* Did we succeed in fitting into MAX_TRGM_COUNT? */
4023 1744 [ + + ]: 56 : if (totalTrgmCount > MAX_TRGM_COUNT)
1745 : 3 : return false;
1746 : :
1747 : 53 : trgmNFA->totalTrgmCount = (int) totalTrgmCount;
1748 : :
1749 : : /*
1750 : : * Sort color trigrams by colors (will be useful for bsearch in packGraph)
1751 : : * and enumerate the color trigrams that are expanded.
1752 : : */
2557 1753 : 53 : cnumber = 0;
4023 1754 : 53 : qsort(colorTrgms, trgmNFA->colorTrgmsCount, sizeof(ColorTrgmInfo),
1755 : : colorTrgmInfoCmp);
1756 [ + + ]: 328 : for (i = 0; i < trgmNFA->colorTrgmsCount; i++)
1757 : : {
1758 [ + + ]: 275 : if (colorTrgms[i].expanded)
1759 : : {
2557 1760 : 160 : colorTrgms[i].cnumber = cnumber;
1761 : 160 : cnumber++;
1762 : : }
1763 : : }
1764 : :
4023 1765 : 53 : return true;
1766 : : }
1767 : :
1768 : : /*
1769 : : * Expand selected color trigrams into regular trigrams.
1770 : : *
1771 : : * Returns the TRGM array to be passed to the index machinery.
1772 : : * The array must be allocated in rcontext.
1773 : : */
1774 : : static TRGM *
1775 : 53 : expandColorTrigrams(TrgmNFA *trgmNFA, MemoryContext rcontext)
1776 : : {
1777 : : TRGM *trg;
1778 : : trgm *p;
1779 : : int i;
1780 : : TrgmColorInfo blankColor;
1781 : : trgm_mb_char blankChar;
1782 : :
1783 : : /* Set up "blank" color structure containing a single zero character */
1784 : 53 : memset(blankChar.bytes, 0, sizeof(blankChar.bytes));
1785 : 53 : blankColor.wordCharsCount = 1;
1786 : 53 : blankColor.wordChars = &blankChar;
1787 : :
1788 : : /* Construct the trgm array */
1789 : : trg = (TRGM *)
1790 : 53 : MemoryContextAllocZero(rcontext,
1791 : : TRGMHDRSIZE +
1792 : 53 : trgmNFA->totalTrgmCount * sizeof(trgm));
1793 : 53 : trg->flag = ARRKEY;
1794 : 53 : SET_VARSIZE(trg, CALCGTSIZE(ARRKEY, trgmNFA->totalTrgmCount));
1795 : 53 : p = GETARR(trg);
1796 [ + + ]: 328 : for (i = 0; i < trgmNFA->colorTrgmsCount; i++)
1797 : : {
1798 : 275 : ColorTrgmInfo *colorTrgm = &trgmNFA->colorTrgms[i];
1799 : : TrgmColorInfo *c[3];
1800 : : trgm_mb_char s[3];
1801 : : int j,
1802 : : i1,
1803 : : i2,
1804 : : i3;
1805 : :
1806 : : /* Ignore any unexpanded trigrams ... */
1807 [ + + ]: 275 : if (!colorTrgm->expanded)
1808 : 115 : continue;
1809 : :
1810 : : /* Get colors, substituting the dummy struct for COLOR_BLANK */
1811 [ + + ]: 640 : for (j = 0; j < 3; j++)
1812 : : {
1813 [ + + ]: 480 : if (colorTrgm->ctrgm.colors[j] != COLOR_BLANK)
1814 : 413 : c[j] = &trgmNFA->colorInfo[colorTrgm->ctrgm.colors[j]];
1815 : : else
1816 : 67 : c[j] = &blankColor;
1817 : : }
1818 : :
1819 : : /* Iterate over all possible combinations of colors' characters */
1820 [ + + ]: 377 : for (i1 = 0; i1 < c[0]->wordCharsCount; i1++)
1821 : : {
1822 : 217 : s[0] = c[0]->wordChars[i1];
1823 [ + + ]: 728 : for (i2 = 0; i2 < c[1]->wordCharsCount; i2++)
1824 : : {
1825 : 511 : s[1] = c[1]->wordChars[i2];
1826 [ + + ]: 1970 : for (i3 = 0; i3 < c[2]->wordCharsCount; i3++)
1827 : : {
1828 : 1459 : s[2] = c[2]->wordChars[i3];
1829 : 1459 : fillTrgm(p, s);
1830 : 1459 : p++;
1831 : : }
1832 : : }
1833 : : }
1834 : : }
1835 : :
1836 : 53 : return trg;
1837 : : }
1838 : :
1839 : : /*
1840 : : * Convert trigram into trgm datatype.
