}
if ( word ) {
- U8 *lpos= points[ (pointpos - trie->wordlen[word-1] ) % maxlen ];
+ U8 *lpos= points[ (pointpos - trie->wordinfo[word].len) % maxlen ];
if (!leftmost || lpos < leftmost) {
DEBUG_r(accepted_word=word);
leftmost= lpos;
}
}
if ( aho->states[ state ].wordnum ) {
- U8 *lpos = points[ (pointpos - trie->wordlen[aho->states[ state ].wordnum-1]) % maxlen ];
+ U8 *lpos = points[ (pointpos - trie->wordinfo[aho->states[ state ].wordnum].len) % maxlen ];
if (!leftmost || lpos < leftmost) {
DEBUG_r(accepted_word=aho->states[ state ].wordnum);
leftmost = lpos;
#define REPORT_CODE_OFF 32
-/* Make sure there is a test for this +1 options in re_tests */
-#define TRIE_INITAL_ACCEPT_BUFFLEN 4;
-
#define CHRTEST_UNINIT -1001 /* c1/c2 haven't been calculated yet */
#define CHRTEST_VOID -1000 /* the c1/c2 "next char" test should be skipped */
}
/* FALL THROUGH */
case TRIE:
+ /* the basic plan of execution of the trie is:
+ * At the beginning, run though all the states, and
+ * find the longest-matching word. Also remember the position
+ * of the shortest matching word. For example, this pattern:
+ * 1 2 3 4 5
+ * ab|a|x|abcd|abc
+ * when matched against the string "abcde", will generate
+ * accept states for all words except 3, with the longest
+ * matching word being 4, and the shortest being 1 (with
+ * the position being after char 1 of the string).
+ *
+ * Then for each matching word, in word order (i.e. 1,2,4,5),
+ * we run the remainder of the pattern; on each try setting
+ * the current position to the character following the word,
+ * returning to try the next word on failure.
+ *
+ * We avoid having to build a list of words at runtime by
+ * using a compile-time structure, wordinfo[].prev, which
+ * gives, for each word, the previous accepting word (if any).
+ * In the case above it would contain the mappings 1->2, 2->0,
+ * 3->0, 4->5, 5->1. We can use this table to generate, from
+ * the longest word (4 above), a list of all words, by
+ * following the list of prev pointers; this gives us the
+ * unordered list 4,5,1,2. Then given the current word we have
+ * just tried, we can go through the list and find the
+ * next-biggest word to try (so if we just failed on word 2,
+ * the next in the list is 4).
+ *
+ * Since at runtime we don't record the matching position in
+ * the string for each word, we have to work that out for
+ * each word we're about to process. The wordinfo table holds
+ * the character length of each word; given that we recorded
+ * at the start: the position of the shortest word and its
+ * length in chars, we just need to move the pointer the
+ * difference between the two char lengths. Depending on
+ * Unicode status and folding, that's cheap or expensive.
+ *
+ * This algorithm is optimised for the case where are only a
+ * small number of accept states, i.e. 0,1, or maybe 2.
+ * With lots of accepts states, and having to try all of them,
+ * it becomes quadratic on number of accept states to find all
+ * the next words.
+ */
+
{
/* what type of TRIE am I? (utf8 makes this contextual) */
DECL_TRIE_TYPE(scan);
STRLEN len = 0;
STRLEN foldlen = 0;
U8 *uscan = (U8*)NULL;
- STRLEN bufflen=0;
- SV *sv_accept_buff = NULL;
U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
+ U32 charcount = 0; /* how many input chars we have matched */
+ U32 accepted = 0; /* have we seen any accepting states? */
- ST.accepted = 0; /* how many accepting states we have seen */
ST.B = next;
ST.jump = trie->jump;
ST.me = scan;
- /*
- traverse the TRIE keeping track of all accepting states
- we transition through until we get to a failing node.
- */
+ ST.firstpos = NULL;
+ ST.longfold = FALSE; /* char longer if folded => it's harder */
+ ST.nextword = 0;
+
+ /* fully traverse the TRIE; note the position of the
+ shortest accept state and the wordnum of the longest
+ accept state */
while ( state && uc <= (U8*)PL_regeol ) {
U32 base = trie->states[ state ].trans.base;
UV uvc = 0;
U16 charid;
- /* We use charid to hold the wordnum as we don't use it
- for charid until after we have done the wordnum logic.
