statement.h File Reference

A set of methods to operate with statement. More...

#include "node.h"
#include <time.h>

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Data Structures
struct	_statement
	The statement structure. More...
Typedefs
typedef _statement	Statement
	The statement structure.
Enumerations
enum	ex_flags { STATEMENT_RETURN_LIE = 1, STATEMENT_SET_LIE = 1 }
enum	statement_mask {   NO_MASK = 0, CONTEXT_MASK = 1, PREDICATE_MASK = 2, SUBJECT_MASK = 4,   OBJECT_MASK = 8, MASK_ALL = 15 }
	Statement mask bits. More...
enum	statement_op { STATEMENT_OP_UNSET = 0, STATEMENT_OP_SET = 1, STATEMENT_OP_UNDEF = 2 }
	Statement operation field type. More...
Functions
STORAGE_TYPE void	statement_clear (Statement *stmt)
	Clears the statement's nodes.
STORAGE_TYPE Statement *	statement_clone (const Statement *src)
	Creates a copy of the source statement.
STORAGE_TYPE Statement *	statement_create (const Node *context, const Node *predicate, const Node *subject, const Node *object)
	Creates new statement object with filled values.
STORAGE_TYPE Statement *	statement_create_with_op (const Node *c, const Node *p, const Node *s, const Node *o, statement_op op)
	Creates a new statement with given operation.
STORAGE_TYPE void	statement_free (Statement *stmt)
	Destroys the statement.
STORAGE_TYPE const Node *	statement_get_context (const Statement *stmt)
	The statement context accessor.
STORAGE_TYPE time_t	statement_get_end (const Statement *stmt)
STORAGE_TYPE int	statement_get_mask (const Statement *stmt)
	The statement mask accessor.
STORAGE_TYPE const Node *	statement_get_object (const Statement *stmt)
	The statement object accessor.
STORAGE_TYPE statement_op	statement_get_op (const Statement *stmt)
	Returns statement operation.
STORAGE_TYPE const Node *	statement_get_predicate (const Statement *stmt)
	The statement predicate accessor.
STORAGE_TYPE time_t	statement_get_start (const Statement *stmt)
STORAGE_TYPE const Node *	statement_get_subject (const Statement *stmt)
	The statement subject accessor.
STORAGE_TYPE void	statement_init (Statement *stmt, const Node *c, const Node *p, const Node *s, const Node *o)
STORAGE_TYPE int	statement_match (const Statement *mask, const Statement *stmt)
	Check the matching of stmt against mask returns zero if there is no match and positive value otherwise.
STORAGE_TYPE Statement *	statement_new ()
	Creates empty statement object.
STORAGE_TYPE void	statement_result_append (Statement **result, Statement *s)
	Appends a new statement to the statement bunch.
STORAGE_TYPE void	statement_result_compact (unsigned *count, Statement ***result)
	Compacts the statement bunch.
STORAGE_TYPE unsigned int	statement_result_count (Statement *result)
STORAGE_TYPE void	statement_result_free (Statement **result)
	Destroys the result model_storage_get() and model_storage_get_nr() functions.
STORAGE_TYPE int	statement_result_pop (Statement **result, Statement *head)
	Withdraws the head of a list and returns it.
STORAGE_TYPE void	statement_result_remove (Statement **result, Statement *stmt)
	Removes from the bunch and frees the statement with given index.
STORAGE_TYPE void	statement_set_context (Statement *stmt, const Node *context)
	Sets the context of the statement.
STORAGE_TYPE void	statement_set_end (Statement *stmt, time_t t)
STORAGE_TYPE void	statement_set_mask (Statement *stmt, int mask)
	Sets the mask of the statement.
STORAGE_TYPE void	statement_set_object (Statement *stmt, const Node *object)
	Sets the object of the statement.
STORAGE_TYPE Statement *	statement_set_op (Statement *stmt, statement_op operation)
	Sets statement operation.
STORAGE_TYPE void	statement_set_predicate (Statement *stmt, const Node *predicate)
	Sets the predicate of the statement.
STORAGE_TYPE void	statement_set_start (Statement *stmt, time_t t)
STORAGE_TYPE void	statement_set_subject (Statement *stmt, const Node *subject)
	Sets the subject of the statement.
STORAGE_TYPE void	statement_swap_op (Statement *op)
	Swaps the operation of the statement and its previsous state.
STORAGE_TYPE Statement *	stmt_from_strings (const char *c, const char *p, const char *s, const char *o)
	Creates new statement that contains nodes, created from given literals.
STORAGE_TYPE void	stmt_init_from_strings (Statement *stmt, const char *c, const char *p, const char *s, const char *o)
	Automatically creates nodes from strings and initializes a statement with them.

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Detailed Description

A set of methods to operate with statement.

The statement holds four members (context, predicate, subject, object). These members are all of Node (Node) type.

To create a new statement:

 Statement *s;
 Node a,b,c,d;
 char *prefix = "noprefix";
 node_init_string(&a, prefix, "Context");
 node_init_string(&b, prefix, "Predicate");
 node_init_string(&c, prefix, "Subject");
 node_init_string(&d, prefix, "Object");
 s = statement_create(&a, &b, &c, &d); 

Becasue of the statement manages its fields by itself, for changing one of the filed you should use the propriate statement_set_xxx() accessor. Other fields (not of Node type) can be accessed directly as Statement structure members.

See also:

statement_set_context(), statement_set_predicate(), statement_set_subject(), statement_set_object()

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Typedef Documentation

typedef struct _statement Statement

The statement structure. Contains the quadruplet nodes: context, predicate, subject and object. It also contains the mask bits.

