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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 18:00:34 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 18:00:34 +0000
commit3f619478f796eddbba6e39502fe941b285dd97b1 (patch)
treee2c7b5777f728320e5b5542b6213fd3591ba51e2 /sql/item_xmlfunc.cc
parentInitial commit. (diff)
downloadmariadb-3f619478f796eddbba6e39502fe941b285dd97b1.tar.xz
mariadb-3f619478f796eddbba6e39502fe941b285dd97b1.zip
Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'sql/item_xmlfunc.cc')
-rw-r--r--sql/item_xmlfunc.cc3130
1 files changed, 3130 insertions, 0 deletions
diff --git a/sql/item_xmlfunc.cc b/sql/item_xmlfunc.cc
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+++ b/sql/item_xmlfunc.cc
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+/* Copyright (c) 2005, 2019, Oracle and/or its affiliates.
+ Copyright (c) 2009, 2021, MariaDB
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+#include "mariadb.h"
+#include "sql_priv.h"
+/*
+ It is necessary to include set_var.h instead of item.h because there
+ are dependencies on include order for set_var.h and item.h. This
+ will be resolved later.
+*/
+#include "sql_class.h" // set_var.h: THD
+#include "set_var.h"
+#include "my_xml.h"
+#include "sp_pcontext.h"
+#include "sql_class.h" // THD
+
+/*
+ TODO: future development directions:
+ 1. add nodeset_to_nodeset_comparator
+ 2. add lacking functions:
+ - name()
+ - lang()
+ - string()
+ - id()
+ - translate()
+ - local-name()
+ - starts-with()
+ - namespace-uri()
+ - substring-after()
+ - normalize-space()
+ - substring-before()
+ 3. add lacking axis:
+ - following-sibling
+ - following,
+ - preceding-sibling
+ - preceding
+*/
+
+
+/* Structure to store a parsed XML tree */
+typedef struct my_xml_node_st
+{
+ uint level; /* level in XML tree, 0 means root node */
+ enum my_xml_node_type type; /* node type: node, or attribute, or text */
+ uint parent; /* link to the parent */
+ const char *beg; /* beginning of the name or text */
+ const char *end; /* end of the name or text */
+ const char *tagend; /* where this tag ends */
+} MY_XML_NODE;
+
+
+/* Lexical analyzer token */
+typedef struct my_xpath_lex_st
+{
+ int term; /* token type, see MY_XPATH_LEX_XXXXX below */
+ const char *beg; /* beginnign of the token */
+ const char *end; /* end of the token */
+} MY_XPATH_LEX;
+
+
+/* XPath function creator */
+typedef struct my_xpath_function_names_st
+{
+ const char *name; /* function name */
+ size_t length; /* function name length */
+ size_t minargs; /* min number of arguments */
+ size_t maxargs; /* max number of arguments */
+ Item *(*create)(struct my_xpath_st *xpath, Item **args, uint nargs);
+} MY_XPATH_FUNC;
+
+
+/* XPath query parser */
+typedef struct my_xpath_st
+{
+ THD *thd;
+ int debug;
+ MY_XPATH_LEX query; /* Whole query */
+ MY_XPATH_LEX lasttok; /* last scanned token */
+ MY_XPATH_LEX prevtok; /* previous scanned token */
+ int axis; /* last scanned axis */
+ int extra; /* last scanned "extra", context dependent */
+ MY_XPATH_FUNC *func; /* last scanned function creator */
+ Item *item; /* current expression */
+ Item *context; /* last scanned context */
+ Item *rootelement; /* The root element */
+ Native *context_cache; /* last context provider */
+ String *pxml; /* Parsed XML, an array of MY_XML_NODE */
+ CHARSET_INFO *cs; /* character set/collation string comparison */
+ int error;
+} MY_XPATH;
+
+
+static Type_handler_long_blob type_handler_xpath_nodeset;
+
+
+/*
+ Common features of the functions returning a node set.
+*/
+class Item_nodeset_func :public Item_str_func
+{
+protected:
+ NativeNodesetBuffer tmp_native_value, tmp2_native_value;
+ MY_XPATH_FLT *fltbeg, *fltend;
+ MY_XML_NODE *nodebeg, *nodeend;
+ uint numnodes;
+public:
+ String *pxml;
+ NativeNodesetBuffer context_cache;
+ Item_nodeset_func(THD *thd, String *pxml_arg):
+ Item_str_func(thd), pxml(pxml_arg) {}
+ Item_nodeset_func(THD *thd, Item *a, String *pxml_arg):
+ Item_str_func(thd, a), pxml(pxml_arg) {}
+ Item_nodeset_func(THD *thd, Item *a, Item *b, String *pxml_arg):
+ Item_str_func(thd, a, b), pxml(pxml_arg) {}
+ Item_nodeset_func(THD *thd, Item *a, Item *b, Item *c, String *pxml_arg):
+ Item_str_func(thd, a, b, c), pxml(pxml_arg) {}
+ void prepare_nodes()
+ {
+ nodebeg= (MY_XML_NODE*) pxml->ptr();
+ nodeend= (MY_XML_NODE*) (pxml->ptr() + pxml->length());
+ numnodes= (uint)(nodeend - nodebeg);
+ }
+ void prepare(THD *thd, Native *nodeset)
+ {
+ prepare_nodes();
+ args[0]->val_native(thd, &tmp_native_value);
+ fltbeg= (MY_XPATH_FLT*) tmp_native_value.ptr();
+ fltend= (MY_XPATH_FLT*) tmp_native_value.end();
+ nodeset->length(0);
+ }
+ const Type_handler *type_handler() const override
+ {
+ return &type_handler_xpath_nodeset;
+ }
+ const Type_handler *fixed_type_handler() const override
+ {
+ return &type_handler_xpath_nodeset;
+ }
+ Field *create_tmp_field_ex(MEM_ROOT *root, TABLE *table, Tmp_field_src *src,
+ const Tmp_field_param *param) override
+ {
+ DBUG_ASSERT(0);
+ return NULL;
+ }
+ String *val_str(String *str) override
+ {
+ prepare_nodes();
+ val_native(current_thd, &tmp2_native_value);
+ fltbeg= (MY_XPATH_FLT*) tmp2_native_value.ptr();
+ fltend= (MY_XPATH_FLT*) tmp2_native_value.end();
+ String active;
+ active.alloc(numnodes);
+ bzero((char*) active.ptr(), numnodes);
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ MY_XML_NODE *node;
+ uint j;
+ for (j=0, node= nodebeg ; j < numnodes; j++, node++)
+ {
+ if (node->type == MY_XML_NODE_TEXT &&
+ node->parent == flt->num)
+ active[j]= 1;
+ }
+ }
+
+ str->length(0);
+ str->set_charset(collation.collation);
+ for (uint i=0 ; i < numnodes; i++)
+ {
+ if(active[i])
+ {
+ if (str->length())
+ str->append(" ", 1, &my_charset_latin1);
+ str->append(nodebeg[i].beg, nodebeg[i].end - nodebeg[i].beg);
+ }
+ }
+ return str;
+ }
+ bool fix_length_and_dec(THD *thd) override
+ {
+ max_length= MAX_BLOB_WIDTH;
+ collation.collation= pxml->charset();
+ // To avoid premature evaluation, mark all nodeset functions as non-const.
+ used_tables_cache= RAND_TABLE_BIT;
+ const_item_cache= false;
+ return FALSE;
+ }
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("nodeset") };
+ }
+ bool check_vcol_func_processor(void *arg) override
+ {
+ return mark_unsupported_function(func_name(), arg, VCOL_IMPOSSIBLE);
+ }
+
+};
+
+
+/* Returns an XML root */
+class Item_nodeset_func_rootelement :public Item_nodeset_func
+{
+public:
+ Item_nodeset_func_rootelement(THD *thd, String *pxml):
+ Item_nodeset_func(thd, pxml) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_rootelement") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_rootelement>(thd, this); }
+};
+
+
+/* Returns a Union of two node sets */
+class Item_nodeset_func_union :public Item_nodeset_func
+{
+public:
+ Item_nodeset_func_union(THD *thd, Item *a, Item *b, String *pxml):
+ Item_nodeset_func(thd, a, b, pxml) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_union") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_union>(thd, this); }
+};
+
+
+/* Makes one step towards the given axis */
+class Item_nodeset_func_axisbyname :public Item_nodeset_func
+{
+ const char *node_name;
+ uint node_namelen;
+public:
+ Item_nodeset_func_axisbyname(THD *thd, Item *a, const char *n_arg, uint l_arg,
+ String *pxml):
+ Item_nodeset_func(thd, a, pxml), node_name(n_arg), node_namelen(l_arg) { }
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_axisbyname") };
+ }
+ bool validname(MY_XML_NODE *n)
+ {
+ if (node_name[0] == '*')
+ return 1;
+ return (node_namelen == (uint) (n->end - n->beg)) &&
+ !memcmp(node_name, n->beg, node_namelen);
+ }
+};
+
+
+/* Returns self */
+class Item_nodeset_func_selfbyname: public Item_nodeset_func_axisbyname
+{
+public:
+ Item_nodeset_func_selfbyname(THD *thd, Item *a, const char *n_arg, uint l_arg,
+ String *pxml):
+ Item_nodeset_func_axisbyname(thd, a, n_arg, l_arg, pxml) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_selfbyname") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_selfbyname>(thd, this); }
+};
+
+
+/* Returns children */
+class Item_nodeset_func_childbyname: public Item_nodeset_func_axisbyname
+{
+public:
+ Item_nodeset_func_childbyname(THD *thd, Item *a, const char *n_arg, uint l_arg,
+ String *pxml):
+ Item_nodeset_func_axisbyname(thd, a, n_arg, l_arg, pxml) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_childbyname") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_childbyname>(thd, this); }
+};
+
+
+/* Returns descendants */
+class Item_nodeset_func_descendantbyname: public Item_nodeset_func_axisbyname
+{
+ bool need_self;
+public:
+ Item_nodeset_func_descendantbyname(THD *thd, Item *a, const char *n_arg, uint l_arg,
+ String *pxml, bool need_self_arg):
+ Item_nodeset_func_axisbyname(thd, a, n_arg, l_arg, pxml),
+ need_self(need_self_arg) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_descendantbyname") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_descendantbyname>(thd, this); }
+};
+
+
+/* Returns ancestors */
+class Item_nodeset_func_ancestorbyname: public Item_nodeset_func_axisbyname
+{
+ bool need_self;
+public:
+ Item_nodeset_func_ancestorbyname(THD *thd, Item *a, const char *n_arg, uint l_arg,
+ String *pxml, bool need_self_arg):
+ Item_nodeset_func_axisbyname(thd, a, n_arg, l_arg, pxml),
+ need_self(need_self_arg) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_ancestorbyname") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_ancestorbyname>(thd, this); }
+};
+
+
+/* Returns parents */
+class Item_nodeset_func_parentbyname: public Item_nodeset_func_axisbyname
+{
+public:
+ Item_nodeset_func_parentbyname(THD *thd, Item *a, const char *n_arg, uint l_arg,
+ String *pxml):
+ Item_nodeset_func_axisbyname(thd, a, n_arg, l_arg, pxml) {}
+
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_parentbyname") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_parentbyname>(thd, this); }
+};
+
+
+/* Returns attributes */
+class Item_nodeset_func_attributebyname: public Item_nodeset_func_axisbyname
+{
+public:
+ Item_nodeset_func_attributebyname(THD *thd, Item *a, const char *n_arg,
+ uint l_arg, String *pxml):
+ Item_nodeset_func_axisbyname(thd, a, n_arg, l_arg, pxml) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_attributebyname") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_attributebyname>(thd, this); }
+};
+
+
+/*
+ Condition iterator: goes through all nodes in the current
+ context and checks a condition, returning those nodes
+ giving TRUE condition result.
