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

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/**
* Copyright 2008 Digital Bazaar, Inc.
*
* This file is part of librdfa.
*
* librdfa is Free Software, and can be licensed under any of the
* following three licenses:
*
* 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-* at the top of this software distribution for more
* information regarding the details of each license.
*
* The librdfa library is the Fastest RDFa Parser in the Universe. It is
* a stream parser, meaning that it takes an XML data as input and spits
* out RDF triples as it comes across them in the stream. Due to this
* processing approach, librdfa has a very, very small memory footprint.
* It is also very fast and can operate on hundreds of gigabytes of XML
* data without breaking a sweat.
*
* Usage:
*
* rdfacontext* context = rdfa_create_context(BASE_URI);
* context->callback_data = your_user_data;
* rdfa_set_triple_handler(context, &process_triple);
* rdfa_set_buffer_filler(context, &fill_buffer);
* rdfa_parse(context);
* rdfa_free_context(context);
*
* @author Manu Sporny
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "rdfa_utils.h"
#include "rdfa.h"
#define READ_BUFFER_SIZE 4096
void rdfa_init_context(rdfacontext* context)
{
// the [parent subject] is set to the [base] value;
context->parent_subject = NULL;
if(context->base != NULL)
{
context->parent_subject =
rdfa_replace_string(context->parent_subject, context->base);
}
// the [parent object] is set to null;
context->parent_object = NULL;
#ifndef LIBRDFA_IN_RAPTOR
// the [list of URI mappings] is cleared;
context->uri_mappings = (char**)rdfa_create_mapping(MAX_URI_MAPPINGS);
#endif
// the [list of incomplete triples] is cleared;
context->incomplete_triples = rdfa_create_list(3);
// the [language] is set to null.
context->language = NULL;
// set the [current object resource] to null;
context->current_object_resource = NULL;
// 1. First, the local values are initialized, as follows:
//
// * the [recurse] flag is set to 'true';
context->recurse = 1;
// * the [skip element] flag is set to 'false';
context->skip_element = 0;
// * [new subject] is set to null;
context->new_subject = NULL;
// * [current object resource] is set to null;
context->current_object_resource = NULL;
// * the [local list of URI mappings] is set to the list of URI
// mappings from the [evaluation context];
// NOTE: This step is done in rdfa_create_new_element_context()
// * the [local list of incomplete triples] is set to null;
context->local_incomplete_triples = rdfa_create_list(3);
// * the [current language] value is set to the [language] value
// from the [evaluation context].
// NOTE: This step is done in rdfa_create_new_element_context()
// The next set of variables are initialized to make the C compiler
// and valgrind happy - they are not a part of the RDFa spec.
context->bnode_count = 0;
context->underscore_colon_bnode_name = NULL;
context->xml_literal_namespaces_inserted = 0;
context->content = NULL;
context->datatype = NULL;
context->property = NULL;
context->plain_literal = NULL;
context->plain_literal_size = 0;
context->xml_literal = NULL;
context->xml_literal_size = 0;
// FIXME: completing incomplete triples always happens now, change
// all of the code to reflect that.
//context->callback_data = NULL;
}
/**
* Read the head of the XHTML document and determines the base IRI for
* the document.
*
* @param context the current working context.
* @param working_buffer the current working buffer.
* @param wb_allocated the number of bytes that have been allocated to
* the working buffer.
*
* @return the size of the data available in the working buffer.
*/
static size_t rdfa_init_base(
rdfacontext* context, char** working_buffer, size_t* working_buffer_size,
char* temp_buffer, size_t bytes_read)
{
size_t temp_buffer_size = sizeof(char) * READ_BUFFER_SIZE;
char* head_end = NULL;
size_t offset = context->wb_offset;
// search for the end of <head>, stop if <head> was found
// extend the working buffer size
if((offset + bytes_read) > *working_buffer_size)
{
*working_buffer_size += temp_buffer_size;
*working_buffer = (char*)realloc(working_buffer, *working_buffer_size);
}
// append to the working buffer
memmove(*working_buffer + offset, temp_buffer, bytes_read);
// search for the end of </head> in
head_end = strstr(*working_buffer, "</head>");
if(head_end == NULL)
head_end = strstr(*working_buffer, "</HEAD>");
context->wb_offset += bytes_read;
if(head_end == NULL)
return bytes_read;
// if </head> was found, search for <base and extract the base URI
if(head_end != NULL)
{
char* base_start = strstr(*working_buffer, "<base ");
if(base_start == NULL)
base_start = strstr(*working_buffer, "<BASE ");
if(base_start != NULL)
{
char* href_start = strstr(base_start, "href=");
char* uri_start = href_start + 6;
char* uri_end = index(uri_start, '"');
if((uri_start != NULL) && (uri_end != NULL))
{
if(*uri_start != '"')
{
size_t uri_size = uri_end - uri_start;
char* temp_uri = (char*)malloc(sizeof(char) * uri_size + 1);
strncpy(temp_uri, uri_start, uri_size);
temp_uri[uri_size] = '\0';
// TODO: This isn't in the processing rules, should it
// be? Setting current_object_resource will make
// sure that the BASE element is inherited by all
// subcontexts.
