+/*
+ 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 */
+
+/* Unset TRE_USE_ALLOCA to avoid using the stack to hold all the state
+ info while running */
+#undef TRE_USE_ALLOCA
+
+#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;
+ tre_tag_t *tags;
+} tre_tnfa_reach_t;
+
+typedef struct {
+ int pos;
+ tre_tag_t **tags;
+} tre_reach_pos_t;
+
+
+#ifdef TRE_DEBUG
+static void
+tre_print_reach1(tre_tnfa_transition_t *state, tre_tag_t *tags, int num_tags)
+{
+ DPRINT((" %p", (void *)state));
+ if (num_tags > 0)
+ {
+ DPRINT(("/"));
+ tre_print_tags(tags, num_tags);
+ }
+}
+
+static void
+tre_print_reach(const tre_tnfa_t *tnfa, tre_tnfa_reach_t *reach, int num_tags)
+{
+ while (reach->state != NULL)
+ {
+ tre_print_reach1(reach->state, reach->tags, num_tags);
+ 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, tre_tag_t *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;
+#ifdef TRE_STR_USER
+ int str_user_end = 0;
+#endif /* TRE_STR_USER */
+
+ 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) */
+#ifdef TRE_DEBUG
+ int once;
+#endif /* TRE_DEBUG */
+ tre_tag_t *tmp_tags = NULL;
+ tre_tag_t *tmp_iptr;
+ int tbytes;
+ int touch = 1;
+
+#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 rbytes, pbytes, 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;
+ total_bytes =
+ (sizeof(long) - 1) * 4 /* for alignment paddings */
+ + (rbytes + tbytes * tnfa->num_states) * 2 + tbytes + pbytes;
+
+ DPRINT(("tre_tnfa_run_parallel, allocate %d bytes\n", total_bytes));
+ /* 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 += tbytes;
+ reach_next[i].tags = (void *)tmp_buf;
+ tmp_buf += tbytes;
+ }
+ }
+
+ 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;
+ memset(reach_next_i->tags, 0, tbytes);
+ tag_i = trans_i->tags;
+ if (tag_i)
+ {
+ while (*tag_i >= 0)
+ {
+ if (*tag_i < num_tags)
+ tre_tag_set(reach_next_i->tags, *tag_i, pos, touch);
+ tag_i++;
+ }
+ touch++;
+ }
+ if (reach_next_i->state == tnfa->final)
+ {
+ DPRINT((" found empty match\n"));
+ match_eo = pos;
+ memcpy(match_tags, reach_next_i->tags, tbytes);
+ }
+ 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)
+ {
+#ifdef TRE_STR_USER
+ if (type == STR_USER)
+ {
+ if (str_user_end)
+ break;
+ }
+ else
+#endif /* TRE_STR_USER */
+ 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;
+
+#ifdef TRE_DEBUG
+ once = 0;
+#endif /* TRE_DEBUG */
+
+ /* 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. */
+ memcpy(tmp_tags, reach_i->tags, tbytes);
+ tag_i = trans_i->tags;
+ if (tag_i != NULL)
+ {
+ while (*tag_i >= 0)
+ {
+ if (*tag_i < num_tags)
+ tre_tag_set(tmp_tags, *tag_i, pos, touch);
+ tag_i++;
+ }
+ touch++;
+ }
+
+ /* For each new transition, weed out those that don't
+ fulfill the minimal matching conditions. */
+ if (tnfa->num_minimals && match_eo >= 0)
+ {
+ int skip = 0;
+#ifdef TRE_DEBUG
+ if (!once)
+ {
+ DPRINT(("Checking minimal conditions: match_eo=%d "
+ "match_tags=", match_eo));
+ tre_print_tags(match_tags, num_tags);
+ DPRINT(("\n"));
+ once++;
+ }
+#endif /* TRE_DEBUG */
+ 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 (tre_minimal_tag_order(start, end, match_tags,
+ tmp_tags) > 0)
+ {
+ skip = 1;
+ break;
+ }
+ }
+ if (skip)
+ {
+#ifdef TRE_DEBUG
+ DPRINT((" Throwing out"));
+ tre_print_reach1(reach_i->state, tmp_tags,
+ num_tags);
+ DPRINT(("\n"));
+#endif /* TRE_DEBUG */
+ continue;
+ }
+ }
+
+ 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
+ && tre_tag_get(reach_next_i->tags, 0) <=
+ tre_tag_get(match_tags, 0))))
+ {
+#ifdef TRE_DEBUG
+ DPRINT((" found match"));
+ tre_print_reach1(trans_i->state, reach_next_i->tags, num_tags);
+ DPRINT(("\n"));
+#endif /* TRE_DEBUG */
+ match_eo = pos;
+ memcpy(match_tags, reach_next_i->tags, tbytes);
+ }
+ 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)
+ {
+#ifdef TRE_DEBUG
+ DPRINT((" found better match"));
+ tre_print_reach1(trans_i->state, tmp_tags, num_tags);
+ DPRINT(("\n"));
+#endif /* TRE_DEBUG */
+ match_eo = pos;
+ memcpy(match_tags, tmp_tags, tbytes);
+ }
+ tmp_tags = tmp_iptr;
+ }
+ }
+ }
+ }
+ }
+ reach_next_i->state = NULL;
+ }
+
+ DPRINT(("match end offset = %d\n", match_eo));
+
+ *match_end_ofs = match_eo;
+#ifdef TRE_DEBUG
+ if (match_tags)
+ {
+ DPRINT(("Winning tags="));
+ tre_print_tags_all(match_tags, num_tags);
+ DPRINT((" touch=%d\n", touch));
+ }
+#endif /* TRE_DEBUG */
+
+#ifndef TRE_USE_ALLOCA
+ if (buf)
+ xfree(buf);
+#endif /* !TRE_USE_ALLOCA */
+
+ return match_eo >= 0 ? REG_OK : REG_NOMATCH;
+}
+
+/* EOF */
projects / apple / libc.git / blobdiff