blob: 4da73ad223689a153cec78d1f51e1be7546500d8 [file] [log] [blame]
Radek Krejcib1646a92018-11-02 16:08:26 +01001/**
2 * @file xpath.h
3 * @author Michal Vasko <mvasko@cesnet.cz>
4 * @brief YANG XPath evaluation functions header
5 *
Michal Vasko519fd602020-05-26 12:17:39 +02006 * Copyright (c) 2015 - 2020 CESNET, z.s.p.o.
Radek Krejcib1646a92018-11-02 16:08:26 +01007 *
8 * This source code is licensed under BSD 3-Clause License (the "License").
9 * You may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * https://opensource.org/licenses/BSD-3-Clause
13 */
14
Michal Vasko14676352020-05-29 11:35:55 +020015#ifndef LY_XPATH_H
16#define LY_XPATH_H
Radek Krejcib1646a92018-11-02 16:08:26 +010017
Radek Krejciad97c5f2020-06-30 09:19:28 +020018#include <stddef.h>
Michal Vasko69730152020-10-09 16:30:07 +020019#include <stdint.h>
Radek Krejcib1646a92018-11-02 16:08:26 +010020
Michal Vaskoc5a22832020-08-20 13:21:33 +020021#include "compat.h"
Radek Krejcie7b95092019-05-15 11:03:07 +020022#include "log.h"
Radek Krejci77114102021-03-10 15:21:57 +010023#include "tree.h"
Radek Krejci535ea9f2020-05-29 16:01:05 +020024#include "tree_schema.h"
Radek Krejcie7b95092019-05-15 11:03:07 +020025
26struct ly_ctx;
Radek Krejci77114102021-03-10 15:21:57 +010027struct lyd_node;
Radek Krejcie7b95092019-05-15 11:03:07 +020028
Radek Krejcib1646a92018-11-02 16:08:26 +010029/*
30 * XPath evaluator fully compliant with http://www.w3.org/TR/1999/REC-xpath-19991116/
31 * except the following restrictions in the grammar.
32 *
33 * PARSED GRAMMAR
34 *
35 * Full axes are not supported, abbreviated forms must be used,
36 * variables are not supported, "id()" function is not supported,
37 * and processing instruction and comment nodes are not supported,
38 * which is also reflected in the grammar. Undefined rules and
39 * constants are tokens.
40 *
41 * Modified full grammar:
42 *
43 * [1] Expr ::= OrExpr // just an alias
44 *
45 * [2] LocationPath ::= RelativeLocationPath | AbsoluteLocationPath
46 * [3] AbsoluteLocationPath ::= '/' RelativeLocationPath? | '//' RelativeLocationPath
47 * [4] RelativeLocationPath ::= Step | RelativeLocationPath '/' Step | RelativeLocationPath '//' Step
48 * [5] Step ::= '@'? NodeTest Predicate* | '.' | '..'
49 * [6] NodeTest ::= NameTest | NodeType '(' ')'
Michal Vaskod3678892020-05-21 10:06:58 +020050 * [7] NameTest ::= '*' | NCName ':' '*' | QName
51 * [8] NodeType ::= 'text' | 'node'
52 * [9] Predicate ::= '[' Expr ']'
53 * [10] PrimaryExpr ::= '(' Expr ')' | Literal | Number | FunctionCall
54 * [11] FunctionCall ::= FunctionName '(' ( Expr ( ',' Expr )* )? ')'
55 * [12] PathExpr ::= LocationPath | PrimaryExpr Predicate*
Radek Krejcib1646a92018-11-02 16:08:26 +010056 * | PrimaryExpr Predicate* '/' RelativeLocationPath
57 * | PrimaryExpr Predicate* '//' RelativeLocationPath
Michal Vaskod3678892020-05-21 10:06:58 +020058 * [13] OrExpr ::= AndExpr | OrExpr 'or' AndExpr
59 * [14] AndExpr ::= EqualityExpr | AndExpr 'and' EqualityExpr
60 * [15] EqualityExpr ::= RelationalExpr | EqualityExpr '=' RelationalExpr
Radek Krejcib1646a92018-11-02 16:08:26 +010061 * | EqualityExpr '!=' RelationalExpr