context->current_object_resource =
rdfa_replace_string(context->current_object_resource,
temp_uri);
context->base =
rdfa_replace_string(context->base,
temp_uri);
free(temp_uri);
}
}
}
}
return bytes_read;
}
/**
* Creates a new context for the current element by cloning certain
* parts of the old context on the top of the given stack.
*
* @param context_stack the context stack that is associated with this
* processing run.
*/
static rdfacontext* rdfa_create_new_element_context(rdfalist* context_stack)
{
rdfacontext* parent_context = (rdfacontext*)
context_stack->items[context_stack->num_items - 1]->data;
rdfacontext* rval = rdfa_create_context(parent_context->base);
// * Otherwise, the values are:
// * the [ base ] is set to the [ base ] value of the current
// [ evaluation context ];
rval->base = rdfa_replace_string(rval->base, parent_context->base);
rdfa_init_context(rval);
// copy the URI mappings
#ifndef LIBRDFA_IN_RAPTOR
if(rval->uri_mappings != NULL)
{
rdfa_free_mapping(rval->uri_mappings);
}
rval->uri_mappings = rdfa_copy_mapping(parent_context->uri_mappings);
#endif
// inherit the parent context's language
if(parent_context->language != NULL)
{
rval->language =
rdfa_replace_string(rval->language, parent_context->language);
}
// set the triple callback
rval->triple_callback = parent_context->triple_callback;
rval->buffer_filler_callback = parent_context->buffer_filler_callback;
// inherit the bnode count, _: bnode name, recurse flag, and state
// of the xml_literal_namespace_insertion
rval->bnode_count = parent_context->bnode_count;
rval->underscore_colon_bnode_name =
rdfa_replace_string(rval->underscore_colon_bnode_name,
parent_context->underscore_colon_bnode_name);
rval->recurse = parent_context->recurse;
rval->skip_element = 0;
rval->callback_data = parent_context->callback_data;
rval->xml_literal_namespaces_inserted =
parent_context->xml_literal_namespaces_inserted;
// inherit the parent context's new_subject
// TODO: This is not anywhere in the syntax processing document
//if(parent_context->new_subject != NULL)
//{
// rval->new_subject = rdfa_replace_string(
// rval->new_subject, parent_context->new_subject);
//}
if(parent_context->skip_element == 0)
{
// o the [ parent subject ] is set to the value of [ new subject ],
// if non-null, or the value of the [ parent subject ] of the
// current [ evaluation context ];
if(parent_context->new_subject != NULL)
{
rval->parent_subject = rdfa_replace_string(
rval->parent_subject, parent_context->new_subject);
}
else
{
rval->parent_subject = rdfa_replace_string(
rval->parent_subject, parent_context->parent_subject);
}
// o the [ parent object ] is set to value of [ current object
// resource ], if non-null, or the value of [ new subject ], if
// non-null, or the value of the [ parent subject ] of the
// current [ evaluation context ];
if(parent_context->current_object_resource != NULL)
{
rval->parent_object =
rdfa_replace_string(
rval->parent_object, parent_context->current_object_resource);
}
else if(parent_context->new_subject != NULL)
{
rval->parent_object =
rdfa_replace_string(
rval->parent_object, parent_context->new_subject);
}
else
{
rval->parent_object =
rdfa_replace_string(
rval->parent_object, parent_context->parent_subject);
}
// copy the incomplete triples
if(rval->incomplete_triples != NULL)
{
rdfa_free_list(rval->incomplete_triples);
}
// o the [ list of incomplete triples ] is set to the [ local list
// of incomplete triples ];
rval->incomplete_triples =
rdfa_copy_list(parent_context->local_incomplete_triples);
}
else
{
rval->parent_subject = rdfa_replace_string(
rval->parent_subject, parent_context->parent_subject);
rval->parent_object = rdfa_replace_string(
rval->parent_object, parent_context->parent_object);
// copy the incomplete triples
if(rval->incomplete_triples != NULL)
{
