Set of helpers working on a subset of xpath expressions used of node identification Functions modify inputs arguments by placing termination zero at appropriate places to save up string duplication. The state of processing is stored in sr_xpath_ctx_t opaque for user. It allows to continue in processing where the processing stopped or recover processed input. More...

Data Structures
struct	sr_xpath_ctx_s
	State of xpath parsing. User must not modify nor rely on the content of the structure. More...

Typedefs
typedef struct sr_xpath_ctx_s	sr_xpath_ctx_t
	State of xpath parsing. User must not modify nor rely on the content of the structure. More...

Functions
char *	sr_xpath_key_value (char xpath, const char node_name, const char key_name, sr_xpath_ctx_t state)
	Looks up the value of the key in a node specified by name. More...

char *	sr_xpath_key_value_idx (char xpath, size_t node_index, size_t key_index, sr_xpath_ctx_t state)
	Looks up the value of the key in a node specified by index. First node has index zero. More...

char *	sr_xpath_last_node (char xpath, sr_xpath_ctx_t state)
	Returns pointer to the last node. More...

char *	sr_xpath_next_key_name (char xpath, sr_xpath_ctx_t state)
	Returns the name of the next key at the current level in processed xpath. More...

char *	sr_xpath_next_key_value (char xpath, sr_xpath_ctx_t state)
	Returns the value of the next key at the current level in processed xpath. More...

char *	sr_xpath_next_node (char xpath, sr_xpath_ctx_t state)
	The function returns a pointer to the following node. If xpath is not NULL returns the first node name, otherwise returns the subsequent node according to the state. More...

char *	sr_xpath_next_node_with_ns (char xpath, sr_xpath_ctx_t state)
	Same as sr_xpath_next_node with the difference that namespace is included in result if present in xpath. More...

char *	sr_xpath_node (char xpath, const char node_name, sr_xpath_ctx_t *state)
	Returns a pointer to the node specified by name. It searches from the beginning of the xpath, returns first match. Can be used to jump at the desired node xpath and subsequent analysis of key values. More...

char *	sr_xpath_node_idx (char xpath, size_t index, sr_xpath_ctx_t state)
	Returns node specified by index starting at the begin of expression. First node has index 0. More...

char *	sr_xpath_node_idx_rel (char xpath, size_t index, sr_xpath_ctx_t state)
	Return node specified by index. Following node has index zero. More...

char *	sr_xpath_node_key_value (char xpath, const char key, sr_xpath_ctx_t *state)
	Looks up the value for the key at the current level in xpath. More...

char *	sr_xpath_node_key_value_idx (char xpath, size_t index, sr_xpath_ctx_t state)
	Looks up the value for the key at the current level in xpath specified by index. First key has index zero. More...

char *	sr_xpath_node_name (const char *xpath)
	Returns pointer to the string after the last slash in xpath (node name). More...

int	sr_xpath_node_name_eq (const char xpath, const char node_str)
	Compares string after the last slash in xpath (node name) with provided string. More...

char *	sr_xpath_node_rel (char xpath, const char node_name, sr_xpath_ctx_t *state)
	Similar to sr_xpath_node. The difference is that search start at current node according to the state. More...

void	sr_xpath_recover (sr_xpath_ctx_t *state)
	Recovers the xpath string to the original state (puts back the character that was replaced by termination zero). More...

Detailed Description

Set of helpers working on a subset of xpath expressions used of node identification Functions modify inputs arguments by placing termination zero at appropriate places to save up string duplication. The state of processing is stored in sr_xpath_ctx_t opaque for user. It allows to continue in processing where the processing stopped or recover processed input.

Similarly to strtok function in all subsequent calls that is supposed to work with the same input xpath must be NULL.

Note: All of these functions are quite inefficient! If that matters, it is best not to use them.

Data Structure Documentation

struct sr_xpath_ctx_s

State of xpath parsing. User must not modify nor rely on the content of the structure.

Definition at line 45 of file xpath.h.

Data Fields
char *	begining	Pointer to the begining of the processed string
char *	current_node	Pointer to the currently processed node, used as a context for key search
char	replaced_char	Character that was overwritten by the last termination 0
char *	replaced_position	Pointer to the posistion where the last terminating 0 by was written

Typedef Documentation

typedef struct sr_xpath_ctx_s sr_xpath_ctx_t

State of xpath parsing. User must not modify nor rely on the content of the structure.

Function Documentation

char* sr_xpath_key_value	(	char *	xpath,
		const char *	node_name,
		const char *	key_name,
		sr_xpath_ctx_t *	state
	)

Looks up the value of the key in a node specified by name.

Parameters

[in]	xpath
[in]	node_name
[in]	key_name
[in]	state

Returns: Pointer to the key value, NULL if not found

char* sr_xpath_key_value_idx	(	char *	xpath,
		size_t	node_index,
		size_t	key_index,
		sr_xpath_ctx_t *	state
	)

Looks up the value of the key in a node specified by index. First node has index zero.