1841 : : */
1842 : : static void
1843 : 1459 : fillTrgm(trgm *ptrgm, trgm_mb_char s[3])
1844 : : {
1845 : : char str[3 * MAX_MULTIBYTE_CHAR_LEN],
1846 : : *p;
1847 : : int i,
1848 : : j;
1849 : :
1850 : : /* Write multibyte string into "str" (we don't need null termination) */
1851 : 1459 : p = str;
1852 : :
1853 [ + + ]: 5836 : for (i = 0; i < 3; i++)
1854 : : {
1855 [ + + ]: 4377 : if (s[i].bytes[0] != 0)
1856 : : {
1857 [ + - + + ]: 8232 : for (j = 0; j < MAX_MULTIBYTE_CHAR_LEN && s[i].bytes[j]; j++)
1858 : 4116 : *p++ = s[i].bytes[j];
1859 : : }
1860 : : else
1861 : : {
1862 : : /* Emit a space in place of COLOR_BLANK */
1863 : 261 : *p++ = ' ';
1864 : : }
1865 : : }
1866 : :
1867 : : /* Convert "str" to a standard trigram (possibly hashing it) */
1868 : 1459 : compact_trigram(ptrgm, str, p - str);
1869 : 1459 : }
1870 : :
1871 : : /*
1872 : : * Merge two states of graph.
1873 : : */
1874 : : static void
1875 : 103 : mergeStates(TrgmState *state1, TrgmState *state2)
1876 : : {
1877 [ - + ]: 103 : Assert(state1 != state2);
1878 [ - + ]: 103 : Assert(!state1->parent);
1879 [ - + ]: 103 : Assert(!state2->parent);
1880 : :
1881 : : /* state1 absorbs state2's flags */
2608 1882 : 103 : state1->flags |= state2->flags;
1883 : :
1884 : : /* state2, and indirectly all its children, become children of state1 */
4023 1885 : 103 : state2->parent = state1;
1886 : 103 : }
1887 : :
1888 : : /*
1889 : : * Compare function for sorting of color trigrams by their colors.
1890 : : */
1891 : : static int
1892 : 5089 : colorTrgmInfoCmp(const void *p1, const void *p2)
1893 : : {
1894 : 5089 : const ColorTrgmInfo *c1 = (const ColorTrgmInfo *) p1;
1895 : 5089 : const ColorTrgmInfo *c2 = (const ColorTrgmInfo *) p2;
1896 : :
1897 : 5089 : return memcmp(&c1->ctrgm, &c2->ctrgm, sizeof(ColorTrgm));
1898 : : }
1899 : :
1900 : : /*
1901 : : * Compare function for sorting color trigrams in descending order of
1902 : : * their penalty fields.
1903 : : */
1904 : : static int
3662 1905 : 423 : colorTrgmInfoPenaltyCmp(const void *p1, const void *p2)
1906 : : {
1907 : 423 : float4 penalty1 = ((const ColorTrgmInfo *) p1)->penalty;
1908 : 423 : float4 penalty2 = ((const ColorTrgmInfo *) p2)->penalty;
1909 : :
1910 [ + + ]: 423 : if (penalty1 < penalty2)
4023 1911 : 127 : return 1;
3662 1912 [ + + ]: 296 : else if (penalty1 == penalty2)
4023 1913 : 162 : return 0;
1914 : : else
1915 : 134 : return -1;
1916 : : }
1917 : :
1918 : :
1919 : : /*---------------------
1920 : : * Subroutines for packing the graph into final representation (stage 4).