rdfa_free_list(rval->incomplete_triples);
}
rval->incomplete_triples =
rdfa_copy_list(parent_context->incomplete_triples);
// copy the local list of incomplete triples
if(rval->local_incomplete_triples != NULL)
{
rdfa_free_list(rval->local_incomplete_triples);
}
rval->local_incomplete_triples =
rdfa_copy_list(parent_context->local_incomplete_triples);
}
#ifdef LIBRDFA_IN_RAPTOR
rval->base_uri = parent_context->base_uri;
rval->sax2 = parent_context->sax2;
rval->namespace_handler = parent_context->namespace_handler;
rval->namespace_handler_user_data = parent_context->namespace_handler_user_data;
rval->error_handlers = parent_context->error_handlers;
#endif
return rval;
}
#ifdef LIBRDFA_IN_RAPTOR
static int
raptor_nspace_compare(const void *a, const void *b)
{
raptor_namespace* ns_a=*(raptor_namespace**)a;
raptor_namespace* ns_b=*(raptor_namespace**)b;
if(!ns_a->prefix)
return 1;
else if(!ns_b->prefix)
return -1;
else
return strcmp((const char*)ns_b->prefix, (const char*)ns_a->prefix);
}
#endif
/**
* Handles the start_element call
*/
static void XMLCALL
start_element(void* user_data, const char* name, const char** attributes)
{
rdfalist* context_stack = (rdfalist*) user_data;
rdfacontext* context = rdfa_create_new_element_context(context_stack);
const char** aptr = attributes;
const char* xml_lang = NULL;
const char* about_curie = NULL;
char* about = NULL;
const char* src_curie = NULL;
char* src = NULL;
const char* type_of_curie = NULL;
rdfalist* type_of = NULL;
const char* rel_curie = NULL;
rdfalist* rel = NULL;
const char* rev_curie = NULL;
rdfalist* rev = NULL;
const char* property_curie = NULL;
rdfalist* property = NULL;
const char* resource_curie = NULL;
char* resource = NULL;
const char* href_curie = NULL;
char* href = NULL;
const char* content = NULL;
const char* datatype_curie = NULL;
char* datatype = NULL;
unsigned char insert_xml_lang_in_xml_literal = 0;
rdfa_push_item(context_stack, context, RDFALIST_FLAG_CONTEXT);
if(DEBUG)
{
printf("DEBUG: ------- START - %s -------\n", name);
}
// start the XML Literal text
if(context->xml_literal == NULL)
{
context->xml_literal = rdfa_replace_string(context->xml_literal, "<");
context->xml_literal_size = 1;
}
else
{
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, "<", 1);
}
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
name, strlen(name));
if(!context->xml_literal_namespaces_inserted)
{
// append namespaces to XML Literal
#ifdef LIBRDFA_IN_RAPTOR
raptor_namespace_stack* nstack = &context->sax2->namespaces;
raptor_namespace* ns;
raptor_namespace* ns_list[32];
int ns_size;
#else
char** umap = context->uri_mappings;
#endif
char* umap_key = NULL;
char* umap_value = NULL;
insert_xml_lang_in_xml_literal = 1;
#ifdef LIBRDFA_IN_RAPTOR
ns_size=0;
for(ns=nstack->top; ns; ns=ns->next) {
int skip=0;
int i;
if(ns->depth < 1)
continue;
for(i=0; i< ns_size; i++) {
raptor_namespace* ns2=ns_list[i];
if((!ns->prefix && !ns2->prefix) ||
(ns->prefix && ns2->prefix &&
!strcmp((const char*)ns->prefix, (const char*)ns2->prefix))) {
/* this prefix was seen (overridden) earlier so skip */
skip=1;
break;
}
}
if(!skip)
ns_list[ns_size++]=ns;
}
qsort((void*)ns_list, ns_size, sizeof(raptor_namespace*),
raptor_nspace_compare);
while(ns_size > 0)
#else
while(*umap != NULL)
#endif
{
unsigned char namespace_already_defined = 0;
const char* predefined_namespace = NULL;
const char* predefined_namespace_value = NULL;
// get the next mapping to process
#ifdef LIBRDFA_IN_RAPTOR
ns=ns_list[--ns_size];
umap_key = (char*)raptor_namespace_get_prefix(ns);
if(!umap_key)
umap_key=(char*)XMLNS_DEFAULT_MAPPING;
umap_value = (char*)raptor_uri_as_string(raptor_namespace_get_uri(ns));
#else
rdfa_next_mapping(umap++, &umap_key, &umap_value);
umap++;
#endif
// check to make sure that the namespace isn't already
// defined in the current element.
