X-Git-Url: http://git.indexdata.com/?p=yaz-moved-to-github.git;a=blobdiff_plain;f=src%2Fnfa.c;h=fe6362ea7f4841235151b441c2fe239b009a099b;hp=0eee5e8ad4a334ec1c87b985a5ff5e5d639d2a10;hb=e4368af2ede9079d33e7a8fd280d29b2bde1d1ad;hpb=2af6f28e5d261fa873d96611a10c56fc76681685;ds=sidebyside

diff --git a/src/nfa.c b/src/nfa.c
index 0eee5e8..fe6362e 100644
--- a/src/nfa.c
+++ b/src/nfa.c
@@ -1,7 +1,7 @@
 /*  Copyright (C) 2006, Index Data ApS
  *  See the file LICENSE for details.
  * 
- *  $Id: nfa.c,v 1.5 2006-05-04 18:58:54 adam Exp $ 
+ *  $Id: nfa.c,v 1.12 2006-07-14 13:06:38 heikki Exp $ 
  */
 
 /**
@@ -23,7 +23,9 @@
  *  strings with it.
  */
 
+
 #include <stdio.h>
+#include <string.h>
 #include <yaz/nfa.h>
 #include <yaz/nmem.h> 
 
@@ -75,6 +77,21 @@ struct yaz_nfa_transition {
 #define LOOP_LIMIT 100
 
 
+typedef enum {
+    conv_none,
+    conv_string,
+    conv_backref,
+    conv_range
+} yaz_nfa_converter_type;
+
+struct yaz_nfa_converter {
+    yaz_nfa_converter *next;
+    yaz_nfa_converter_type type;
+    yaz_nfa_char *string;
+    size_t strlen;
+    int backref_no;
+    int char_diff;
+};
 
 
 /* * * * * * *
@@ -85,18 +102,19 @@ yaz_nfa *yaz_nfa_init() {
     NMEM my_nmem = nmem_create();
     yaz_nfa *n = nmem_malloc(my_nmem, sizeof(yaz_nfa));
     n->nmem = my_nmem;
-    n->nstates = 0;
-    n->laststate = 0;
-    n->firststate = 0;
-    n->nbackrefs = 0;
+    n->nbackrefs = 1;  /* we always have #0, last range match */
     n->curr_backrefs = 0;
     n->best_backrefs = 0;
     n->lastmatch = YAZ_NFA_NOMATCH;
+    n->nstates = 0;
+    n->laststate = 0;
+    n->firststate = n->laststate ;
     return n;
 }
 
 void yaz_nfa_destroy(yaz_nfa *n) {
-    nmem_destroy(n->nmem);
+    if (n && n->nmem)
+        nmem_destroy(n->nmem);
 }
 
 
@@ -125,7 +143,7 @@ yaz_nfa_state *yaz_nfa_add_state(yaz_nfa *n) {
 
 int yaz_nfa_set_result(yaz_nfa *n, yaz_nfa_state *s, void *result) {
     if ((s->result)&&result)
-        return 1;
+        return YAZ_NFA_ALREADY;
     s->result = result;
     return 0;
 }
@@ -141,7 +159,7 @@ int yaz_nfa_set_backref_point(yaz_nfa *n, yaz_nfa_state *s,
            int is_start ){
     if (is_start) {
         if (s->backref_start)
-            return 1;
+            return YAZ_NFA_ALREADY;
         s->backref_start = backref_number;
         if (n->nbackrefs<=backref_number) {
             n->nbackrefs = backref_number+1;
@@ -153,9 +171,9 @@ int yaz_nfa_set_backref_point(yaz_nfa *n, yaz_nfa_state *s,
         }
     } else {
         if (s->backref_end)
-            return 1;
-        if (n->nbackrefs<backref_number) 
-            return 2; /* can't end a backref that has not been started */
+            return YAZ_NFA_ALREADY;
+        if (n->nbackrefs<=backref_number) 
+            return YAZ_NFA_NOSTART; 
         s->backref_end = backref_number;
     }
     return 0; /* ok */
@@ -177,6 +195,8 @@ void yaz_nfa_add_transition(yaz_nfa *n,
         yaz_nfa_char range_start, 
         yaz_nfa_char range_end) {
     yaz_nfa_transition *t = nmem_malloc(n->nmem, sizeof(yaz_nfa_transition));
+    if (!from_state)
+        from_state = n->firststate;
     t->range_start = range_start;
     t->range_end = range_end;
     t->to_state = to_state;
@@ -223,10 +243,13 @@ yaz_nfa_state *yaz_nfa_add_range(yaz_nfa *n,
         yaz_nfa_state *s,
         yaz_nfa_char range_start, 
         yaz_nfa_char range_end) {
-    yaz_nfa_state *nextstate;
+    yaz_nfa_state *nextstate=0;
     if (!s) /* default to top-level of the nfa */
         s = n->firststate;
-    nextstate = find_single_trans(s, range_start, range_end);
+    if (s)
+        nextstate = find_single_trans(s, range_start, range_end);
+    else
+        s = yaz_nfa_add_state(n); /* create initial state */
     if (!nextstate) {
         nextstate = yaz_nfa_add_state(n);
         yaz_nfa_add_transition(n, s, nextstate, range_start, range_end);
@@ -236,21 +259,25 @@ yaz_nfa_state *yaz_nfa_add_range(yaz_nfa *n,
 
