XPath parser control block. More...

#include <xpath.h>

Collaboration diagram for xpath_pcb_t:

[legend]

Data Fields
dlq_hdr_t	qhdr
	queue header in case saved in a Q

tk_chain_t *	tkc
	token chain for exprstr, Often saved and reset each evaluation so the parse is done only once

xpath_source_t	source
	the prefixes in the QNames in the exprstr MUST be resolved in different contexts. More...

ncx_errinfo_t	errinfo
	must-stmt error info. More...

boolean	logerrors
	T: use log_error F: suppress error messages. More...

boolean	logwrongtype
	T: log wrong-type warnings. More...

boolean	missing_errors
	T: missing node is error.

obj_template_t *	targobj
	these parms are used to parse leafref path-arg limited object tree syntax allowed only targobj is bptr to result object

obj_template_t *	altobj
	bptr to pred. More...

obj_template_t *	varobj
	bptr to key-expr LHS object

xpath_curmode_t	curmode
	select targ/alt/var obj

obj_template_t *	obj
	these parms are used by leafref and XPath1 parsing obj is a bptr to start object

ncx_module_t *	objmod
	module containing obj. More...

ncx_module_t *	impmod
	[sub]module containing obj

ncx_module_t *	rootmod
	YPW-1416: track module in progress during deviation validation of leafref type replacement. More...

obj_template_t *	docroot
	document root. More...

obj_template_t *	startobj
	start object set for rpc,notif validation

val_value_t *	val
	saved state for the current() function result

val_value_t *	val_docroot
	cfg->root for db

xpath_document_t	doctype
	document context for this evaluation

struct xpath_get2_node_t_ *	val_get2
	YPW-1342 the context node can be one of the following nodes. More...

uint32	flags
	internal processing flags for managing XPath state

xpath_result_t *	result
	The XPath result for this evaluation. More...

xpath_resnode_t	context
	additive XPath1 context back- pointer to current step results. More...

xpath_result_t *	context_result
	internal context result during processing

xpath_getvar_fn_t	getvar_fn
	The getvar_fn callback function may be set to allow user variables to be supported in this XPath expression.

void *	cookie
	The cookie registered with the getvar_fn.

dlq_hdr_t	varbindQ
	The varbindQ may be used instead of the getvar_fn to store user variables to be supported in this XPath expression.

const struct xpath_fncb_t_ *	functions
	The function Q is a copy of the global Q It is not hardwired in case app-specific extensions are added later – array of xpath_fncb_t.

dlq_hdr_t	result_cacheQ
	Performance Caches. More...

dlq_hdr_t	resnode_cacheQ
	Q of xpath_resnode_t. More...

uint32	result_count
	The count of entries in the result_cacheQ.

uint32	resnode_count
	The count of entries in the resnode_cacheQ.

boolean	backptrs_mode
	must/when/data-rule obj_template_t backptr caching support backptrs in use

boolean	backptrs_manual_clear
	manual clear of backptrs needed

uint8	backptrs_flags
	internal state for backptr handling

ncx_xpath_type_t	xpath_type
	expression context

boolean	xpath_predicate
	true when processing a predicate

status_t	parseres
	first and second pass parsing results. More...

status_t	validateres
	validation stage result

status_t	valueres
	evaluation stage result

ncx_error_t	tkerr
	saved error info for the agent to process

boolean	seen
	internal yangdiff support

void *	yang_pcb
	backptr to yang parser control block in progress used to force an inline import instead of returning a mod-not-found error

dlq_hdr_t	get2_cbQ
	if GET2 callbacks needed to process the XPath expression then they will be stored in this queue and xpath_resnode_t structs will point at the get2 control block inside this Q that was used to retrieve the value

ses_cb_t *	scb
	backptr to session control block in progress. More...

xml_msg_hdr_t *	mhdr
	backptr to the message header in progress if processing an XPath select filter for NETCONF

struct getcb_get2_t_ *	get2cb
	the getcb for a NACM data rule test

dlq_hdr_t	pred_entQ
	Internal state processing, Q of xpath_pred_ent_t.

obj_template_t *	nonconfig_warn_obj
	backptr to object causing nonconfig warning if that is being checked in the obj_walker_fn callback in xpath1.c

dlq_hdr_t	get2_aio_cbQ
	if AIO GET2 callbacks needed to process the XPath expression then The Subtree returned from AIO GET2 callback will be split into separate level nodes and stored in this Queue. More...

boolean	disabled_obj_ok
	YPW-1774: need to ignore if-feature=false while validating leafref path-stmt. More...

ncx_sm_rootcb_t *	rootcb
	YPW-2079: backptr for current ROOTCB; used in leafref processing.

obj_template_t *	when_obj
	check special context rules for when-stmt If the when_obj is set then the original context and this object are checked to make sure the correct child nodes are visible as required in RFC 7950, sec. More...