if(attributes != NULL)
{
const char** attrs = attributes;
while((*attrs != NULL) && !namespace_already_defined)
{
predefined_namespace = *attrs++;
predefined_namespace_value = *attrs++;
if((strcmp(predefined_namespace, umap_key) == 0) ||
(strcmp(umap_key, XMLNS_DEFAULT_MAPPING) == 0))
{
namespace_already_defined = 1;
}
}
}
// if the namespace isn't already defined on the element,
// copy it to the XML Literal string.
if(!namespace_already_defined)
{
// append the namespace attribute to the XML Literal
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
" xmlns", strlen(" xmlns"));
// check to see if we're dumping the standard XHTML namespace or
// a user-defined XML namespace
if(strcmp(umap_key, XMLNS_DEFAULT_MAPPING) != 0)
{
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, ":", 1);
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
umap_key, strlen(umap_key));
}
// append the namespace value
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, "=\"", 2);
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
umap_value, strlen(umap_value));
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, "\"", 1);
}
else
{
// append the namespace value
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, " ", 1);
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
predefined_namespace, strlen(predefined_namespace));
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, "=\"", 2);
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
predefined_namespace_value, strlen(predefined_namespace_value));
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, "\"", 1);
}
namespace_already_defined = 0;
}
context->xml_literal_namespaces_inserted = 1;
}
// prepare all of the RDFa-specific attributes we are looking for.
// scan all of the attributes for the RDFa-specific attributes
if(aptr != NULL)
{
while(*aptr != NULL)
{
const char* attr;
const char* value;
char* literal_text;
attr = *aptr++;
value = *aptr++;
// append the attribute-value pair to the XML literal
literal_text = (char*)malloc(strlen(attr) + strlen(value) + 5);
sprintf(literal_text, " %s=\"%s\"", attr, value);
if(strstr("xmlns", attr) == NULL)
{
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
literal_text, strlen(literal_text));
}
free(literal_text);
if(strcmp(attr, "about") == 0)
{
about_curie = value;
about = rdfa_resolve_curie(
context, about_curie, CURIE_PARSE_ABOUT_RESOURCE);
}
else if(strcmp(attr, "src") == 0)
{
src_curie = value;
src = rdfa_resolve_curie(context, src_curie, CURIE_PARSE_HREF_SRC);
}
else if(strcmp(attr, "typeof") == 0)
{
type_of_curie = value;
type_of = rdfa_resolve_curie_list(
context, type_of_curie,
CURIE_PARSE_INSTANCEOF_DATATYPE);
}
else if(strcmp(attr, "rel") == 0)
{
rel_curie = value;
rel = rdfa_resolve_curie_list(
context, rel_curie, CURIE_PARSE_RELREV);
}
else if(strcmp(attr, "rev") == 0)
{
rev_curie = value;
rev = rdfa_resolve_curie_list(
context, rev_curie, CURIE_PARSE_RELREV);
}
else if(strcmp(attr, "property") == 0)
{
property_curie = value;
property =
rdfa_resolve_curie_list(
context, property_curie, CURIE_PARSE_PROPERTY);
}
else if(strcmp(attr, "resource") == 0)
{
resource_curie = value;
resource = rdfa_resolve_curie(
context, resource_curie, CURIE_PARSE_ABOUT_RESOURCE);
}
else if(strcmp(attr, "href") == 0)
{
href_curie = value;
href =
rdfa_resolve_curie(context, href_curie, CURIE_PARSE_HREF_SRC);
}
else if(strcmp(attr, "content") == 0)
{
content = value;
}
else if(strcmp(attr, "datatype") == 0)
{
datatype_curie = value;
datatype = rdfa_resolve_curie(context, datatype_curie,
CURIE_PARSE_INSTANCEOF_DATATYPE);
}
#ifndef LIBRDFA_IN_RAPTOR
else if(strcmp(attr, "xml:lang") == 0)
{
xml_lang = value;
}
else if(strstr(attr, "xmlns") != NULL)
{
// 2. Next the [current element] is parsed for
// [URI mapping]s and these are added to the
// [local list of URI mappings]. Note that a
// [URI mapping] will simply overwrite any current
// mapping in the list that has the same name;
rdfa_update_uri_mappings(context, attr, value);
}
#endif
}
}
#ifdef LIBRDFA_IN_RAPTOR
if(context->sax2)
xml_lang=(const char*)raptor_sax2_inscope_xml_language(context->sax2);
#endif
// check to see if we should append an xml:lang to the XML Literal
// if one is defined in the context and does not exist on the element.
