/* tre-match-parallel.c - TRE parallel regex matching engine Copyright (C) 2001-2004 Ville Laurikari . This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 (June 1991) as published by the Free Software Foundation. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* This algorithm searches for matches basically by reading characters in the searched string one by one, starting at the beginning. All matching paths in the TNFA are traversed in parallel. When two or more paths reach the same state, exactly one is chosen according to tag ordering rules; if returning submatches is not required it does not matter which path is chosen. The worst case time required for finding the leftmost and longest match, or determining that there is no match, is always linearly dependent on the length of the text being searched. This algorithm cannot handle TNFAs with back referencing nodes. See `tre-match-backtrack.c'. */ #ifdef HAVE_CONFIG_H #include #endif /* HAVE_CONFIG_H */ #ifdef TRE_USE_ALLOCA /* AIX requires this to be the first thing in the file. */ #ifndef __GNUC__ # if HAVE_ALLOCA_H # include # else # ifdef _AIX #pragma alloca # else # ifndef alloca /* predefined by HP cc +Olibcalls */ char *alloca (); # endif # endif # endif #endif #endif /* TRE_USE_ALLOCA */ #include #include #include #ifdef HAVE_WCHAR_H #include #endif /* HAVE_WCHAR_H */ #ifdef HAVE_WCTYPE_H #include #endif /* HAVE_WCTYPE_H */ #ifndef TRE_WCHAR #include #endif /* !TRE_WCHAR */ #ifdef HAVE_MALLOC_H #include #endif /* HAVE_MALLOC_H */ #include "tre-internal.h" #include "tre-match-utils.h" #include "regex.h" #include "xmalloc.h" typedef struct { tre_tnfa_transition_t *state; int *tags; } tre_tnfa_reach_t; typedef struct { int pos; int **tags; } tre_reach_pos_t; #ifdef TRE_DEBUG static void tre_print_reach(const tre_tnfa_t *tnfa, tre_tnfa_reach_t *reach, int num_tags) { int i; while (reach->state != NULL) { DPRINT((" %p", (void *)reach->state)); if (num_tags > 0) { DPRINT(("/")); for (i = 0; i < num_tags; i++) { DPRINT(("%d:%d", i, reach->tags[i])); if (i < (num_tags-1)) DPRINT((",")); } } reach++; } DPRINT(("\n")); } #endif /* TRE_DEBUG */ reg_errcode_t tre_tnfa_run_parallel(const tre_tnfa_t *tnfa, const void *string, int len, tre_str_type_t type, int *match_tags, int eflags, int *match_end_ofs) { /* State variables required by GET_NEXT_WCHAR. */ tre_char_t prev_c = 0, next_c = 0; const char *str_byte = string; int pos = -1; unsigned int pos_add_next = 1; #ifdef TRE_WCHAR const wchar_t *str_wide = string; #ifdef TRE_MBSTATE mbstate_t mbstate; #endif /* TRE_MBSTATE */ #endif /* TRE_WCHAR */ int reg_notbol = eflags & REG_NOTBOL; int reg_noteol = eflags & REG_NOTEOL; int reg_newline = tnfa->cflags & REG_NEWLINE; int str_user_end = 0; char *buf; tre_tnfa_transition_t *trans_i; tre_tnfa_reach_t *reach, *reach_next, *reach_i, *reach_next_i; tre_reach_pos_t *reach_pos; int *tag_i; int num_tags, i; int match_eo = -1; /* end offset of match (-1 if no match found yet) */ int new_match = 0; int *tmp_tags = NULL; int *tmp_iptr; #ifdef TRE_MBSTATE memset(&mbstate, '\0', sizeof(mbstate)); #endif /* TRE_MBSTATE */ DPRINT(("tre_tnfa_run_parallel, input type %d\n", type)); if (!match_tags) num_tags = 0; else num_tags = tnfa->num_tags; /* Allocate memory for temporary data required for matching. This needs to be done for every matching operation to be thread safe. This allocates everything in a single large block from the stack frame using alloca() or with malloc() if alloca is unavailable. */ { int tbytes, rbytes, pbytes, xbytes, total_bytes; char *tmp_buf; /* Compute the length of the block we need. */ tbytes = sizeof(*tmp_tags) * num_tags; rbytes = sizeof(*reach_next) * (tnfa->num_states + 1); pbytes = sizeof(*reach_pos) * tnfa->num_states; xbytes = sizeof(int) * num_tags; total_bytes = (sizeof(long) - 1) * 4 /* for alignment paddings */ + (rbytes + xbytes * tnfa->num_states) * 2 + tbytes + pbytes; /* Allocate the memory. */ #ifdef TRE_USE_ALLOCA buf = alloca(total_bytes); #else /* !TRE_USE_ALLOCA */ buf = xmalloc(total_bytes); #endif /* !TRE_USE_ALLOCA */ if (buf == NULL) return REG_ESPACE; memset(buf, 0, total_bytes); /* Get the various pointers within tmp_buf (properly aligned). */ tmp_tags = (void *)buf; tmp_buf = buf + tbytes; tmp_buf += ALIGN(tmp_buf, long); reach_next = (void *)tmp_buf; tmp_buf += rbytes; tmp_buf += ALIGN(tmp_buf, long); reach = (void *)tmp_buf; tmp_buf += rbytes; tmp_buf += ALIGN(tmp_buf, long); reach_pos = (void *)tmp_buf; tmp_buf += pbytes; tmp_buf += ALIGN(tmp_buf, long); for (i = 0; i < tnfa->num_states; i++) { reach[i].tags = (void *)tmp_buf; tmp_buf += xbytes; reach_next[i].tags = (void *)tmp_buf; tmp_buf += xbytes; } } for (i = 0; i < tnfa->num_states; i++) reach_pos[i].pos = -1; /* If only one character can start a match, find it first. */ if (tnfa->first_char >= 0 && type == STR_BYTE && str_byte) { const char *orig_str = str_byte; int first = tnfa->first_char; if (len >= 0) str_byte = memchr(orig_str, first, len); else str_byte = strchr(orig_str, first); if (str_byte == NULL) { #ifndef TRE_USE_ALLOCA if (buf) xfree(buf); #endif /* !TRE_USE_ALLOCA */ return REG_NOMATCH; } DPRINT(("skipped %d chars\n", str_byte - orig_str)); if (str_byte >= orig_str + 1) prev_c = (unsigned char)*(str_byte - 1); next_c = (unsigned char)*str_byte; pos = str_byte - orig_str; if (len < 0 || pos < len) str_byte++; } else { GET_NEXT_WCHAR(); pos = 0; } #if 0 /* Skip over characters that cannot possibly be the first character of a match. */ if (tnfa->firstpos_chars != NULL) { char *chars = tnfa->firstpos_chars; if (len < 0) { const char *orig_str = str_byte; /* XXX - use strpbrk() and wcspbrk() because they might be optimized for the target architecture. Try also strcspn() and wcscspn() and compare the speeds. */ while (next_c != L'\0' && !chars[next_c]) { next_c = *str_byte++; } prev_c = *(str_byte - 2); pos += str_byte - orig_str; DPRINT(("skipped %d chars\n", str_byte - orig_str)); } else { while (pos <= len && !chars[next_c]) { prev_c = next_c; next_c = (unsigned char)(*str_byte++); pos++; } } } #endif DPRINT(("length: %d\n", len)); DPRINT(("pos:chr/code | states and tags\n")); DPRINT(("-------------+------------------------------------------------\n")); reach_next_i = reach_next; while (1) { /* If no match found yet, add the initial states to `reach_next'. */ if (match_eo < 0) { DPRINT((" init >")); trans_i = tnfa->initial; while (trans_i->state != NULL) { if (reach_pos[trans_i->state_id].pos < pos) { if (trans_i->assertions && CHECK_ASSERTIONS(trans_i->assertions)) { DPRINT(("assertion failed\n")); trans_i++; continue; } DPRINT((" %p", (void *)trans_i->state)); reach_next_i->state = trans_i->state; for (i = 0; i < num_tags; i++) reach_next_i->tags[i] = -1; tag_i = trans_i->tags; if (tag_i) while (*tag_i >= 0) { if (*tag_i < num_tags) reach_next_i->tags[*tag_i] = pos; tag_i++; } if (reach_next_i->state == tnfa->final) { DPRINT((" found empty match\n")); match_eo = pos; new_match = 1; for (i = 0; i < num_tags; i++) match_tags[i] = reach_next_i->tags[i]; } reach_pos[trans_i->state_id].pos = pos; reach_pos[trans_i->state_id].tags = &reach_next_i->tags; reach_next_i++; } trans_i++; } DPRINT(("\n")); reach_next_i->state = NULL; } else { if (num_tags == 0 || reach_next_i == reach_next) /* We have found a match. */ break; } /* Check for end of string. */ if (len < 0) { if (type == STR_USER) { if (str_user_end) break; } else if (next_c == L'\0') break; } else { if (pos >= len) break; } GET_NEXT_WCHAR(); #ifdef TRE_DEBUG DPRINT(("%3d:%2lc/%05d |", pos - 1, (tre_cint_t)prev_c, (int)prev_c)); tre_print_reach(tnfa, reach_next, num_tags); DPRINT(("%3d:%2lc/%05d |", pos, (tre_cint_t)next_c, (int)next_c)); tre_print_reach(tnfa, reach_next, num_tags); #endif /* TRE_DEBUG */ /* Swap `reach' and `reach_next'. */ reach_i = reach; reach = reach_next; reach_next = reach_i; /* For each state in `reach', weed out states that don't fulfill the minimal matching conditions. */ if (tnfa->num_minimals && new_match) { new_match = 0; reach_next_i = reach_next; for (reach_i = reach; reach_i->state; reach_i++) { int i; int skip = 0; for (i = 0; tnfa->minimal_tags[i] >= 0; i += 2) { int end = tnfa->minimal_tags[i]; int start = tnfa->minimal_tags[i + 1]; DPRINT((" Minimal start %d, end %d\n", start, end)); if (end >= num_tags) { DPRINT((" Throwing %p out.\n", reach_i->state)); skip = 1; break; } else if (reach_i->tags[start] == match_tags[start] && reach_i->tags[end] < match_tags[end]) { DPRINT((" Throwing %p out because t%d < %d\n", reach_i->state, end, match_tags[end])); skip = 1; break; } } if (!skip) { int *tmp_iptr; reach_next_i->state = reach_i->state; tmp_iptr = reach_next_i->tags; reach_next_i->tags = reach_i->tags; reach_i->tags = tmp_iptr; reach_next_i++; } } reach_next_i->state = NULL; /* Swap `reach' and `reach_next'. */ reach_i = reach; reach = reach_next; reach_next = reach_i; } /* For each state in `reach' see if there is a transition leaving with the current input symbol to a state not yet in `reach_next', and add the destination states to `reach_next'. */ reach_next_i = reach_next; for (reach_i = reach; reach_i->state; reach_i++) { for (trans_i = reach_i->state; trans_i->state; trans_i++) { /* Does this transition match the input symbol? */ if (trans_i->code_min <= prev_c && trans_i->code_max >= prev_c) { if (trans_i->assertions && (CHECK_ASSERTIONS(trans_i->assertions) /* Handle character class transitions. */ || ((trans_i->assertions & ASSERT_CHAR_CLASS) && !(tnfa->cflags & REG_ICASE) && !tre_isctype((tre_cint_t)prev_c, trans_i->u.class)) || ((trans_i->assertions & ASSERT_CHAR_CLASS) && (tnfa->cflags & REG_ICASE) && (!tre_isctype(tre_tolower((tre_cint_t)prev_c), trans_i->u.class) && !tre_isctype(tre_toupper((tre_cint_t)prev_c), trans_i->u.class))) || ((trans_i->assertions & ASSERT_CHAR_CLASS_NEG) && tre_neg_char_classes_match(trans_i->neg_classes, (tre_cint_t)prev_c, tnfa->cflags & REG_ICASE)))) { DPRINT(("assertion failed\n")); continue; } /* Compute the tags after this transition. */ for (i = 0; i < num_tags; i++) tmp_tags[i] = reach_i->tags[i]; tag_i = trans_i->tags; if (tag_i != NULL) while (*tag_i >= 0) { if (*tag_i < num_tags) tmp_tags[*tag_i] = pos; tag_i++; } if (reach_pos[trans_i->state_id].pos < pos) { /* Found an unvisited node. */ reach_next_i->state = trans_i->state; tmp_iptr = reach_next_i->tags; reach_next_i->tags = tmp_tags; tmp_tags = tmp_iptr; reach_pos[trans_i->state_id].pos = pos; reach_pos[trans_i->state_id].tags = &reach_next_i->tags; if (reach_next_i->state == tnfa->final && (match_eo == -1 || (num_tags > 0 && reach_next_i->tags[0] <= match_tags[0]))) { DPRINT((" found match %p\n", trans_i->state)); match_eo = pos; new_match = 1; for (i = 0; i < num_tags; i++) match_tags[i] = reach_next_i->tags[i]; } reach_next_i++; } else { assert(reach_pos[trans_i->state_id].pos == pos); /* Another path has also reached this state. We choose the winner by examining the tag values for both paths. */ if (tre_tag_order(num_tags, tnfa->tag_directions, tmp_tags, *reach_pos[trans_i->state_id].tags)) { /* The new path wins. */ tmp_iptr = *reach_pos[trans_i->state_id].tags; *reach_pos[trans_i->state_id].tags = tmp_tags; if (trans_i->state == tnfa->final) { DPRINT((" found better match\n")); match_eo = pos; new_match = 1; for (i = 0; i < num_tags; i++) match_tags[i] = tmp_tags[i]; } tmp_tags = tmp_iptr; } } } } } reach_next_i->state = NULL; } DPRINT(("match end offset = %d\n", match_eo)); #ifndef TRE_USE_ALLOCA if (buf) xfree(buf); #endif /* !TRE_USE_ALLOCA */ *match_end_ofs = match_eo; return match_eo >= 0 ? REG_OK : REG_NOMATCH; } /* EOF */