 yaz_nfa_state *yaz_nfa_add_sequence(yaz_nfa *n, 
         yaz_nfa_state *s, 
-        yaz_nfa_char *seq ){
-    yaz_nfa_state *nextstate;
+        yaz_nfa_char *seq,
+        size_t seq_len){
+    yaz_nfa_state *nextstate=0;
     if (!s) /* default to top-level of the nfa */
         s = n->firststate;
-    nextstate = find_single_trans(s, *seq, *seq);
+    if (s) 
+        nextstate = find_single_trans(s, *seq, *seq);
     if (nextstate) {
         seq++;
-        if (!*seq) /* whole sequence matched */
+        seq_len--;
+        if (!seq_len) /* whole sequence matched */
             return nextstate;
         else
-            return yaz_nfa_add_sequence(n, nextstate, seq);
+            return yaz_nfa_add_sequence(n, nextstate, seq,seq_len);
     } else { /* no next state, build the rest */
-        while (*seq) {
+        while (seq_len) {
             s = yaz_nfa_add_range(n, s, *seq, *seq);
             seq++;
+            seq_len--;
         }
         return s;
     }
@@ -266,7 +293,7 @@ yaz_nfa_state *yaz_nfa_add_sequence(yaz_nfa *n,
 struct matcher {
     yaz_nfa *n; 
     yaz_nfa_char *longest;
-    int bestnode;
+    int bestnode; 
     void *result;
     int errorcode;
     int empties; /* count how many consecutive empty transitions */
@@ -278,33 +305,36 @@ struct matcher {
 
 static void match_state(
               yaz_nfa_state *s, 
-              yaz_nfa_char *inchar,
-              size_t incharsleft,
-              struct matcher *m ) {
+              yaz_nfa_char *prevmatch,
+              yaz_nfa_char *inchar,   
+              size_t incharsleft,    
+              struct matcher *m ) {   
     yaz_nfa_transition *t = s->lasttrans;
     if (s->backref_start) 
         m->n->curr_backrefs[s->backref_start].start = inchar;
     if (s->backref_end) 
-        m->n->curr_backrefs[s->backref_end].end = inchar;
+        m->n->curr_backrefs[s->backref_end].end = prevmatch;
     if (t) {
         if (incharsleft) {
             do {
                 t = t->next;
-                if ( (( t->range_start <= *inchar ) && ( t->range_end >= *inchar )) ){
+                if ( (( t->range_start <= *inchar ) && 
+                      ( t->range_end >= *inchar )) ){
                     m->empties = 0;
                     if (t->range_start!=t->range_end){
                         /* backref 0 is special: the last range operation */
                         m->n->curr_backrefs[0].start = inchar;
                         m->n->curr_backrefs[0].end = inchar;
                     }
-                    match_state(t->to_state, inchar+1, incharsleft-1, m);
-                    /* yes, descent to all matching nodes, even if overrun, */
-                    /* since we can find a better one later */
-                } else if (( t->range_start==EMPTY_START) && (t->range_end==EMPTY_END)) {
+                    match_state(t->to_state, inchar, 
+                            inchar+1, incharsleft-1, m);
+                } else if (( t->range_start==EMPTY_START) && 
+                           (t->range_end==EMPTY_END)) {
                     if ( m->empties++ > LOOP_LIMIT ) 
                         m->errorcode= YAZ_NFA_LOOP;
                     else
-                        match_state(t->to_state, inchar, incharsleft, m);
+                        match_state(t->to_state, prevmatch, 
+                                inchar, incharsleft, m);
                 }
             } while (t != s->lasttrans );
         } else {
@@ -335,7 +365,7 @@ static void match_state(
 
