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audacity/lib-src/redland/librdf/rdf_query_results.c
ra 58caf78a86 Move library tree where it belongs
2010-01-24 09:19:39 +00:00

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/* -*- Mode: c; c-basic-offset: 2 -*-
*
* rdf_query.c - RDF Query Results
*
* Copyright (C) 2004-2008, David Beckett http://www.dajobe.org/
* Copyright (C) 2004-2005, University of Bristol, UK http://www.bristol.ac.uk/
*
* This package is Free Software and part of Redland http://librdf.org/
*
* It is licensed under the following three licenses as alternatives:
* 1. GNU Lesser General Public License (LGPL) V2.1 or any newer version
* 2. GNU General Public License (GPL) V2 or any newer version
* 3. Apache License, V2.0 or any newer version
*
* You may not use this file except in compliance with at least one of
* the above three licenses.
*
* See LICENSE.html or LICENSE.txt at the top of this package for the
* complete terms and further detail along with the license texts for
* the licenses in COPYING.LIB, COPYING and LICENSE-2.0.txt respectively.
*
*
*/
#ifdef HAVE_CONFIG_H
#include <rdf_config.h>
#endif
#ifdef WIN32
#include <win32_rdf_config.h>
#endif
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h> /* for abort() as used in errors */
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#endif
#include <redland.h>
#include <rdf_query.h>
/**
* librdf_query_results_get_count:
* @query_results: #librdf_query_results query results
*
* Get number of bindings so far.
*
* Return value: number of bindings found so far
**/
int
librdf_query_results_get_count(librdf_query_results *query_results)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, 1);
if(query_results->query->factory->results_get_count)
return query_results->query->factory->results_get_count(query_results);
else
return 1;
}
/**
* librdf_query_results_next:
* @query_results: #librdf_query_results query results
*
* Move to the next result.
*
* Return value: non-0 if failed or results exhausted
**/
int
librdf_query_results_next(librdf_query_results *query_results)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, 1);
if(query_results->query->factory->results_next)
return query_results->query->factory->results_next(query_results);
else
return 1;
}
/**
* librdf_query_results_finished:
* @query_results: #librdf_query_results query results
*
* Find out if binding results are exhausted.
*
* Return value: non-0 if results are finished or query failed
**/
int
librdf_query_results_finished(librdf_query_results *query_results)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, 1);
if(query_results->query->factory->results_finished)
return query_results->query->factory->results_finished(query_results);
else
return 1;
}
/**
* librdf_query_results_get_bindings:
* @query_results: #librdf_query_results query results
* @names: pointer to an array of binding names (or NULL)
* @values: pointer to an array of binding value #librdf_node (or NULL)
*
* Get all binding names, values for current result.
*
* If names is not NULL, it is set to the address of a shared array
* of names of the bindings (an output parameter). These names
* are shared and must not be freed by the caller
*
* If values is not NULL, it is used as an array to store pointers
* to the librdf_node* of the results. These nodes must be freed
* by the caller. The size of the array is determined by the
* number of names of bindings, returned by
* librdf_query_get_bindings_count dynamically or
* will be known in advanced if hard-coded into the query string.
*
* Example
*
* const char **names=NULL;
* librdf_node* values[10];
*
* if(librdf_query_results_get_bindings(results, &amp;names, values))
* ...
*
* Return value: non-0 if the assignment failed
**/
int
librdf_query_results_get_bindings(librdf_query_results *query_results,
const char ***names, librdf_node **values)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, 1);
if(query_results->query->factory->results_get_bindings)
return query_results->query->factory->results_get_bindings(query_results, names, values);
else
return 1;
}
/**
* librdf_query_results_get_binding_value:
* @query_results: #librdf_query_results query results
* @offset: offset of binding name into array of known names
*
* Get one binding value for the current result.
*
* Return value: a new #librdf_node binding value or NULL on failure
**/
librdf_node*
librdf_query_results_get_binding_value(librdf_query_results *query_results,
int offset)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, NULL);
if(query_results->query->factory->results_get_binding_value)
return query_results->query->factory->results_get_binding_value(query_results, offset);
else
return NULL;
}
/**
* librdf_query_results_get_binding_name:
* @query_results: #librdf_query_results query results
* @offset: offset of binding name into array of known names
*
* Get binding name for the current result.
*
* Return value: a pointer to a shared copy of the binding name or NULL on failure
**/
const char*
librdf_query_results_get_binding_name(librdf_query_results *query_results, int offset)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, NULL);
if(query_results->query->factory->results_get_binding_name)
return query_results->query->factory->results_get_binding_name(query_results, offset);
else
return NULL;
}
/**
* librdf_query_results_get_binding_value_by_name:
* @query_results: #librdf_query_results query results
* @name: variable name
*
* Get one binding value for a given name in the current result.