Michal Vaskod3678892020-05-21 10:06:58 +020062 * [16] RelationalExpr ::= AdditiveExpr
Radek Krejcib1646a92018-11-02 16:08:26 +010063 * | RelationalExpr '<' AdditiveExpr
64 * | RelationalExpr '>' AdditiveExpr
65 * | RelationalExpr '<=' AdditiveExpr
66 * | RelationalExpr '>=' AdditiveExpr
Michal Vaskod3678892020-05-21 10:06:58 +020067 * [17] AdditiveExpr ::= MultiplicativeExpr
Radek Krejcib1646a92018-11-02 16:08:26 +010068 * | AdditiveExpr '+' MultiplicativeExpr
69 * | AdditiveExpr '-' MultiplicativeExpr
Michal Vaskod3678892020-05-21 10:06:58 +020070 * [18] MultiplicativeExpr ::= UnaryExpr
Radek Krejcib1646a92018-11-02 16:08:26 +010071 * | MultiplicativeExpr '*' UnaryExpr
72 * | MultiplicativeExpr 'div' UnaryExpr
73 * | MultiplicativeExpr 'mod' UnaryExpr
Michal Vaskod3678892020-05-21 10:06:58 +020074 * [19] UnaryExpr ::= UnionExpr | '-' UnaryExpr
75 * [20] UnionExpr ::= PathExpr | UnionExpr '|' PathExpr
Radek Krejcib1646a92018-11-02 16:08:26 +010076 */
77
78/* expression tokens allocation */
79#define LYXP_EXPR_SIZE_START 10
80#define LYXP_EXPR_SIZE_STEP 5
81
82/* XPath matches allocation */
83#define LYXP_SET_SIZE_START 2
84#define LYXP_SET_SIZE_STEP 2
85
86/* building string when casting */
87#define LYXP_STRING_CAST_SIZE_START 64
88#define LYXP_STRING_CAST_SIZE_STEP 16
89
90/**
91 * @brief Tokens that can be in an XPath expression.
92 */
93enum lyxp_token {
94 LYXP_TOKEN_NONE = 0,
95 LYXP_TOKEN_PAR1, /* '(' */
96 LYXP_TOKEN_PAR2, /* ')' */
97 LYXP_TOKEN_BRACK1, /* '[' */
98 LYXP_TOKEN_BRACK2, /* ']' */
99 LYXP_TOKEN_DOT, /* '.' */
100 LYXP_TOKEN_DDOT, /* '..' */
101 LYXP_TOKEN_AT, /* '@' */
102 LYXP_TOKEN_COMMA, /* ',' */
103 /* LYXP_TOKEN_DCOLON, * '::' * axes not supported */
104 LYXP_TOKEN_NAMETEST, /* NameTest */
105 LYXP_TOKEN_NODETYPE, /* NodeType */
106 LYXP_TOKEN_FUNCNAME, /* FunctionName */
Michal Vasko3e48bf32020-06-01 08:39:07 +0200107 LYXP_TOKEN_OPER_LOG, /* Operator 'and', 'or' */
108 LYXP_TOKEN_OPER_EQUAL, /* Operator '=' */
109 LYXP_TOKEN_OPER_NEQUAL, /* Operator '!=' */
110 LYXP_TOKEN_OPER_COMP, /* Operator '<', '<=', '>', '>=' */
111 LYXP_TOKEN_OPER_MATH, /* Operator '+', '-', '*', 'div', 'mod', '-' (unary) */
112 LYXP_TOKEN_OPER_UNI, /* Operator '|' */
113 LYXP_TOKEN_OPER_PATH, /* Operator '/' */
114 LYXP_TOKEN_OPER_RPATH, /* Operator '//' (recursive path) */
Radek Krejcib1646a92018-11-02 16:08:26 +0100115 /* LYXP_TOKEN_AXISNAME, * AxisName * axes not supported */
116 LYXP_TOKEN_LITERAL, /* Literal - with either single or double quote */
117 LYXP_TOKEN_NUMBER /* Number */
118};
119
120/**
121 * @brief XPath (sub)expressions that can be repeated.
122 */
123enum lyxp_expr_type {
124 LYXP_EXPR_NONE = 0,
125 LYXP_EXPR_OR,
126 LYXP_EXPR_AND,
127 LYXP_EXPR_EQUALITY,
128 LYXP_EXPR_RELATIONAL,
129 LYXP_EXPR_ADDITIVE,
130 LYXP_EXPR_MULTIPLICATIVE,
131 LYXP_EXPR_UNARY,
Michal Vasko69730152020-10-09 16:30:07 +0200132 LYXP_EXPR_UNION
Radek Krejcib1646a92018-11-02 16:08:26 +0100133};
134
135/**
Michal Vasko03ff5a72019-09-11 13:49:33 +0200136 * @brief Types of context nodes, #LYXP_NODE_ROOT_CONFIG used only in when or must conditions.