if((xml_lang == NULL) && (context->language != NULL) &&
insert_xml_lang_in_xml_literal)
{
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
" xml:lang=\"", strlen(" xml:lang=\""));
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
context->language, strlen(context->language));
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, "\"", 1);
}
// close the XML Literal value
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, ">", 1);
// 3. The [current element] is also parsed for any language
// information, and [language] is set in the [current
// evaluation context];
rdfa_update_language(context, xml_lang);
/***************** FOR DEBUGGING PURPOSES ONLY ******************/
if(DEBUG)
{
if(about != NULL)
{
printf("DEBUG: @about = %s\n", about);
}
if(src != NULL)
{
printf("DEBUG: @src = %s\n", src);
}
if(type_of != NULL)
{
printf("DEBUG: @type_of = ");
rdfa_print_list(type_of);
}
if(rel != NULL)
{
printf("DEBUG: @rel = ");
rdfa_print_list(rel);
}
if(rev != NULL)
{
printf("DEBUG: @rev = ");
rdfa_print_list(rev);
}
if(property != NULL)
{
printf("DEBUG: @property = ");
rdfa_print_list(property);
}
if(resource != NULL)
{
printf("DEBUG: @resource = %s\n", resource);
}
if(href != NULL)
{
printf("DEBUG: @href = %s\n", href);
}
if(content != NULL)
{
printf("DEBUG: @content = %s\n", content);
}
if(datatype != NULL)
{
printf("DEBUG: @datatype = %s\n", datatype);
}
}
// TODO: This isn't part of the processing model, it needs to be
// included and is a correction for the last item in step #4.
if((about == NULL) && (src == NULL) && (type_of == NULL) &&
(rel == NULL) && (rev == NULL) && (property == NULL) &&
(resource == NULL) && (href == NULL))
{
context->skip_element = 1;
}
if((rel == NULL) && (rev == NULL))
{
// 4. If the [current element] contains no valid @rel or @rev
// URI, obtained according to the section on CURIE and URI
// Processing, then the next step is to establish a value for
// [new subject]. Any of the attributes that can carry a
// resource can set [new subject];
rdfa_establish_new_subject(
context, name, about, src, resource, href, type_of);
}
else
{
// 5. If the [current element] does contain a valid @rel or @rev
// URI, obtained according to the section on CURIE and URI
// Processing, then the next step is to establish both a value
// for [new subject] and a value for [current object resource]:
rdfa_establish_new_subject_with_relrev(
context, name, about, src, resource, href, type_of);
}
if(context->new_subject != NULL)
{
if(DEBUG)
{
printf("DEBUG: new_subject = %s\n", context->new_subject);
}
// 6. If in any of the previous steps a [new subject] was set to
// a non-null value,
// it is now used to provide a subject for type values;
if(type_of != NULL)
{
rdfa_complete_type_triples(context, type_of);
}
// Note that none of this block is executed if there is no
// [new subject] value, i.e., [new subject] remains null.
}
if(context->current_object_resource != NULL)
{
// 7. If in any of the previous steps a [current object resource]
// was set to a non-null value, it is now used to generate triples
rdfa_complete_relrev_triples(context, rel, rev);
}
else if((rel != NULL) || (rev != NULL))
{
// 8. If however [current object resource] was set to null, but
// there are predicates present, then they must be stored as
// [incomplete triple]s, pending the discovery of a subject that
// can be used as the object. Also, [current object resource]
// should be set to a newly created [bnode]
rdfa_save_incomplete_triples(context, rel, rev);
}
// Ensure to re-insert XML Literal namespace information from this
// point on...