Detailed Description

XPath parser control block.

This is the main control block used by external code.

An xpath_pcb_t is saved in a val_value_t when the node is parsed in XML. This is required so the namespace ID mappings can be gathered,

This struct is also saved in YANG validation code, especially for must, when, and leafref validation. Results are often cached in an xpath_result_t and saved with this struct

Field Documentation

◆ altobj

obj_template_t* altobj

bptr to pred.

RHS object

◆ context

xpath_resnode_t context

additive XPath1 context back- pointer to current step results.

initially NULL and modified until the expression is done relative context

◆ disabled_obj_ok

boolean disabled_obj_ok

YPW-1774: need to ignore if-feature=false while validating leafref path-stmt.

It is possible and valid if both the pointing-at leafref and the pointed-at leaf are both disabled with the same if-feature-stmt in both leafs

◆ docroot

obj_template_t* docroot

document root.

Usually a bptr to <config> obj

◆ errinfo

ncx_errinfo_t errinfo

must-stmt error info.

Extracted from the YANG module. Only used if this evaluation is for a must-stmt

◆ get2_aio_cbQ

dlq_hdr_t get2_aio_cbQ

if AIO GET2 callbacks needed to process the XPath expression then The Subtree returned from AIO GET2 callback will be split into separate level nodes and stored in this Queue.

So the xpath_resnode_t structs will point at the getcb that will be constructed using the values inside this Q that was used to retrieve the value Q of xpath_aio_cb_t

◆ logerrors

boolean logerrors

T: use log_error F: suppress error messages.

The parser is used for YANG validation, client validation server validation, and server datastore searches. Errors and warnings are often suppressed by the server.

◆ logwrongtype

boolean logwrongtype

T: log wrong-type warnings.

this is ignored if logerrors=false
this gets set to false if the expression starts with a double-slash. Need to suppress for widcard matches.

◆ objmod

ncx_module_t* objmod

module containing obj.

This is an important parameter for YANG validation and generating error messages for the correct module

◆ parseres

status_t parseres

first and second pass parsing results.

the next phase will not execute until all previous phases have a NO_ERR status

◆ resnode_cacheQ

dlq_hdr_t resnode_cacheQ

Q of xpath_resnode_t.

This is used to avoid malloc and free constantly while processing each step in a path expression.

◆ result

xpath_result_t* result

The XPath result for this evaluation.

Not always used

◆ result_cacheQ

dlq_hdr_t result_cacheQ

Performance Caches.

The xpath_result_t and xpath_resnode_t structs are used in many intermediate operations

These Qs are used to cache these structs instead of calling malloc and free constantly

The XPATH_RESULT_CACHE_MAX and XPATH_RESNODE_CACHE_MAX constants are used to control the max cache sizes This is not user-configurable (TBD).

The result_cacheQ is a Q of xpath_result_t used when intermediate results are needed.

◆ rootmod

ncx_module_t* rootmod

YPW-1416: track module in progress during deviation validation of leafref type replacement.

dev for this mod-in progress

◆ scb

ses_cb_t* scb

backptr to session control block in progress.

If GET2 nodes processing, it's required to SCB to be available, so the GET2 nodes processing can supply GET2 callback functions with SCB

◆ source

xpath_source_t source

the prefixes in the QNames in the exprstr MUST be resolved in different contexts.

For must/when/leafref XPath, the prefix is a module prefix which must match an import statement in the 'mod' import Q

For XML context (NETCONF PDU 'select' attribute) the prefix is part of an extended name, representing XML namespace for the module that defines that node

◆ val_get2

struct xpath_get2_node_t_* val_get2

YPW-1342 the context node can be one of the following nodes.

    obj_template_t  -->  pcb->obj
    val_value_t     -->  pcb->val
    xpath_get2_node_t  -->  pcb->val_get2

◆ when_obj

obj_template_t* when_obj

check special context rules for when-stmt If the when_obj is set then the original context and this object are checked to make sure the correct child nodes are visible as required in RFC 7950, sec.

7.21.5

The documentation for this struct was generated from the following file:

xpath.h

Data Fields