/R-2.10.1-patched/src/extra/tre/tre-match-parallel.c
C | 501 lines | 400 code | 46 blank | 55 comment | 91 complexity | 2f02025814b159c0f2ddf30d311bf715 MD5 | raw file
Possible License(s): GPL-3.0, LGPL-2.0, LGPL-3.0, BSD-3-Clause, AGPL-3.0, GPL-2.0, LGPL-2.1
- /*
- 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 "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((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 */