*
* Return value: a new #librdf_node binding value or NULL on failure
**/
librdf_node*
librdf_query_results_get_binding_value_by_name(librdf_query_results *query_results, const char *name)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, NULL);
if(query_results->query->factory->results_get_binding_value_by_name)
return query_results->query->factory->results_get_binding_value_by_name(query_results, name);
else
return NULL;
}
/**
* librdf_query_results_get_bindings_count:
* @query_results: #librdf_query_results query results
*
* Get the number of bound variables in the result.
*
* Return value: <0 if failed or results exhausted
**/
int
librdf_query_results_get_bindings_count(librdf_query_results *query_results)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, 1);
if(query_results->query->factory->results_get_bindings_count)
return query_results->query->factory->results_get_bindings_count(query_results);
else
return -1;
}
/**
* librdf_free_query_results:
* @query_results: #librdf_query_results object
*
* Destructor - destroy a #librdf_query_results object.
*
**/
void
librdf_free_query_results(librdf_query_results* query_results)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN(query_results, librdf_query_results);
if(query_results->query->factory->free_results)
query_results->query->factory->free_results(query_results);
librdf_query_remove_query_result(query_results->query, query_results);
LIBRDF_FREE(librdf_query_results, query_results);
}
/**
* librdf_query_results_to_counted_string:
* @query_results: #librdf_query_results object
* @format_uri: URI of syntax to format to
* @base_uri: Base URI of output formatted syntax or NULL
* @length_p: Pointer to where to store length of string or NULL
*
* Turn a query results into a string.
*
* Values of format_uri currently supported (via Rasqal) are:
* http://www.w3.org/TR/2004/WD-rdf-sparql-XMLres-20041221/
*
* The base URI may be used for the generated syntax, depending
* on the format.
*
* The returned string must be freed by the caller
*
* Return value: new string value or NULL on failure
**/
unsigned char*
librdf_query_results_to_counted_string(librdf_query_results *query_results,
librdf_uri *format_uri,
librdf_uri *base_uri,
size_t *length_p)
{
librdf_query_results_formatter *formatter;
void *string=NULL;
size_t string_length=0;
raptor_iostream *iostr;
int error=0;
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, NULL);
iostr=raptor_new_iostream_to_string(&string, &string_length, malloc);
if(!iostr)
return NULL;
formatter=librdf_new_query_results_formatter(query_results,
NULL /* name */,
format_uri);
if(!formatter) {
error=1;
goto tidy;
}
if(librdf_query_results_formatter_write(iostr, formatter,
query_results, base_uri))
error=1;
librdf_free_query_results_formatter(formatter);
tidy:
raptor_free_iostream(iostr);
/* string is available only after the iostream is finished
* - clean it up here on error */
if(error) {
if(string) {
raptor_free_memory(string);
string=NULL;
}
}
else if(length_p)
*length_p=string_length;
return (unsigned char *)string;
}
/**
* librdf_query_results_to_string:
* @query_results: #librdf_query_results object
* @format_uri: URI of syntax to format to
* @base_uri: Base URI of output formatted syntax
*
* Turn a query results into a string.
*
* See librdf_query_results_to_counted_string for information on the
* format_uri and base_uri parameters.
*
* The returned string must be freed by the caller
*
* Return value: new string value or NULL on failure
**/
unsigned char*
librdf_query_results_to_string(librdf_query_results *query_results,
librdf_uri *format_uri,
librdf_uri *base_uri) {
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, librdf_query_results, NULL);
return librdf_query_results_to_counted_string(query_results,
format_uri, base_uri, NULL);
}
/**
* librdf_query_results_to_file_handle:
* @query_results: #librdf_query_results object
* @handle: file handle to write to
* @format_uri: URI of syntax to format to
* @base_uri: Base URI of output formatted syntax
*
* Write a query results to a FILE*.
*
* See librdf_query_results_to_counted_string for information on the
* format_uri and base_uri parameters.