if(property != NULL)
{
context->xml_literal_namespaces_inserted = 0;
}
// save these for processing steps #9 and #10
context->property = property;
context->content = rdfa_replace_string(context->datatype, content);
context->datatype = rdfa_replace_string(context->datatype, datatype);
// free the resolved CURIEs
free(about);
free(src);
rdfa_free_list(type_of);
rdfa_free_list(rel);
rdfa_free_list(rev);
free(resource);
free(href);
free(datatype);
}
static void XMLCALL character_data(void *user_data, const char *s, int len)
{
rdfalist* context_stack = (rdfalist*)user_data;
rdfacontext* context = (rdfacontext*)
context_stack->items[context_stack->num_items - 1]->data;
char *buffer = (char*)malloc(len + 1);
memset(buffer, 0, len + 1);
memcpy(buffer, s, len);
// append the text to the current context's plain literal
if(context->plain_literal == NULL)
{
context->plain_literal =
rdfa_replace_string(context->plain_literal, buffer);
context->plain_literal_size = len;
}
else
{
context->plain_literal = rdfa_n_append_string(
context->plain_literal, &context->plain_literal_size, buffer, len);
}
// append the text to the current context's XML literal
if(context->xml_literal == NULL)
{
context->xml_literal =
rdfa_replace_string(context->xml_literal, buffer);
context->xml_literal_size = len;
}
else
{
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size, buffer, len);
}
//printf("plain_literal: %s\n", context->plain_literal);
//printf("xml_literal: %s\n", context->xml_literal);
free(buffer);
}
static void XMLCALL
end_element(void *user_data, const char *name)
{
rdfalist* context_stack = (rdfalist*)user_data;
rdfacontext* context = (rdfacontext*)rdfa_pop_item(context_stack);
rdfacontext* parent_context = (rdfacontext*)
context_stack->items[context_stack->num_items - 1]->data;
// append the text to the current context's XML literal
char* buffer = (char*)malloc(strlen(name) + 4);
if(DEBUG)
{
printf("DEBUG: </%s>\n", name);
}
sprintf(buffer, "</%s>", name);
if(context->xml_literal == NULL)
{
context->xml_literal =
rdfa_replace_string(context->xml_literal, buffer);
context->xml_literal_size = strlen(buffer);
}
else
{
context->xml_literal = rdfa_n_append_string(
context->xml_literal, &context->xml_literal_size,
buffer, strlen(buffer));
}
free(buffer);
// 9. The next step of the iteration is to establish any
// [current object literal];
// generate the complete object literal triples
if(context->property != NULL)
{
// save the current xml literal
char* saved_xml_literal = context->xml_literal;
char* content_start = NULL;
char* content_end = NULL;
// ensure to mark only the inner-content of the XML node for
// processing the object literal.
buffer = NULL;
if(context->xml_literal != NULL)
{
// get the data between the first tag and the last tag
content_start = index(context->xml_literal, '>');
content_end = rindex(context->xml_literal, '<');
if((content_start != NULL) && (content_end != NULL))
{
// set content end to null terminator
context->xml_literal = ++content_start;
*content_end = '\0';
}
}
// process data between first tag and last tag
// this needs the xml literal to be null terminated
rdfa_complete_object_literal_triples(context);
if(content_end != NULL)
{
// set content end back
*content_end = '<';
}
if(saved_xml_literal != NULL)
{
// restore xml literal
context->xml_literal = saved_xml_literal;
}
}
//printf(context->plain_literal);
// append the XML literal and plain text literals to the parent
// literals
if(context->xml_literal != NULL)
{
if(parent_context->xml_literal == NULL)
{
parent_context->xml_literal =
rdfa_replace_string(
parent_context->xml_literal, context->xml_literal);
parent_context->xml_literal_size = context->xml_literal_size;
}
else
{
parent_context->xml_literal =
rdfa_n_append_string(
parent_context->xml_literal, &parent_context->xml_literal_size,
context->xml_literal, context->xml_literal_size);
}
// if there is an XML literal, there is probably a plain literal
if(context->plain_literal != NULL)
{
if(parent_context->plain_literal == NULL)
{
parent_context->plain_literal =
rdfa_replace_string(
parent_context->plain_literal, context->plain_literal);
parent_context->plain_literal_size = context->plain_literal_size;
}
else
{
parent_context->plain_literal =
rdfa_n_append_string(
parent_context->plain_literal,
&parent_context->plain_literal_size,
context->plain_literal,
context->plain_literal_size);
}
}
}
// preserve the bnode count by copying it to the parent_context