137 */
138enum lyxp_node_type {
Michal Vasko2caefc12019-11-14 16:07:56 +0100139 LYXP_NODE_NONE, /* invalid node type */
140
Michal Vasko03ff5a72019-09-11 13:49:33 +0200141 /* XML document roots */
142 LYXP_NODE_ROOT, /* access to all the data (node value first top-level node) */
143 LYXP_NODE_ROOT_CONFIG, /* <running> data context, no state data (node value first top-level node) */
144
145 /* XML elements */
Michal Vasko9f96a052020-03-10 09:41:45 +0100146 LYXP_NODE_ELEM, /* YANG data element (most common) */
147 LYXP_NODE_TEXT, /* YANG data text element (extremely specific use, unlikely to be ever needed) */
148 LYXP_NODE_META /* YANG metadata (do not use for the context node) */
Michal Vasko03ff5a72019-09-11 13:49:33 +0200149};
150
151/**
Radek Krejcib1646a92018-11-02 16:08:26 +0100152 * @brief Structure holding a parsed XPath expression.
153 */
154struct lyxp_expr {
155 enum lyxp_token *tokens; /* array of tokens */
156 uint16_t *tok_pos; /* array of the token offsets in expr */
157 uint16_t *tok_len; /* array of token lengths in expr */
158 enum lyxp_expr_type **repeat; /* array of expression types that this token begins and is repeated ended with 0,
159 more in the comment after this declaration */
160 uint16_t used; /* used array items */
161 uint16_t size; /* allocated array items */
162
163 const char *expr; /* the original XPath expression */
164};
165
166/*
167 * lyxp_expr repeat
168 *
169 * This value is NULL for all the tokens that do not begin an
170 * expression which can be repeated. Otherwise it is an array
171 * of expression types that this token begins. These values
172 * are used during evaluation to know whether we need to
173 * duplicate the current context or not and to decide what
174 * the current expression is (for example, if we are only
175 * starting the parsing and the first token has no repeat,
176 * we do not parse it as an OrExpr but directly as PathExpr).
177 * Examples:
178 *
179 * Expression: "/ *[key1 and key2 or key1 < key2]"
180 * Tokens: '/', '*', '[', NameTest, 'and', NameTest, 'or', NameTest, '<', NameTest, ']'
181 * Repeat: NULL, NULL, NULL, [AndExpr, NULL, NULL, NULL, [RelationalExpr, NULL, NULL, NULL
182 * OrExpr, 0],
183 * 0],
184 *
185 * Expression: "//node[key and node2]/key | /cont"
186 * Tokens: '//', 'NameTest', '[', 'NameTest', 'and', 'NameTest', ']', '/', 'NameTest', '|', '/', 'NameTest'
187 * Repeat: [UnionExpr, NULL, NULL, [AndExpr, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
188 * 0], 0],
189 *
190 * Operators between expressions which this concerns:
191 * 'or', 'and', '=', '!=', '<', '>', '<=', '>=', '+', '-', '*', 'div', 'mod', '|'
192 */
193
194/**
195 * @brief Supported types of (partial) XPath results.
196 */
197enum lyxp_set_type {
Michal Vaskod3678892020-05-21 10:06:58 +0200198 LYXP_SET_NODE_SET = 0,
Michal Vasko03ff5a72019-09-11 13:49:33 +0200199 LYXP_SET_SCNODE_SET,
Radek Krejcib1646a92018-11-02 16:08:26 +0100200 LYXP_SET_BOOLEAN,
201 LYXP_SET_NUMBER,
202 LYXP_SET_STRING
203};
Radek Krejcib1646a92018-11-02 16:08:26 +0100204
205/**
206 * @brief Item stored in an XPath set hash table.
207 */
208struct lyxp_set_hash_node {
209 struct lyd_node *node;
210 enum lyxp_node_type type;
211} _PACKED;
212
Radek Krejcib1646a92018-11-02 16:08:26 +0100213/**
214 * @brief XPath set - (partial) result.