- We define an alias just so that the wordnum logic reads
- more naturally. */
-
-#define got_wordnum charid
- got_wordnum = trie->states[ state ].wordnum;
-
- if ( got_wordnum ) {
- if ( ! ST.accepted ) {
- ENTER;
- SAVETMPS; /* XXX is this necessary? dmq */
- bufflen = TRIE_INITAL_ACCEPT_BUFFLEN;
- sv_accept_buff=newSV(bufflen *
- sizeof(reg_trie_accepted) - 1);
- SvCUR_set(sv_accept_buff, 0);
- SvPOK_on(sv_accept_buff);
- sv_2mortal(sv_accept_buff);
- SAVETMPS;
- ST.accept_buff =
- (reg_trie_accepted*)SvPV_nolen(sv_accept_buff );
- }
- do {
- if (ST.accepted >= bufflen) {
- bufflen *= 2;
- ST.accept_buff =(reg_trie_accepted*)
- SvGROW(sv_accept_buff,
- bufflen * sizeof(reg_trie_accepted));
+ U16 wordnum;
+ wordnum = trie->states[ state ].wordnum;
+
+ if (wordnum) { /* it's an accept state */
+ if (!accepted) {
+ accepted = 1;
+ /* record first match position */
+ if (ST.longfold) {
+ ST.firstpos = (U8*)locinput;
+ ST.firstchars = 0;
}
- SvCUR_set(sv_accept_buff,SvCUR(sv_accept_buff)
- + sizeof(reg_trie_accepted));
-
-
- ST.accept_buff[ST.accepted].wordnum = got_wordnum;
- ST.accept_buff[ST.accepted].endpos = uc;
- ++ST.accepted;
- } while (trie->nextword && (got_wordnum= trie->nextword[got_wordnum]));
+ else {
+ ST.firstpos = uc;
+ ST.firstchars = charcount;
+ }
+ }
+ if (!ST.nextword || wordnum < ST.nextword)
+ ST.nextword = wordnum;
+ ST.topword = wordnum;
}
-#undef got_wordnum
DEBUG_TRIE_EXECUTE_r({
DUMP_EXEC_POS( (char *)uc, scan, do_utf8 );
PerlIO_printf( Perl_debug_log,
- "%*s %sState: %4"UVxf" Accepted: %4"UVxf" ",
+ "%*s %sState: %4"UVxf" Accepted: %c ",
2+depth * 2, "", PL_colors[4],
- (UV)state, (UV)ST.accepted );
+ (UV)state, (accepted ? 'Y' : 'N'));
});
+ /* read a char and goto next state */
if ( base ) {
REXEC_TRIE_READ_CHAR(trie_type, trie, widecharmap, uc,
uscan, len, uvc, charid, foldlen,
foldbuf, uniflags);
-
+ charcount++;
+ if (foldlen>0)
+ ST.longfold = TRUE;
if (charid &&
(base + charid > trie->uniquecharcount )
&& (base + charid - 1 - trie->uniquecharcount
charid, uvc, (UV)state, PL_colors[5] );
);
}
- if (!ST.accepted )
+ if (!accepted)
sayNO;
+ /* calculate total number of accept states */
+ {
+ U16 w = ST.topword;
+ accepted = 0;
+ while (w) {
+ w = trie->wordinfo[w].prev;
+ accepted++;
+ }
+ ST.accepted = accepted;
+ }
+
DEBUG_EXECUTE_r(
PerlIO_printf( Perl_debug_log,
"%*s %sgot %"IVdf" possible matches%s\n",
REPORT_CODE_OFF + depth * 2, "",
PL_colors[4], (IV)ST.accepted, PL_colors[5] );
);
+ goto trie_first_try; /* jump into the fail handler */
}}
- goto trie_first_try; /* jump into the fail handler */
/* NOTREACHED */
- case TRIE_next_fail: /* we failed - try next alterative */
+
+ case TRIE_next_fail: /* we failed - try next alternative */
if ( ST.jump) {
REGCP_UNWIND(ST.cp);
for (n = *PL_reglastparen; n > ST.lastparen; n--)
PL_regoffs[n].end = -1;
*PL_reglastparen = n;
}
- trie_first_try:
- if (do_cutgroup) {
- do_cutgroup = 0;
- no_final = 0;
- }
-
- if ( ST.jump) {
- ST.lastparen = *PL_reglastparen;
- REGCP_SET(ST.cp);
- }
- if ( ST.accepted == 1 ) {
- /* only one choice left - just continue */
- DEBUG_EXECUTE_r({
- AV *const trie_words
- = MUTABLE_AV(rexi->data->data[ARG(ST.me)+TRIE_WORDS_OFFSET]);
- SV ** const tmp = av_fetch( trie_words,
- ST.accept_buff[ 0 ].wordnum-1, 0 );
- SV *sv= tmp ? sv_newmortal() : NULL;
-
- PerlIO_printf( Perl_debug_log,
- "%*s %sonly one match left: #%d <%s>%s\n",
- REPORT_CODE_OFF+depth*2, "", PL_colors[4],
- ST.accept_buff[ 0 ].wordnum,
- tmp ? pv_pretty(sv, SvPV_nolen_const(*tmp), SvCUR(*tmp), 0,
- PL_colors[0], PL_colors[1],
- (SvUTF8(*tmp) ? PERL_PV_ESCAPE_UNI : 0)
- )
- : "not compiled under -Dr",