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Enumeration Type Documentation

enum ex_flags

Enumerator: STATEMENT_RETURN_LIE  STATEMENT_SET_LIE

enum statement_mask

Statement mask bits. Enumerator: NO_MASK  NULL mask. CONTEXT_MASK  Context field is masked. PREDICATE_MASK  Predicate field is masked. SUBJECT_MASK  Subject field is masked. OBJECT_MASK  Object field is masked. MASK_ALL  All fields are masked.

enum statement_op

Statement operation field type. Enumerator: STATEMENT_OP_UNSET  Unset statement operation. Statement should be or was unset (in the context of transaction). It makes sense only in the values passed to model_storage_set() and model_storage_set_nr() funcitons or values filled by notification_read() function, STATEMENT_OP_SET  Set statement operation. The Statement sould be or was set (in the context of transaction) It mases sence only in the values passed to model_storage_set() and model_storage_set_nr() functions or values filled by notification_read() function. STATEMENT_OP_UNDEF  Internal statement operation. It is used in stmtbase only.

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Function Documentation

STORAGE_TYPE void statement_clear (  Statement *  stmt  )

Clears the statement's nodes. Note: It destroys the nodes the stmt reffers to.

STORAGE_TYPE Statement* statement_clone (  const Statement *  src  )

Creates a copy of the source statement. The newly created statement refers to the same nodes and mask as the source statement.

STORAGE_TYPE Statement* statement_create (  const Node *  context, const Node *  predicate, const Node *  subject, const Node *  object )

Creates new statement object with filled values. The nodes passed to this function are cloned and managed by it So the caller is responsible for the arguments (depending on how has he got them).

STORAGE_TYPE Statement* statement_create_with_op (  const Node *  c, const Node *  p, const Node *  s, const Node *  o, statement_op  op )

Creates a new statement with given operation. op -- operation of this statement

STORAGE_TYPE void statement_free (  Statement *  stmt  )

Destroys the statement. Note: It destroys the nodes the stmt reffers to.

STORAGE_TYPE const Node* statement_get_context (  const Statement *  stmt  )

The statement context accessor.

STORAGE_TYPE time_t statement_get_end (  const Statement *  stmt  )

STORAGE_TYPE int statement_get_mask (  const Statement *  stmt  )

The statement mask accessor.

STORAGE_TYPE const Node* statement_get_object (  const Statement *  stmt  )

The statement object accessor.

STORAGE_TYPE statement_op statement_get_op (  const Statement *  stmt  )

Returns statement operation.

STORAGE_TYPE const Node* statement_get_predicate (  const Statement *  stmt  )

The statement predicate accessor.

STORAGE_TYPE time_t statement_get_start (  const Statement *  stmt  )

STORAGE_TYPE const Node* statement_get_subject (  const Statement *  stmt  )

The statement subject accessor.

STORAGE_TYPE void statement_init (  Statement *  stmt, const Node *  c, const Node *  p, const Node *  s, const Node *  o )

STORAGE_TYPE int statement_match (  const Statement *  mask, const Statement *  stmt )

Check the matching of stmt against mask returns zero if there is no match and positive value otherwise.

STORAGE_TYPE Statement* statement_new (   )

Creates empty statement object.

STORAGE_TYPE void statement_result_append (  Statement **  result, Statement *  s )

Appends a new statement to the statement bunch. This function automatically reallocates the memory for the list of statements. The result should be cleared with statement_result_free() function.

STORAGE_TYPE void statement_result_compact (  unsigned *  count, Statement ***  result )

Compacts the statement bunch. Statement result should be compactified after massive removing with statement_result_remove() function and before any usage. This function reallocates the memory for the list compacted. Deprecated: This function is not needed any more.

STORAGE_TYPE unsigned int statement_result_count (  Statement *  result  )

STORAGE_TYPE void statement_result_free (  Statement **  result  )

Destroys the result model_storage_get() and model_storage_get_nr() functions.

STORAGE_TYPE int statement_result_pop (  Statement **  result, Statement *  head )

Withdraws the head of a list and returns it. Returns: 0 if the list if empty, 1 if the head was withdrawn successfully.

STORAGE_TYPE void statement_result_remove (  Statement **  result, Statement *  stmt )

Removes from the bunch and frees the statement with given index. The result should be compacted with statement_result_compact() function

STORAGE_TYPE void statement_set_context (  Statement *  stmt, const Node *  context )

Sets the context of the statement.

STORAGE_TYPE void statement_set_end (  Statement *  stmt, time_t  t )

STORAGE_TYPE void statement_set_mask (  Statement *  stmt, int  mask )

Sets the mask of the statement.

STORAGE_TYPE void statement_set_object (  Statement *  stmt, const Node *  object )

Sets the object of the statement.

STORAGE_TYPE Statement* statement_set_op (  Statement *  stmt, statement_op  operation )

Sets statement operation. Returns: the pointer to the same statement.

STORAGE_TYPE void statement_set_predicate (  Statement *  stmt, const Node *  predicate )

Sets the predicate of the statement.

STORAGE_TYPE void statement_set_start (  Statement *  stmt, time_t  t )

STORAGE_TYPE void statement_set_subject (  Statement *  stmt, const Node *  subject )

Sets the subject of the statement.

STORAGE_TYPE void statement_swap_op (  Statement *  op  )

Swaps the operation of the statement and its previsous state.

STORAGE_TYPE Statement* stmt_from_strings (  const char *  c, const char *  p, const char *  s, const char *  o )

Creates new statement that contains nodes, created from given literals.

STORAGE_TYPE void stmt_init_from_strings (  Statement *  stmt, const char *  c, const char *  p, const char *  s, const char *  o )

Automatically creates nodes from strings and initializes a statement with them.

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