+*/
+class Item_nodeset_func_predicate :public Item_nodeset_func
+{
+public:
+ Item_nodeset_func_predicate(THD *thd, Item *a, Item *b, String *pxml):
+ Item_nodeset_func(thd, a, b, pxml) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_predicate") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_predicate>(thd, this); }
+};
+
+
+/* Selects nodes with a given position in context */
+class Item_nodeset_func_elementbyindex :public Item_nodeset_func
+{
+public:
+ Item_nodeset_func_elementbyindex(THD *thd, Item *a, Item *b, String *pxml):
+ Item_nodeset_func(thd, a, b, pxml) { }
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_elementbyindex") };
+ }
+ bool val_native(THD *thd, Native *nodeset) override;
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_func_elementbyindex>(thd, this); }
+};
+
+
+/*
+ Converts its argument into a boolean value.
+ * a number is true if it is non-zero
+ * a node-set is true if and only if it is non-empty
+ * a string is true if and only if its length is non-zero
+*/
+class Item_xpath_cast_bool :public Item_bool_func
+{
+ String *pxml;
+ NativeNodesetBuffer tmp_native_value;
+public:
+ Item_xpath_cast_bool(THD *thd, Item *a, String *pxml_arg):
+ Item_bool_func(thd, a), pxml(pxml_arg) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_cast_bool") };
+ }
+ longlong val_int() override
+ {
+ if (args[0]->fixed_type_handler() == &type_handler_xpath_nodeset)
+ {
+ args[0]->val_native(current_thd, &tmp_native_value);
+ return tmp_native_value.elements() == 1 ? 1 : 0;
+ }
+ return args[0]->val_real() ? 1 : 0;
+ }
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_xpath_cast_bool>(thd, this); }
+};
+
+
+/*
+ Converts its argument into a number
+*/
+class Item_xpath_cast_number :public Item_real_func
+{
+public:
+ Item_xpath_cast_number(THD *thd, Item *a): Item_real_func(thd, a) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_cast_number") };
+ }
+ double val_real() override { return args[0]->val_real(); }
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_xpath_cast_number>(thd, this); }
+};
+
+
+/*
+ Context cache, for predicate
+*/
+class Item_nodeset_context_cache :public Item_nodeset_func
+{
+public:
+ Native *native_cache;
+ Item_nodeset_context_cache(THD *thd, Native *native_arg, String *pxml):
+ Item_nodeset_func(thd, pxml), native_cache(native_arg) { }
+ bool val_native(THD *, Native *nodeset) override
+ {
+ return nodeset->copy(*native_cache);
+ }
+ bool fix_length_and_dec(THD *thd) override
+ { max_length= MAX_BLOB_WIDTH; return FALSE; }
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_context_cache>(thd, this); }
+};
+
+
+class Item_func_xpath_position :public Item_long_func
+{
+ String *pxml;
+ NativeNodesetBuffer tmp_native_value;
+public:
+ Item_func_xpath_position(THD *thd, Item *a, String *p):
+ Item_long_func(thd, a), pxml(p) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_position") };
+ }
+ bool fix_length_and_dec(THD *thd) override { max_length=10; return FALSE; }
+ longlong val_int() override
+ {
+ args[0]->val_native(current_thd, &tmp_native_value);
+ if (tmp_native_value.elements() == 1)
+ return tmp_native_value.element(0).pos + 1;
+ return 0;
+ }
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_func_xpath_position>(thd, this); }
+};
+
+
+class Item_func_xpath_count :public Item_long_func
+{
+ String *pxml;
+ NativeNodesetBuffer tmp_native_value;
+public:
+ Item_func_xpath_count(THD *thd, Item *a, String *p):
+ Item_long_func(thd, a), pxml(p) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_count") };
+ }
+ bool fix_length_and_dec(THD *thd) override { max_length=10; return FALSE; }
+ longlong val_int() override
+ {
+ uint predicate_supplied_context_size;
+ args[0]->val_native(current_thd, &tmp_native_value);
+ if (tmp_native_value.elements() == 1 &&
+ (predicate_supplied_context_size= tmp_native_value.element(0).size))
+ return predicate_supplied_context_size;
+ return tmp_native_value.elements();
+ }
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_func_xpath_count>(thd, this); }
+};
+
+
+class Item_func_xpath_sum :public Item_real_func
+{
+ String *pxml;
+ NativeNodesetBuffer tmp_native_value;
+public:
+ Item_func_xpath_sum(THD *thd, Item *a, String *p):
+ Item_real_func(thd, a), pxml(p) {}
+
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_sum") };
+ }
+ double val_real() override
+ {
+ double sum= 0;
+ args[0]->val_native(current_thd, &tmp_native_value);
+ MY_XPATH_FLT *fltbeg= (MY_XPATH_FLT*) tmp_native_value.ptr();
+ MY_XPATH_FLT *fltend= (MY_XPATH_FLT*) tmp_native_value.end();
+ uint numnodes= pxml->length() / sizeof(MY_XML_NODE);
+ MY_XML_NODE *nodebeg= (MY_XML_NODE*) pxml->ptr();
+
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ MY_XML_NODE *self= &nodebeg[flt->num];
+ for (uint j= flt->num + 1; j < numnodes; j++)
+ {
+ MY_XML_NODE *node= &nodebeg[j];
+ if (node->level <= self->level)
+ break;
+ if ((node->parent == flt->num) &&
+ (node->type == MY_XML_NODE_TEXT))
+ {
+ char *end;
+ int err;
+ double add= collation.collation->strntod((char*) node->beg,
+ node->end - node->beg, &end, &err);
+ if (!err)
+ sum+= add;
+ }
+ }
+ }
+ return sum;
+ }
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_func_xpath_sum>(thd, this); }
+};
+
+
+/**
+ A string whose value may be changed during execution.
+*/
+class Item_string_xml_non_const: public Item_string
+{
+public:
+ Item_string_xml_non_const(THD *thd, const char *str, uint length,
+ CHARSET_INFO *cs):
+ Item_string(thd, str, length, cs)
+ { }
+ bool const_item() const { return false ; }
+ bool basic_const_item() const { return false; }
+ void set_value(const char *str, uint length, CHARSET_INFO *cs)
+ {
+ str_value.set(str, length, cs);
+ }
+ Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs)
+ {
+ /*
+ Item_string::safe_charset_converter() does not accept non-constants.
+ Note, conversion is not really needed here anyway.
+ */
+ return this;
+ }
+};
+
+
+class Item_nodeset_to_const_comparator :public Item_bool_func
+{
+ String *pxml;
+ NativeNodesetBuffer tmp_nodeset;
+public:
+ Item_nodeset_to_const_comparator(THD *thd, Item *nodeset, Item *cmpfunc,
+ String *p):
+ Item_bool_func(thd, nodeset, cmpfunc), pxml(p) {}
+ LEX_CSTRING func_name_cstring() const override
+ {
+ return { STRING_WITH_LEN("xpath_nodeset_to_const_comparator") };
+ }
+ bool check_vcol_func_processor(void *arg) override
+ {
+ return mark_unsupported_function(func_name(), arg, VCOL_IMPOSSIBLE);
+ }
+ Field *create_tmp_field_ex(MEM_ROOT *root, TABLE *table, Tmp_field_src *src,
+ const Tmp_field_param *param) override
+ {
+ DBUG_ASSERT(0);
+ return NULL;
+ }
+ longlong val_int() override
+ {
+ Item_func *comp= (Item_func*)args[1];
+ Item_string_xml_non_const *fake=
+ (Item_string_xml_non_const*)(comp->arguments()[0]);
+ args[0]->val_native(current_thd, &tmp_nodeset);
+ MY_XPATH_FLT *fltbeg= (MY_XPATH_FLT*) tmp_nodeset.ptr();
+ MY_XPATH_FLT *fltend= (MY_XPATH_FLT*) tmp_nodeset.end();
+ MY_XML_NODE *nodebeg= (MY_XML_NODE*) pxml->ptr();
+ uint numnodes= pxml->length() / sizeof(MY_XML_NODE);
+
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ MY_XML_NODE *self= &nodebeg[flt->num];
+ for (uint j= flt->num + 1; j < numnodes; j++)
+ {
+ MY_XML_NODE *node= &nodebeg[j];
+ if (node->level <= self->level)
+ break;
+ if ((node->parent == flt->num) &&
+ (node->type == MY_XML_NODE_TEXT))
+ {
+ fake->set_value(node->beg, (uint)(node->end - node->beg),
+ collation.collation);
+ if (args[1]->val_int())
+ return 1;
+ }
+ }
+ }
+ return 0;
+ }
+ Item *get_copy(THD *thd) override
+ { return get_item_copy<Item_nodeset_to_const_comparator>(thd, this); }
+};
+
+
+bool Item_nodeset_func_rootelement::val_native(THD *thd, Native *nodeset)
+{
+ nodeset->length(0);
+ return MY_XPATH_FLT(0, 0).append_to(nodeset);
+}
+
+
+bool Item_nodeset_func_union::val_native(THD *thd, Native *nodeset)
+{
+ uint num_nodes= pxml->length() / sizeof(MY_XML_NODE);
+ NativeNodesetBuffer set0, set1;
+ args[0]->val_native(thd, &set0);
+ args[1]->val_native(thd, &set1);
+ String both_str;
+ both_str.alloc(num_nodes);
+ char *both= (char*) both_str.ptr();
+ bzero((void*)both, num_nodes);
+ MY_XPATH_FLT *flt;
+
+ fltbeg= (MY_XPATH_FLT*) set0.ptr();
+ fltend= (MY_XPATH_FLT*) set0.end();
+ for (flt= fltbeg; flt < fltend; flt++)
+ both[flt->num]= 1;
+
+ fltbeg= (MY_XPATH_FLT*) set1.ptr();
+ fltend= (MY_XPATH_FLT*) set1.end();
+ for (flt= fltbeg; flt < fltend; flt++)
+ both[flt->num]= 1;
+
+ nodeset->length(0);
+ for (uint i= 0, pos= 0; i < num_nodes; i++)
+ {
+ if (both[i])
+ MY_XPATH_FLT(i, pos++).append_to(nodeset);
+ }
+ return false;
+}
+
+
+bool Item_nodeset_func_selfbyname::val_native(THD *thd, Native *nodeset)
+{
+ prepare(thd, nodeset);
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ uint pos= 0;
+ MY_XML_NODE *self= &nodebeg[flt->num];
+ if (validname(self))
+ MY_XPATH_FLT(flt->num, pos++).append_to(nodeset);
+ }
+ return false;
+}
+
+
+bool Item_nodeset_func_childbyname::val_native(THD *thd, Native *nodeset)
+{
+ prepare(thd, nodeset);
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ MY_XML_NODE *self= &nodebeg[flt->num];
+ for (uint pos= 0, j= flt->num + 1 ; j < numnodes; j++)
+ {
+ MY_XML_NODE *node= &nodebeg[j];
+ if (node->level <= self->level)
+ break;
+ if ((node->parent == flt->num) &&
+ (node->type == MY_XML_NODE_TAG) &&
+ validname(node))
+ MY_XPATH_FLT(j, pos++).append_to(nodeset);
+ }
+ }
+ return false;
+}
+
+
+bool Item_nodeset_func_descendantbyname::val_native(THD *thd, Native *nodeset)
+{
+ prepare(thd, nodeset);
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ uint pos= 0;
+ MY_XML_NODE *self= &nodebeg[flt->num];
+ if (need_self && validname(self))
+ MY_XPATH_FLT(flt->num, pos++).append_to(nodeset);
+ for (uint j= flt->num + 1 ; j < numnodes ; j++)
+ {
+ MY_XML_NODE *node= &nodebeg[j];
+ if (node->level <= self->level)
+ break;
+ if ((node->type == MY_XML_NODE_TAG) && validname(node))
+ MY_XPATH_FLT(j, pos++).append_to(nodeset);
+ }
+ }
+ return false;
+}
+
+
+bool Item_nodeset_func_ancestorbyname::val_native(THD *thd, Native *nodeset)
+{
+ char *active;
+ String active_str;
+ prepare(thd, nodeset);
+ active_str.alloc(numnodes);
+ active= (char*) active_str.ptr();
+ bzero((void*)active, numnodes);
+ uint pos= 0;
+
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ /*
+ Go to the root and add all nodes on the way.