1921 : : *---------------------
1922 : : */
1923 : :
1924 : : /*
1925 : : * Pack expanded graph into final representation.
1926 : : *
1927 : : * The result data must be allocated in rcontext.
1928 : : */
1929 : : static TrgmPackedGraph *
1930 : 53 : packGraph(TrgmNFA *trgmNFA, MemoryContext rcontext)
1931 : : {
2557 1932 : 53 : int snumber = 2,
1933 : : arcIndex,
1934 : : arcsCount;
1935 : : HASH_SEQ_STATUS scan_status;
1936 : : TrgmState *state;
1937 : : TrgmPackArcInfo *arcs;
1938 : : TrgmPackedArc *packedArcs;
1939 : : TrgmPackedGraph *result;
1940 : : int i,
1941 : : j;
1942 : :
1943 : : /* Enumerate surviving states, giving init and fin reserved numbers */
4023 1944 : 53 : hash_seq_init(&scan_status, trgmNFA->states);
1945 [ + + ]: 755 : while ((state = (TrgmState *) hash_seq_search(&scan_status)) != NULL)
1946 : : {
1947 [ + + ]: 971 : while (state->parent)
1948 : 322 : state = state->parent;
1949 : :
2557 1950 [ + + ]: 649 : if (state->snumber < 0)
1951 : : {
2608 1952 [ + + ]: 546 : if (state->flags & TSTATE_INIT)
2557 1953 : 53 : state->snumber = 0;
2608 1954 [ + + ]: 493 : else if (state->flags & TSTATE_FIN)
2557 1955 : 57 : state->snumber = 1;
1956 : : else
1957 : : {
1958 : 436 : state->snumber = snumber;
1959 : 436 : snumber++;
1960 : : }
1961 : : }
1962 : : }
1963 : :
1964 : : /* Collect array of all arcs */
1965 : : arcs = (TrgmPackArcInfo *)
4023 1966 : 53 : palloc(sizeof(TrgmPackArcInfo) * trgmNFA->arcsCount);
1967 : 53 : arcIndex = 0;
1968 : 53 : hash_seq_init(&scan_status, trgmNFA->states);
1969 [ + + ]: 702 : while ((state = (TrgmState *) hash_seq_search(&scan_status)) != NULL)
1970 : : {
1971 : 649 : TrgmState *source = state;
1972 : : ListCell *cell;
1973 : :
1974 [ + + ]: 971 : while (source->parent)
1975 : 322 : source = source->parent;
1976 : :
1977 [ + + + + : 1372 : foreach(cell, state->arcs)
+ + ]
1978 : : {
1979 : 723 : TrgmArc *arc = (TrgmArc *) lfirst(cell);
1980 : 723 : TrgmState *target = arc->target;
1981 : :
1982 [ + + ]: 1352 : while (target->parent)
1983 : 629 : target = target->parent;
1984 : :
2557 1985 [ + + ]: 723 : if (source->snumber != target->snumber)
1986 : : {
1987 : : ColorTrgmInfo *ctrgm;
1988 : :
4023 1989 : 566 : ctrgm = (ColorTrgmInfo *) bsearch(&arc->ctrgm,
1990 : 566 : trgmNFA->colorTrgms,
1991 : 566 : trgmNFA->colorTrgmsCount,
1992 : : sizeof(ColorTrgmInfo),
1993 : : colorTrgmInfoCmp);
1994 [ - + ]: 566 : Assert(ctrgm != NULL);
1995 [ - + ]: 566 : Assert(ctrgm->expanded);
1996 : :
2557 1997 : 566 : arcs[arcIndex].sourceState = source->snumber;
1998 : 566 : arcs[arcIndex].targetState = target->snumber;
1999 : 566 : arcs[arcIndex].colorTrgm = ctrgm->cnumber;
4023 2000 : 566 : arcIndex++;
2001 : : }
2002 : : }
2003 : : }
2004 : :
2005 : : /* Sort arcs to ease duplicate detection */
2006 : 53 : qsort(arcs, arcIndex, sizeof(TrgmPackArcInfo), packArcInfoCmp);
2007 : :