215 */
216struct lyxp_set {
217 enum lyxp_set_type type;
218 union {
219 struct lyxp_set_node {
220 struct lyd_node *node;
221 enum lyxp_node_type type;
222 uint32_t pos;
223 } *nodes;
Michal Vasko03ff5a72019-09-11 13:49:33 +0200224 struct lyxp_set_scnode {
225 struct lysc_node *scnode;
Radek Krejcib1646a92018-11-02 16:08:26 +0100226 enum lyxp_node_type type;
Radek Krejcif13b87b2020-12-01 22:02:17 +0100227
Michal Vaskod97959c2020-12-10 12:18:28 +0100228/* _START and _ATOM values should have grouped values */
Radek Krejcif13b87b2020-12-01 22:02:17 +0100229#define LYXP_SET_SCNODE_START -2 /**< scnode not traversed, currently (the only node) in context */
230#define LYXP_SET_SCNODE_START_USED -1 /**< scnode not traversed except for the eval start, not currently in the context */
231#define LYXP_SET_SCNODE_ATOM 0 /**< scnode was traversed, but not currently in the context */
232#define LYXP_SET_SCNODE_ATOM_CTX 1 /**< scnode currently in context */
233#define LYXP_SET_SCNODE_ATOM_NEW_CTX 2 /**< scnode in context and just added, so skip it for the current operation */
234#define LYXP_SET_SCNODE_ATOM_PRED_CTX 3 /**< includes any higher value - scnode is not in context because we are in
235 a predicate and this scnode was used/will be used later */
236 int32_t in_ctx; /**< values defined as LYXP_SET_SCNODE_* */
Michal Vasko03ff5a72019-09-11 13:49:33 +0200237 } *scnodes;
Michal Vasko9f96a052020-03-10 09:41:45 +0100238 struct lyxp_set_meta {
239 struct lyd_meta *meta;
Radek Krejcib1646a92018-11-02 16:08:26 +0100240 enum lyxp_node_type type;
Michal Vasko9f96a052020-03-10 09:41:45 +0100241 uint32_t pos; /* if node_type is LYXP_SET_NODE_META, it is the parent node position */
242 } *meta;
Radek Krejcib1646a92018-11-02 16:08:26 +0100243 char *str;
244 long double num;
Radek Krejci857189e2020-09-01 13:26:36 +0200245 ly_bool bln; /* boolean */
Radek Krejcib1646a92018-11-02 16:08:26 +0100246 } val;
247
Michal Vasko03ff5a72019-09-11 13:49:33 +0200248 /* this is valid only for type LYXP_SET_NODE_SET and LYXP_SET_SCNODE_SET */
Radek Krejcib1646a92018-11-02 16:08:26 +0100249 uint32_t used;
250 uint32_t size;
Radek Krejcib1646a92018-11-02 16:08:26 +0100251 struct hash_table *ht;
Michal Vasko03ff5a72019-09-11 13:49:33 +0200252
253 /* XPath context information, this is valid only for type LYXP_SET_NODE_SET */
Radek Krejcib1646a92018-11-02 16:08:26 +0100254 uint32_t ctx_pos;
255 uint32_t ctx_size;
Michal Vasko03ff5a72019-09-11 13:49:33 +0200256
257 /* general context */
258 struct ly_ctx *ctx;
259 union {
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200260 const struct lyd_node *cur_node;
261 const struct lysc_node *cur_scnode;
Michal Vasko03ff5a72019-09-11 13:49:33 +0200262 };
Michal Vasko5e0e6eb2019-11-06 15:47:50 +0100263 enum lyxp_node_type root_type;
Michal Vasko6b26e742020-07-17 15:02:10 +0200264 const struct lysc_node *context_op;
Michal Vaskof03ed032020-03-04 13:31:44 +0100265 const struct lyd_node *tree;
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200266 const struct lys_module *cur_mod;
Radek Krejci8df109d2021-04-23 12:19:08 +0200267 LY_VALUE_FORMAT format;
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200268 void *prefix_data;
Radek Krejcib1646a92018-11-02 16:08:26 +0100269};
270
271/**
Michal Vasko24cddf82020-06-01 08:17:01 +0200272 * @brief Print an XPath token \p tok type.
273 *
274 * @param[in] tok Token to print.
275 * @return Token type string.
276 */
277const char *lyxp_print_token(enum lyxp_token tok);
278
279/**
Michal Vasko03ff5a72019-09-11 13:49:33 +0200280 * @brief Evaluate an XPath expression on data. Be careful when using this function, the result can often
281 * be confusing without thorough understanding of XPath evaluation rules defined in RFC 7950.