 int yaz_nfa_match(yaz_nfa *n, 
            yaz_nfa_char **inbuff, 
-           size_t incharsleft,
+           size_t *incharsleft,
            void **result ){
     struct matcher m;
     int sz;
@@ -348,7 +378,8 @@ int yaz_nfa_match(yaz_nfa *n,
     m.longest=*inbuff;
     m.bestnode = n->nstates;
     m.result = 0;
-    m.errorcode = 0;
+    m.errorcode = YAZ_NFA_SUCCESS;
+    m.empties = 0;
     sz = sizeof( struct yaz_nfa_backref_info) * n->nbackrefs;
     if (!n->curr_backrefs) {
         n->curr_backrefs = nmem_malloc( n->nmem, sz);
@@ -361,18 +392,18 @@ int yaz_nfa_match(yaz_nfa *n,
         n->best_backrefs[i].end = 0;
     }
 
-    match_state(n->firststate, *inbuff, incharsleft, &m);
-    if (m.result) {
-        *result = m.result;
-        *inbuff = m.longest;
-        if (m.errorcode)
-            n->lastmatch = m.errorcode;
-        else
-            n->lastmatch= YAZ_NFA_SUCCESS;
-        return n->lastmatch;
+    match_state(n->firststate, *inbuff, *inbuff, *incharsleft, &m);
+    if (m.errorcode==YAZ_NFA_SUCCESS) {
+        if (!m.result)
+            m.errorcode=YAZ_NFA_NOMATCH;
+        else {
+            *incharsleft -= (m.longest-*inbuff);
+            *result = m.result;
+            *inbuff = m.longest;
+        }
     }
-    n->lastmatch = YAZ_NFA_NOMATCH;
-    return n->lastmatch; 
+    n->lastmatch=m.errorcode;
+    return m.errorcode;
 }
 
 
@@ -380,18 +411,254 @@ int yaz_nfa_get_backref( yaz_nfa *n,
                 int backref_no,
                 yaz_nfa_char **start,
                 yaz_nfa_char **end) {
-    if (backref_no>=n->nbackrefs)
-        return 2;
-    if (backref_no<0)
-        return 2;
-    if (n->lastmatch== YAZ_NFA_NOMATCH)
-        return 1;  /* accept other errors, they return partial matches*/
+    if (backref_no >= n->nbackrefs)
+        return YAZ_NFA_NOSUCHBACKREF;
+    if (backref_no < 0)
+        return YAZ_NFA_NOSUCHBACKREF;
+    if (n->lastmatch != YAZ_NFA_SUCCESS)
+        return YAZ_NFA_NOMATCH;  
 
     *start = n->best_backrefs[backref_no].start;
     *end = n->best_backrefs[backref_no].end;
     return 0;
 }
 