+ Don't add the root if context is the root itelf
+ */
+ MY_XML_NODE *self= &nodebeg[flt->num];
+ if (need_self && validname(self))
+ {
+ active[flt->num]= 1;
+ pos++;
+ }
+
+ for (uint j= self->parent; nodebeg[j].parent != j; j= nodebeg[j].parent)
+ {
+ if (flt->num && validname(&nodebeg[j]))
+ {
+ active[j]= 1;
+ pos++;
+ }
+ }
+ }
+
+ for (uint j= 0; j < numnodes ; j++)
+ {
+ if (active[j])
+ MY_XPATH_FLT(j, --pos).append_to(nodeset);
+ }
+ return false;
+}
+
+
+bool Item_nodeset_func_parentbyname::val_native(THD *thd, Native *nodeset)
+{
+ char *active;
+ String active_str;
+ prepare(thd, nodeset);
+ active_str.alloc(numnodes);
+ active= (char*) active_str.ptr();
+ bzero((void*)active, numnodes);
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ uint j= nodebeg[flt->num].parent;
+ if (flt->num && validname(&nodebeg[j]))
+ active[j]= 1;
+ }
+ for (uint j= 0, pos= 0; j < numnodes ; j++)
+ {
+ if (active[j])
+ MY_XPATH_FLT(j, pos++).append_to(nodeset);
+ }
+ return false;
+}
+
+
+bool Item_nodeset_func_attributebyname::val_native(THD *thd, Native *nodeset)
+{
+ prepare(thd, nodeset);
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ MY_XML_NODE *self= &nodebeg[flt->num];
+ for (uint pos=0, j= flt->num + 1 ; j < numnodes; j++)
+ {
+ MY_XML_NODE *node= &nodebeg[j];
+ if (node->level <= self->level)
+ break;
+ if ((node->parent == flt->num) &&
+ (node->type == MY_XML_NODE_ATTR) &&
+ validname(node))
+ MY_XPATH_FLT(j, pos++).append_to(nodeset);
+ }
+ }
+ return false;
+}
+
+
+bool Item_nodeset_func_predicate::val_native(THD *thd, Native *str)
+{
+ Item_nodeset_func *nodeset_func= (Item_nodeset_func*) args[0];
+ uint pos= 0, size;
+ prepare(thd, str);
+ size= (uint)(fltend - fltbeg);
+ for (MY_XPATH_FLT *flt= fltbeg; flt < fltend; flt++)
+ {
+ nodeset_func->context_cache.length(0);
+ MY_XPATH_FLT(flt->num, flt->pos, size).
+ append_to(&nodeset_func->context_cache);
+ if (args[1]->val_int())
+ MY_XPATH_FLT(flt->num, pos++).append_to(str);
+ }
+ return false;
+}
+
+
+bool Item_nodeset_func_elementbyindex::val_native(THD *thd, Native *nodeset)
+{
+ Item_nodeset_func *nodeset_func= (Item_nodeset_func*) args[0];
+ prepare(thd, nodeset);
+ MY_XPATH_FLT *flt;
+ uint pos, size= (uint)(fltend - fltbeg);
+ for (pos= 0, flt= fltbeg; flt < fltend; flt++)
+ {
+ nodeset_func->context_cache.length(0);
+ MY_XPATH_FLT(flt->num, flt->pos, size).
+ append_to(&nodeset_func->context_cache);
+ int index= (int) (args[1]->val_int()) - 1;
+ if (index >= 0 &&
+ (flt->pos == (uint) index ||
+ (args[1]->type_handler()->is_bool_type())))
+ MY_XPATH_FLT(flt->num, pos++).append_to(nodeset);
+ }
+ return false;
+}
+
+
+/*
+ If item is a node set, then casts it to boolean,
+ otherwise returns the item itself.
+*/
+static Item* nodeset2bool(MY_XPATH *xpath, Item *item)
+{
+ if (item->fixed_type_handler() == &type_handler_xpath_nodeset)
+ return new (xpath->thd->mem_root)
+ Item_xpath_cast_bool(xpath->thd, item, xpath->pxml);
+ return item;
+}
+
+
+/*
+ XPath lexical tokens
+*/
+#define MY_XPATH_LEX_DIGITS 'd'
+#define MY_XPATH_LEX_IDENT 'i'
+#define MY_XPATH_LEX_STRING 's'
+#define MY_XPATH_LEX_SLASH '/'
+#define MY_XPATH_LEX_LB '['
+#define MY_XPATH_LEX_RB ']'
+#define MY_XPATH_LEX_LP '('
+#define MY_XPATH_LEX_RP ')'
+#define MY_XPATH_LEX_EQ '='
+#define MY_XPATH_LEX_LESS '<'
+#define MY_XPATH_LEX_GREATER '>'
+#define MY_XPATH_LEX_AT '@'
+#define MY_XPATH_LEX_COLON ':'
+#define MY_XPATH_LEX_ASTERISK '*'
+#define MY_XPATH_LEX_DOT '.'
+#define MY_XPATH_LEX_VLINE '|'
+#define MY_XPATH_LEX_MINUS '-'
+#define MY_XPATH_LEX_PLUS '+'
+#define MY_XPATH_LEX_EXCL '!'
+#define MY_XPATH_LEX_COMMA ','
+#define MY_XPATH_LEX_DOLLAR '$'
+#define MY_XPATH_LEX_ERROR 'A'
+#define MY_XPATH_LEX_EOF 'B'
+#define MY_XPATH_LEX_AND 'C'
+#define MY_XPATH_LEX_OR 'D'
+#define MY_XPATH_LEX_DIV 'E'
+#define MY_XPATH_LEX_MOD 'F'
+#define MY_XPATH_LEX_FUNC 'G'
+#define MY_XPATH_LEX_NODETYPE 'H'
+#define MY_XPATH_LEX_AXIS 'I'
+#define MY_XPATH_LEX_LE 'J'
+#define MY_XPATH_LEX_GE 'K'
+
+
+/*
+ XPath axis type
+*/
+#define MY_XPATH_AXIS_ANCESTOR 0
+#define MY_XPATH_AXIS_ANCESTOR_OR_SELF 1
+#define MY_XPATH_AXIS_ATTRIBUTE 2
+#define MY_XPATH_AXIS_CHILD 3
+#define MY_XPATH_AXIS_DESCENDANT 4
+#define MY_XPATH_AXIS_DESCENDANT_OR_SELF 5
+#define MY_XPATH_AXIS_FOLLOWING 6
+#define MY_XPATH_AXIS_FOLLOWING_SIBLING 7
+#define MY_XPATH_AXIS_NAMESPACE 8
+#define MY_XPATH_AXIS_PARENT 9
+#define MY_XPATH_AXIS_PRECEDING 10
+#define MY_XPATH_AXIS_PRECEDING_SIBLING 11
+#define MY_XPATH_AXIS_SELF 12
+
+
+/*
+ Create scalar comparator
+
+ SYNOPSYS
+ Create a comparator function for scalar arguments,
+ for the given arguments and operation.
+
+ RETURN
+ The newly created item.
+*/
+static Item *eq_func(THD *thd, int oper, Item *a, Item *b)
+{
+ MEM_ROOT *mem_root= thd->mem_root;
+ switch (oper)
+ {
+ case '=': return new (mem_root) Item_func_eq(thd, a, b);
+ case '!': return new (mem_root) Item_func_ne(thd, a, b);
+ case MY_XPATH_LEX_GE: return new (mem_root) Item_func_ge(thd, a, b);
+ case MY_XPATH_LEX_LE: return new (mem_root) Item_func_le(thd, a, b);
+ case MY_XPATH_LEX_GREATER: return new (mem_root) Item_func_gt(thd, a, b);
+ case MY_XPATH_LEX_LESS: return new (mem_root) Item_func_lt(thd, a, b);
+ }
+ return 0;
+}
+
+
+/*
+ Create scalar comparator
+
+ SYNOPSYS
+ Create a comparator function for scalar arguments,
+ for the given arguments and reverse operation, e.g.
+
+ A > B is converted into B < A
+
+ RETURN
+ The newly created item.
+*/
+static Item *eq_func_reverse(THD *thd, int oper, Item *a, Item *b)
+{
+ MEM_ROOT *mem_root= thd->mem_root;
+ switch (oper)
+ {
+ case '=': return new (mem_root) Item_func_eq(thd, a, b);
+ case '!': return new (mem_root) Item_func_ne(thd, a, b);
+ case MY_XPATH_LEX_GE: return new (mem_root) Item_func_le(thd, a, b);
+ case MY_XPATH_LEX_LE: return new (mem_root) Item_func_ge(thd, a, b);
+ case MY_XPATH_LEX_GREATER: return new (mem_root) Item_func_lt(thd, a, b);
+ case MY_XPATH_LEX_LESS: return new (mem_root) Item_func_gt(thd, a, b);
+ }
+ return 0;
+}
+
+
+/*
+ Create a comparator
+
+ SYNOPSYS
+ Create a comparator for scalar or non-scalar arguments,
+ for the given arguments and operation.
+
+ RETURN
+ The newly created item.
+*/
+static Item *create_comparator(MY_XPATH *xpath,
+ int oper, MY_XPATH_LEX *context,
+ Item *a, Item *b)
+{
+ if (a->fixed_type_handler() != &type_handler_xpath_nodeset &&
+ b->fixed_type_handler() != &type_handler_xpath_nodeset)
+ {
+ return eq_func(xpath->thd, oper, a, b); // two scalar arguments
+ }
+ else if (a->fixed_type_handler() == &type_handler_xpath_nodeset &&
+ b->fixed_type_handler() == &type_handler_xpath_nodeset)
+ {
+ uint len= (uint)(xpath->query.end - context->beg);
+ if (len <= 32)
+ my_printf_error(ER_UNKNOWN_ERROR,
+ "XPATH error: "
+ "comparison of two nodesets is not supported: '%.*s'",
+ MYF(0), len, context->beg);
+ else
+ my_printf_error(ER_UNKNOWN_ERROR,
+ "XPATH error: "
+ "comparison of two nodesets is not supported: '%.32T'",
+ MYF(0), context->beg);
+
+ return 0; // TODO: Comparison of two nodesets
+ }
+ else
+ {
+ /*
+ Compare a node set to a scalar value.
+ We just create a fake Item_string_xml_non_const() argument,
+ which will be filled to the partular value
+ in a loop through all of the nodes in the node set.
+ */
+
+ THD *thd= xpath->thd;
+ Item_string *fake= (new (thd->mem_root)
+ Item_string_xml_non_const(thd, "", 0, xpath->cs));
+ Item_nodeset_func *nodeset;
+ Item *scalar, *comp;
+ if (a->fixed_type_handler() == &type_handler_xpath_nodeset)
+ {
+ nodeset= (Item_nodeset_func*) a;
+ scalar= b;
+ comp= eq_func(thd, oper, (Item*)fake, scalar);
+ }
+ else
+ {
+ nodeset= (Item_nodeset_func*) b;
+ scalar= a;
+ comp= eq_func_reverse(thd, oper, fake, scalar);
+ }
+ return (new (thd->mem_root)
+ Item_nodeset_to_const_comparator(thd, nodeset, comp, xpath->pxml));
+ }
+}
+
+
+/*
+ Create a step
+
+ SYNOPSYS
+ Create a step function for the given argument and axis.
+
+ RETURN
+ The newly created item.