Radek Krejcib1646a92018-11-02 16:08:26 +0100282 *
Michal Vasko400e9672021-01-11 13:39:17 +0100283 * @param[in] ctx libyang context to use.
Michal Vaskoecd62de2019-11-13 12:35:11 +0100284 * @param[in] exp Parsed XPath expression to be evaluated.
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200285 * @param[in] cur_mod Current module for the expression (where it was "instantiated").
Michal Vasko03ff5a72019-09-11 13:49:33 +0200286 * @param[in] format Format of the XPath expression (more specifcally, of any used prefixes).
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200287 * @param[in] prefix_data Format-specific prefix data (see ::ly_resolve_prefix).
288 * @param[in] ctx_node Current (context) data node, NULL in case of the root node.
Michal Vaskof03ed032020-03-04 13:31:44 +0100289 * @param[in] tree Data tree on which to perform the evaluation, it must include all the available data (including
Michal Vaskod3bb12f2020-12-04 14:33:09 +0100290 * the tree of @p ctx_node). Can be any node of the tree, it is adjusted.
Michal Vasko004d3152020-06-11 19:59:22 +0200291 * @param[out] set Result set.
Radek Krejcib1646a92018-11-02 16:08:26 +0100292 * @param[in] options Whether to apply some evaluation restrictions.
Michal Vasko004d3152020-06-11 19:59:22 +0200293 * @return LY_EVALID for invalid argument types/count,
294 * @return LY_EINCOMPLETE for unresolved when,
295 * @return LY_EINVAL, LY_EMEM, LY_EINT for other errors.
Radek Krejcib1646a92018-11-02 16:08:26 +0100296 */
Michal Vasko400e9672021-01-11 13:39:17 +0100297LY_ERR lyxp_eval(const struct ly_ctx *ctx, const struct lyxp_expr *exp, const struct lys_module *cur_mod,
Radek Krejci8df109d2021-04-23 12:19:08 +0200298 LY_VALUE_FORMAT format, void *prefix_data, const struct lyd_node *ctx_node, const struct lyd_node *tree,
Michal Vasko400e9672021-01-11 13:39:17 +0100299 struct lyxp_set *set, uint32_t options);
Michal Vasko03ff5a72019-09-11 13:49:33 +0200300
Radek Krejcib1646a92018-11-02 16:08:26 +0100301/**
Michal Vasko03ff5a72019-09-11 13:49:33 +0200302 * @brief Get all the partial XPath nodes (atoms) that are required for @p exp to be evaluated.
Radek Krejcib1646a92018-11-02 16:08:26 +0100303 *
Michal Vasko400e9672021-01-11 13:39:17 +0100304 * @param[in] ctx libyang context to use.
Michal Vasko03ff5a72019-09-11 13:49:33 +0200305 * @param[in] exp Parsed XPath expression to be evaluated.
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200306 * @param[in] cur_mod Current module for the expression (where it was "instantiated").
Michal Vasko03ff5a72019-09-11 13:49:33 +0200307 * @param[in] format Format of the XPath expression (more specifcally, of any used prefixes).
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200308 * @param[in] prefix_data Format-specific prefix data (see ::ly_resolve_prefix).
309 * @param[in] ctx_scnode Current (context) schema node, NULL in case of the root node.
Michal Vasko004d3152020-06-11 19:59:22 +0200310 * @param[out] set Result set.
Radek Krejcib1646a92018-11-02 16:08:26 +0100311 * @param[in] options Whether to apply some evaluation restrictions, one flag must always be used.
Radek Krejci8678fa42020-08-18 16:07:28 +0200312 * @return LY_ERR (same as ::lyxp_eval()).
