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Diffstat (limited to 'lib/tre-match-parallel.c')
| -rw-r--r-- | lib/tre-match-parallel.c | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/lib/tre-match-parallel.c b/lib/tre-match-parallel.c new file mode 100644 index 0000000000000..0d6ec173c5332 --- /dev/null +++ b/lib/tre-match-parallel.c @@ -0,0 +1,501 @@ +/* + tre-match-parallel.c - TRE parallel regex matching engine + + This software is released under a BSD-style license. + See the file LICENSE for details and copyright. + +*/ + +/* + 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 <config.h> +#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 <alloca.h> +# else +# ifdef _AIX + #pragma alloca +# else +# ifndef alloca /* predefined by HP cc +Olibcalls */ +char *alloca (); +# endif +# endif +# endif +#endif +#endif /* TRE_USE_ALLOCA */ + +#include <assert.h> +#include <stdlib.h> +#include <string.h> +#ifdef HAVE_WCHAR_H +#include <wchar.h> +#endif /* HAVE_WCHAR_H */ +#ifdef HAVE_WCTYPE_H +#include <wctype.h> +#endif /* HAVE_WCTYPE_H */ +#ifndef TRE_WCHAR +#include <ctype.h> +#endif /* !TRE_WCHAR */ +#ifdef HAVE_MALLOC_H +#include <malloc.h> +#endif /* HAVE_MALLOC_H */ + +#include "tre-internal.h" +#include "tre-match-utils.h" +#include "tre.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((unsigned)total_bytes); +#endif /* !TRE_USE_ALLOCA */ + if (buf == NULL) + return REG_ESPACE; + memset(buf, 0, (size_t)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, (size_t)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 %lu chars\n", (unsigned long)(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 (/*CONSTCOND*/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 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) + { + 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 <= (tre_cint_t)prev_c && + trans_i->code_max >= (tre_cint_t)prev_c) + { + if (trans_i->assertions + && (CHECK_ASSERTIONS(trans_i->assertions) + || CHECK_CHAR_CLASSES(trans_i, tnfa, eflags))) + { + 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 */ |