+*/
+static Item* nametestfunc(MY_XPATH *xpath,
+ int type, Item *arg, const char *beg, uint len)
+{
+ THD *thd= xpath->thd;
+ MEM_ROOT *mem_root= thd->mem_root;
+
+ DBUG_ASSERT(arg != 0);
+ DBUG_ASSERT(arg->fixed_type_handler() == &type_handler_xpath_nodeset);
+ DBUG_ASSERT(beg != 0);
+ DBUG_ASSERT(len > 0);
+
+ Item *res;
+ switch (type)
+ {
+ case MY_XPATH_AXIS_ANCESTOR:
+ res= new (mem_root) Item_nodeset_func_ancestorbyname(thd, arg, beg, len,
+ xpath->pxml, 0);
+ break;
+ case MY_XPATH_AXIS_ANCESTOR_OR_SELF:
+ res= new (mem_root) Item_nodeset_func_ancestorbyname(thd, arg, beg, len,
+ xpath->pxml, 1);
+ break;
+ case MY_XPATH_AXIS_PARENT:
+ res= new (mem_root) Item_nodeset_func_parentbyname(thd, arg, beg, len,
+ xpath->pxml);
+ break;
+ case MY_XPATH_AXIS_DESCENDANT:
+ res= new (mem_root) Item_nodeset_func_descendantbyname(thd, arg, beg, len,
+ xpath->pxml, 0);
+ break;
+ case MY_XPATH_AXIS_DESCENDANT_OR_SELF:
+ res= new (mem_root) Item_nodeset_func_descendantbyname(thd, arg, beg, len,
+ xpath->pxml, 1);
+ break;
+ case MY_XPATH_AXIS_ATTRIBUTE:
+ res= new (mem_root) Item_nodeset_func_attributebyname(thd, arg, beg, len,
+ xpath->pxml);
+ break;
+ case MY_XPATH_AXIS_SELF:
+ res= new (mem_root) Item_nodeset_func_selfbyname(thd, arg, beg, len,
+ xpath->pxml);
+ break;
+ default:
+ res= new (mem_root) Item_nodeset_func_childbyname(thd, arg, beg, len,
+ xpath->pxml);
+ }
+ return res;
+}
+
+
+/*
+ Tokens consisting of one character, for faster lexical analyzer.
+*/
+static char simpletok[128]=
+{
+ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+/*
+ ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ?
+ @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] ^ _
+ ` a b c d e f g h i j k l m n o p q r s t u v w x y z { | } ~ \200
+*/
+ 0,1,0,0,1,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1,0,
+ 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,0,0,
+ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0
+};
+
+
+/*
+ XPath keywords
+*/
+struct my_xpath_keyword_names_st
+{
+ int tok;
+ const char *name;
+ size_t length;
+ int extra;
+};
+
+
+static struct my_xpath_keyword_names_st my_keyword_names[] =
+{
+ {MY_XPATH_LEX_AND , "and" , 3, 0 },
+ {MY_XPATH_LEX_OR , "or" , 2, 0 },
+ {MY_XPATH_LEX_DIV , "div" , 3, 0 },
+ {MY_XPATH_LEX_MOD , "mod" , 3, 0 },
+ {0,NULL,0,0}
+};
+
+
+static struct my_xpath_keyword_names_st my_axis_names[]=
+{
+ {MY_XPATH_LEX_AXIS,"ancestor" , 8,MY_XPATH_AXIS_ANCESTOR },
+ {MY_XPATH_LEX_AXIS,"ancestor-or-self" ,16,MY_XPATH_AXIS_ANCESTOR_OR_SELF },
+ {MY_XPATH_LEX_AXIS,"attribute" , 9,MY_XPATH_AXIS_ATTRIBUTE },
+ {MY_XPATH_LEX_AXIS,"child" , 5,MY_XPATH_AXIS_CHILD },
+ {MY_XPATH_LEX_AXIS,"descendant" ,10,MY_XPATH_AXIS_DESCENDANT },
+ {MY_XPATH_LEX_AXIS,"descendant-or-self",18,MY_XPATH_AXIS_DESCENDANT_OR_SELF},
+ {MY_XPATH_LEX_AXIS,"following" , 9,MY_XPATH_AXIS_FOLLOWING },
+ {MY_XPATH_LEX_AXIS,"following-sibling" ,17,MY_XPATH_AXIS_FOLLOWING_SIBLING },
+ {MY_XPATH_LEX_AXIS,"namespace" , 9,MY_XPATH_AXIS_NAMESPACE },
+ {MY_XPATH_LEX_AXIS,"parent" , 6,MY_XPATH_AXIS_PARENT },
+ {MY_XPATH_LEX_AXIS,"preceding" , 9,MY_XPATH_AXIS_PRECEDING },
+ {MY_XPATH_LEX_AXIS,"preceding-sibling" ,17,MY_XPATH_AXIS_PRECEDING_SIBLING },
+ {MY_XPATH_LEX_AXIS,"self" , 4,MY_XPATH_AXIS_SELF },
+ {0,NULL,0,0}
+};
+
+
+static struct my_xpath_keyword_names_st my_nodetype_names[]=
+{
+ {MY_XPATH_LEX_NODETYPE, "comment" , 7, 0 },
+ {MY_XPATH_LEX_NODETYPE, "text" , 4, 0 },
+ {MY_XPATH_LEX_NODETYPE, "processing-instruction" , 22,0 },
+ {MY_XPATH_LEX_NODETYPE, "node" , 4, 0 },
+ {0,NULL,0,0}
+};
+
+
+/*
+ Lookup a keyword
+
+ SYNOPSYS
+ Check that the last scanned identifier is a keyword.
+
+ RETURN
+ - Token type, on lookup success.
+ - MY_XPATH_LEX_IDENT, on lookup failure.
+*/
+static int
+my_xpath_keyword(MY_XPATH *x,
+ struct my_xpath_keyword_names_st *keyword_names,
+ const char *beg, const char *end)
+{
+ struct my_xpath_keyword_names_st *k;
+ size_t length= end-beg;
+ for (k= keyword_names; k->name; k++)
+ {
+ if (length == k->length && !strncasecmp(beg, k->name, length))
+ {
+ x->extra= k->extra;
+ return k->tok;
+ }
+ }
+ return MY_XPATH_LEX_IDENT;
+}
+
+
+/*
+ Functions to create an item, a-la those in item_create.cc
+*/
+
+static Item *create_func_true(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return (Item*) Item_true;
+}
+
+
+static Item *create_func_false(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return (Item*) Item_false;
+}
+
+
+static Item *create_func_not(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return new (xpath->thd->mem_root)
+ Item_func_not(xpath->thd, nodeset2bool(xpath, args[0]));
+}
+
+
+static Item *create_func_ceiling(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return new (xpath->thd->mem_root) Item_func_ceiling(xpath->thd, args[0]);
+}
+
+
+static Item *create_func_floor(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return new (xpath->thd->mem_root) Item_func_floor(xpath->thd, args[0]);
+}
+
+
+static Item *create_func_bool(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return new (xpath->thd->mem_root)
+ Item_xpath_cast_bool(xpath->thd, args[0], xpath->pxml);
+}
+
+
+static Item *create_func_number(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return new (xpath->thd->mem_root)
+ Item_xpath_cast_number(xpath->thd, args[0]);
+}
+
+
+static Item *create_func_string_length(MY_XPATH *xpath, Item **args,
+ uint nargs)
+{
+ Item *arg= nargs ? args[0] : xpath->context;
+ return arg ? new (xpath->thd->mem_root)
+ Item_func_char_length(xpath->thd, arg) : 0;
+}
+
+
+static Item *create_func_round(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return new (xpath->thd->mem_root)
+ Item_func_round(xpath->thd, args[0],
+ new (xpath->thd->mem_root)
+ Item_int(xpath->thd, (char *) "0", 0, 1), 0);
+}
+
+
+static Item *create_func_last(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return (xpath->context ?
+ new (xpath->thd->mem_root)
+ Item_func_xpath_count(xpath->thd, xpath->context, xpath->pxml) :
+ NULL);
+}
+
+
+static Item *create_func_position(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return (xpath->context ?
+ new (xpath->thd->mem_root)
+ Item_func_xpath_position(xpath->thd, xpath->context, xpath->pxml) :
+ NULL);
+}
+
+
+static Item *create_func_contains(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return (new (xpath->thd->mem_root)
+ Item_xpath_cast_bool(xpath->thd,
+ new (xpath->thd->mem_root)
+ Item_func_locate(xpath->thd, args[0], args[1]),
+ xpath->pxml));
+}
+
+
+static Item *create_func_concat(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ return new (xpath->thd->mem_root)
+ Item_func_concat(xpath->thd, args[0], args[1]);
+}
+
+
+static Item *create_func_substr(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ THD *thd= xpath->thd;
+ if (nargs == 2)
+ return new (thd->mem_root) Item_func_substr(thd, args[0], args[1]);
+ return new (thd->mem_root) Item_func_substr(thd, args[0], args[1], args[2]);
+}
+
+
+static Item *create_func_count(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ if (args[0]->fixed_type_handler() != &type_handler_xpath_nodeset)
+ return 0;
+ return new (xpath->thd->mem_root) Item_func_xpath_count(xpath->thd, args[0], xpath->pxml);
+}
+
+
+static Item *create_func_sum(MY_XPATH *xpath, Item **args, uint nargs)
+{
+ if (args[0]->fixed_type_handler() != &type_handler_xpath_nodeset)
+ return 0;
+ return new (xpath->thd->mem_root)
+ Item_func_xpath_sum(xpath->thd, args[0], xpath->pxml);
+}
+
+
+/*
+ Functions names. Separate lists for names with
+ lengths 3,4,5 and 6 for faster lookups.
+*/
+static MY_XPATH_FUNC my_func_names3[]=
+{
+ {"sum", 3, 1 , 1 , create_func_sum},
+ {"not", 3, 1 , 1 , create_func_not},
+ {0 , 0, 0 , 0, 0}
+};
+
+
+static MY_XPATH_FUNC my_func_names4[]=
+{
+ {"last", 4, 0, 0, create_func_last},
+ {"true", 4, 0, 0, create_func_true},
+ {"name", 4, 0, 1, 0},
+ {"lang", 4, 1, 1, 0},
+ {0 , 0, 0, 0, 0}
+};
+
+
+static MY_XPATH_FUNC my_func_names5[]=
+{
+ {"count", 5, 1, 1, create_func_count},
+ {"false", 5, 0, 0, create_func_false},
+ {"floor", 5, 1, 1, create_func_floor},
+ {"round", 5, 1, 1, create_func_round},
+ {0 , 0, 0, 0, 0}
+};
+
+
+static MY_XPATH_FUNC my_func_names6[]=
+{
+ {"concat", 6, 2, 255, create_func_concat},
+ {"number", 6, 0, 1 , create_func_number},
+ {"string", 6, 0, 1 , 0},
+ {0 , 0, 0, 0 , 0}
+};
+
+
+/* Other functions, with name longer than 6, all together */
+static MY_XPATH_FUNC my_func_names[] =
+{
+ {"id" , 2 , 1 , 1 , 0},
+ {"boolean" , 7 , 1 , 1 , create_func_bool},
+ {"ceiling" , 7 , 1 , 1 , create_func_ceiling},
+ {"position" , 8 , 0 , 0 , create_func_position},
+ {"contains" , 8 , 2 , 2 , create_func_contains},
+ {"substring" , 9 , 2 , 3 , create_func_substr},
+ {"translate" , 9 , 3 , 3 , 0},
+
+ {"local-name" , 10 , 0 , 1 , 0},
+ {"starts-with" , 11 , 2 , 2 , 0},
+ {"namespace-uri" , 13 , 0 , 1 , 0},
+ {"string-length" , 13 , 0 , 1 , create_func_string_length},
+ {"substring-after" , 15 , 2 , 2 , 0},
+ {"normalize-space" , 15 , 0 , 1 , 0},
+ {"substring-before" , 16 , 2 , 2 , 0},
+
+ {NULL,0,0,0,0}
+};
+
+
+/*
+ Lookup a function by name
+
+ SYNOPSYS
+ Lookup a function by its name.
+
+ RETURN
+ Pointer to a MY_XPATH_FUNC variable on success.
+ 0 - on failure.
+
+*/
+MY_XPATH_FUNC *
+my_xpath_function(const char *beg, const char *end)
+{
+ MY_XPATH_FUNC *k, *function_names;
+ uint length= (uint)(end-beg);
+ switch (length)
+ {
+ case 1: return 0;
+ case 3: function_names= my_func_names3; break;
+ case 4: function_names= my_func_names4; break;
+ case 5: function_names= my_func_names5; break;
+ case 6: function_names= my_func_names6; break;
+ default: function_names= my_func_names;
+ }
+ for (k= function_names; k->name; k++)
+ if (k->create && length == k->length && !strncasecmp(beg, k->name, length))
+ return k;
+ return NULL;
+}
+
+
+/* Initialize a lex analyzer token */
+static void
+my_xpath_lex_init(MY_XPATH_LEX *lex,
+ const char *str, const char *strend)
+{
+ lex->beg= str;
+ lex->end= strend;
+}
+
+
+/* Initialize an XPath query parser */
+static void
+my_xpath_init(MY_XPATH *xpath)
+{
+ bzero((void*)xpath, sizeof(xpath[0]));
+}
+
+
+static int
+my_xdigit(int c)
+{
+ return ((c) >= '0' && (c) <= '9');
+}
+
+
+/*
+ Scan the next token
+
+ SYNOPSYS
+ Scan the next token from the input.