*
* Return value: non 0 on failure
**/
int
librdf_query_results_to_file_handle(librdf_query_results *query_results,
FILE *handle,
librdf_uri *format_uri,
librdf_uri *base_uri)
{
raptor_iostream *iostr;
librdf_query_results_formatter *formatter;
int status;
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, query_results, 1);
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(handle, FILE*, 1);
iostr=raptor_new_iostream_to_file_handle(handle);
if(!iostr)
return 1;
formatter=librdf_new_query_results_formatter(query_results,
NULL /* name */,
format_uri);
if(!formatter) {
raptor_free_iostream(iostr);
return 1;
}
status=librdf_query_results_formatter_write(iostr, formatter,
query_results, base_uri);
librdf_free_query_results_formatter(formatter);
raptor_free_iostream(iostr);
return status;
}
/**
* librdf_query_results_to_file:
* @query_results: #librdf_query_results object
* @name: filename to write to
* @format_uri: URI of syntax to format to
* @base_uri: Base URI of output formatted syntax
*
* Write a query results to a file.
*
* See librdf_query_results_to_counted_string for information on the
* format_uri and base_uri parameters.
*
* Return value: non 0 on failure
**/
int
librdf_query_results_to_file(librdf_query_results *query_results,
const char *name,
librdf_uri *format_uri,
librdf_uri *base_uri) {
FILE* fh;
int status;
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, query_results, 1);
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(name, string, 1);
fh=fopen(name, "w+");
if(!fh) {
librdf_log(query_results->query->world, 0, LIBRDF_LOG_ERROR,
LIBRDF_FROM_QUERY, NULL,
"failed to open file '%s' for writing - %s",
name, strerror(errno));
return 1;
}
status=librdf_query_results_to_file_handle(query_results, fh,
format_uri, base_uri);
fclose(fh);
return status;
}
/**
* librdf_query_results_is_bindings:
* @query_results: #librdf_query_results object
*
* Test if librdf_query_results is variable bindings format.
*
* Return value: non-0 if true
**/
int
librdf_query_results_is_bindings(librdf_query_results* query_results) {
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, query_results, -1);
if(query_results->query->factory->results_is_bindings)
return query_results->query->factory->results_is_bindings(query_results);
else
return -1;
}
/**
* librdf_query_results_is_boolean:
* @query_results: #librdf_query_results object
*
* Test if librdf_query_results is boolean format.
*
* If this function returns true, the result can be retrieved by
* librdf_query_results_get_boolean().
*
* Return value: non-0 if true
**/
int
librdf_query_results_is_boolean(librdf_query_results* query_results) {
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, query_results, -1);
if(query_results->query->factory->results_is_boolean)
return query_results->query->factory->results_is_boolean(query_results);
else
return -1;
}
/**
* librdf_query_results_is_graph:
* @query_results: #librdf_query_results object
*
* Test if librdf_query_results is RDF graph format.
*
* Return value: non-0 if true
**/
int
librdf_query_results_is_graph(librdf_query_results* query_results) {
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, query_results, -1);
if(query_results->query->factory->results_is_graph)
return query_results->query->factory->results_is_graph(query_results);
else
return -1;
}
/**
* librdf_query_results_is_syntax:
* @query_results: #librdf_query_results object
*
* Test if librdf_query_results is a syntax.
*
* If this function returns true, the ONLY result available
* from this query is a syntax that can be serialized using
* one of the #query_result_formatter class methods or with
* librdf_query_results_to_counted_string(), librdf_query_results_to_string(),
* librdf_query_results_to_file_handle() or librdf_query_results_to_file()
*
* Return value: non-0 if true
**/
int
librdf_query_results_is_syntax(librdf_query_results* query_results)
{
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, query_results, -1);
if(query_results->query->factory->results_is_syntax)
return query_results->query->factory->results_is_syntax(query_results);
else
return -1;
}
/**
* librdf_query_results_get_boolean:
* @query_results: #librdf_query_results query_results
*
* Get boolean query result.
*
* The return value is only meaningful if this is a boolean
* query result - see #librdf_query_results_is_boolean
*
* Return value: boolean query result - >0 is true, 0 is false, <0 on error or finished
*/
int
librdf_query_results_get_boolean(librdf_query_results* query_results) {
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, query_results, -1);
if(query_results->query->factory->results_get_boolean)
return query_results->query->factory->results_get_boolean(query_results);
else
return -1;
}
/**
* librdf_query_results_as_stream:
* @query_results: #librdf_query_results query_results
*
* Get a query result as an RDF graph in #librdf_stream form
*
* The return value is only meaningful if this is an RDF graph
* query result - see #librdf_query_results_is_graph
*
* Return value: a new #librdf_stream result or NULL on error
*/
librdf_stream*
librdf_query_results_as_stream(librdf_query_results* query_results) {
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, query_results, NULL);
if(query_results->query->factory->results_as_stream)
return query_results->query->factory->results_as_stream(query_results);
else
return NULL;
}
/**
* librdf_new_query_results_formatter:
* @query_results: #librdf_query_results query_results
* @name: the query results format name (or NULL)
* @uri: #librdf_uri query results format uri (or NULL)
*
* Constructor - create a new librdf_query_results_formatter object by identified format.
