blob: 1ef3dfcfd922bcf0bd06b5f8224998e86ad18eb7 [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
aPiecekbf968d92021-05-27 14:35:05 +020090/* Maximum number of nested expressions. */
91#define LYXP_MAX_BLOCK_DEPTH 100
92
Radek Krejcib1646a92018-11-02 16:08:26 +010093/**
94 * @brief Tokens that can be in an XPath expression.
95 */
96enum lyxp_token {
97 LYXP_TOKEN_NONE = 0,
98 LYXP_TOKEN_PAR1, /* '(' */
99 LYXP_TOKEN_PAR2, /* ')' */
100 LYXP_TOKEN_BRACK1, /* '[' */
101 LYXP_TOKEN_BRACK2, /* ']' */
102 LYXP_TOKEN_DOT, /* '.' */
103 LYXP_TOKEN_DDOT, /* '..' */
104 LYXP_TOKEN_AT, /* '@' */
105 LYXP_TOKEN_COMMA, /* ',' */
106 /* LYXP_TOKEN_DCOLON, * '::' * axes not supported */
107 LYXP_TOKEN_NAMETEST, /* NameTest */
108 LYXP_TOKEN_NODETYPE, /* NodeType */
109 LYXP_TOKEN_FUNCNAME, /* FunctionName */
Michal Vasko3e48bf32020-06-01 08:39:07 +0200110 LYXP_TOKEN_OPER_LOG, /* Operator 'and', 'or' */
111 LYXP_TOKEN_OPER_EQUAL, /* Operator '=' */
112 LYXP_TOKEN_OPER_NEQUAL, /* Operator '!=' */
113 LYXP_TOKEN_OPER_COMP, /* Operator '<', '<=', '>', '>=' */
114 LYXP_TOKEN_OPER_MATH, /* Operator '+', '-', '*', 'div', 'mod', '-' (unary) */
115 LYXP_TOKEN_OPER_UNI, /* Operator '|' */
116 LYXP_TOKEN_OPER_PATH, /* Operator '/' */
117 LYXP_TOKEN_OPER_RPATH, /* Operator '//' (recursive path) */
Radek Krejcib1646a92018-11-02 16:08:26 +0100118 /* LYXP_TOKEN_AXISNAME, * AxisName * axes not supported */
119 LYXP_TOKEN_LITERAL, /* Literal - with either single or double quote */
120 LYXP_TOKEN_NUMBER /* Number */
121};
122
123/**
124 * @brief XPath (sub)expressions that can be repeated.
125 */
126enum lyxp_expr_type {
127 LYXP_EXPR_NONE = 0,
128 LYXP_EXPR_OR,
129 LYXP_EXPR_AND,
130 LYXP_EXPR_EQUALITY,
131 LYXP_EXPR_RELATIONAL,
132 LYXP_EXPR_ADDITIVE,
133 LYXP_EXPR_MULTIPLICATIVE,
134 LYXP_EXPR_UNARY,
Michal Vasko69730152020-10-09 16:30:07 +0200135 LYXP_EXPR_UNION
Radek Krejcib1646a92018-11-02 16:08:26 +0100136};
137
138/**
Michal Vasko03ff5a72019-09-11 13:49:33 +0200139 * @brief Types of context nodes, #LYXP_NODE_ROOT_CONFIG used only in when or must conditions.
140 */
141enum lyxp_node_type {
Michal Vasko2caefc12019-11-14 16:07:56 +0100142 LYXP_NODE_NONE, /* invalid node type */
143
Michal Vasko03ff5a72019-09-11 13:49:33 +0200144 /* XML document roots */
145 LYXP_NODE_ROOT, /* access to all the data (node value first top-level node) */
146 LYXP_NODE_ROOT_CONFIG, /* <running> data context, no state data (node value first top-level node) */
147
148 /* XML elements */
Michal Vasko9f96a052020-03-10 09:41:45 +0100149 LYXP_NODE_ELEM, /* YANG data element (most common) */
150 LYXP_NODE_TEXT, /* YANG data text element (extremely specific use, unlikely to be ever needed) */
151 LYXP_NODE_META /* YANG metadata (do not use for the context node) */
Michal Vasko03ff5a72019-09-11 13:49:33 +0200152};
153
154/**
Radek Krejcib1646a92018-11-02 16:08:26 +0100155 * @brief Structure holding a parsed XPath expression.