+ lex->term is set to the scanned token type.
+ lex->beg and lex->end are set to the beginning
+ and to the end of the token.
+ RETURN
+ N/A
+*/
+static void
+my_xpath_lex_scan(MY_XPATH *xpath,
+ MY_XPATH_LEX *lex, const char *beg, const char *end)
+{
+ int ch, ctype, length;
+ for ( ; beg < end && *beg == ' ' ; beg++) ; // skip leading spaces
+ lex->beg= beg;
+
+ if (beg >= end)
+ {
+ lex->end= beg;
+ lex->term= MY_XPATH_LEX_EOF; // end of line reached
+ return;
+ }
+
+ // Check ident, or a function call, or a keyword
+ if ((length= xpath->cs->ctype(&ctype,
+ (const uchar*) beg,
+ (const uchar*) end)) > 0 &&
+ ((ctype & (_MY_L | _MY_U)) || *beg == '_'))
+ {
+ // scan until the end of the identifier
+ for (beg+= length;
+ (length= xpath->cs->ctype(&ctype,
+ (const uchar*) beg,
+ (const uchar*) end)) > 0 &&
+ ((ctype & (_MY_L | _MY_U | _MY_NMR)) ||
+ *beg == '_' || *beg == '-' || *beg == '.') ;
+ beg+= length) /* no op */;
+ lex->end= beg;
+
+ if (beg < end)
+ {
+ if (*beg == '(')
+ {
+ /*
+ check if a function call, e.g.: count(/a/b)
+ or a nodetype test, e.g.: /a/b/text()
+ */
+ if ((xpath->func= my_xpath_function(lex->beg, beg)))
+ lex->term= MY_XPATH_LEX_FUNC;
+ else
+ lex->term= my_xpath_keyword(xpath, my_nodetype_names,
+ lex->beg, beg);
+ return;
+ }
+ // check if an axis specifier, e.g.: /a/b/child::*
+ else if (*beg == ':' && beg + 1 < end && beg[1] == ':')
+ {
+ lex->term= my_xpath_keyword(xpath, my_axis_names,
+ lex->beg, beg);
+ return;
+ }
+ }
+ // check if a keyword
+ lex->term= my_xpath_keyword(xpath, my_keyword_names,
+ lex->beg, beg);
+ return;
+ }
+
+
+ ch= *beg++;
+
+ if (ch > 0 && ch < 128 && simpletok[ch])
+ {
+ // a token consisting of one character found
+ lex->end= beg;
+ lex->term= ch;
+ return;
+ }
+
+
+ if (my_xdigit(ch)) // a sequence of digits
+ {
+ for ( ; beg < end && my_xdigit(*beg) ; beg++) ;
+ lex->end= beg;
+ lex->term= MY_XPATH_LEX_DIGITS;
+ return;
+ }
+
+ if (ch == '"' || ch == '\'') // a string: either '...' or "..."
+ {
+ for ( ; beg < end && *beg != ch ; beg++) ;
+ if (beg < end)
+ {
+ lex->end= beg+1;
+ lex->term= MY_XPATH_LEX_STRING;
+ return;
+ }
+ else
+ {
+ // unexpected end-of-line, without closing quot sign
+ lex->end= end;
+ lex->term= MY_XPATH_LEX_ERROR;
+ return;
+ }
+ }
+
+ lex->end= beg;
+ lex->term= MY_XPATH_LEX_ERROR; // unknown character
+ return;
+}
+
+
+/*
+ Scan the given token
+
+ SYNOPSYS
+ Scan the given token and rotate lasttok to prevtok on success.
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int
+my_xpath_parse_term(MY_XPATH *xpath, int term)
+{
+ if (xpath->lasttok.term == term && !xpath->error)
+ {
+ xpath->prevtok= xpath->lasttok;
+ my_xpath_lex_scan(xpath, &xpath->lasttok,
+ xpath->lasttok.end, xpath->query.end);
+ return 1;
+ }
+ return 0;
+}
+
+
+/*
+ Scan AxisName
+
+ SYNOPSYS
+ Scan an axis name and store the scanned axis type into xpath->axis.
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_AxisName(MY_XPATH *xpath)
+{
+ int rc= my_xpath_parse_term(xpath, MY_XPATH_LEX_AXIS);
+ xpath->axis= xpath->extra;
+ return rc;
+}
+
+
+/*********************************************
+** Grammar rules, according to http://www.w3.org/TR/xpath
+** Implemented using recursive descendant method.
+** All the following grammar processing functions accept
+** a single "xpath" argument and return 1 on success and 0 on error.
+** They also modify "xpath" argument by creating new items.
+*/
+
+/* [9] PredicateExpr ::= Expr */
+#define my_xpath_parse_PredicateExpr(x) my_xpath_parse_Expr((x))
+
+/* [14] Expr ::= OrExpr */
+#define my_xpath_parse_Expr(x) my_xpath_parse_OrExpr((x))
+
+static int my_xpath_parse_LocationPath(MY_XPATH *xpath);
+static int my_xpath_parse_AbsoluteLocationPath(MY_XPATH *xpath);
+static int my_xpath_parse_RelativeLocationPath(MY_XPATH *xpath);
+static int my_xpath_parse_AbbreviatedStep(MY_XPATH *xpath);
+static int my_xpath_parse_Step(MY_XPATH *xpath);
+static int my_xpath_parse_AxisSpecifier(MY_XPATH *xpath);
+static int my_xpath_parse_NodeTest(MY_XPATH *xpath);
+static int my_xpath_parse_AbbreviatedAxisSpecifier(MY_XPATH *xpath);
+static int my_xpath_parse_NameTest(MY_XPATH *xpath);
+static int my_xpath_parse_FunctionCall(MY_XPATH *xpath);
+static int my_xpath_parse_Number(MY_XPATH *xpath);
+static int my_xpath_parse_FilterExpr(MY_XPATH *xpath);
+static int my_xpath_parse_PathExpr(MY_XPATH *xpath);
+static int my_xpath_parse_OrExpr(MY_XPATH *xpath);
+static int my_xpath_parse_UnaryExpr(MY_XPATH *xpath);
+static int my_xpath_parse_MultiplicativeExpr(MY_XPATH *xpath);
+static int my_xpath_parse_AdditiveExpr(MY_XPATH *xpath);
+static int my_xpath_parse_RelationalExpr(MY_XPATH *xpath);
+static int my_xpath_parse_AndExpr(MY_XPATH *xpath);
+static int my_xpath_parse_EqualityExpr(MY_XPATH *xpath);
+static int my_xpath_parse_VariableReference(MY_XPATH *xpath);
+
+
+/*
+ Scan LocationPath
+
+ SYNOPSYS
+
+ [1] LocationPath ::= RelativeLocationPath
+ | AbsoluteLocationPath
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_LocationPath(MY_XPATH *xpath)
+{
+ Item *context= xpath->context;
+
+ if (!xpath->context)
+ xpath->context= xpath->rootelement;
+ int rc= my_xpath_parse_RelativeLocationPath(xpath) ||
+ my_xpath_parse_AbsoluteLocationPath(xpath);
+
+ xpath->item= xpath->context;
+ xpath->context= context;
+ return rc;
+}
+
+
+/*
+ Scan Absolute Location Path
+
+ SYNOPSYS
+
+ [2] AbsoluteLocationPath ::= '/' RelativeLocationPath?
+ | AbbreviatedAbsoluteLocationPath
+ [10] AbbreviatedAbsoluteLocationPath ::= '//' RelativeLocationPath
+
+ We combine these two rules into one rule for better performance:
+
+ [2,10] AbsoluteLocationPath ::= '/' RelativeLocationPath?
+ | '//' RelativeLocationPath
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_AbsoluteLocationPath(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_SLASH))
+ return 0;
+
+ xpath->context= xpath->rootelement;
+
+ if (my_xpath_parse_term(xpath, MY_XPATH_LEX_SLASH))
+ {
+ xpath->context= new (xpath->thd->mem_root)
+ Item_nodeset_func_descendantbyname(xpath->thd,
+ xpath->context,
+ "*", 1,
+ xpath->pxml, 1);
+ return my_xpath_parse_RelativeLocationPath(xpath);
+ }
+
+ my_xpath_parse_RelativeLocationPath(xpath);
+
+ return (xpath->error == 0);
+}
+
+
+/*
+ Scan Relative Location Path
+
+ SYNOPSYS
+
+ For better performance we combine these two rules
+
+ [3] RelativeLocationPath ::= Step
+ | RelativeLocationPath '/' Step
+ | AbbreviatedRelativeLocationPath
+ [11] AbbreviatedRelativeLocationPath ::= RelativeLocationPath '//' Step
+
+
+ Into this one:
+
+ [3-11] RelativeLocationPath ::= Step
+ | RelativeLocationPath '/' Step
+ | RelativeLocationPath '//' Step
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_RelativeLocationPath(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_Step(xpath))
+ return 0;
+ while (my_xpath_parse_term(xpath, MY_XPATH_LEX_SLASH))
+ {
+ if (my_xpath_parse_term(xpath, MY_XPATH_LEX_SLASH))
+ xpath->context= new (xpath->thd->mem_root)
+ Item_nodeset_func_descendantbyname(xpath->thd,
+ xpath->context,
+ "*", 1,
+ xpath->pxml, 1);
+ if (!my_xpath_parse_Step(xpath))
+ {
+ xpath->error= 1;
+ return 0;
+ }
+ }
+ return 1;
+}
+
+
+/*
+ Scan non-abbreviated or abbreviated Step
+
+ SYNOPSYS
+
+ [4] Step ::= AxisSpecifier NodeTest Predicate*
+ | AbbreviatedStep
+ [8] Predicate ::= '[' PredicateExpr ']'
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int
+my_xpath_parse_AxisSpecifier_NodeTest_opt_Predicate_list(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_AxisSpecifier(xpath))
+ return 0;
+
+ if (!my_xpath_parse_NodeTest(xpath))
+ return 0;
+
+ while (my_xpath_parse_term(xpath, MY_XPATH_LEX_LB))
+ {
+ Item *prev_context= xpath->context;
+ Native *context_cache;
+ context_cache= &((Item_nodeset_func*)xpath->context)->context_cache;
+ xpath->context= new (xpath->thd->mem_root)
+ Item_nodeset_context_cache(xpath->thd, context_cache, xpath->pxml);
+ xpath->context_cache= context_cache;
+
+ if(!my_xpath_parse_PredicateExpr(xpath))
+ {
+ xpath->error= 1;
+ return 0;
+ }
+
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_RB))
+ {
+ xpath->error= 1;
+ return 0;
+ }
+
+ xpath->item= nodeset2bool(xpath, xpath->item);
+
+ const Type_handler *fh;
+ if ((fh= xpath->item->fixed_type_handler()) && fh->is_bool_type())
+ {
+ xpath->context= new (xpath->thd->mem_root)
+ Item_nodeset_func_predicate(xpath->thd, prev_context,
+ xpath->item,
+ xpath->pxml);
+ }
+ else
+ {
+ xpath->context= new (xpath->thd->mem_root)
+ Item_nodeset_func_elementbyindex(xpath->thd,
+ prev_context,
+ xpath->item,
+ xpath->pxml);
+ }
+ }
+ return 1;
+}
+
+
+static int my_xpath_parse_Step(MY_XPATH *xpath)
+{
+ return
+ my_xpath_parse_AxisSpecifier_NodeTest_opt_Predicate_list(xpath) ||
+ my_xpath_parse_AbbreviatedStep(xpath);
+}
+
+
+/*
+ Scan Abbreviated Axis Specifier
+
+ SYNOPSYS
+ [5] AxisSpecifier ::= AxisName '::'
+ | AbbreviatedAxisSpecifier
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_AbbreviatedAxisSpecifier(MY_XPATH *xpath)
+{
+ if (my_xpath_parse_term(xpath, MY_XPATH_LEX_AT))
+ xpath->axis= MY_XPATH_AXIS_ATTRIBUTE;
+ else
+ xpath->axis= MY_XPATH_AXIS_CHILD;
+ return 1;
+}
+
+
+/*
+ Scan non-abbreviated axis specifier
+
+ SYNOPSYS
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_AxisName_colon_colon(MY_XPATH *xpath)
+{
+ return my_xpath_parse_AxisName(xpath) &&
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_COLON) &&
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_COLON);
+}
+
+
+/*
+ Scan Abbreviated AxisSpecifier
+
+ SYNOPSYS
+ [13] AbbreviatedAxisSpecifier ::= '@'?