*
* A query results format can be named or identified by a URI, both
* of which are optional. The default query results format will be used
* if both are NULL. librdf_query_results_formats_enumerate() returns
* information on the known query results names, labels and URIs.
*
* Return value: a new #librdf_query_results_formatter object or NULL on failure
*/
librdf_query_results_formatter*
librdf_new_query_results_formatter(librdf_query_results* query_results,
const char *name, librdf_uri* uri)
{
if(query_results->query->factory->new_results_formatter)
return query_results->query->factory->new_results_formatter(query_results, name, uri);
else
return NULL;
}
/**
* librdf_new_query_results_formatter_by_mime_type:
* @query_results: #librdf_query_results query_results
* @mime_type: mime type name
*
* Constructor - create a new librdf_query_results_formatter object by mime type.
*
* A query results format generates a syntax with a mime type which
* may be requested with this constructor.
* Note that there may be several formatters that generate the same
* MIME Type (such as SPARQL XML results format drafts) and in thot
* case the librdf_new_query_results_formatter() constructor allows
* selecting of a specific one by name or URI.
*
* Return value: a new #librdf_query_results_formatter object or NULL on failure
*/
librdf_query_results_formatter*
librdf_new_query_results_formatter_by_mime_type(librdf_query_results* query_results,
const char *mime_type)
{
if(query_results->query->factory->new_results_formatter_by_mime_type)
return query_results->query->factory->new_results_formatter_by_mime_type(query_results, mime_type);
else
return NULL;
}
/**
* librdf_free_query_results_formatter:
* @formatter: #librdf_query_results_formatter object
*
* Destructor - destroy a #librdf_query_results_formatter object.
**/
void
librdf_free_query_results_formatter(librdf_query_results_formatter* formatter)
{
if(formatter->query_results->query->factory->free_results_formatter)
formatter->query_results->query->factory->free_results_formatter(formatter);
}
/**
* librdf_query_results_formatter_write:
* @iostr: #raptor_iostream to write the query to
* @formatter: #librdf_query_results_formatter object
* @results: #librdf_query_results query results format
* @base_uri: #librdf_uri base URI of the output format
*
* Write the query results using the given formatter to an iostream
*
* See librdf_query_results_formats_enumerate() to get the
* list of syntax URIs and their description.
*
* Return value: non-0 on failure
**/
int
librdf_query_results_formatter_write(raptor_iostream *iostr,
librdf_query_results_formatter* formatter,
librdf_query_results* query_results,
librdf_uri *base_uri)
{
if(query_results->query->factory->results_formatter_write)
return query_results->query->factory->results_formatter_write(iostr,
formatter,
query_results,
base_uri);
else
return 1;
}
/**
* librdf_query_results_formats_check:
* @world: #librdf_world
* @name: the query results format name (or NULL)
* @uri: #librdf_uri query results format uri (or NULL)
* @mime_type: mime type name
*
* Check if a query results formatter exists for the requested format.
*
* Return value: non-0 if a formatter exists.
**/
int
librdf_query_results_formats_check(librdf_world* world,
const char *name, librdf_uri* uri,
const char *mime_type)
{
librdf_world_open(world);
/* FIXME - this should use some kind of registration but for now
* it is safe to assume Rasqal does it all
*/
return rasqal_query_results_formats_check(world->rasqal_world_ptr,
name, (raptor_uri*)uri, mime_type);
}
/**
* librdf_query_results_formats_enumerate:
* @world: #librdf_world
* @counter: index into the list of query result syntaxes
* @name: pointer to store the name of the query result syntax (or NULL)
* @label: pointer to store query result syntax readable label (or NULL)
* @uri_string: pointer to store query result syntax URI string (or NULL)
* @mime_type: pointer to store query result syntax mime type string (or NULL)
*
* Get information on query result syntaxes.
*
* All returned strings are shared and must be copied if needed to be
* used dynamically.
*
* Return value: non 0 on failure of if counter is out of range
*/
int
librdf_query_results_formats_enumerate(librdf_world* world,
const unsigned int counter,
const char **name,
const char **label,
const unsigned char **uri_string,
const char **mime_type)
{
librdf_world_open(world);
/* FIXME - this should use some kind of registration but for now
* it is safe to assume Rasqal does it all
*/
return rasqal_query_results_formats_enumerate(world->rasqal_world_ptr,
counter, name, label,
uri_string, mime_type,
/*flags=*/ NULL);
}
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