pquery.c

harvest是一个下载html网页得机器人

/*
 * Copyright (c) 1995-2003, Index Data.
 * See the file LICENSE for details.
 *
 * $Id: pquery.c,v 1.20 2003/01/06 08:20:29 adam Exp $
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

#include <yaz/proto.h>
#include <yaz/oid.h>
#include <yaz/pquery.h>

static oid_value p_query_dfset = VAL_NONE;

struct yaz_pqf_parser {
    const char *query_buf;
    const char *query_ptr;
    const char *lex_buf;
    size_t lex_len;
    int query_look;
    char *left_sep;
    char *right_sep;
    int escape_char;
    int term_type;
    int external_type;
    int error;
};

static Z_RPNStructure *rpn_structure (struct yaz_pqf_parser *li, ODR o,
                                      oid_proto, 
                                      int num_attr, int max_attr, 
                                      int *attr_list, char **attr_clist,
				      oid_value *attr_set);

static enum oid_value query_oid_getvalbyname (struct yaz_pqf_parser *li)
{
    enum oid_value value;
    char buf[32];

    if (li->lex_len > 31)
        return VAL_NONE;
    memcpy (buf, li->lex_buf, li->lex_len);
    buf[li->lex_len] = '\0';
    value = oid_getvalbyname (buf);
    return value;
}

static int compare_term (struct yaz_pqf_parser *li, const char *src,
                         size_t off)
{
    size_t len=strlen(src);
    
    if (li->lex_len == len+off && !memcmp (li->lex_buf+off, src, len-off))
	return 1;
    return 0;
}

static int query_token (struct yaz_pqf_parser *li)
{
    int sep_char = ' ';
    const char *sep_match;
    const char **qptr = &li->query_ptr;

    while (**qptr == ' ')
        (*qptr)++;
    if (**qptr == '\0')
        return 0;
    li->lex_len = 0;
    if ((sep_match = strchr (li->left_sep, **qptr)))
    {
	sep_char = li->right_sep[sep_match - li->left_sep];
        ++(*qptr);
    }
    li->lex_buf = *qptr;
   
    if (**qptr == li->escape_char && isdigit ((*qptr)[1]))
    {
	++(li->lex_len);
	++(*qptr);
	return 'l';
    }
    while (**qptr && **qptr != sep_char)
    {
	if (**qptr == '\\')
	{
	    ++(li->lex_len);
	    ++(*qptr);
	}
	++(li->lex_len);
	++(*qptr);
    }
    if (**qptr)
	++(*qptr);
    if (sep_char == ' ' &&
        li->lex_len >= 1 && li->lex_buf[0] == li->escape_char)
    {
	if (compare_term (li, "and", 1))
	    return 'a';
        if (compare_term (li, "or", 1))
            return 'o';
        if (compare_term (li, "not", 1))
            return 'n';
        if (compare_term (li, "attr", 1))
            return 'l';
        if (compare_term (li, "set", 1))
            return 's';
        if (compare_term (li, "attrset", 1))
            return 'r';
        if (compare_term (li, "prox", 1))
            return 'p';
        if (compare_term (li, "term", 1))
            return 'y';
    }
    return 't';
}

static int lex (struct yaz_pqf_parser *li)
{
    return li->query_look = query_token (li);
}

static int escape_string(char *out_buf, const char *in, int len)
{

    char *out = out_buf;
    while (--len >= 0)
	if (*in == '\\' && len > 0)
	{
	    --len;
	    switch (*++in)
	    {
	    case 't':
		*out++ = '\t';
		break;
	    case 'n':
		*out++ = '\n';
		break;
	    case 'r':
		*out++ = '\r';
		break;
	    case 'f':
		*out++ = '\f';
		break;
	    case 'x':
		if (len > 1)
		{
		    char s[4];
		    int n = 0;
		    s[0] = *++in;
		    s[1] = *++in;
		    s[2] = '\0';
		    len = len - 2;
		    sscanf (s, "%x", &n);
		    *out++ = n;
		}
		break;
	    case '0':
	    case '1':
	    case '2':
	    case '3':
		if (len > 1)
		{
		    char s[4];
		    int n = 0;
		    s[0] = *in;
		    s[1] = *++in;		    
		    s[2] = *++in;
		    s[3] = '\0';
		    len = len - 2;
		    sscanf (s, "%o", &n);
		    *out++ = n;
		}
		break;
	    default:
		*out++ = *in;
		break;
	    }
	    in++;
	}
	else
	    *out++ = *in++;
    return out - out_buf;
}