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_AxisSpecifier(MY_XPATH *xpath)
+{
+ return my_xpath_parse_AxisName_colon_colon(xpath) ||
+ my_xpath_parse_AbbreviatedAxisSpecifier(xpath);
+}
+
+
+/*
+ Scan NodeType followed by parens
+
+ SYNOPSYS
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_NodeTest_lp_rp(MY_XPATH *xpath)
+{
+ return my_xpath_parse_term(xpath, MY_XPATH_LEX_NODETYPE) &&
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_LP) &&
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_RP);
+}
+
+
+/*
+ Scan NodeTest
+
+ SYNOPSYS
+
+ [7] NodeTest ::= NameTest
+ | NodeType '(' ')'
+ | 'processing-instruction' '(' Literal ')'
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_NodeTest(MY_XPATH *xpath)
+{
+ return my_xpath_parse_NameTest(xpath) ||
+ my_xpath_parse_NodeTest_lp_rp(xpath);
+}
+
+
+/*
+ Scan Abbreviated Step
+
+ SYNOPSYS
+
+ [12] AbbreviatedStep ::= '.' | '..'
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_AbbreviatedStep(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_DOT))
+ return 0;
+ if (my_xpath_parse_term(xpath, MY_XPATH_LEX_DOT))
+ xpath->context= new (xpath->thd->mem_root)
+ Item_nodeset_func_parentbyname(xpath->thd,
+ xpath->context, "*",
+ 1, xpath->pxml);
+ return 1;
+}
+
+
+/*
+ Scan Primary Expression
+
+ SYNOPSYS
+
+ [15] PrimaryExpr ::= VariableReference
+ | '(' Expr ')'
+ | Literal
+ | Number
+ | FunctionCall
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_lp_Expr_rp(MY_XPATH *xpath)
+{
+ return my_xpath_parse_term(xpath, MY_XPATH_LEX_LP) &&
+ my_xpath_parse_Expr(xpath) &&
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_RP);
+}
+static int my_xpath_parse_PrimaryExpr_literal(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_STRING))
+ return 0;
+ xpath->item= new (xpath->thd->mem_root)
+ Item_string(xpath->thd, xpath->prevtok.beg + 1,
+ (uint)(xpath->prevtok.end - xpath->prevtok.beg - 2),
+ xpath->cs);
+ return 1;
+}
+static int my_xpath_parse_PrimaryExpr(MY_XPATH *xpath)
+{
+ return
+ my_xpath_parse_lp_Expr_rp(xpath) ||
+ my_xpath_parse_VariableReference(xpath) ||
+ my_xpath_parse_PrimaryExpr_literal(xpath) ||
+ my_xpath_parse_Number(xpath) ||
+ my_xpath_parse_FunctionCall(xpath);
+}
+
+
+/*
+ Scan Function Call
+
+ SYNOPSYS
+ [16] FunctionCall ::= FunctionName '(' ( Argument ( ',' Argument )* )? ')'
+ [17] Argument ::= Expr
+
+ RETURN
+ 1 - success
+ 0 - failure
+
+*/
+static int my_xpath_parse_FunctionCall(MY_XPATH *xpath)
+{
+ Item *args[256];
+ uint nargs;
+
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_FUNC))
+ return 0;
+
+ MY_XPATH_FUNC *func= xpath->func;
+
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_LP))
+ return 0;
+
+ for (nargs= 0 ; nargs < func->maxargs; )
+ {
+ if (!my_xpath_parse_Expr(xpath))
+ {
+ if (nargs < func->minargs)
+ return 0;
+ goto right_paren;
+ }
+ args[nargs++]= xpath->item;
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_COMMA))
+ {
+ if (nargs < func->minargs)
+ return 0;
+ else
+ break;
+ }
+ }
+
+right_paren:
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_RP))
+ return 0;
+
+ return ((xpath->item= func->create(xpath, args, nargs))) ? 1 : 0;
+}
+
+
+/*
+ Scan Union Expression
+
+ SYNOPSYS
+ [18] UnionExpr ::= PathExpr
+ | UnionExpr '|' PathExpr
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_UnionExpr(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_PathExpr(xpath))
+ return 0;
+
+ while (my_xpath_parse_term(xpath, MY_XPATH_LEX_VLINE))
+ {
+ Item *prev= xpath->item;
+ if (prev->fixed_type_handler() != &type_handler_xpath_nodeset)
+ return 0;
+
+ if (!my_xpath_parse_PathExpr(xpath)
+ || xpath->item->fixed_type_handler() != &type_handler_xpath_nodeset)
+ {
+ xpath->error= 1;
+ return 0;
+ }
+ xpath->item= new (xpath->thd->mem_root)
+ Item_nodeset_func_union(xpath->thd, prev, xpath->item,
+ xpath->pxml);
+ }
+ return 1;
+}
+
+
+/*
+ Scan Path Expression
+
+ SYNOPSYS
+
+ [19] PathExpr ::= LocationPath
+ | FilterExpr
+ | FilterExpr '/' RelativeLocationPath
+ | FilterExpr '//' RelativeLocationPath
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int
+my_xpath_parse_FilterExpr_opt_slashes_RelativeLocationPath(MY_XPATH *xpath)
+{
+ Item *context= xpath->context;
+ int rc;
+
+ if (!my_xpath_parse_FilterExpr(xpath))
+ return 0;
+
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_SLASH))
+ return 1;
+
+ if (xpath->item->fixed_type_handler() != &type_handler_xpath_nodeset)
+ {
+ xpath->lasttok= xpath->prevtok;
+ xpath->error= 1;
+ return 0;
+ }
+
+ /*
+ The context for the next relative path is the nodeset
+ returned by FilterExpr
+ */
+ xpath->context= xpath->item;
+
+ /* treat double slash (//) as /descendant-or-self::node()/ */
+ if (my_xpath_parse_term(xpath, MY_XPATH_LEX_SLASH))
+ xpath->context= new (xpath->thd->mem_root)
+ Item_nodeset_func_descendantbyname(xpath->thd,
+ xpath->context,
+ "*", 1,
+ xpath->pxml, 1);
+ rc= my_xpath_parse_RelativeLocationPath(xpath);
+
+ /* push back the context and restore the item */
+ xpath->item= xpath->context;
+ xpath->context= context;
+ return rc;
+}
+static int my_xpath_parse_PathExpr(MY_XPATH *xpath)
+{
+ return my_xpath_parse_LocationPath(xpath) ||
+ my_xpath_parse_FilterExpr_opt_slashes_RelativeLocationPath(xpath);
+}
+
+
+
+/*
+ Scan Filter Expression
+
+ SYNOPSYS
+ [20] FilterExpr ::= PrimaryExpr
+ | FilterExpr Predicate
+
+ or in other words:
+
+ [20] FilterExpr ::= PrimaryExpr Predicate*
+
+ RETURN
+ 1 - success
+ 0 - failure
+
+*/
+static int my_xpath_parse_FilterExpr(MY_XPATH *xpath)
+{
+ return my_xpath_parse_PrimaryExpr(xpath);
+}
+
+
+/*
+ Scan Or Expression
+
+ SYNOPSYS
+ [21] OrExpr ::= AndExpr
+ | OrExpr 'or' AndExpr
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_OrExpr(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_AndExpr(xpath))
+ return 0;
+
+ while (my_xpath_parse_term(xpath, MY_XPATH_LEX_OR))
+ {
+ Item *prev= xpath->item;
+ if (!my_xpath_parse_AndExpr(xpath))
+ {
+ xpath->error= 1;
+ return 0;
+ }
+ xpath->item= new (xpath->thd->mem_root)
+ Item_cond_or(xpath->thd, nodeset2bool(xpath, prev),
+ nodeset2bool(xpath, xpath->item));
+ }
+ return 1;
+}
+
+
+/*
+ Scan And Expression
+
+ SYNOPSYS
+ [22] AndExpr ::= EqualityExpr
+ | AndExpr 'and' EqualityExpr
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_AndExpr(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_EqualityExpr(xpath))
+ return 0;
+
+ while (my_xpath_parse_term(xpath, MY_XPATH_LEX_AND))
+ {
+ Item *prev= xpath->item;
+ if (!my_xpath_parse_EqualityExpr(xpath))
+ {
+ xpath->error= 1;
+ return 0;
+ }
+
+ xpath->item= new (xpath->thd->mem_root)
+ Item_cond_and(xpath->thd, nodeset2bool(xpath, prev),
+ nodeset2bool(xpath, xpath->item));
+ }
+ return 1;
+}
+
+
+/*
+ Scan Equality Expression
+
+ SYNOPSYS
+ [23] EqualityExpr ::= RelationalExpr
+ | EqualityExpr '=' RelationalExpr
+ | EqualityExpr '!=' RelationalExpr
+ or in other words:
+
+ [23] EqualityExpr ::= RelationalExpr ( EqualityOperator EqualityExpr )*
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_ne(MY_XPATH *xpath)
+{
+ MY_XPATH_LEX prevtok= xpath->prevtok;
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_EXCL))
+ return 0;
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_EQ))
+ {
+ /* Unget the exclamation mark */
+ xpath->lasttok= xpath->prevtok;
+ xpath->prevtok= prevtok;
+ return 0;
+ }
+ return 1;
+}
+static int my_xpath_parse_EqualityOperator(MY_XPATH *xpath)
+{
+ if (my_xpath_parse_ne(xpath))
+ {
+ xpath->extra= '!';
+ return 1;
+ }
+ if (my_xpath_parse_term(xpath, MY_XPATH_LEX_EQ))
+ {
+ xpath->extra= '=';
+ return 1;
+ }
+ return 0;
+}
+static int my_xpath_parse_EqualityExpr(MY_XPATH *xpath)
+{
+ MY_XPATH_LEX operator_context;
+ if (!my_xpath_parse_RelationalExpr(xpath))
+ return 0;
+
+ operator_context= xpath->lasttok;
+ while (my_xpath_parse_EqualityOperator(xpath))
+ {
+ Item *prev= xpath->item;
+ int oper= xpath->extra;
+ if (!my_xpath_parse_RelationalExpr(xpath))
+ {
+ xpath->error= 1;
+ return 0;
+ }
+
+ if (!(xpath->item= create_comparator(xpath, oper, &operator_context,
+ prev, xpath->item)))
+ return 0;
+
+ operator_context= xpath->lasttok;
+ }
+ return 1;
+}
+
+
+/*
+ Scan Relational Expression
+
+ SYNOPSYS
+
+ [24] RelationalExpr ::= AdditiveExpr
+ | RelationalExpr '<' AdditiveExpr
+ | RelationalExpr '>' AdditiveExpr
+ | RelationalExpr '<=' AdditiveExpr
+ | RelationalExpr '>=' AdditiveExpr
+ or in other words:
+
+ [24] RelationalExpr ::= AdditiveExpr (RelationalOperator RelationalExpr)*
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_RelationalOperator(MY_XPATH *xpath)
+{
+ if (my_xpath_parse_term(xpath, MY_XPATH_LEX_LESS))
+ {
+ xpath->extra= my_xpath_parse_term(xpath, MY_XPATH_LEX_EQ) ?
+ MY_XPATH_LEX_LE : MY_XPATH_LEX_LESS;
+ return 1;
+ }
+ else if (my_xpath_parse_term(xpath, MY_XPATH_LEX_GREATER))
+ {
+ xpath->extra= my_xpath_parse_term(xpath, MY_XPATH_LEX_EQ) ?
