XML Parser for tiny systems. More...

Collaboration diagram for XML Parser:

Defines
#define	MAX_UXMLTAG_SIZE 512
	Maximum tag size including brackets.
#define	MAX_UXMLTKN_SIZE 64
	Maximum token size.
Functions
char *	UxmlParseTag (char data, char tkn, size_t size)
	Retrieve the next token from an XML tag.
int	UxmlFilterMatch (char name, char *filt)
	Check if name matches filter list.
UXML_NODE *	UxmlParseStream (FILE stream, char f_tags, char *f_attr)
	Parse XML stream.
UXML_NODE *	UxmlNodeCreate (char *name)
	Allocate a new tree node.
int	UxmlNodeAddAttrib (UXML_NODE node, char name, char *value)
	Add an attribute to the specified node.
UXML_NODE *	UxmlTreeAddSibling (UXML_NODE node, UXML_NODE sibling)
	Add a sibling to the specified node.
UXML_NODE *	UxmlTreeAddChild (UXML_NODE node, UXML_NODE child)
	Add a child to the specified node.
void	UxmlTreeDestroy (UXML_NODE *node)
	Release all memory of an XML tree structure.

Detailed Description

XML Parser for tiny systems.

Define Documentation

#define MAX_UXMLTAG_SIZE 512

Maximum tag size including brackets.

Larger tags will be silently discarded.

Referenced by UxmlParseStream().

#define MAX_UXMLTKN_SIZE 64

Maximum token size.

Larger tokens will be cut to the specified size. This may be fine for attribute values containing lengthy descriptions, but may be disastrous for tag or attribute names.

Referenced by UxmlParseStream().

Function Documentation

char* UxmlParseTag	(	char *	data,
		char *	tkn,
		size_t	size
	)

Retrieve the next token from an XML tag.

Parameters:

data	Pointer to the next character within the string to parse.
tkn	Pointer to the buffer that receives the next token.
size	Size of the token buffer.

Returns:: Pointer to the character following the one parsed last.

References NULL, and rc.

Referenced by UxmlParseStream().

int UxmlFilterMatch	(	char *	name,
		char **	filt
	)

Check if name matches filter list.

Parameters:

name	String to check against list.
filt	Array of filter strings.

Returns:: 1 if the name matches at list one filter string. Otherwise 0 is returned.

References NULL, and strcasecmp.

Referenced by UxmlParseStream().

UXML_NODE* UxmlParseStream	(	FILE *	stream,
		char **	f_tags,
		char **	f_attr
	)

Parse XML stream.

This is the main routine of the Micro XML Stream Parser. It reads the XML document from a previously opened stream and creates a corresponding tree structure.

Note, that this is a minimal and probably incomplete implementation, which had been specifically created to parse the SHOUTcast radio station list. On the other hand, it offers a practical XML parser solution for embedded systems with very low memory resources. Unlike most other implementations, it does not require to copy the whole XML document into internal memory. Instead, the parser reads and interprets individual tags. Furthermore, the caller may specify tag and attribute filters to reduce the resulting tree size. Be aware, that because of filtering the root of the tree may have siblings.

Normally the parser will return when the end of a file is reached. On TCP connections this may be either on connection close or timeout. If closing and re-opening connections may create too much overhead and timeouts are too slow, an EOF (ASCII 0) may be sent alternatively.

Parameters:

stream	The stream to read from.
f_tags	Optional tag filter, which points to an array of tag names to include. All other tags will be discarded. This can be used to limit memory consumption of the tree structure. Note, that this filtering may result in a tree structure, which is different from the structure of the original document. Set to NULL to disable tag filtering.
f_attr	Optional attribute filter, which points to an array of attribute names to include. All other attributes will be discarded. Like the tag filter, it can be used to limit memory consumption of the tree structure. Set to NULL to disable attribute filtering.

Returns:: Pointer to a newly allocated UXML_NODE tree structure. NULL may be returned in case of an error. The caller should use UxmlTreeDestroy() to release the memory allocated by the tree.

References free(), malloc(), MAX_UXMLTAG_SIZE, MAX_UXMLTKN_SIZE, NULL, NutHeapAvailable, strcasecmp, strdup(), strlen(), UxmlFilterMatch(), UxmlNodeAddAttrib(), UxmlNodeCreate(), UxmlParseTag(), UxmlTreeAddChild(), UxmlTreeAddSibling(), _UXML_NODE::xmln_name, and _UXML_NODE::xmln_parent.

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UXML_NODE* UxmlNodeCreate ( char * name )

Allocate a new tree node.

Parameters:

name	Name of the node to add.

Returns:: Pointer to the new node. In case of an error, NULL is returned.

References malloc(), memcpy(), memset(), NULL, strlen(), and _UXML_NODE::xmln_name.

Referenced by UxmlParseStream().

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int UxmlNodeAddAttrib	(	UXML_NODE *	node,
		char *	name,
		char *	value
	)

Add an attribute to the specified node.

Parameters:

node	The attribute is added to this node.
name	Attribute's name.
value	Attribute's value.

Returns:: 0 on success, -1 otherwise.

References attr, free(), malloc(), NULL, strdup(), _UXML_ATTRIB::xmla_name, _UXML_ATTRIB::xmla_next, _UXML_ATTRIB::xmla_value, and _UXML_NODE::xmln_attribs.

Referenced by UxmlParseStream().

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UXML_NODE* UxmlTreeAddSibling	(	UXML_NODE *	node,
		UXML_NODE *	sibling
	)

Add a sibling to the specified node.

Parameters:

node	The sibling is added to this node.
child	Sibling to add.

Returns:: Pointer to the sibling node.

References NULL, _UXML_NODE::xmln_next, and _UXML_NODE::xmln_parent.

Referenced by UxmlParseStream(), and UxmlTreeAddChild().

UXML_NODE* UxmlTreeAddChild	(	UXML_NODE *	node,
		UXML_NODE *	child
	)

Add a child to the specified node.

Parameters:

node	The child is added to this node.
child	Child to add.

Returns:: Pointer to the child node.

References NULL, UxmlTreeAddSibling(), _UXML_NODE::xmln_child, and _UXML_NODE::xmln_parent.

Referenced by UxmlParseStream().

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void UxmlTreeDestroy ( UXML_NODE * node )

Release all memory of an XML tree structure.

Parameters:

node	Pointer to the root entry.

References UxmlTreeDestroy(), _UXML_NODE::xmln_child, and _UXML_NODE::xmln_next.

Referenced by UxmlTreeDestroy().

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Defines

Functions

Detailed Description

Define Documentation

Function Documentation