static int p_query_parse_attr(struct yaz_pqf_parser *li, ODR o,
			      int num_attr, int *attr_list,
			      char **attr_clist, oid_value *attr_set)
{
    const char *cp;
    if (!(cp = strchr (li->lex_buf, '=')) ||
	(size_t) (cp-li->lex_buf) > li->lex_len)
    {
	attr_set[num_attr] = query_oid_getvalbyname (li);
	if (attr_set[num_attr] == VAL_NONE)
        {
            li->error = YAZ_PQF_ERROR_ATTSET;
	    return 0;
        }
	if (!lex (li))
        {
            li->error = YAZ_PQF_ERROR_MISSING;
            return 0;
        }
	if (!(cp = strchr (li->lex_buf, '=')))
        {
            li->error = YAZ_PQF_ERROR_BADATTR;
	    return 0;
        }
    }
    else 
    {
	if (num_attr > 0)
	    attr_set[num_attr] = attr_set[num_attr-1];
	else
	    attr_set[num_attr] = VAL_NONE;
    }
    attr_list[2*num_attr] = atoi(li->lex_buf);
	cp++;
    if (*cp >= '0' && *cp <= '9')
    {
	attr_list[2*num_attr+1] = atoi (cp);
	attr_clist[num_attr] = 0;
    }
    else
    {
	int len = li->lex_len - (cp - li->lex_buf);
	attr_list[2*num_attr+1] = 0;
	attr_clist[num_attr] = (char *) odr_malloc (o, len+1);
	len = escape_string(attr_clist[num_attr], cp, len);
	attr_clist[num_attr][len] = '\0';
    }
    return 1;
}

static Z_AttributesPlusTerm *rpn_term (struct yaz_pqf_parser *li, ODR o,
                                       oid_proto proto, 
                                       int num_attr, int *attr_list,
				       char **attr_clist, oid_value *attr_set)
{
    Z_AttributesPlusTerm *zapt;
    Odr_oct *term_octet;
    Z_Term *term;
    Z_AttributeElement **elements;

    zapt = (Z_AttributesPlusTerm *)odr_malloc (o, sizeof(*zapt));
    term_octet = (Odr_oct *)odr_malloc (o, sizeof(*term_octet));
    term = (Z_Term *)odr_malloc (o, sizeof(*term));

    if (!num_attr)
        elements = (Z_AttributeElement**)odr_nullval();
    else
    {
        int i, k = 0;
        int *attr_tmp;

        elements = (Z_AttributeElement**)
	    odr_malloc (o, num_attr * sizeof(*elements));

        attr_tmp = (int *)odr_malloc (o, num_attr * 2 * sizeof(int));
        memcpy (attr_tmp, attr_list, num_attr * 2 * sizeof(int));
        for (i = num_attr; --i >= 0; )
        {
            int j;
            for (j = i+1; j<num_attr; j++)
                if (attr_tmp[2*j] == attr_tmp[2*i])
                    break;
            if (j < num_attr)
                continue;
            elements[k] =
                (Z_AttributeElement*)odr_malloc (o,sizeof(**elements));
            elements[k]->attributeType = &attr_tmp[2*i];
	    elements[k]->attributeSet =
		yaz_oidval_to_z3950oid(o, CLASS_ATTSET, attr_set[i]);