+ MY_XPATH_LEX_GE : MY_XPATH_LEX_GREATER;
+ return 1;
+ }
+ return 0;
+}
+static int my_xpath_parse_RelationalExpr(MY_XPATH *xpath)
+{
+ MY_XPATH_LEX operator_context;
+ if (!my_xpath_parse_AdditiveExpr(xpath))
+ return 0;
+ operator_context= xpath->lasttok;
+ while (my_xpath_parse_RelationalOperator(xpath))
+ {
+ Item *prev= xpath->item;
+ int oper= xpath->extra;
+
+ if (!my_xpath_parse_AdditiveExpr(xpath))
+ {
+ xpath->error= 1;
+ return 0;
+ }
+
+ if (!(xpath->item= create_comparator(xpath, oper, &operator_context,
+ prev, xpath->item)))
+ return 0;
+ operator_context= xpath->lasttok;
+ }
+ return 1;
+}
+
+
+/*
+ Scan Additive Expression
+
+ SYNOPSYS
+
+ [25] AdditiveExpr ::= MultiplicativeExpr
+ | AdditiveExpr '+' MultiplicativeExpr
+ | AdditiveExpr '-' MultiplicativeExpr
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_AdditiveOperator(MY_XPATH *xpath)
+{
+ return my_xpath_parse_term(xpath, MY_XPATH_LEX_PLUS) ||
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_MINUS);
+}
+static int my_xpath_parse_AdditiveExpr(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_MultiplicativeExpr(xpath))
+ return 0;
+
+ while (my_xpath_parse_AdditiveOperator(xpath))
+ {
+ int oper= xpath->prevtok.term;
+ Item *prev= xpath->item;
+ THD *thd= xpath->thd;
+
+ if (!my_xpath_parse_MultiplicativeExpr(xpath))
+ {
+ xpath->error= 1;
+ return 0;
+ }
+
+ if (oper == MY_XPATH_LEX_PLUS)
+ xpath->item= new (thd->mem_root)
+ Item_func_plus(thd, prev, xpath->item);
+ else
+ xpath->item= new (thd->mem_root)
+ Item_func_minus(thd, prev, xpath->item);
+ };
+ return 1;
+}
+
+
+/*
+ Scan Multiplicative Expression
+
+ SYNOPSYS
+
+ [26] MultiplicativeExpr ::= UnaryExpr
+ | MultiplicativeExpr MultiplyOperator UnaryExpr
+ | MultiplicativeExpr 'div' UnaryExpr
+ | MultiplicativeExpr 'mod' UnaryExpr
+ or in other words:
+
+ [26] MultiplicativeExpr ::= UnaryExpr (MulOper MultiplicativeExpr)*
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_MultiplicativeOperator(MY_XPATH *xpath)
+{
+ return
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_ASTERISK) ||
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_DIV) ||
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_MOD);
+}
+static int my_xpath_parse_MultiplicativeExpr(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_UnaryExpr(xpath))
+ return 0;
+
+ THD *thd= xpath->thd;
+ while (my_xpath_parse_MultiplicativeOperator(xpath))
+ {
+ int oper= xpath->prevtok.term;
+ Item *prev= xpath->item;
+ if (!my_xpath_parse_UnaryExpr(xpath))
+ {
+ xpath->error= 1;
+ return 0;
+ }
+ switch (oper)
+ {
+ case MY_XPATH_LEX_ASTERISK:
+ xpath->item= new (thd->mem_root) Item_func_mul(thd, prev, xpath->item);
+ break;
+ case MY_XPATH_LEX_DIV:
+ xpath->item= new (thd->mem_root) Item_func_int_div(thd, prev, xpath->item);
+ break;
+ case MY_XPATH_LEX_MOD:
+ xpath->item= new (thd->mem_root) Item_func_mod(thd, prev, xpath->item);
+ break;
+ }
+ }
+ return 1;
+}
+
+
+/*
+ Scan Unary Expression
+
+ SYNOPSYS
+
+ [27] UnaryExpr ::= UnionExpr
+ | '-' UnaryExpr
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_UnaryExpr(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_MINUS))
+ return my_xpath_parse_UnionExpr(xpath);
+ if (!my_xpath_parse_UnaryExpr(xpath))
+ return 0;
+ xpath->item= new (xpath->thd->mem_root)
+ Item_func_neg(xpath->thd, xpath->item);
+ return 1;
+}
+
+
+/**
+ A helper class to make a null-terminated string from XPath fragments.
+ The string is allocated on the THD memory root.
+*/
+class XPath_cstring_null_terminated: public LEX_CSTRING
+{
+public:
+ XPath_cstring_null_terminated(THD *thd, const char *str, size_t length)
+ {
+ if (thd->make_lex_string(this, str, length))
+ static_cast<LEX_CSTRING>(*this)= empty_clex_str;
+ }
+};
+
+
+/*
+ Scan Number
+
+ SYNOPSYS
+
+ [30] Number ::= Digits ('.' Digits?)? | '.' Digits)
+
+ or in other words:
+
+ [30] Number ::= Digits
+ | Digits '.'
+ | Digits '.' Digits
+ | '.' Digits
+
+ Note: the last rule is not supported yet,
+ as it is in conflict with abbreviated step.
+ 1 + .123 does not work,
+ 1 + 0.123 does.
+ Perhaps it is better to move this code into lex analyzer.
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int my_xpath_parse_Number(MY_XPATH *xpath)
+{
+ const char *beg;
+ THD *thd;
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_DIGITS))
+ return 0;
+ beg= xpath->prevtok.beg;
+ thd= xpath->thd;
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_DOT))
+ {
+ XPath_cstring_null_terminated nr(thd, beg, xpath->prevtok.end - beg);
+ xpath->item= new (thd->mem_root) Item_int(thd, nr.str, (uint) nr.length);
+ }
+ else
+ {
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_DIGITS);
+ XPath_cstring_null_terminated nr(thd, beg, xpath->prevtok.end - beg);
+ xpath->item= new (thd->mem_root) Item_float(thd, nr.str, (uint) nr.length);
+ }
+ return 1;
+}
+
+
+/*
+ Scan NCName.
+
+ SYNOPSYS
+
+ The keywords AND, OR, MOD, DIV are valid identitiers
+ when they are in identifier context:
+
+ SELECT
+ ExtractValue('<and><or><mod><div>VALUE</div></mod></or></and>',
+ '/and/or/mod/div')
+ -> VALUE
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+
+static int
+my_xpath_parse_NCName(MY_XPATH *xpath)
+{
+ return
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_IDENT) ||
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_AND) ||
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_OR) ||
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_MOD) ||
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_DIV) ? 1 : 0;
+}
+
+
+/*
+ QName grammar can be found in a separate document
+ http://www.w3.org/TR/REC-xml-names/#NT-QName
+
+ [6] QName ::= (Prefix ':')? LocalPart
+ [7] Prefix ::= NCName
+ [8] LocalPart ::= NCName
+*/
+
+static int
+my_xpath_parse_QName(MY_XPATH *xpath)
+{
+ const char *beg;
+ if (!my_xpath_parse_NCName(xpath))
+ return 0;
+ beg= xpath->prevtok.beg;
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_COLON))
+ return 1; /* Non qualified name */
+ if (!my_xpath_parse_NCName(xpath))
+ return 0;
+ xpath->prevtok.beg= beg;
+ return 1;
+}
+
+
+/**
+ Scan Variable reference
+
+ @details Implements parsing of two syntax structures:
+
+ 1. Standard XPath syntax [36], for SP variables:
+
+ VariableReference ::= '$' QName
+
+ Finds a SP variable with the given name.
+ If outside of a SP context, or variable with
+ the given name doesn't exists, then error is returned.
+
+ 2. Non-standard syntax - MySQL extension for user variables:
+
+ VariableReference ::= '$' '@' QName
+
+ Item, corresponding to the variable, is returned
+ in xpath->item in both cases.
+
+ @param xpath pointer to XPath structure
+
+ @return Operation status
+ @retval 1 Success
+ @retval 0 Failure
+*/
+
+static int
+my_xpath_parse_VariableReference(MY_XPATH *xpath)
+{
+ LEX_CSTRING name;
+ THD *thd= xpath->thd;
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_DOLLAR))
+ return 0;
+ const char *dollar_pos= xpath->prevtok.beg;
+ if (!dollar_pos)
+ return 0;
+ int user_var= my_xpath_parse_term(xpath, MY_XPATH_LEX_AT);
+ if (!((user_var &&
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_IDENT))) &&
+ !my_xpath_parse_term(xpath, MY_XPATH_LEX_IDENT))
+ return 0;
+
+ name.length= xpath->prevtok.end - xpath->prevtok.beg;
+ name.str= (char*) xpath->prevtok.beg;
+
+ if (user_var)
+ xpath->item= new (thd->mem_root) Item_func_get_user_var(thd, &name);
+ else
+ {
+ sp_variable *spv;
+ const Sp_rcontext_handler *rh;
+ LEX *lex;
+ /*
+ We call lex->find_variable() rather than thd->lex->spcont->find_variable()
+ to make sure package body variables are properly supported.
+ */
+ if ((lex= thd->lex) &&
+ (spv= lex->find_variable(&name, &rh)))
+ {
+ Item_splocal *splocal= new (thd->mem_root)
+ Item_splocal(thd, rh, &name, spv->offset, spv->type_handler(), 0);
+#ifdef DBUG_ASSERT_EXISTS
+ if (splocal)
+ splocal->m_sp= lex->sphead;
+#endif
+ xpath->item= (Item*) splocal;
+ }
+ else
+ {
+ xpath->item= NULL;
+ DBUG_ASSERT(xpath->query.end > dollar_pos);
+ uint len= (uint)(xpath->query.end - dollar_pos);
+ if (len <= 32)
+ my_printf_error(ER_UNKNOWN_ERROR, "Unknown XPATH variable at: '%.*s'",
+ MYF(0), len, dollar_pos);
+ else
+ my_printf_error(ER_UNKNOWN_ERROR, "Unknown XPATH variable at: '%.32T'",
+ MYF(0), dollar_pos);
+ }
+ }
+ return xpath->item ? 1 : 0;
+}
+
+
+/*
+ Scan Name Test
+
+ SYNOPSYS
+
+ [37] NameTest ::= '*'
+ | NCName ':' '*'
+ | QName
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int
+my_xpath_parse_NodeTest_QName(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_QName(xpath))
+ return 0;
+ DBUG_ASSERT(xpath->context);
+ uint len= (uint)(xpath->prevtok.end - xpath->prevtok.beg);
+ xpath->context= nametestfunc(xpath, xpath->axis, xpath->context,
+ xpath->prevtok.beg, len);
+ return 1;
+}
+static int
+my_xpath_parse_NodeTest_asterisk(MY_XPATH *xpath)
+{
+ if (!my_xpath_parse_term(xpath, MY_XPATH_LEX_ASTERISK))
+ return 0;
+ DBUG_ASSERT(xpath->context);
+ xpath->context= nametestfunc(xpath, xpath->axis, xpath->context, "*", 1);
+ return 1;
+}
+static int
+my_xpath_parse_NameTest(MY_XPATH *xpath)
+{
+ return my_xpath_parse_NodeTest_asterisk(xpath) ||
+ my_xpath_parse_NodeTest_QName(xpath);
+}
+
+
+/*
+ Scan an XPath expression
+
+ SYNOPSYS
+ Scan xpath expression.
+ The expression is returned in xpath->expr.