- PL_colors[5] );
- });
- PL_reginput = (char *)ST.accept_buff[ 0 ].endpos;
- /* in this case we free tmps/leave before we call regmatch
- as we wont be using accept_buff again. */
-
- locinput = PL_reginput;
- nextchr = UCHARAT(locinput);
- if ( !ST.jump || !ST.jump[ST.accept_buff[0].wordnum])
- scan = ST.B;
- else
- scan = ST.me + ST.jump[ST.accept_buff[0].wordnum];
- if (!has_cutgroup) {
- FREETMPS;
- LEAVE;
- } else {
- ST.accepted--;
- PUSH_YES_STATE_GOTO(TRIE_next, scan);
- }
-
- continue; /* execute rest of RE */
- }
-
- if ( !ST.accepted-- ) {
+ if (!--ST.accepted) {
DEBUG_EXECUTE_r({
PerlIO_printf( Perl_debug_log,
"%*s %sTRIE failed...%s\n",
PL_colors[4],
PL_colors[5] );
});
- FREETMPS;
- LEAVE;
sayNO_SILENT;
- /*NOTREACHED*/
- }
+ }
+ {
+ /* Find next-highest word to process. Note that this code
+ * is O(N^2) per trie run (O(N) per branch), so keep tight */
+ register U16 min = 0;
+ register U16 word;
+ register U16 const nextword = ST.nextword;
+ register reg_trie_wordinfo * const wordinfo
+ = ((reg_trie_data*)rexi->data->data[ARG(ST.me)])->wordinfo;
+ for (word=ST.topword; word; word=wordinfo[word].prev) {
+ if (word > nextword && (!min || word < min))
+ min = word;
+ }
+ ST.nextword = min;
+ }
- /*
- There are at least two accepting states left. Presumably
- the number of accepting states is going to be low,
- typically two. So we simply scan through to find the one
- with lowest wordnum. Once we find it, we swap the last
- state into its place and decrement the size. We then try to
- match the rest of the pattern at the point where the word
- ends. If we succeed, control just continues along the
- regex; if we fail we return here to try the next accepting
- state
- */
+ trie_first_try:
+ if (do_cutgroup) {
+ do_cutgroup = 0;
+ no_final = 0;
+ }
- {
- U32 best = 0;
- U32 cur;
- for( cur = 1 ; cur <= ST.accepted ; cur++ ) {
- DEBUG_TRIE_EXECUTE_r(
- PerlIO_printf( Perl_debug_log,
- "%*s %sgot %"IVdf" (%d) as best, looking at %"IVdf" (%d)%s\n",
- REPORT_CODE_OFF + depth * 2, "", PL_colors[4],
- (IV)best, ST.accept_buff[ best ].wordnum, (IV)cur,
- ST.accept_buff[ cur ].wordnum, PL_colors[5] );
- );
+ if ( ST.jump) {
+ ST.lastparen = *PL_reglastparen;
+ REGCP_SET(ST.cp);
+ }
- if (ST.accept_buff[cur].wordnum <
- ST.accept_buff[best].wordnum)
- best = cur;
+ /* find start char of end of current word */
+ {
+ U32 chars; /* how many chars to skip */
+ U8 *uc = ST.firstpos;
+ reg_trie_data * const trie
+ = (reg_trie_data*)rexi->data->data[ARG(ST.me)];
+
+ assert((trie->wordinfo[ST.nextword].len - trie->prefixlen)
+ >= ST.firstchars);
+ chars = (trie->wordinfo[ST.nextword].len - trie->prefixlen)
+ - ST.firstchars;
+
+ if (ST.longfold) {
+ /* the hard option - fold each char in turn and find
+ * its folded length (which may be different */
+ U8 foldbuf[UTF8_MAXBYTES_CASE + 1];
+ STRLEN foldlen;
+ STRLEN len;
+ UV uvc;
+ U8 *uscan;
+
+ while (chars) {
+ if (do_utf8) {
+ uvc = utf8n_to_uvuni((U8*)uc, UTF8_MAXLEN, &len,
+ uniflags);
+ uc += len;
+ }
+ else {
+ uvc = *uc;
+ uc++;
+ }
+ uvc = to_uni_fold(uvc, foldbuf, &foldlen);
+ uscan = foldbuf;
+ while (foldlen) {
+ if (!--chars)
+ break;
+ uvc = utf8n_to_uvuni(uscan, UTF8_MAXLEN, &len,
+ uniflags);
+ uscan += len;
+ foldlen -= len;
+ }
+ }
}
+ else {
+ if (do_utf8)
+ while (chars--)
+ uc += UTF8SKIP(uc);
+ else
+ uc += chars;
+ }
+ PL_reginput = (char *)uc;
+ }
- DEBUG_EXECUTE_r({
- AV *const trie_words
- = MUTABLE_AV(rexi->data->data[ARG(ST.me)+TRIE_WORDS_OFFSET]);
- SV ** const tmp = av_fetch( trie_words,
- ST.accept_buff[ best ].wordnum - 1, 0 );
- regnode *nextop=(!ST.jump || !ST.jump[ST.accept_buff[best].wordnum]) ?
- ST.B :
- ST.me + ST.jump[ST.accept_buff[best].wordnum];
- SV *sv= tmp ? sv_newmortal() : NULL;
-
- PerlIO_printf( Perl_debug_log,
- "%*s %strying alternation #%d <%s> at node #%d %s\n",
- REPORT_CODE_OFF+depth*2, "", PL_colors[4],
- ST.accept_buff[best].wordnum,
- tmp ? pv_pretty(sv, SvPV_nolen_const(*tmp), SvCUR(*tmp), 0,
- PL_colors[0], PL_colors[1],
- (SvUTF8(*tmp) ? PERL_PV_ESCAPE_UNI : 0)
- ) : "not compiled under -Dr",
- REG_NODE_NUM(nextop),
- PL_colors[5] );
- });
+ scan = (ST.jump && ST.jump[ST.nextword])
+ ? ST.me + ST.jump[ST.nextword]
+ : ST.B;
- if ( best<ST.accepted ) {
- reg_trie_accepted tmp = ST.accept_buff[ best ];
- ST.accept_buff[ best ] = ST.accept_buff[ ST.accepted ];
- ST.accept_buff[ ST.accepted ] = tmp;
- best = ST.accepted;
- }
- PL_reginput = (char *)ST.accept_buff[ best ].endpos;
- if ( !ST.jump || !ST.jump[ST.accept_buff[best].wordnum]) {
- scan = ST.B;
- } else {
- scan = ST.me + ST.jump[ST.accept_buff[best].wordnum];
- }
- PUSH_YES_STATE_GOTO(TRIE_next, scan);
- /* NOTREACHED */
+ DEBUG_EXECUTE_r({
+ PerlIO_printf( Perl_debug_log,
+ "%*s %sTRIE matched word #%d, continuing%s\n",
+ REPORT_CODE_OFF+depth*2, "",
+ PL_colors[4],
+ ST.nextword,
+ PL_colors[5]
+ );
+ });
+
+ if (ST.accepted > 1 || has_cutgroup) {
+ PUSH_STATE_GOTO(TRIE_next, scan);
+ /* NOTREACHED */
}
+ /* only one choice left - just continue */
+ DEBUG_EXECUTE_r({
+ AV *const trie_words
+ = MUTABLE_AV(rexi->data->data[ARG(ST.me)+TRIE_WORDS_OFFSET]);
+ SV ** const tmp = av_fetch( trie_words,
+ ST.nextword-1, 0 );
+ SV *sv= tmp ? sv_newmortal() : NULL;
+
+ PerlIO_printf( Perl_debug_log,
+ "%*s %sonly one match left, short-circuiting: #%d <%s>%s\n",
+ REPORT_CODE_OFF+depth*2, "", PL_colors[4],
+ ST.nextword,
+ tmp ? pv_pretty(sv, SvPV_nolen_const(*tmp), SvCUR(*tmp), 0,
+ PL_colors[0], PL_colors[1],
+ (SvUTF8(*tmp) ? PERL_PV_ESCAPE_UNI : 0)
+ )
+ : "not compiled under -Dr",
+ PL_colors[5] );
+ });
+
+ locinput = PL_reginput;
+ nextchr = UCHARAT(locinput);
+ continue; /* execute rest of RE */
/* NOTREACHED */
- case TRIE_next:
- /* we dont want to throw this away, see bug 57042*/
- if (oreplsv != GvSV(PL_replgv))
- sv_setsv(oreplsv, GvSV(PL_replgv));
- FREETMPS;
- LEAVE;
- sayYES;
#undef ST
case EXACT: {
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