+/* * * * * * * * * * * * * *
+ * Converters 
+ * * * * * * * * * * * * * */
+
+static yaz_nfa_converter *create_null_converter ( yaz_nfa *n) {
+    yaz_nfa_converter *c;
+    c=nmem_malloc(n->nmem, sizeof(yaz_nfa_converter));
+    c->next=0;
+    c->type=conv_none;
+    c->string=0;
+    c->strlen=0;
+    c->backref_no=0;
+    c->char_diff=0;
+    return c;
+}
+
+yaz_nfa_converter *yaz_nfa_create_string_converter (
+                yaz_nfa *n,
+                yaz_nfa_char *string,
+                size_t length){
+    yaz_nfa_converter *c;
+    size_t i;
+    c=create_null_converter(n);
+    c->type=conv_string;
+    c->string=nmem_malloc(n->nmem, length*sizeof(yaz_nfa_char));
+    for (i=0;i<length;i++)
+        c->string[i]=string[i];
+    c->strlen=length;
+    return c;
+}
+
+yaz_nfa_converter *yaz_nfa_create_backref_converter (
+                   yaz_nfa *n, int backref_no ) {
+    yaz_nfa_converter *c;
+    c=create_null_converter(n);
+    c->type=conv_backref;
+    c->backref_no=backref_no;
+    return c;
+}
+
+yaz_nfa_converter *yaz_nfa_create_range_converter (
+                yaz_nfa *n, int backref_no,
+                yaz_nfa_char from_char,
+                yaz_nfa_char to_char){
+    yaz_nfa_converter *c;
+    c=create_null_converter(n);
+    c->type=conv_range;
+    c->backref_no=backref_no;
+    c->char_diff=to_char - from_char;
+    return c;
+    
+}
+
+
+void yaz_nfa_append_converter (
+                yaz_nfa *n,
+                yaz_nfa_converter *startpoint,
+                yaz_nfa_converter *newconverter) {
+    while (startpoint->next)
+        startpoint=startpoint->next;
+    startpoint->next=newconverter;
+}
+
+static int string_convert (
+                yaz_nfa *n,
+                yaz_nfa_converter *c,
+                yaz_nfa_char **outbuff,
+                size_t *outcharsleft){
+    size_t sz=c->strlen;
+    yaz_nfa_char *p=c->string;
+    while (sz--) {
+        if ((*outcharsleft)-- <= 0)
+            return YAZ_NFA_NOSPACE;
+        **outbuff=*p++;
+        (*outbuff)++;
+    }
+    return YAZ_NFA_SUCCESS;
+}
+static int backref_convert (
+                yaz_nfa *n,
+                yaz_nfa_converter *c,
+                yaz_nfa_char **outbuff,
+                size_t *outcharsleft){
+    yaz_nfa_char *cp1,*cp2;
+    int i;
+    i = yaz_nfa_get_backref(n,c->backref_no, &cp1, &cp2);
+    if ( i == YAZ_NFA_NOSUCHBACKREF) /* no backref, produce no output */
+        return YAZ_NFA_SUCCESS; 
+    if ( i == YAZ_NFA_NOMATCH ) /* no match in dfa */
+        return 1; /* should not happen */
+    while (cp2 >= cp1) {
+        if ((*outcharsleft)-- <= 0)
+            return YAZ_NFA_NOSPACE;
+        **outbuff=*cp1++;
+        (*outbuff)++;
+    }
+    return YAZ_NFA_SUCCESS;
+}
+
+static int range_convert (
+                yaz_nfa *n,
+                yaz_nfa_converter *c,
+                yaz_nfa_char **outbuff,
+                size_t *outcharsleft){
+    yaz_nfa_char *cp1=0, *cp2=0;
+    int i;
+    i = yaz_nfa_get_backref(n,c->backref_no, &cp1, &cp2);
+    if (i == YAZ_NFA_NOSUCHBACKREF) /* no backref, produce no output, not ok */
+        return YAZ_NFA_NOSUCHBACKREF; /* should not happen */
+    if (i == YAZ_NFA_NOMATCH) /* no match in dfa */
+        return YAZ_NFA_NOMATCH; /* should not happen */
+    while (cp2 >= cp1) {
+        if ((*outcharsleft)-- <= 0)
+            return YAZ_NFA_NOSPACE;
+        **outbuff=(*cp1++) + c->char_diff ;
+        (*outbuff)++;
+    }
+    return YAZ_NFA_SUCCESS;
+}
+
+
+int yaz_nfa_run_converters(
+                yaz_nfa *n,
+                yaz_nfa_converter *c,
+                yaz_nfa_char **outbuff,
+                size_t *outcharsleft){
+    int rc=0;
+    while (c && !rc) {
+        switch(c->type) {
+            case conv_string:
+                rc=string_convert(n,c,outbuff,outcharsleft);
+                break;
+            case conv_backref:
+                rc=backref_convert(n,c,outbuff,outcharsleft);
+                break;
+            case conv_range:
+                rc=range_convert(n,c,outbuff,outcharsleft);
+                break;
+            default:
+                rc=YAZ_NFA_INTERNAL; /* should never happen */
+        }
+        c=c->next;
+    }
+    return rc;
+}
+
+/* * * * * * * *
+ * High-level interface
+ * These routines build the nfa and add converters, all 
+ * in one go.
+ * * * * * * * */
+
+int yaz_nfa_add_string_rule( yaz_nfa *n,
+        yaz_nfa_char *from_string,
+        size_t        from_length,
+        yaz_nfa_char *to_string,
+        size_t        to_length ) {
+    yaz_nfa_state *s= 
+        yaz_nfa_add_sequence(n, 0, from_string,from_length);
+    yaz_nfa_converter *c=
+        yaz_nfa_create_string_converter(n,to_string,to_length);
+    return yaz_nfa_set_result(n,s,c);
+}
+
+int yaz_nfa_add_ascii_string_rule( yaz_nfa *n,
+                        char *from_string,
+                        char *to_string) {
+    size_t from_len = strlen(from_string);
+    size_t to_len = strlen(to_string);
+    yaz_nfa_char *from_buf=
+        nmem_malloc(n->nmem, from_len*sizeof(yaz_nfa_char));
+    yaz_nfa_char *to_buf=
+        nmem_malloc(n->nmem, to_len*sizeof(yaz_nfa_char));
+    size_t i;
+    for (i=0;i<from_len;i++) 
+        from_buf[i]=from_string[i];
+    for (i=0;i<to_len;i++) 
+        to_buf[i]=to_string[i];
+    return yaz_nfa_add_string_rule(n,from_buf, from_len,
+            to_buf, to_len);
+}
+
+int yaz_nfa_add_char_range_rule (yaz_nfa *n,
+        yaz_nfa_char range_start,
+        yaz_nfa_char range_end,
+        yaz_nfa_char output_range_start) {
+    yaz_nfa_state *s= 
+        yaz_nfa_add_range(n, 0, range_start, range_end);
+    yaz_nfa_converter *c=
+        yaz_nfa_create_range_converter(n,0,range_start, output_range_start);
+    return yaz_nfa_set_result(n,s,c);
+}
+
+int yaz_nfa_add_char_string_rule (yaz_nfa *n,
+        yaz_nfa_char range_start,
+        yaz_nfa_char range_end,
+        yaz_nfa_char* to_string,
+        size_t to_length) {
+    yaz_nfa_state *s= 
+        yaz_nfa_add_range(n, 0, range_start, range_end);
+    yaz_nfa_converter *c=
+        yaz_nfa_create_string_converter(n,to_string,to_length);
+    return yaz_nfa_set_result(n,s,c);
+}
+
+
+int yaz_nfa_convert_slice (yaz_nfa *n,
+        yaz_nfa_char **inbuff, 
+        size_t *incharsleft,
+        yaz_nfa_char **outbuff,
+        size_t *outcharsleft) {
+    void *resptr;
+    yaz_nfa_converter *conv;
+    int rc;
+
+    if (*outcharsleft==0)
+        rc=YAZ_NFA_NOSPACE; /* no room in outbuff */
+    else if (*incharsleft==0) 
+        rc = YAZ_NFA_SUCCESS; /* all done */
+    else {
+        rc=yaz_nfa_match(n, inbuff, incharsleft, &resptr);
+        if (rc==YAZ_NFA_SUCCESS) {
+            conv= (yaz_nfa_converter *)resptr;
+            rc=yaz_nfa_run_converters(n,conv,outbuff,outcharsleft);    
+        } else if (rc==YAZ_NFA_NOMATCH) {
+            **outbuff = **inbuff; 
+            (*outbuff)++;
+            (*inbuff)++;
+            (*outcharsleft)--;
+            (*incharsleft)--;
+            rc=YAZ_NFA_SUCCESS; 
+        }
+        /* else just return the error code */
+    }
+    return rc;
+}
 