parent_context->bnode_count = context->bnode_count;
parent_context->underscore_colon_bnode_name = \
rdfa_replace_string(parent_context->underscore_colon_bnode_name,
context->underscore_colon_bnode_name);
// 10. If the [ skip element ] flag is 'false', and [ new subject ]
// was set to a non-null value, then any [ incomplete triple ]s
// within the current context should be completed:
if((context->skip_element == 0) && (context->new_subject != NULL))
{
rdfa_complete_incomplete_triples(context);
}
// free the context
rdfa_free_context(context);
}
#ifdef LIBRDFA_IN_RAPTOR
static void raptor_rdfa_start_element(void *user_data,
raptor_xml_element *xml_element)
{
raptor_qname* qname=raptor_xml_element_get_name(xml_element);
int attr_count=raptor_xml_element_get_attributes_count(xml_element);
raptor_qname** attrs=raptor_xml_element_get_attributes(xml_element);
unsigned char* qname_string=raptor_qname_to_counted_name(qname, NULL);
char** attr=NULL;
int i;
if(attr_count > 0) {
attr=(char**)malloc(sizeof(char*) * (1+(attr_count*2)));
for(i=0; i<attr_count; i++) {
attr[2*i]=(char*)raptor_qname_to_counted_name(attrs[i], NULL);
attr[1+(2*i)]=(char*)raptor_qname_get_value(attrs[i]);
}
attr[2*i]=NULL;
}
start_element(user_data, (char*)qname_string, (const char**)attr);
raptor_free_memory(qname_string);
if(attr) {
for(i=0; i<attr_count; i++)
raptor_free_memory(attr[2*i]);
free(attr);
}
}
static void raptor_rdfa_end_element(void *user_data,
raptor_xml_element* xml_element)
{
raptor_qname* qname=raptor_xml_element_get_name(xml_element);
unsigned char* qname_string=raptor_qname_to_counted_name(qname, NULL);
end_element(user_data, (const char*)qname_string);
raptor_free_memory(qname_string);
}
static void raptor_rdfa_character_data(void *user_data,
raptor_xml_element* xml_element,
const unsigned char *s, int len)
{
character_data(user_data, (const char *)s, len);
}
static void raptor_rdfa_namespace_handler(void *user_data,
raptor_namespace* nspace)
{
rdfalist* context_stack = (rdfalist*)user_data;
rdfacontext* context = (rdfacontext*)
context_stack->items[context_stack->num_items - 1]->data;
if(context->namespace_handler)
(*context->namespace_handler)(context->namespace_handler_user_data,
nspace);
}
#endif
rdfacontext* rdfa_create_context(const char* base)
{
rdfacontext* rval = NULL;
size_t base_length = strlen(base);
// if the base isn't specified, don't create a context
if(base_length > 0)
{
rval = (rdfacontext*)malloc(sizeof(rdfacontext));
rval->base = NULL;
rval->base = rdfa_replace_string(rval->base, base);
/* parse state */
rval->wb_allocated = 0;
rval->working_buffer = NULL;
rval->wb_offset = 0;
#ifdef LIBRDFA_IN_RAPTOR
rval->base_uri = NULL;
rval->sax2 = NULL;
rval->namespace_handler = NULL;
rval->namespace_handler_user_data = NULL;
#else
rval->parser = NULL;
#endif
rval->done = 0;
rval->context_stack = NULL;
rval->wb_preread = 0;
rval->preread = 0;
}
else
{
printf("OMG!\n");
}
return rval;
}
void rdfa_free_context(rdfacontext* context)
{
if(context->base)
{
free(context->base);
}
if(context->parent_subject != NULL)
{
free(context->parent_subject);
}
if(context->parent_object != NULL)
{
free(context->parent_object);
}
#ifndef LIBRDFA_IN_RAPTOR
if(context->uri_mappings != NULL)
{
rdfa_free_mapping(context->uri_mappings);
}
#endif
if(context->incomplete_triples != NULL)
{
rdfa_free_list(context->incomplete_triples);
}
if(context->language != NULL)
{
free(context->language);
}
if(context->underscore_colon_bnode_name != NULL)
{
free(context->underscore_colon_bnode_name);
}
if(context->new_subject != NULL)
{
free(context->new_subject);
}
if(context->current_object_resource != NULL)
{
free(context->current_object_resource);
}
if(context->content != NULL)
{
free(context->content);
}
if(context->datatype != NULL)
{
free(context->datatype);
}
if(context->property != NULL)
{
rdfa_free_list(context->property);
}
if(context->plain_literal != NULL)
{
free(context->plain_literal);
}
if(context->xml_literal != NULL)
{
free(context->xml_literal);
}
// TODO: These should be moved into their own data structure
if(context->local_incomplete_triples != NULL)
{
rdfa_free_list(context->local_incomplete_triples);
}
// this field is not NULL only on the rdfacontext* at the top of the stack
if(context->context_stack != NULL)
{
void* rval;
// free the stack ensuring that we do not delete this context if
// it is in the list (which it may be, if parsing ended on error)
