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#include <string.h>
#ifdef HAVE_TIDY_ULONG_VERSION
#define __USE_MISC
#include <sys/types.h>
#undef __USE_MISC
#endif
#include <tidy/tidy.h>
#include <tidy/buffio.h>
#include "linkextractor.h"
#include "urlutils.h"
#define MENU_HEADER "<?xml version=\"1.0\"?><wvmenu>"
#define MENU_FOOTER "</wvmenu>"
struct LinkExtractor {
const LinkTemplates *link_templates;
TidyBuffer html_buffer;
gchar *baseurl;
};
static GPtrArray *extract_links(const LinkExtractor *self, TidyDoc tdoc);
static void free_link(gpointer p);
static void get_links_recursively(TidyDoc tdoc,
TidyNode node,
const LinkTemplates *link_templates,
const gchar *baseurl,
GPtrArray *links_found);
static gchar *parse_link_title(TidyDoc tdoc, TidyNode node);
static void get_text_content(TidyDoc tdoc, TidyNode node, TidyBuffer* buf);
static void remove_duplicate_urls(GPtrArray *links);
static void insert_links_with_longest_titles(gpointer data, gpointer userdata);
LinkExtractor *link_extractor_create(const LinkTemplates *link_templates, const gchar *baseurl) {
LinkExtractor *extractor;
extractor = malloc(sizeof(LinkExtractor));
memset(extractor, 0, sizeof(LinkExtractor));
extractor->link_templates = link_templates;
tidyBufInit(&extractor->html_buffer);
extractor->baseurl = baseurl ? g_strdup(baseurl) : g_strdup("");
return extractor;
}
void link_extractor_delete(LinkExtractor *self) {
if (self) {
tidyBufFree(&self->html_buffer);
g_free(self->baseurl);
free(self);
}
}
void link_extractor_append(LinkExtractor *self, const char *buf, size_t len) {
tidyBufAppend(&self->html_buffer, (void *)buf, len);
}
GPtrArray *link_extractor_get_links(LinkExtractor *self) {
GPtrArray *links = NULL;
TidyDoc tdoc;
int err;
TidyBuffer errbuf; // swallow errors here instead of printing to stderr
tdoc = tidyCreate();
tidyOptSetBool(tdoc, TidyForceOutput, yes);
tidyOptSetInt(tdoc, TidyWrapLen, 4096);
tidyBufInit(&errbuf);
tidySetErrorBuffer(tdoc, &errbuf);
tidySetInCharEncoding(tdoc, "utf8");
err = tidyParseBuffer(tdoc, &self->html_buffer);
if (err >= 0) {
err = tidyCleanAndRepair(tdoc);
if ( err >= 0 ) {
links = extract_links(self, tdoc);
remove_duplicate_urls(links);
}
}
tidyBufFree(&errbuf);
tidyRelease(tdoc);
return links;
}
GPtrArray *extract_links(const LinkExtractor *self, TidyDoc tdoc) {
GPtrArray *links = g_ptr_array_new_full(0, free_link);
TidyNode root = tidyGetBody(tdoc);
get_links_recursively(tdoc, root, self->link_templates, self->baseurl, links);
return links;
}
void get_links_recursively(TidyDoc tdoc, TidyNode node,
const LinkTemplates *link_templates,
const gchar *baseurl,
GPtrArray *links_found) {
TidyNode child;
for (child = tidyGetChild(node); child; child = tidyGetNext(child)) {
if (tidyNodeIsA(child)) {
TidyAttr href_attr = tidyAttrGetById(child, TidyAttr_HREF);
ctmbstr href = tidyAttrValue(href_attr);
if (href && *href != '\0' && href[strlen(href)-1] != '#') {
gchar *absolute_href = relative_url_to_absolute(baseurl, href);
const LinkAction *action = \
link_templates_get_action(link_templates, absolute_href);
if (action) {
LinkActionType type = link_action_get_type(action);
gchar *title = parse_link_title(tdoc, child);
Link *link = link_create(absolute_href, title, type);
g_ptr_array_add(links_found, link);
g_free(title);
}
g_free(absolute_href);
}
} else {
TidyNodeType node_type = tidyNodeGetType(node);
if (node_type == TidyNode_Root || node_type == TidyNode_Start) {
get_links_recursively(tdoc, child, link_templates, baseurl, links_found);
}
}
}
}
gchar *parse_link_title(TidyDoc tdoc, TidyNode node) {
gchar *title;
TidyAttr title_attr = tidyAttrGetById(node, TidyAttr_TITLE);
if (title_attr) {
ctmbstr tidy_title = tidyAttrValue(title_attr);
title = g_strdup(tidy_title);
} else {
TidyBuffer titlebuf;
tidyBufInit(&titlebuf);
get_text_content(tdoc, node, &titlebuf);
tidyBufPutByte(&titlebuf, '\0');
title = g_strdup((const gchar*)titlebuf.bp);
tidyBufFree(&titlebuf);
}
g_strstrip(title);
return title;
}
void get_text_content(TidyDoc tdoc, TidyNode node, TidyBuffer* buf) {
if (tidyNodeGetType(node) == TidyNode_Text) {
TidyBuffer content;
tidyBufInit(&content);
tidyNodeGetValue(tdoc, node, &content);
tidyBufAppend(buf, content.bp, content.size);
} else {
TidyNode child;
for (child = tidyGetChild(node); child; child = tidyGetNext(child)) {
get_text_content(tdoc, child, buf);
}
}
}
void remove_duplicate_urls(GPtrArray *links) {
/* Remove links with duplicated URLs. Keep the link with the longest
* title on the assumption that it is more informative. Keep the
* sort order. */
if (links->len <= 1)
return;
/* seen_urls maps an href (char *) to Link * which has the longest
* title. Both keys and values are borrowed references!
*/
GHashTable *seen_urls = g_hash_table_new(g_str_hash, g_str_equal);
g_ptr_array_foreach(links, insert_links_with_longest_titles, seen_urls);
/* Delete links which are not in the hash table */
int i = 0;
while (i < links->len) {
Link *link = g_ptr_array_index(links, i);
const char *href = link_get_href(link);
Link *link_with_longest_title =
(Link *)g_hash_table_lookup(seen_urls, href);
if (link == link_with_longest_title) {
i++;
} else {
g_ptr_array_remove_index(links, i);
}
}
g_hash_table_unref(seen_urls);
}
void insert_links_with_longest_titles(gpointer data, gpointer userdata) {
Link *link = (Link *)data;
GHashTable *hashtable = (GHashTable *)userdata;
int title_len = strlen(link_get_title(link));
const char *href = link_get_href(link);
Link *prev_link = (Link *)g_hash_table_lookup(hashtable, href);
int prev_link_title_len = 0;
if (prev_link)
prev_link_title_len = strlen(link_get_title(prev_link));
if (!prev_link || (prev_link_title_len < title_len)) {
g_hash_table_replace(hashtable, (gpointer)href, (gpointer)link);
}
}
void free_link(gpointer p) {
link_delete((Link *)p);
}
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