+
+ RETURN
+ 1 - success
+ 0 - failure
+*/
+static int
+my_xpath_parse(MY_XPATH *xpath, const char *str, const char *strend)
+{
+ my_xpath_lex_init(&xpath->query, str, strend);
+ my_xpath_lex_init(&xpath->prevtok, str, strend);
+ my_xpath_lex_scan(xpath, &xpath->lasttok, str, strend);
+
+ xpath->rootelement= new (xpath->thd->mem_root)
+ Item_nodeset_func_rootelement(xpath->thd,
+ xpath->pxml);
+
+ return (my_xpath_parse_Expr(xpath) &&
+ my_xpath_parse_term(xpath, MY_XPATH_LEX_EOF));
+}
+
+
+bool Item_xml_str_func::fix_length_and_dec(THD *thd)
+{
+ max_length= MAX_BLOB_WIDTH;
+ return agg_arg_charsets_for_comparison(collation, args, arg_count);
+}
+
+
+bool Item_xml_str_func::fix_fields(THD *thd, Item **ref)
+{
+ String *xp;
+ MY_XPATH xpath;
+ int rc;
+
+ if (Item_str_func::fix_fields(thd, ref))
+ return true;
+
+ status_var_increment(current_thd->status_var.feature_xml);
+
+ nodeset_func= 0;
+
+
+ if (collation.collation->mbminlen > 1)
+ {
+ /* UCS2 is not supported */
+ my_printf_error(ER_UNKNOWN_ERROR,
+ "Character set '%s' is not supported by XPATH",
+ MYF(0), collation.collation->cs_name.str);
+ return true;
+ }
+
+ if (!args[1]->const_item())
+ {
+ my_printf_error(ER_UNKNOWN_ERROR,
+ "Only constant XPATH queries are supported", MYF(0));
+ return true;
+ }
+
+ /*
+ Get the XPath query text from args[1] and cache it in m_xpath_query.
+ Its fragments will be referenced by items created during my_xpath_parse(),
+ e.g. by Item_nodeset_func_axisbyname::node_name.
+ */
+ if (!(xp= args[1]->val_str(&m_xpath_query)) ||
+ (xp != &m_xpath_query && m_xpath_query.copy(*xp)))
+ return false; // Will return NULL
+ my_xpath_init(&xpath);
+ xpath.thd= thd;
+ xpath.cs= collation.collation;
+ xpath.debug= 0;
+ xpath.pxml= xml.parsed();
+ xml.set_charset(collation.collation);
+
+ rc= my_xpath_parse(&xpath, xp->ptr(), xp->ptr() + xp->length());
+
+ if (!rc)
+ {
+ uint clen= (uint)(xpath.query.end - xpath.lasttok.beg);
+ if (clen <= 32)
+ my_printf_error(ER_UNKNOWN_ERROR, "XPATH syntax error: '%.*s'",
+ MYF(0), clen, xpath.lasttok.beg);
+ else
+ my_printf_error(ER_UNKNOWN_ERROR, "XPATH syntax error: '%.32T'",
+ MYF(0), xpath.lasttok.beg);
+
+ return true;
+ }
+
+ /*
+ Parsing XML is a heavy operation, so if the first argument is constant,
+ then parse XML only one time and cache the parsed representation
+ together with raw text representation.
+
+ Note, we cannot cache the entire function result even if
+ the first and the second arguments are constants, because
+ the XPath expression may have user and SP variable references,
+ so the function result can vary between executions.
+ */
+ if ((args[0]->const_item() && get_xml(&xml, true)) ||
+ !(nodeset_func= xpath.item))
+ return false; // Will return NULL
+
+ return nodeset_func->fix_fields(thd, &nodeset_func);
+}
+
+
+#define MAX_LEVEL 256
+typedef struct
+{
+ uint level;
+ String *pxml; // parsed XML
+ uint pos[MAX_LEVEL]; // Tag position stack
+ uint parent; // Offset of the parent of the current node
+} MY_XML_USER_DATA;
+
+
+static bool
+append_node(String *str, MY_XML_NODE *node)
+{
+ /*
+ If "str" doesn't have space for a new node,
+ it will allocate two times more space that it has had so far.
+ (2*len+512) is a heuristic value,
+ which gave the best performance during tests.
+ The ideas behind this formula are:
+ - It allows to have a very small number of reallocs:
+ about 10 reallocs on a 1Mb-long XML value.
+ - At the same time, it avoids excessive memory use.
+ */
+ if (str->reserve(sizeof(MY_XML_NODE), 2 * str->length() + 512))
+ return TRUE;
+ str->q_append((const char*) node, sizeof(MY_XML_NODE));
+ return FALSE;
+}
+
+
+/*
+ Process tag beginning
+
+ SYNOPSYS
+
+ A call-back function executed when XML parser
+ is entering a tag or an attribute.
+ Appends the new node into data->pxml.
+ Increments data->level.
+
+ RETURN
+ Currently only MY_XML_OK
+*/
+extern "C" int xml_enter(MY_XML_PARSER *st,const char *attr, size_t len);
+
+int xml_enter(MY_XML_PARSER *st,const char *attr, size_t len)
+{
+ MY_XML_USER_DATA *data= (MY_XML_USER_DATA*)st->user_data;
+ uint numnodes= data->pxml->length() / sizeof(MY_XML_NODE);
+ MY_XML_NODE node;
+
+ node.parent= data->parent; // Set parent for the new node to old parent
+ data->parent= numnodes; // Remember current node as new parent
+ DBUG_ASSERT(data->level < MAX_LEVEL);
+ data->pos[data->level]= numnodes;
+ if (data->level < MAX_LEVEL - 1)
+ node.level= data->level++;
+ else
+ return MY_XML_ERROR;
+ node.type= st->current_node_type; // TAG or ATTR
+ node.beg= attr;
+ node.end= attr + len;
+ return append_node(data->pxml, &node) ? MY_XML_ERROR : MY_XML_OK;
+}
+
+
+/*
+ Process text node
+
+ SYNOPSYS
+
+ A call-back function executed when XML parser
+ is entering into a tag or an attribute textual value.
+ The value is appended into data->pxml.
+
+ RETURN
+ Currently only MY_XML_OK
+*/
+extern "C" int xml_value(MY_XML_PARSER *st,const char *attr, size_t len);
+
+int xml_value(MY_XML_PARSER *st,const char *attr, size_t len)
+{
+ MY_XML_USER_DATA *data= (MY_XML_USER_DATA*)st->user_data;
+ MY_XML_NODE node;
+
+ node.parent= data->parent; // Set parent for the new text node to old parent
+ node.level= data->level;
+ node.type= MY_XML_NODE_TEXT;
+ node.beg= attr;
+ node.end= attr + len;
+ return append_node(data->pxml, &node) ? MY_XML_ERROR : MY_XML_OK;
+}
+
+
+/*
+ Leave a tag or an attribute
+
+ SYNOPSYS
+
+ A call-back function executed when XML parser
+ is leaving a tag or an attribute.
+ Decrements data->level.
+
+ RETURN
+ Currently only MY_XML_OK
+*/
+extern "C" int xml_leave(MY_XML_PARSER *st,const char *attr, size_t len);
+
+int xml_leave(MY_XML_PARSER *st,const char *attr, size_t len)
+{
+ MY_XML_USER_DATA *data= (MY_XML_USER_DATA*)st->user_data;
+ DBUG_ASSERT(data->level > 0);
+ data->level--;
+
+ MY_XML_NODE *nodes= (MY_XML_NODE*) data->pxml->ptr();
+ data->parent= nodes[data->parent].parent;
+ nodes+= data->pos[data->level];
+ nodes->tagend= st->cur;
+
+ return MY_XML_OK;
+}
+
+
+/*
+ Parse raw XML
+
+ SYNOPSYS
+
+ RETURN
+ false on success
+ true on error
+*/
+bool Item_xml_str_func::XML::parse()
+{
+ MY_XML_PARSER p;
+ MY_XML_USER_DATA user_data;
+ int rc;
+
+ m_parsed_buf.length(0);
+
+ /* Prepare XML parser */
+ my_xml_parser_create(&p);
+ p.flags= MY_XML_FLAG_RELATIVE_NAMES | MY_XML_FLAG_SKIP_TEXT_NORMALIZATION;
+ user_data.level= 0;
+ user_data.pxml= &m_parsed_buf;
+ user_data.parent= 0;
+ my_xml_set_enter_handler(&p, xml_enter);
+ my_xml_set_value_handler(&p, xml_value);
+ my_xml_set_leave_handler(&p, xml_leave);
+ my_xml_set_user_data(&p, (void*) &user_data);
+
+ /* Add root node */
+ p.current_node_type= MY_XML_NODE_TAG;
+ xml_enter(&p, m_raw_ptr->ptr(), 0);
+
+ /* Execute XML parser */
+ if ((rc= my_xml_parse(&p, m_raw_ptr->ptr(), m_raw_ptr->length())) != MY_XML_OK)
+ {
+ THD *thd= current_thd;
+ char buf[128];
+ my_snprintf(buf, sizeof(buf)-1, "parse error at line %d pos %lu: %s",
+ my_xml_error_lineno(&p) + 1,
+ (ulong) my_xml_error_pos(&p) + 1,
+ my_xml_error_string(&p));
+ push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+ ER_WRONG_VALUE,
+ ER_THD(thd, ER_WRONG_VALUE), "XML", buf);
+ m_raw_ptr= (String *) 0;
+ }
+ my_xml_parser_free(&p);
+
+ return rc != MY_XML_OK;
+}
+
+
+/*
+ Parse the raw XML from the given source,
+ optionally cache the raw XML,
+ remember the pointer to the raw XML.
+*/
+bool Item_xml_str_func::XML::parse(String *raw_xml, bool cache)
+{
+ m_raw_ptr= raw_xml;
+ if (cache)
+ {
+ m_cached= true;
+ if (m_raw_ptr != &m_raw_buf && m_raw_buf.copy(*m_raw_ptr))
+ {
+ m_raw_ptr= (String *) 0;
+ return true;
+ }
+ m_raw_ptr= &m_raw_buf;
+ }
+ return parse();
+}
+
+
+const MY_XML_NODE *Item_xml_str_func::XML::node(uint idx)
+{
+ const MY_XML_NODE *nodebeg= (MY_XML_NODE*) m_parsed_buf.ptr();
+ DBUG_ASSERT(idx < m_parsed_buf.length() / sizeof (MY_XML_NODE));
+ return nodebeg + idx;
+}
+
+
+String *Item_func_xml_extractvalue::val_str(String *str)
+{
+ String *res;
+ null_value= 0;
+ if (!nodeset_func || get_xml(&xml) ||
+ !(res= nodeset_func->val_str(str)))
+ {
+ null_value= 1;
+ return 0;
+ }
+ return res;
+}
+
+
+bool Item_func_xml_update::collect_result(String *str,
+ const MY_XML_NODE *cut,
+ const String *replace)
+{
+ uint offs= cut->type == MY_XML_NODE_TAG ? 1 : 0;
+ const char *end= cut->tagend + offs;
+ str->length(0);
+ str->set_charset(collation.collation);
+ return
+ /* Put the XML part preceding the replaced piece */
+ str->append(xml.raw()->ptr(), cut->beg - xml.raw()->ptr() - offs) ||
+ /* Put the replacement */
+ str->append(replace->ptr(), replace->length()) ||
+ /* Put the XML part following the replaced piece */
+ str->append(end, xml.raw()->ptr() + xml.raw()->length() - end);
+}
+
+
+String *Item_func_xml_update::val_str(String *str)
+{
+ String *rep;
+
+ null_value= 0;
+ if (!nodeset_func || get_xml(&xml) ||
+ !(rep= args[2]->val_str(&tmp_value3)) ||
+ nodeset_func->type_handler() != &type_handler_xpath_nodeset ||
+ nodeset_func->val_native(current_thd, &tmp_native_value2))
+ {
+ null_value= 1;
+ return 0;
+ }
+
+ MY_XPATH_FLT *fltbeg= (MY_XPATH_FLT*) tmp_native_value2.ptr();
+ MY_XPATH_FLT *fltend= (MY_XPATH_FLT*) tmp_native_value2.end();
+
+ /* Allow replacing of one tag only */
+ if (fltend - fltbeg != 1)
+ {
+ /* TODO: perhaps add a warning that more than one tag selected */
+ return xml.raw();
+ }
+
+ const MY_XML_NODE *nodebeg= xml.node(fltbeg->num);
+
+ if (!nodebeg->level)
+ {
+ /*
+ Root element, without NameTest:
+ UpdateXML(xml, '/', 'replacement');
+ Just return the replacement string.
+ */
+ return rep;
+ }
+
+ return collect_result(str, nodebeg, rep) ? (String *) NULL : str;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 01:01:22 +0000