do {
rval=rdfa_pop_item(context->context_stack);
if(rval && rval != context)
rdfa_free_context(rval);
} while(rval);
free(context->context_stack->items);
free(context->context_stack);
}
if(context->working_buffer != NULL)
{
free(context->working_buffer);
}
free(context);
}
void rdfa_set_triple_handler(rdfacontext* context, triple_handler_fp th)
{
context->triple_callback = th;
}
void rdfa_set_buffer_filler(rdfacontext* context, buffer_filler_fp bf)
{
context->buffer_filler_callback = bf;
}
int rdfa_parse_start(rdfacontext* context)
{
// create the buffers and expat parser
int rval = RDFA_PARSE_SUCCESS;
context->wb_allocated = sizeof(char) * READ_BUFFER_SIZE;
context->working_buffer = (char*)calloc(context->wb_allocated, sizeof(char));
#ifndef LIBRDFA_IN_RAPTOR
context->parser = XML_ParserCreate(NULL);
#endif
context->done = 0;
context->context_stack = rdfa_create_list(32);
// initialize the context stack
rdfa_push_item(context->context_stack, context, RDFALIST_FLAG_CONTEXT);
#ifdef LIBRDFA_IN_RAPTOR
context->sax2 = raptor_new_sax2(context->context_stack,
context->error_handlers);
#else
#endif
// set up the context stack
#ifdef LIBRDFA_IN_RAPTOR
raptor_sax2_set_start_element_handler(context->sax2,
raptor_rdfa_start_element);
raptor_sax2_set_end_element_handler(context->sax2,
raptor_rdfa_end_element);
raptor_sax2_set_characters_handler(context->sax2,
raptor_rdfa_character_data);
raptor_sax2_set_namespace_handler(context->sax2,
raptor_rdfa_namespace_handler);
#else
XML_SetUserData(context->parser, context->context_stack);
XML_SetElementHandler(context->parser, start_element, end_element);
XML_SetCharacterDataHandler(context->parser, character_data);
#endif
rdfa_init_context(context);
#ifdef LIBRDFA_IN_RAPTOR
context->base_uri=raptor_new_uri((const unsigned char*)context->base);
raptor_sax2_parse_start(context->sax2, context->base_uri);
#endif
return rval;
}
int rdfa_parse_chunk(rdfacontext* context, char* data, size_t wblen, int done)
{
// it is an error to call this before rdfa_parse_start()
if(context->done)
{
return RDFA_PARSE_FAILED;
}
if(!context->preread)
{
// search for the <base> tag and use the href contained therein to
// set the parsing context.
context->wb_preread = rdfa_init_base(context,
&context->working_buffer, &context->wb_allocated, data, wblen);
// contisnue looking if in first 131072 bytes of data
if(!context->base && context->wb_preread < (1<<17))
return RDFA_PARSE_SUCCESS;
#ifdef LIBRDFA_IN_RAPTOR
if(raptor_sax2_parse_chunk(context->sax2,
(const unsigned char*)context->working_buffer,
context->wb_offset, done))
{
return RDFA_PARSE_FAILED;
}
#else
if(XML_Parse(context->parser, context->working_buffer,
context->wb_offset, 0) == XML_STATUS_ERROR)
{
fprintf(stderr,
"%s at line %d, column %d\n",
XML_ErrorString(XML_GetErrorCode(context->parser)),
XML_GetCurrentLineNumber(context->parser),
XML_GetCurrentColumnNumber(context->parser));
return RDFA_PARSE_FAILED;
}
#endif
context->preread = 1;
return RDFA_PARSE_SUCCESS;
}
// otherwise just parse the block passed in
#ifdef LIBRDFA_IN_RAPTOR
if(raptor_sax2_parse_chunk(context->sax2, (const unsigned char*)data, wblen, done))
{
return RDFA_PARSE_FAILED;
}
#else
if(XML_Parse(context->parser, data, wblen, done) == XML_STATUS_ERROR)
{
fprintf(stderr,
"%s at line %d, column %d.\n",
XML_ErrorString(XML_GetErrorCode(context->parser)),
XML_GetCurrentLineNumber(context->parser),
XML_GetCurrentColumnNumber(context->parser));
return RDFA_PARSE_FAILED;
}
#endif
return RDFA_PARSE_SUCCESS;
}
void rdfa_parse_end(rdfacontext* context)
{
// deinitialize context stack
rdfa_pop_item(context->context_stack);
// Free the expat parser and the like
#ifdef LIBRDFA_IN_RAPTOR
if(context->base_uri)
raptor_free_uri(context->base_uri);
raptor_free_sax2(context->sax2);
context->sax2=NULL;
#else
// free parser
XML_ParserFree(context->parser);
#endif
}
int rdfa_parse(rdfacontext* context)
{
int rval;
rval = rdfa_parse_start(context);
if(rval != RDFA_PARSE_SUCCESS)
{
context->done = 1;
return rval;
}
do
{
size_t wblen;
int done;
wblen = context->buffer_filler_callback(
context->working_buffer, context->wb_allocated,
context->callback_data);
done = (wblen == 0);
rval = rdfa_parse_chunk(
context, context->working_buffer, wblen, done);
context->done=done;
}
while(!context->done && rval == RDFA_PARSE_SUCCESS);
rdfa_parse_end(context);
return rval;
}
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