Add existing project files

lib/linkmap.py

@@ -0,0 +1,120 @@
+
+
+from html.parser import HTMLParser
+from random import sample
+from requests import get as request_get
+from sys import stderr
+from urllib.parse import urlparse
+
+
+class _HTMLExternalLinkFinder(HTMLParser):
+
+    links = []
+
+    def handle_starttag(self, tag, attrs):
+        if tag == "a":
+            for a in attrs:
+                attr, val = a
+                if attr == "href":
+                    if val.startswith("https://") or val.startswith("http://"):
+                        if not val in self.links:
+                            self.links.append(val)
+    
+    def get_links(self, input_html:str):
+        self.feed(input_html)
+        return self.links
+
+
+class LinkMap:
+
+    links = []
+    link_connections = [
+        # (link1, link2)
+    ]
+
+    def add_link_connection(self, link1, link2):
+        if not link1 in self.links:
+            self.links.append(link1)
+        if not link2 in self.links:
+            self.links.append(link2)
+        self.link_connections.append((link1, link2))
+    
+    def add_link(self, link):
+        if not link in self.links:
+            self.links.append(link)
+
+
+class LinkMapFromSitelinksGenerator:
+
+    site_request_max_len = 10000000 # bytes
+    site_request_timeout = 10 # seconds
+    already_visited = []
+    generated_linkmap = LinkMap()
+    max_links_per_site = 3
+    max_depth = 3
+    enable_log = False
+
+    def log(self, something):
+        if self.enable_log:
+            print(something, file=stderr)
+
+    def _get_html(self, url:str) -> str:
+        html_content = ""
+        # receive up to self.site_request_max_len bytes after a maximum of self.site_request_timeout seconds
+        self.log("-----" + url)
+        response = request_get(url, stream=True, timeout=self.site_request_timeout)
+        response.raise_for_status()
+        content_size = 0
+        content_chunks = []
+        for chunk in response.iter_content(1024, decode_unicode=True):
+            content_size += len(chunk)
+            if content_size > self.site_request_max_len:
+                self.log(f"Maximum content length exceeded! received: {content_size} (maximum: {self.site_request_max_len})")
+                break
+            else:
+                content_chunks.append(chunk)
+        html_content = "".join(content_chunks)
+        return html_content
+
+    def _get_linked_sites(self, url:str):
+        sites = []
+        if not url in self.already_visited:
+            try:
+                html = self._get_html(url)
+                found_links = _HTMLExternalLinkFinder().get_links(html)
+                found_links = sample(found_links, min(self.max_links_per_site, len(found_links)))
+                self.log("\n".join(found_links))
+                for l in found_links:
+                    if l != None:
+                        sites.append(l)
+                self.already_visited.append(url)
+            except KeyboardInterrupt:
+                exit("KeyboardInterrupt")
+            except Exception as e:
+                self.log("An exception occcured while trying to get links from '" + url + "': ")
+                self.log(e)
+        return sites
+
+    def _generate_linkmap(self, start_urls:list, _current_depth:int):
+        linkdict = {}
+        for url in start_urls:
+            linkdict[url] = {}
+            self.generated_linkmap.add_link(url)
+            linked_sites = self._get_linked_sites(url)
+            for l in linked_sites:
+                if l != url:
+                    linkdict[url][l] = {}
+                    self.generated_linkmap.add_link_connection(url, l)
+        if _current_depth < self.max_depth:
+            for url in linkdict:
+                linkdict[url] = self._generate_linkmap(list(linkdict[url]), _current_depth + 1)
+
+    def generate(self, start_url:str, max_depth:int=3, max_links_per_site:int=3):
+        self.already_visited = []
+        self.generated_linkmap = LinkMap()
+        self.max_links_per_site = max_links_per_site
+        self.max_depth = max_depth
+        self._generate_linkmap([start_url], 1)
+
+    def get_linkmap(self) -> LinkMap:
+        return self.generated_linkmap