Radek Krejcib1646a92018-11-02 16:08:26 +0100313 */
Michal Vasko400e9672021-01-11 13:39:17 +0100314LY_ERR lyxp_atomize(const struct ly_ctx *ctx, const struct lyxp_expr *exp, const struct lys_module *cur_mod,
Radek Krejci8df109d2021-04-23 12:19:08 +0200315 LY_VALUE_FORMAT format, void *prefix_data, const struct lysc_node *ctx_scnode, struct lyxp_set *set,
Michal Vasko400e9672021-01-11 13:39:17 +0100316 uint32_t options);
Radek Krejcib1646a92018-11-02 16:08:26 +0100317
Radek Krejcibed13942020-10-19 16:06:28 +0200318/* used only internally, maps with @ref findxpathoptions */
Michal Vaskocdad7122020-11-09 21:04:44 +0100319#define LYXP_IGNORE_WHEN 0x01 /**< Ignore unevaluated when in data nodes and do not return ::LY_EINCOMPLETE. */
320#define LYXP_SCHEMA 0x02 /**< Apply data node access restrictions defined for 'when' and 'must' evaluation. */
321#define LYXP_SCNODE 0x04 /**< No special tree access modifiers. */
322#define LYXP_SCNODE_SCHEMA LYS_FIND_XP_SCHEMA /**< Apply node access restrictions defined for 'when' and 'must' evaluation. */
323#define LYXP_SCNODE_OUTPUT LYS_FIND_XP_OUTPUT /**< Search RPC/action output nodes instead of input ones. */
324#define LYXP_SCNODE_ALL 0x1C /**< mask for all the LYXP_* values */
Radek Krejcib1646a92018-11-02 16:08:26 +0100325
326/**
Radek Krejcib1646a92018-11-02 16:08:26 +0100327 * @brief Cast XPath set to another type.
328 * Indirectly context position aware.
329 *
330 * @param[in] set Set to cast.
331 * @param[in] target Target type to cast \p set into.
Michal Vasko03ff5a72019-09-11 13:49:33 +0200332 * @return LY_ERR
Radek Krejcib1646a92018-11-02 16:08:26 +0100333 */
Michal Vasko5e0e6eb2019-11-06 15:47:50 +0100334LY_ERR lyxp_set_cast(struct lyxp_set *set, enum lyxp_set_type target);
Michal Vasko03ff5a72019-09-11 13:49:33 +0200335
Radek Krejcib1646a92018-11-02 16:08:26 +0100336/**
Michal Vaskod3678892020-05-21 10:06:58 +0200337 * @brief Free dynamic content of a set.
338 *
339 * @param[in] set Set to modify.
340 */
341void lyxp_set_free_content(struct lyxp_set *set);
342
343/**
Michal Vaskoecd62de2019-11-13 12:35:11 +0100344 * @brief Insert schema node into set.
345 *
346 * @param[in] set Set to insert into.
347 * @param[in] node Node to insert.
348 * @param[in] node_type Node type of @p node.
Radek Krejciaa6b53f2020-08-27 15:19:03 +0200349 * @param[out] index_p Optional pointer to store index if the inserted @p node.
350 * @return LY_SUCCESS on success.
351 * @return LY_EMEM on memory allocation failure.
Michal Vaskoecd62de2019-11-13 12:35:11 +0100352 */
Michal Vaskoee38a5d2020-11-09 21:02:18 +0100353LY_ERR lyxp_set_scnode_insert_node(struct lyxp_set *set, const struct lysc_node *node, enum lyxp_node_type node_type,
354 uint32_t *index_p);
Michal Vaskoecd62de2019-11-13 12:35:11 +0100355
356/**
357 * @brief Check for duplicates in a schema node set.
358 *
359 * @param[in] set Set to check.
360 * @param[in] node Node to look for in @p set.
361 * @param[in] node_type Type of @p node.
362 * @param[in] skip_idx Index from @p set to skip.
Radek Krejciaa6b53f2020-08-27 15:19:03 +0200363 * @param[out] index_p Optional pointer to store index if the node is found.
Radek Krejci857189e2020-09-01 13:26:36 +0200364 * @return Boolean value whether the @p node found or not.
Michal Vaskoecd62de2019-11-13 12:35:11 +0100365 */
Radek Krejci857189e2020-09-01 13:26:36 +0200366ly_bool lyxp_set_scnode_contains(struct lyxp_set *set, const struct lysc_node *node, enum lyxp_node_type node_type,
Radek Krejciaa6b53f2020-08-27 15:19:03 +0200367 int skip_idx, uint32_t *index_p);
Michal Vaskoecd62de2019-11-13 12:35:11 +0100368
369/**
370 * @brief Merge 2 schema node sets.
371 *
372 * @param[in] set1 Set to merge into.
373 * @param[in] set2 Set to merge. Its content is freed.
374 */
375void lyxp_set_scnode_merge(struct lyxp_set *set1, struct lyxp_set *set2);
376
377/**
Radek Krejcib1646a92018-11-02 16:08:26 +0100378 * @brief Parse an XPath expression into a structure of tokens.
379 * Logs directly.
380 *
Michal Vasko03ff5a72019-09-11 13:49:33 +0200381 * https://www.w3.org/TR/1999/REC-xpath-19991116/#exprlex
Radek Krejcib1646a92018-11-02 16:08:26 +0100382 *
383 * @param[in] ctx Context for errors.
Radek Krejcif03a9e22020-09-18 20:09:31 +0200384 * @param[in] expr_str XPath expression to parse. It is duplicated.
Michal Vasko004d3152020-06-11 19:59:22 +0200385 * @param[in] expr_len Length of @p expr, can be 0 if @p expr is 0-terminated.
386 * @param[in] reparse Whether to re-parse the expression to finalize full XPath parsing and fill
387 * information about expressions and their operators (fill repeat).
Radek Krejcif03a9e22020-09-18 20:09:31 +0200388 * @param[out] expr_p Pointer to return the filled expression structure.
389 * @return LY_SUCCESS in case of success.
390 * @return LY_EMEM in case of memory allocation failure.
391 * @return LY_EVALID in case of invalid XPath expression in @p expr_str.
Radek Krejcib1646a92018-11-02 16:08:26 +0100392 */
Michal Vaskoee38a5d2020-11-09 21:02:18 +0100393LY_ERR lyxp_expr_parse(const struct ly_ctx *ctx, const char *expr_str, size_t expr_len, ly_bool reparse,
394 struct lyxp_expr **expr_p);
Michal Vasko004d3152020-06-11 19:59:22 +0200395
396/**
397 * @brief Duplicate parsed XPath expression.
398 *
399 * @param[in] ctx Context with a dictionary.
400 * @param[in] exp Parsed expression.
Michal Vasko1734be92020-09-22 08:55:10 +0200401 * @param[out] dup Duplicated structure.
402 * @return LY_ERR value.
Michal Vasko004d3152020-06-11 19:59:22 +0200403 */
Michal Vasko1734be92020-09-22 08:55:10 +0200404LY_ERR lyxp_expr_dup(const struct ly_ctx *ctx, const struct lyxp_expr *exp, struct lyxp_expr **dup);
Michal Vasko14676352020-05-29 11:35:55 +0200405
406/**
407 * @brief Look at the next token and check its kind.
408 *
409 * @param[in] ctx Context for logging, not logged if NULL.
410 * @param[in] exp Expression to use.
Michal Vasko004d3152020-06-11 19:59:22 +0200411 * @param[in] tok_idx Token index in the expression \p exp.
Michal Vasko14676352020-05-29 11:35:55 +0200412 * @param[in] want_tok Expected token.
413 * @return LY_EINCOMPLETE on EOF,
414 * @return LY_ENOT on non-matching token,
415 * @return LY_SUCCESS on success.
416 */
Michal Vasko004d3152020-06-11 19:59:22 +0200417LY_ERR lyxp_check_token(const struct ly_ctx *ctx, const struct lyxp_expr *exp, uint16_t tok_idx, enum lyxp_token want_tok);
418
419/**
420 * @brief Look at the next token and skip it if it matches the expected one.
421 *
422 * @param[in] ctx Context for logging, not logged if NULL.
423 * @param[in] exp Expression to use.
424 * @param[in,out] tok_idx Token index in the expression \p exp, is updated.
425 * @param[in] want_tok Expected token.
426 * @return LY_EINCOMPLETE on EOF,
427 * @return LY_ENOT on non-matching token,
428 * @return LY_SUCCESS on success.
429 */
430LY_ERR lyxp_next_token(const struct ly_ctx *ctx, const struct lyxp_expr *exp, uint16_t *tok_idx, enum lyxp_token want_tok);
Radek Krejcib1646a92018-11-02 16:08:26 +0100431
432/**
Michal Vasko03ff5a72019-09-11 13:49:33 +0200433 * @brief Frees a parsed XPath expression. @p expr should not be used afterwards.
Radek Krejcib1646a92018-11-02 16:08:26 +0100434 *
435 * @param[in] ctx libyang context of the expression.
436 * @param[in] expr Expression to free.
437 */
Michal Vasko14676352020-05-29 11:35:55 +0200438void lyxp_expr_free(const struct ly_ctx *ctx, struct lyxp_expr *expr);
Radek Krejcib1646a92018-11-02 16:08:26 +0100439
Michal Vasko14676352020-05-29 11:35:55 +0200440#endif /* LY_XPATH_H */