 /* * * * * * * * *
  * Debug routines
@@ -445,7 +712,7 @@ static void dump_state(FILE *F, yaz_nfa_state *s,
             resultstring = s->result;
     }
     fprintf(F, "  state [%d] %s %s",
-            s->num, s->result?"(FINAL)":"", resultstring );
+            s->num, s->result?"(final)":"", resultstring );
     if (s->backref_start) {
         fprintf(F, " start-%d", s->backref_start);
     }
@@ -481,6 +748,45 @@ void yaz_nfa_dump(FILE *F, yaz_nfa *n,
     }
 }
 
+static char buf[5000]="";
+char *yaz_nfa_dump_converter(void *conv)
+{
+    char onebuf[500]="";
+    yaz_nfa_converter *c=conv;
+    yaz_nfa_char *cp;
+    size_t len;
+    *buf=0;
+    while (c) {
+        switch(c->type) {
+            case conv_none:
+                sprintf(onebuf,"(none)" );
+                break;
+            case conv_string:
+                sprintf(onebuf,"(string '" );
+                strcat(buf,onebuf);
+                cp=c->string;
+                len=c->strlen;
+                while (len--) {
+                    onebuf[0]=*cp++;
+                    onebuf[1]=0;
+                    strcat(buf,onebuf);
+                }
+                strcat(buf,"')");
+                onebuf[0]=0;
+                break;
+            case conv_backref:
+                sprintf(onebuf,"(backref %d) ",c->backref_no);
+                break;
+            case conv_range:
+                sprintf(onebuf,"(range %d) ",c->char_diff);
+                break;
+        }
+        strcat(buf,onebuf);
+        c=c->next;
+    } /* while */
+    return buf;
+}
+
 
 /* 
  * Local variables: