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Experimental optimized XPath, multiple keys

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This commit is contained in:
Olof hagsand 2019-12-31 13:29:25 +01:00
parent 7fb452f96e
commit b340c36f79
17 changed files with 681 additions and 279 deletions
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139
lib/src/clixon_xpath_eval.c
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@ -85,6 +85,7 @@
#include "clixon_xml_nsctx.h"
#include "clixon_xpath_ctx.h"
#include "clixon_xpath.h"
#include "clixon_xpath_optimize.h"
#include "clixon_xpath_eval.h"
/* Mapping between XPATH operator string <--> int */
@ -277,107 +278,6 @@ nodetest_recursive(cxobj *xn,
return retval;
}
#ifdef XPATH_LIST_OPTIMIZE
/*! Pattern matching to find fastpath
*
* @param[in] xt XPath tree
* @param[in] xv XML base node
* @param[out] xp XML found node (retval == 1)
* @param[out] key
* @param[out] keyval
* @retval 0 Match
* @retval -1 No match
XPath:
y[k=3] # corresponds to: <name>[<keyname>=<keyval>]
*/
static int
xpath_list_optimize(xpath_tree *xt,
cxobj *xv,
cxobj **xp)
{
int retval = -1;
xpath_tree *xmtop = NULL; /* pattern match tree top */
xpath_tree *xm = NULL;
cg_var *cv0;
cg_var *cv1;
cg_var *cv2;
cvec *match = NULL;
char *name;
char *keyname;
char *keyval;
yang_stmt *yp;
yang_stmt *yc;
/* Parse */
if (xpath_parse("_x[_y='_z']", &xmtop) < 0) /* XXX: "y[k=3]" */
goto done;
/* Go down two steps */
if (xmtop && (xm = xmtop->xs_c0) && (xm = xm->xs_c0))
;
if (xm == NULL)
goto ok;
/* Create a cvec match vector and initialize variables */
if ((match = cvec_new(3)) == NULL){
clicon_err(OE_UNIX, errno, "cvec_new");
goto done;
}
cv0 = cvec_i(match, 0);
cv_name_set(cv0, "_x");
cv_type_set(cv0, CGV_STRING);
cv1 = cvec_i(match, 1);
cv_name_set(cv1, "_y");
cv_type_set(cv1, CGV_STRING);
cv2 = cvec_i(match, 2);
cv_name_set(cv2, "_z");
cv_type_set(cv2, CGV_STRING);
/* Check if equal */
if (xpath_tree_eq(xm, xt, match) != 0)
goto ok; /* no match */
/* Extract variables XXX strdups */
name = cv_string_get(cv0);
keyname = cv_string_get(cv1);
keyval = cv_string_get(cv2);
assert(name && keyname && keyval);
/* Check yang and that only a list with key as index is a special case can do bin search */
if ((yp = xml_spec(xv)) == NULL)
goto ok;
if ((yc = yang_find(yp, 0, name)) == NULL)
goto ok;
if (yang_keyword_get(yc) != Y_LIST)
goto ok;
#if 0
{
cvec *cvv = NULL;
if ((cvv = yang_cvec_get(yc)) == NULL)
goto ok;
if (cvec_len(cvv) != 1)
goto ok;
}
#else
{
int ret;
if ((ret = yang_key_match(yc, keyname)) < 0)
goto done;
if (ret != 1)
goto ok;
}
#endif
if (xml_binsearch(xv, name, keyname, keyval, xp) < 0)
goto done;
retval = 1; /* match */
done:
if (match)
cvec_free(match);
if (xmtop)
xpath_tree_free(xmtop);
return retval;
ok: /* no match, not special case */
retval = 0;
goto done;
}
#endif /* XPATH_LIST_OPTIMIZE */
/*! Evaluate xpath step rule of an XML tree
*
* @param[in] xc0 Incoming context
@ -408,9 +308,7 @@ xp_eval_step(xp_ctx *xc0,
size_t veclen = 0;
xpath_tree *nodetest = xs->xs_c0;
xp_ctx *xc = NULL;
#ifdef XPATH_LIST_OPTIMIZE
int ret;
#endif
/* Create new xc */
if ((xc = ctx_dup(xc0)) == NULL)
@ -441,29 +339,25 @@ xp_eval_step(xp_ctx *xc0,
else for (i=0; i<xc->xc_size; i++){
xv = xc->xc_nodeset[i];
x = NULL;
#ifdef XPATH_LIST_OPTIMIZE
/* Identify XPATH special cases and if match, use binary search.
* it returns: -1 fatal error, quit
* 0: not special case, do normal processing
* 1: special case, use x (found if != NULL)
*/
if ((ret = xpath_list_optimize(xs, xv, &x)) < 0)
goto done;
if (ret == 1){
fprintf(stderr, "XPATH_LIST_OPTIMIZE\n");
if (x)
if ((ret = xpath_optimize_check(xs, xv, &x)) < 0)
goto done;
switch (ret){
case 1: /* optimized */
if (x) /* keep only x */
if (cxvec_append(x, &vec, &veclen) < 0)
goto done;
}
else
#endif
while ((x = xml_child_each(xv, x, CX_ELMNT)) != NULL) {
/* xs->xs_c0 is nodetest */
if (nodetest == NULL || nodetest_eval(x, nodetest, nsc, localonly) == 1){
if (cxvec_append(x, &vec, &veclen) < 0)
goto done;
break;
case 0: /* regular code */
if (ret == 0){ /* No optimization made */
while ((x = xml_child_each(xv, x, CX_ELMNT)) != NULL) {
/* xs->xs_c0 is nodetest */
if (nodetest == NULL || nodetest_eval(x, nodetest, nsc, localonly) == 1){
if (cxvec_append(x, &vec, &veclen) < 0)
goto done;
}
}
}
} /* switch */
}
}
ctx_nodeset_replace(xc, vec, veclen);
@ -1207,3 +1101,4 @@ xp_eval(xp_ctx *xc,
return retval;
} /* xp_eval */