Parameters

[in]	xpath
[in]	node_index
[in]	key_index
[in]	state

Returns: Pointer to the key value, NULL if not found or index out of bound

char* sr_xpath_last_node	(	char *	xpath,
		sr_xpath_ctx_t *	state
	)

Returns pointer to the last node.

Parameters

[in]	xpath
[in]	state

Returns: Pointer to the last node

char* sr_xpath_next_key_name	(	char *	xpath,
		sr_xpath_ctx_t *	state
	)

Returns the name of the next key at the current level in processed xpath.

Parameters

[in]	xpath
[in]	state

Returns: Pointer to the key name, NULL if there are no more keys at the current level

char* sr_xpath_next_key_value	(	char *	xpath,
		sr_xpath_ctx_t *	state
	)

Returns the value of the next key at the current level in processed xpath.

Parameters

[in]	xpath
[in]	state

Returns: Pointer to the key value, NULL if there are no more keys at the current level

char* sr_xpath_next_node	(	char *	xpath,
		sr_xpath_ctx_t *	state
	)

The function returns a pointer to the following node. If xpath is not NULL returns the first node name, otherwise returns the subsequent node according to the state.

The state is modified upon function successful return from function, so the subsequent calls can continue in processing or xpath can be recovered by calling sr_xpath_recover.

Note: It writes terminating zero at the and of the node name.; Skips the namespace if it is present to get node name qualified by namespace use sr_xpath_next_node_with_ns

Parameters

[in]	xpath	- xpath to be processed, can be NULL
[in]	state

Returns: Pointer to the node name, NULL if there are no more node names

char* sr_xpath_next_node_with_ns	(	char *	xpath,
		sr_xpath_ctx_t *	state
	)

Same as sr_xpath_next_node with the difference that namespace is included in result if present in xpath.

Parameters

[in]	xpath	- xpath to be processed, can be NULL if the user wants to continue in processing of previous input
[in]	state

Returns: Pointer to the node name including namespace, NULL if there are no more node names

char* sr_xpath_node	(	char *	xpath,
		const char *	node_name,
		sr_xpath_ctx_t *	state
	)

Returns a pointer to the node specified by name. It searches from the beginning of the xpath, returns first match. Can be used to jump at the desired node xpath and subsequent analysis of key values.

Parameters

[in]	xpath
[in]	node_name
[in]	state

Returns: Pointer to the node, NULL if the node with the specified name is not found

char* sr_xpath_node_idx	(	char *	xpath,
		size_t	index,
		sr_xpath_ctx_t *	state
	)

Returns node specified by index starting at the begin of expression. First node has index 0.

Parameters

[in]	xpath
[in]	index
[in]	state

Returns: Pointer to the specified node, NULL if the index is out of bounds

char* sr_xpath_node_idx_rel	(	char *	xpath,
		size_t	index,
		sr_xpath_ctx_t *	state
	)

Return node specified by index. Following node has index zero.

Parameters

[in]	xpath
[in]	index
[in]	state

Returns: Pointer to the specified node, NULL if the index is out of bounds

char* sr_xpath_node_key_value	(	char *	xpath,
		const char *	key,
		sr_xpath_ctx_t *	state
	)

Looks up the value for the key at the current level in xpath.

Parameters

[in]	xpath
[in]	key	- key name to be looked up
[in]	state

Returns: Key value, NULL if the key with the specified name is not found

char* sr_xpath_node_key_value_idx	(	char *	xpath,
		size_t	index,
		sr_xpath_ctx_t *	state
	)

Looks up the value for the key at the current level in xpath specified by index. First key has index zero.

Parameters

[in]	xpath
[in]	index
[in]	state

Returns: Key value, NULL if the index is out of bound

char* sr_xpath_node_name ( const char * xpath )

Returns pointer to the string after the last slash in xpath (node name).

Note: The returned string can also contain namespace and/or key values if they were specified for the last node in xpath.

Parameters

[in] xpath

Returns: Result, NULL in case of the slash was not found

int sr_xpath_node_name_eq	(	const char *	xpath,
		const char *	node_str
	)

Compares string after the last slash in xpath (node name) with provided string.

Note: The returned string can also contain namespace and/or key values if they were specified for the last node in xpath.

Parameters

[in]	xpath
[in]	node_str	String to test for equality.

Returns: true in case that the Node names are equal, false otherwise

char* sr_xpath_node_rel	(	char *	xpath,
		const char *	node_name,
		sr_xpath_ctx_t *	state
	)

Similar to sr_xpath_node. The difference is that search start at current node according to the state.

Parameters

[in]	xpath
[in]	node_name
[in]	state

Returns: Pointer to the node, NULL if the node with the specified name is not found

void sr_xpath_recover ( sr_xpath_ctx_t * state )

Recovers the xpath string to the original state (puts back the character that was replaced by termination zero).

Parameters

[in] state

Data Structures

Typedefs

Functions

Detailed Description

Data Structure Documentation

Typedef Documentation

Function Documentation