156 */
157struct lyxp_expr {
158 enum lyxp_token *tokens; /* array of tokens */
159 uint16_t *tok_pos; /* array of the token offsets in expr */
160 uint16_t *tok_len; /* array of token lengths in expr */
161 enum lyxp_expr_type **repeat; /* array of expression types that this token begins and is repeated ended with 0,
162 more in the comment after this declaration */
163 uint16_t used; /* used array items */
164 uint16_t size; /* allocated array items */
165
166 const char *expr; /* the original XPath expression */
167};
168
169/*
170 * lyxp_expr repeat
171 *
172 * This value is NULL for all the tokens that do not begin an
173 * expression which can be repeated. Otherwise it is an array
174 * of expression types that this token begins. These values
175 * are used during evaluation to know whether we need to
176 * duplicate the current context or not and to decide what
177 * the current expression is (for example, if we are only
178 * starting the parsing and the first token has no repeat,
179 * we do not parse it as an OrExpr but directly as PathExpr).
180 * Examples:
181 *
182 * Expression: "/ *[key1 and key2 or key1 < key2]"
183 * Tokens: '/', '*', '[', NameTest, 'and', NameTest, 'or', NameTest, '<', NameTest, ']'
184 * Repeat: NULL, NULL, NULL, [AndExpr, NULL, NULL, NULL, [RelationalExpr, NULL, NULL, NULL
185 * OrExpr, 0],
186 * 0],
187 *
188 * Expression: "//node[key and node2]/key | /cont"
189 * Tokens: '//', 'NameTest', '[', 'NameTest', 'and', 'NameTest', ']', '/', 'NameTest', '|', '/', 'NameTest'
190 * Repeat: [UnionExpr, NULL, NULL, [AndExpr, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
191 * 0], 0],
192 *
193 * Operators between expressions which this concerns:
194 * 'or', 'and', '=', '!=', '<', '>', '<=', '>=', '+', '-', '*', 'div', 'mod', '|'
195 */
196
197/**
198 * @brief Supported types of (partial) XPath results.
199 */
200enum lyxp_set_type {
Michal Vaskod3678892020-05-21 10:06:58 +0200201 LYXP_SET_NODE_SET = 0,
Michal Vasko03ff5a72019-09-11 13:49:33 +0200202 LYXP_SET_SCNODE_SET,
Radek Krejcib1646a92018-11-02 16:08:26 +0100203 LYXP_SET_BOOLEAN,
204 LYXP_SET_NUMBER,
205 LYXP_SET_STRING
206};
Radek Krejcib1646a92018-11-02 16:08:26 +0100207
208/**
209 * @brief Item stored in an XPath set hash table.
210 */
211struct lyxp_set_hash_node {
212 struct lyd_node *node;
213 enum lyxp_node_type type;
214} _PACKED;
215
Radek Krejcib1646a92018-11-02 16:08:26 +0100216/**
217 * @brief XPath set - (partial) result.