	    if (attr_clist[i])
	    {
		elements[k]->which = Z_AttributeValue_complex;
		elements[k]->value.complex = (Z_ComplexAttribute *)
		    odr_malloc (o, sizeof(Z_ComplexAttribute));
		elements[k]->value.complex->num_list = 1;
		elements[k]->value.complex->list =
		    (Z_StringOrNumeric **)
		    odr_malloc (o, 1 * sizeof(Z_StringOrNumeric *));
		elements[k]->value.complex->list[0] =
		    (Z_StringOrNumeric *)
		    odr_malloc (o, sizeof(Z_StringOrNumeric));
		elements[k]->value.complex->list[0]->which =
		    Z_StringOrNumeric_string;
		elements[k]->value.complex->list[0]->u.string =
		    attr_clist[i];
		elements[k]->value.complex->semanticAction = (int **)
		    odr_nullval();
		elements[k]->value.complex->num_semanticAction = 0;
	    }
	    else
	    {
		elements[k]->which = Z_AttributeValue_numeric;
		elements[k]->value.numeric = &attr_tmp[2*i+1];
	    }
            k++;
        }
        num_attr = k;
    }
    zapt->attributes = (Z_AttributeList *)
	odr_malloc (o, sizeof(*zapt->attributes));
    zapt->attributes->num_attributes = num_attr;
    zapt->attributes->attributes = elements;

    zapt->term = term;

    term_octet->buf = (unsigned char *)odr_malloc (o, 1 + li->lex_len);
    term_octet->size = term_octet->len =
        escape_string ((char *) (term_octet->buf), li->lex_buf, li->lex_len);
    term_octet->buf[term_octet->size] = 0;  /* null terminate */
    
    switch (li->term_type)
    {
    case Z_Term_general:
        term->which = Z_Term_general;
        term->u.general = term_octet;
        break;
    case Z_Term_characterString:
        term->which = Z_Term_characterString;
        term->u.characterString = (char*) term_octet->buf; 
                                    /* null terminated above */
        break;
    case Z_Term_numeric:
        term->which = Z_Term_numeric;
        term->u.numeric = odr_intdup (o, atoi((char*) (term_octet->buf)));
        break;
    case Z_Term_null:
        term->which = Z_Term_null;
        term->u.null = odr_nullval();
        break;
    case Z_Term_external:
        term->which = Z_Term_external;
	term->u.external = 0;
	break;
    default:
        term->which = Z_Term_null;
        term->u.null = odr_nullval();
        break;
    }
    return zapt;
}

static Z_Operand *rpn_simple (struct yaz_pqf_parser *li, ODR o, oid_proto proto,
                              int num_attr, int *attr_list, char **attr_clist,
                              oid_value *attr_set)
{
    Z_Operand *zo;

    zo = (Z_Operand *)odr_malloc (o, sizeof(*zo));
    switch (li->query_look)
    {
    case 't':
        zo->which = Z_Operand_APT;
        if (!(zo->u.attributesPlusTerm =
              rpn_term (li, o, proto, num_attr, attr_list, attr_clist,
			attr_set)))
            return 0;
        lex (li);
        break;
    case 's':
        lex (li);
        if (!li->query_look)
        {
            li->error = YAZ_PQF_ERROR_MISSING;
            return 0;
        }
        zo->which = Z_Operand_resultSetId;
        zo->u.resultSetId = (char *)odr_malloc (o, li->lex_len+1);
        memcpy (zo->u.resultSetId, li->lex_buf, li->lex_len);
        zo->u.resultSetId[li->lex_len] = '\0';
        lex (li);
        break;
    default:
        /* we're only called if one of the above types are seens so
           this shouldn't happen */
        li->error = YAZ_PQF_ERROR_INTERNAL;
        return 0;
    }
    return zo;
}

static Z_ProximityOperator *rpn_proximity (struct yaz_pqf_parser *li, ODR o)
{
    Z_ProximityOperator *p = (Z_ProximityOperator *)odr_malloc (o, sizeof(*p));

    if (!lex (li))
    {
        li->error = YAZ_PQF_ERROR_MISSING;
        return NULL;
    }
    if (*li->lex_buf == '1')
    {
        p->exclusion = (int *)odr_malloc (o, sizeof(*p->exclusion));
        *p->exclusion = 1;
    } 
    else if (*li->lex_buf == '0')
    {
        p->exclusion = (int *)odr_malloc (o, sizeof(*p->exclusion));
        *p->exclusion = 0;
    }
    else