2008 : : /* We could have duplicates because states were merged. Remove them. */
400 2009 [ + + ]: 53 : if (arcIndex > 1)
2010 : : {
2011 : : /* p1 is probe point, p2 is last known non-duplicate. */
2012 : : TrgmPackArcInfo *p1,
2013 : : *p2;
2014 : :
2015 : 31 : p2 = arcs;
2016 [ + + ]: 546 : for (p1 = arcs + 1; p1 < arcs + arcIndex; p1++)
2017 : : {
2018 [ + + ]: 515 : if (packArcInfoCmp(p1, p2) > 0)
2019 : : {
2020 : 509 : p2++;
2021 : 509 : *p2 = *p1;
2022 : : }
2023 : : }
2024 : 31 : arcsCount = (p2 - arcs) + 1;
2025 : : }
2026 : : else
2027 : 22 : arcsCount = arcIndex;
2028 : :
2029 : : /* Create packed representation */
2030 : : result = (TrgmPackedGraph *)
4023 2031 : 53 : MemoryContextAlloc(rcontext, sizeof(TrgmPackedGraph));
2032 : :
2033 : : /* Pack color trigrams information */
2034 : 53 : result->colorTrigramsCount = 0;
2035 [ + + ]: 328 : for (i = 0; i < trgmNFA->colorTrgmsCount; i++)
2036 : : {
2037 [ + + ]: 275 : if (trgmNFA->colorTrgms[i].expanded)
2038 : 160 : result->colorTrigramsCount++;
2039 : : }
2040 : 53 : result->colorTrigramGroups = (int *)
2041 : 53 : MemoryContextAlloc(rcontext, sizeof(int) * result->colorTrigramsCount);
2042 : 53 : j = 0;
2043 [ + + ]: 328 : for (i = 0; i < trgmNFA->colorTrgmsCount; i++)
2044 : : {
2045 [ + + ]: 275 : if (trgmNFA->colorTrgms[i].expanded)
2046 : : {
2047 : 160 : result->colorTrigramGroups[j] = trgmNFA->colorTrgms[i].count;
2048 : 160 : j++;
2049 : : }
2050 : : }
2051 : :
2052 : : /* Pack states and arcs information */
2557 2053 : 53 : result->statesCount = snumber;
4023 2054 : 53 : result->states = (TrgmPackedState *)
2557 2055 : 53 : MemoryContextAlloc(rcontext, snumber * sizeof(TrgmPackedState));
2056 : : packedArcs = (TrgmPackedArc *)
4023 2057 : 53 : MemoryContextAlloc(rcontext, arcsCount * sizeof(TrgmPackedArc));
2058 : 53 : j = 0;
2557 2059 [ + + ]: 595 : for (i = 0; i < snumber; i++)
2060 : : {
4023 2061 : 542 : int cnt = 0;
2062 : :
2063 : 542 : result->states[i].arcs = &packedArcs[j];
2064 [ + + + + ]: 1102 : while (j < arcsCount && arcs[j].sourceState == i)
2065 : : {
2066 : 560 : packedArcs[j].targetState = arcs[j].targetState;
2067 : 560 : packedArcs[j].colorTrgm = arcs[j].colorTrgm;
2068 : 560 : cnt++;
2069 : 560 : j++;
2070 : : }
2071 : 542 : result->states[i].arcsCount = cnt;
2072 : : }
2073 : :
2074 : : /* Allocate working memory for trigramsMatchGraph() */
2075 : 53 : result->colorTrigramsActive = (bool *)
2076 : 53 : MemoryContextAlloc(rcontext, sizeof(bool) * result->colorTrigramsCount);
2077 : 53 : result->statesActive = (bool *)
2078 : 53 : MemoryContextAlloc(rcontext, sizeof(bool) * result->statesCount);
2079 : 53 : result->statesQueue = (int *)
2080 : 53 : MemoryContextAlloc(rcontext, sizeof(int) * result->statesCount);
2081 : :
2082 : 53 : return result;
2083 : : }
2084 : :
2085 : : /*
2086 : : * Comparison function for sorting TrgmPackArcInfos.
2087 : : *
2088 : : * Compares arcs in following order: sourceState, colorTrgm, targetState.
2089 : : */
2090 : : static int
2091 : 4546 : packArcInfoCmp(const void *a1, const void *a2)
2092 : : {
2093 : 4546 : const TrgmPackArcInfo *p1 = (const TrgmPackArcInfo *) a1;
2094 : 4546 : const TrgmPackArcInfo *p2 = (const TrgmPackArcInfo *) a2;
2095 : :
2096 [ + + ]: 4546 : if (p1->sourceState < p2->sourceState)
2097 : 2179 : return -1;
2098 [ + + ]: 2367 : if (p1->sourceState > p2->sourceState)
2099 : 2050 : return 1;
2100 [ + + ]: 317 : if (p1->colorTrgm < p2->colorTrgm)
2101 : 198 : return -1;
2102 [ + + ]: 119 : if (p1->colorTrgm > p2->colorTrgm)
2103 : 107 : return 1;
2104 [ - + ]: 12 : if (p1->targetState < p2->targetState)
4023 tgl@sss.pgh.pa.us 2105 :UBC 0 : return -1;
4023 tgl@sss.pgh.pa.us 2106 [ - + ]:CBC 12 : if (p1->targetState > p2->targetState)
4023 tgl@sss.pgh.pa.us 2107 :UBC 0 : return 1;
4023 tgl@sss.pgh.pa.us 2108 :CBC 12 : return 0;
2109 : : }
2110 : :
2111 : :
2112 : : /*---------------------
2113 : : * Debugging functions
2114 : : *
2115 : : * These are designed to emit GraphViz files.
2116 : : *---------------------
2117 : : */
2118 : :
2119 : : #ifdef TRGM_REGEXP_DEBUG
2120 : :
2121 : : /*
2122 : : * Print initial NFA, in regexp library's representation
2123 : : */
2124 : : static void
2125 : : printSourceNFA(regex_t *regex, TrgmColorInfo *colors, int ncolors)
2126 : : {
2127 : : StringInfoData buf;
2128 : : int nstates = pg_reg_getnumstates(regex);
2129 : : int state;
2130 : : int i;
2131 : :
2132 : : initStringInfo(&buf);
2133 : :
2134 : : appendStringInfoString(&buf, "\ndigraph sourceNFA {\n");
2135 : :
2136 : : for (state = 0; state < nstates; state++)
2137 : : {
2138 : : regex_arc_t *arcs;
2139 : : int i,
2140 : : arcsCount;
2141 : :
2142 : : appendStringInfo(&buf, "s%d", state);
2143 : : if (pg_reg_getfinalstate(regex) == state)
2144 : : appendStringInfoString(&buf, " [shape = doublecircle]");
2145 : : appendStringInfoString(&buf, ";\n");
2146 : :
2147 : : arcsCount = pg_reg_getnumoutarcs(regex, state);
2148 : : arcs = (regex_arc_t *) palloc(sizeof(regex_arc_t) * arcsCount);
2149 : : pg_reg_getoutarcs(regex, state, arcs, arcsCount);
2150 : :
2151 : : for (i = 0; i < arcsCount; i++)
2152 : : {
2153 : : appendStringInfo(&buf, " s%d -> s%d [label = \"%d\"];\n",
2154 : : state, arcs[i].to, arcs[i].co);
2155 : : }
2156 : :
2157 : : pfree(arcs);
2158 : : }
2159 : :
2160 : : appendStringInfoString(&buf, " node [shape = point ]; initial;\n");
2161 : : appendStringInfo(&buf, " initial -> s%d;\n",
2162 : : pg_reg_getinitialstate(regex));
2163 : :
2164 : : /* Print colors */
2165 : : appendStringInfoString(&buf, " { rank = sink;\n");
2166 : : appendStringInfoString(&buf, " Colors [shape = none, margin=0, label=<\n");
2167 : :
2168 : : for (i = 0; i < ncolors; i++)
2169 : : {
2170 : : TrgmColorInfo *color = &colors[i];
2171 : : int j;
2172 : :
2173 : : appendStringInfo(&buf, "<br/>Color %d: ", i);
2174 : : if (color->expandable)
2175 : : {
2176 : : for (j = 0; j < color->wordCharsCount; j++)
2177 : : {
2178 : : char s[MAX_MULTIBYTE_CHAR_LEN + 1];
2179 : :
2180 : : memcpy(s, color->wordChars[j].bytes, MAX_MULTIBYTE_CHAR_LEN);
2181 : : s[MAX_MULTIBYTE_CHAR_LEN] = '\0';
2182 : : appendStringInfoString(&buf, s);
2183 : : }
2184 : : }
2185 : : else
2186 : : appendStringInfoString(&buf, "not expandable");
2187 : : appendStringInfoChar(&buf, '\n');
2188 : : }
2189 : :
2190 : : appendStringInfoString(&buf, " >];\n");
2191 : : appendStringInfoString(&buf, " }\n");
2192 : : appendStringInfoString(&buf, "}\n");
2193 : :
2194 : : {
2195 : : /* dot -Tpng -o /tmp/source.png < /tmp/source.gv */
2196 : : FILE *fp = fopen("/tmp/source.gv", "w");
2197 : :
2198 : : fprintf(fp, "%s", buf.data);
2199 : : fclose(fp);
2200 : : }
2201 : :
2202 : : pfree(buf.data);
2203 : : }
2204 : :
2205 : : /*
2206 : : * Print expanded graph.
2207 : : */
2208 : : static void
2209 : : printTrgmNFA(TrgmNFA *trgmNFA)
2210 : : {
2211 : : StringInfoData buf;
2212 : : HASH_SEQ_STATUS scan_status;
2213 : : TrgmState *state;
2214 : : TrgmState *initstate = NULL;
2215 : :
2216 : : initStringInfo(&buf);
2217 : :
2218 : : appendStringInfoString(&buf, "\ndigraph transformedNFA {\n");
2219 : :
2220 : : hash_seq_init(&scan_status, trgmNFA->states);
2221 : : while ((state = (TrgmState *) hash_seq_search(&scan_status)) != NULL)
2222 : : {
2223 : : ListCell *cell;
2224 : :
2225 : : appendStringInfo(&buf, "s%d", -state->snumber);
2226 : : if (state->flags & TSTATE_FIN)
2227 : : appendStringInfoString(&buf, " [shape = doublecircle]");
2228 : : if (state->flags & TSTATE_INIT)
2229 : : initstate = state;
2230 : : appendStringInfo(&buf, " [label = \"%d\"]", state->stateKey.nstate);
2231 : : appendStringInfoString(&buf, ";\n");
2232 : :
2233 : : foreach(cell, state->arcs)
2234 : : {
2235 : : TrgmArc *arc = (TrgmArc *) lfirst(cell);
2236 : :
2237 : : appendStringInfo(&buf, " s%d -> s%d [label = \"",
2238 : : -state->snumber, -arc->target->snumber);
2239 : : printTrgmColor(&buf, arc->ctrgm.colors[0]);
2240 : : appendStringInfoChar(&buf, ' ');
2241 : : printTrgmColor(&buf, arc->ctrgm.colors[1]);
2242 : : appendStringInfoChar(&buf, ' ');
2243 : : printTrgmColor(&buf, arc->ctrgm.colors[2]);
2244 : : appendStringInfoString(&buf, "\"];\n");
2245 : : }
2246 : : }
2247 : :
2248 : : if (initstate)
2249 : : {
2250 : : appendStringInfoString(&buf, " node [shape = point ]; initial;\n");
2251 : : appendStringInfo(&buf, " initial -> s%d;\n", -initstate->snumber);
2252 : : }
2253 : :
2254 : : appendStringInfoString(&buf, "}\n");
2255 : :
2256 : : {
2257 : : /* dot -Tpng -o /tmp/transformed.png < /tmp/transformed.gv */
2258 : : FILE *fp = fopen("/tmp/transformed.gv", "w");
2259 : :
2260 : : fprintf(fp, "%s", buf.data);
2261 : : fclose(fp);
2262 : : }
2263 : :
2264 : : pfree(buf.data);
2265 : : }
2266 : :
2267 : : /*
2268 : : * Print a TrgmColor readably.
2269 : : */
2270 : : static void
2271 : : printTrgmColor(StringInfo buf, TrgmColor co)
2272 : : {
2273 : : if (co == COLOR_UNKNOWN)
2274 : : appendStringInfoChar(buf, 'u');
2275 : : else if (co == COLOR_BLANK)
2276 : : appendStringInfoChar(buf, 'b');
2277 : : else
2278 : : appendStringInfo(buf, "%d", (int) co);
2279 : : }
2280 : :
2281 : : /*
2282 : : * Print final packed representation of trigram-based expanded graph.
2283 : : */
2284 : : static void
2285 : : printTrgmPackedGraph(TrgmPackedGraph *packedGraph, TRGM *trigrams)
2286 : : {
2287 : : StringInfoData buf;
2288 : : trgm *p;
2289 : : int i;
2290 : :
2291 : : initStringInfo(&buf);
2292 : :
2293 : : appendStringInfoString(&buf, "\ndigraph packedGraph {\n");
2294 : :
2295 : : for (i = 0; i < packedGraph->statesCount; i++)
2296 : : {
2297 : : TrgmPackedState *state = &packedGraph->states[i];
2298 : : int j;
2299 : :
2300 : : appendStringInfo(&buf, " s%d", i);
2301 : : if (i == 1)
2302 : : appendStringInfoString(&buf, " [shape = doublecircle]");
2303 : :
2304 : : appendStringInfo(&buf, " [label = <s%d>];\n", i);
2305 : :
2306 : : for (j = 0; j < state->arcsCount; j++)
2307 : : {
2308 : : TrgmPackedArc *arc = &state->arcs[j];
2309 : :
2310 : : appendStringInfo(&buf, " s%d -> s%d [label = \"trigram %d\"];\n",
2311 : : i, arc->targetState, arc->colorTrgm);
2312 : : }
2313 : : }
2314 : :
2315 : : appendStringInfoString(&buf, " node [shape = point ]; initial;\n");
2316 : : appendStringInfo(&buf, " initial -> s%d;\n", 0);
2317 : :
2318 : : /* Print trigrams */
2319 : : appendStringInfoString(&buf, " { rank = sink;\n");
2320 : : appendStringInfoString(&buf, " Trigrams [shape = none, margin=0, label=<\n");
2321 : :
2322 : : p = GETARR(trigrams);
2323 : : for (i = 0; i < packedGraph->colorTrigramsCount; i++)
2324 : : {
2325 : : int count = packedGraph->colorTrigramGroups[i];
2326 : : int j;
2327 : :
2328 : : appendStringInfo(&buf, "<br/>Trigram %d: ", i);
2329 : :
2330 : : for (j = 0; j < count; j++)
2331 : : {
2332 : : if (j > 0)
2333 : : appendStringInfoString(&buf, ", ");
2334 : :
2335 : : /*
2336 : : * XXX This representation is nice only for all-ASCII trigrams.
2337 : : */
2338 : : appendStringInfo(&buf, "\"%c%c%c\"", (*p)[0], (*p)[1], (*p)[2]);
2339 : : p++;
2340 : : }
2341 : : }
2342 : :
2343 : : appendStringInfoString(&buf, " >];\n");
2344 : : appendStringInfoString(&buf, " }\n");
2345 : : appendStringInfoString(&buf, "}\n");
2346 : :
2347 : : {
2348 : : /* dot -Tpng -o /tmp/packed.png < /tmp/packed.gv */
2349 : : FILE *fp = fopen("/tmp/packed.gv", "w");
2350 : :
2351 : : fprintf(fp, "%s", buf.data);
2352 : : fclose(fp);
2353 : : }
2354 : :
2355 : : pfree(buf.data);
2356 : : }
2357 : :
2358 : : #endif /* TRGM_REGEXP_DEBUG */
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