218 */
219struct lyxp_set {
220 enum lyxp_set_type type;
221 union {
222 struct lyxp_set_node {
223 struct lyd_node *node;
224 enum lyxp_node_type type;
225 uint32_t pos;
226 } *nodes;
Michal Vasko03ff5a72019-09-11 13:49:33 +0200227 struct lyxp_set_scnode {
228 struct lysc_node *scnode;
Radek Krejcib1646a92018-11-02 16:08:26 +0100229 enum lyxp_node_type type;
Radek Krejcif13b87b2020-12-01 22:02:17 +0100230
Michal Vaskod97959c2020-12-10 12:18:28 +0100231/* _START and _ATOM values should have grouped values */
Radek Krejcif13b87b2020-12-01 22:02:17 +0100232#define LYXP_SET_SCNODE_START -2 /**< scnode not traversed, currently (the only node) in context */
233#define LYXP_SET_SCNODE_START_USED -1 /**< scnode not traversed except for the eval start, not currently in the context */
Michal Vasko1a09b212021-05-06 13:00:10 +0200234#define LYXP_SET_SCNODE_ATOM_NODE 0 /**< scnode was traversed, but not currently in the context */
235#define LYXP_SET_SCNODE_ATOM_VAL 1 /**< scnode was traversed and its value used, but not currently in the context */
236#define LYXP_SET_SCNODE_ATOM_CTX 2 /**< scnode currently in context */
237#define LYXP_SET_SCNODE_ATOM_NEW_CTX 3 /**< scnode in context and just added, so skip it for the current operation */
238#define LYXP_SET_SCNODE_ATOM_PRED_CTX 4 /**< includes any higher value - scnode is not in context because we are in
Radek Krejcif13b87b2020-12-01 22:02:17 +0100239 a predicate and this scnode was used/will be used later */
240 int32_t in_ctx; /**< values defined as LYXP_SET_SCNODE_* */
Michal Vasko03ff5a72019-09-11 13:49:33 +0200241 } *scnodes;
Michal Vasko9f96a052020-03-10 09:41:45 +0100242 struct lyxp_set_meta {
243 struct lyd_meta *meta;
Radek Krejcib1646a92018-11-02 16:08:26 +0100244 enum lyxp_node_type type;
Michal Vasko9f96a052020-03-10 09:41:45 +0100245 uint32_t pos; /* if node_type is LYXP_SET_NODE_META, it is the parent node position */
246 } *meta;
Radek Krejcib1646a92018-11-02 16:08:26 +0100247 char *str;
248 long double num;
Radek Krejci857189e2020-09-01 13:26:36 +0200249 ly_bool bln; /* boolean */
Radek Krejcib1646a92018-11-02 16:08:26 +0100250 } val;
251
Michal Vasko03ff5a72019-09-11 13:49:33 +0200252 /* this is valid only for type LYXP_SET_NODE_SET and LYXP_SET_SCNODE_SET */
Radek Krejcib1646a92018-11-02 16:08:26 +0100253 uint32_t used;
254 uint32_t size;
Radek Krejcib1646a92018-11-02 16:08:26 +0100255 struct hash_table *ht;
Michal Vasko03ff5a72019-09-11 13:49:33 +0200256
257 /* XPath context information, this is valid only for type LYXP_SET_NODE_SET */
Radek Krejcib1646a92018-11-02 16:08:26 +0100258 uint32_t ctx_pos;
259 uint32_t ctx_size;
Michal Vasko03ff5a72019-09-11 13:49:33 +0200260
261 /* general context */
262 struct ly_ctx *ctx;
263 union {
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200264 const struct lyd_node *cur_node;
265 const struct lysc_node *cur_scnode;
Michal Vasko03ff5a72019-09-11 13:49:33 +0200266 };
Michal Vasko5e0e6eb2019-11-06 15:47:50 +0100267 enum lyxp_node_type root_type;
Michal Vasko6b26e742020-07-17 15:02:10 +0200268 const struct lysc_node *context_op;
Michal Vaskof03ed032020-03-04 13:31:44 +0100269 const struct lyd_node *tree;
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200270 const struct lys_module *cur_mod;
Radek Krejci8df109d2021-04-23 12:19:08 +0200271 LY_VALUE_FORMAT format;
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200272 void *prefix_data;
Radek Krejcib1646a92018-11-02 16:08:26 +0100273};
274
275/**
Michal Vasko24cddf82020-06-01 08:17:01 +0200276 * @brief Print an XPath token \p tok type.
277 *
278 * @param[in] tok Token to print.
279 * @return Token type string.
280 */
281const char *lyxp_print_token(enum lyxp_token tok);
282
283/**
Michal Vasko03ff5a72019-09-11 13:49:33 +0200284 * @brief Evaluate an XPath expression on data. Be careful when using this function, the result can often
285 * be confusing without thorough understanding of XPath evaluation rules defined in RFC 7950.
Radek Krejcib1646a92018-11-02 16:08:26 +0100286 *
Michal Vasko400e9672021-01-11 13:39:17 +0100287 * @param[in] ctx libyang context to use.
Michal Vaskoecd62de2019-11-13 12:35:11 +0100288 * @param[in] exp Parsed XPath expression to be evaluated.
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200289 * @param[in] cur_mod Current module for the expression (where it was "instantiated").
aPiecekb0445f22021-06-24 11:34:07 +0200290 * @param[in] format Format of the XPath expression (more specifically, of any used prefixes).
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200291 * @param[in] prefix_data Format-specific prefix data (see ::ly_resolve_prefix).
292 * @param[in] ctx_node Current (context) data node, NULL in case of the root node.
Michal Vaskof03ed032020-03-04 13:31:44 +0100293 * @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 +0100294 * the tree of @p ctx_node). Can be any node of the tree, it is adjusted.
Michal Vasko004d3152020-06-11 19:59:22 +0200295 * @param[out] set Result set.
Radek Krejcib1646a92018-11-02 16:08:26 +0100296 * @param[in] options Whether to apply some evaluation restrictions.
Michal Vasko004d3152020-06-11 19:59:22 +0200297 * @return LY_EVALID for invalid argument types/count,
298 * @return LY_EINCOMPLETE for unresolved when,
299 * @return LY_EINVAL, LY_EMEM, LY_EINT for other errors.
Radek Krejcib1646a92018-11-02 16:08:26 +0100300 */
Michal Vasko400e9672021-01-11 13:39:17 +0100301LY_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 +0200302 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 +0100303 struct lyxp_set *set, uint32_t options);
Michal Vasko03ff5a72019-09-11 13:49:33 +0200304
Radek Krejcib1646a92018-11-02 16:08:26 +0100305/**
Michal Vasko03ff5a72019-09-11 13:49:33 +0200306 * @brief Get all the partial XPath nodes (atoms) that are required for @p exp to be evaluated.
Radek Krejcib1646a92018-11-02 16:08:26 +0100307 *
Michal Vasko400e9672021-01-11 13:39:17 +0100308 * @param[in] ctx libyang context to use.
Michal Vasko03ff5a72019-09-11 13:49:33 +0200309 * @param[in] exp Parsed XPath expression to be evaluated.
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200310 * @param[in] cur_mod Current module for the expression (where it was "instantiated").
aPiecekb0445f22021-06-24 11:34:07 +0200311 * @param[in] format Format of the XPath expression (more specifically, of any used prefixes).
Michal Vasko5d24f6c2020-10-13 13:49:06 +0200312 * @param[in] prefix_data Format-specific prefix data (see ::ly_resolve_prefix).
313 * @param[in] ctx_scnode Current (context) schema node, NULL in case of the root node.
Michal Vasko004d3152020-06-11 19:59:22 +0200314 * @param[out] set Result set.
Radek Krejcib1646a92018-11-02 16:08:26 +0100315 * @param[in] options Whether to apply some evaluation restrictions, one flag must always be used.
Radek Krejci8678fa42020-08-18 16:07:28 +0200316 * @return LY_ERR (same as ::lyxp_eval()).
Radek Krejcib1646a92018-11-02 16:08:26 +0100317 */
Michal Vasko400e9672021-01-11 13:39:17 +0100318LY_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 +0200319 LY_VALUE_FORMAT format, void *prefix_data, const struct lysc_node *ctx_scnode, struct lyxp_set *set,
Michal Vasko400e9672021-01-11 13:39:17 +0100320 uint32_t options);
Radek Krejcib1646a92018-11-02 16:08:26 +0100321
Radek Krejcibed13942020-10-19 16:06:28 +0200322/* used only internally, maps with @ref findxpathoptions */
Michal Vaskocdad7122020-11-09 21:04:44 +0100323#define LYXP_IGNORE_WHEN 0x01 /**< Ignore unevaluated when in data nodes and do not return ::LY_EINCOMPLETE. */
324#define LYXP_SCHEMA 0x02 /**< Apply data node access restrictions defined for 'when' and 'must' evaluation. */
325#define LYXP_SCNODE 0x04 /**< No special tree access modifiers. */
326#define LYXP_SCNODE_SCHEMA LYS_FIND_XP_SCHEMA /**< Apply node access restrictions defined for 'when' and 'must' evaluation. */
327#define LYXP_SCNODE_OUTPUT LYS_FIND_XP_OUTPUT /**< Search RPC/action output nodes instead of input ones. */
328#define LYXP_SCNODE_ALL 0x1C /**< mask for all the LYXP_* values */
aPiecek8b0cc152021-05-31 16:40:31 +0200329#define LYXP_SKIP_EXPR 0x20 /**< The rest of the expression will not be evaluated (lazy evaluation) */
Radek Krejcib1646a92018-11-02 16:08:26 +0100330
331/**
Radek Krejcib1646a92018-11-02 16:08:26 +0100332 * @brief Cast XPath set to another type.
333 * Indirectly context position aware.
334 *
335 * @param[in] set Set to cast.
336 * @param[in] target Target type to cast \p set into.
Michal Vasko03ff5a72019-09-11 13:49:33 +0200337 * @return LY_ERR
Radek Krejcib1646a92018-11-02 16:08:26 +0100338 */
Michal Vasko5e0e6eb2019-11-06 15:47:50 +0100339LY_ERR lyxp_set_cast(struct lyxp_set *set, enum lyxp_set_type target);
Michal Vasko03ff5a72019-09-11 13:49:33 +0200340
Radek Krejcib1646a92018-11-02 16:08:26 +0100341/**
Michal Vaskod3678892020-05-21 10:06:58 +0200342 * @brief Free dynamic content of a set.
343 *
344 * @param[in] set Set to modify.
345 */
346void lyxp_set_free_content(struct lyxp_set *set);
347
348/**
Michal Vaskoecd62de2019-11-13 12:35:11 +0100349 * @brief Insert schema node into set.
350 *
351 * @param[in] set Set to insert into.
352 * @param[in] node Node to insert.
353 * @param[in] node_type Node type of @p node.
Radek Krejciaa6b53f2020-08-27 15:19:03 +0200354 * @param[out] index_p Optional pointer to store index if the inserted @p node.
355 * @return LY_SUCCESS on success.
356 * @return LY_EMEM on memory allocation failure.
Michal Vaskoecd62de2019-11-13 12:35:11 +0100357 */
Michal Vaskoee38a5d2020-11-09 21:02:18 +0100358LY_ERR lyxp_set_scnode_insert_node(struct lyxp_set *set, const struct lysc_node *node, enum lyxp_node_type node_type,
359 uint32_t *index_p);
Michal Vaskoecd62de2019-11-13 12:35:11 +0100360
361/**
362 * @brief Check for duplicates in a schema node set.
363 *
364 * @param[in] set Set to check.
365 * @param[in] node Node to look for in @p set.
366 * @param[in] node_type Type of @p node.
367 * @param[in] skip_idx Index from @p set to skip.
Radek Krejciaa6b53f2020-08-27 15:19:03 +0200368 * @param[out] index_p Optional pointer to store index if the node is found.
Radek Krejci857189e2020-09-01 13:26:36 +0200369 * @return Boolean value whether the @p node found or not.
Michal Vaskoecd62de2019-11-13 12:35:11 +0100370 */
Radek Krejci857189e2020-09-01 13:26:36 +0200371ly_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 +0200372 int skip_idx, uint32_t *index_p);
Michal Vaskoecd62de2019-11-13 12:35:11 +0100373
374/**
375 * @brief Merge 2 schema node sets.
376 *
377 * @param[in] set1 Set to merge into.
378 * @param[in] set2 Set to merge. Its content is freed.
379 */
380void lyxp_set_scnode_merge(struct lyxp_set *set1, struct lyxp_set *set2);
381
382/**
Radek Krejcib1646a92018-11-02 16:08:26 +0100383 * @brief Parse an XPath expression into a structure of tokens.
384 * Logs directly.
385 *
Michal Vasko03ff5a72019-09-11 13:49:33 +0200386 * https://www.w3.org/TR/1999/REC-xpath-19991116/#exprlex
Radek Krejcib1646a92018-11-02 16:08:26 +0100387 *
388 * @param[in] ctx Context for errors.
Radek Krejcif03a9e22020-09-18 20:09:31 +0200389 * @param[in] expr_str XPath expression to parse. It is duplicated.
Michal Vasko004d3152020-06-11 19:59:22 +0200390 * @param[in] expr_len Length of @p expr, can be 0 if @p expr is 0-terminated.
391 * @param[in] reparse Whether to re-parse the expression to finalize full XPath parsing and fill
392 * information about expressions and their operators (fill repeat).
Radek Krejcif03a9e22020-09-18 20:09:31 +0200393 * @param[out] expr_p Pointer to return the filled expression structure.
394 * @return LY_SUCCESS in case of success.
395 * @return LY_EMEM in case of memory allocation failure.
396 * @return LY_EVALID in case of invalid XPath expression in @p expr_str.
Radek Krejcib1646a92018-11-02 16:08:26 +0100397 */
Michal Vaskoee38a5d2020-11-09 21:02:18 +0100398LY_ERR lyxp_expr_parse(const struct ly_ctx *ctx, const char *expr_str, size_t expr_len, ly_bool reparse,
399 struct lyxp_expr **expr_p);
Michal Vasko004d3152020-06-11 19:59:22 +0200400
401/**
402 * @brief Duplicate parsed XPath expression.
403 *
404 * @param[in] ctx Context with a dictionary.
405 * @param[in] exp Parsed expression.
Michal Vasko1734be92020-09-22 08:55:10 +0200406 * @param[out] dup Duplicated structure.
407 * @return LY_ERR value.
Michal Vasko004d3152020-06-11 19:59:22 +0200408 */
Michal Vasko1734be92020-09-22 08:55:10 +0200409LY_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 +0200410
411/**
412 * @brief Look at the next token and check its kind.
413 *
414 * @param[in] ctx Context for logging, not logged if NULL.
415 * @param[in] exp Expression to use.
Michal Vasko004d3152020-06-11 19:59:22 +0200416 * @param[in] tok_idx Token index in the expression \p exp.
Michal Vasko14676352020-05-29 11:35:55 +0200417 * @param[in] want_tok Expected token.
418 * @return LY_EINCOMPLETE on EOF,
419 * @return LY_ENOT on non-matching token,
420 * @return LY_SUCCESS on success.
421 */
Michal Vasko004d3152020-06-11 19:59:22 +0200422LY_ERR lyxp_check_token(const struct ly_ctx *ctx, const struct lyxp_expr *exp, uint16_t tok_idx, enum lyxp_token want_tok);
423
424/**
425 * @brief Look at the next token and skip it if it matches the expected one.
426 *
427 * @param[in] ctx Context for logging, not logged if NULL.
428 * @param[in] exp Expression to use.
429 * @param[in,out] tok_idx Token index in the expression \p exp, is updated.
430 * @param[in] want_tok Expected token.
431 * @return LY_EINCOMPLETE on EOF,
432 * @return LY_ENOT on non-matching token,
433 * @return LY_SUCCESS on success.
434 */
435LY_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 +0100436
437/**
Michal Vasko4911eeb2021-06-28 11:23:05 +0200438 * @brief Look at the next token and skip it if it matches either of the 2 expected ones.
439 *
440 * @param[in] ctx Context for logging, not logged if NULL.
441 * @param[in] exp Expression to use.
442 * @param[in,out] tok_idx Token index in the expression \p exp, is updated.
443 * @param[in] want_tok1 Expected token 1.
444 * @param[in] want_tok2 Expected token 2.
445 * @return LY_EINCOMPLETE on EOF,
446 * @return LY_ENOT on non-matching token,
447 * @return LY_SUCCESS on success.
448 */
449LY_ERR lyxp_next_token2(const struct ly_ctx *ctx, const struct lyxp_expr *exp, uint16_t *tok_idx,
450 enum lyxp_token want_tok1, enum lyxp_token want_tok2);
451
452/**
Michal Vasko03ff5a72019-09-11 13:49:33 +0200453 * @brief Frees a parsed XPath expression. @p expr should not be used afterwards.
Radek Krejcib1646a92018-11-02 16:08:26 +0100454 *
455 * @param[in] ctx libyang context of the expression.
456 * @param[in] expr Expression to free.
457 */
Michal Vasko14676352020-05-29 11:35:55 +0200458void lyxp_expr_free(const struct ly_ctx *ctx, struct lyxp_expr *expr);
Radek Krejcib1646a92018-11-02 16:08:26 +0100459
Michal Vasko14676352020-05-29 11:35:55 +0200460#endif /* LY_XPATH_H */