Add a httpdownloader module to download files using twisted

deluge/httpdownloader.py

@@ -0,0 +1,89 @@
+#
+# httpdownloader.py
+#
+# Copyright (C) 2009 Andrew Resch <andrewresch@gmail.com>
+#
+# Deluge is free software.
+#
+# You may redistribute it and/or modify it under the terms of the
+# GNU General Public License, as published by the Free Software
+# Foundation; either version 3 of the License, or (at your option)
+# any later version.
+#
+# deluge is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with deluge.    If not, write to:
+# 	The Free Software Foundation, Inc.,
+# 	51 Franklin Street, Fifth Floor
+# 	Boston, MA  02110-1301, USA.
+#
+#    In addition, as a special exception, the copyright holders give
+#    permission to link the code of portions of this program with the OpenSSL
+#    library.
+#    You must obey the GNU General Public License in all respects for all of
+#    the code used other than OpenSSL. If you modify file(s) with this
+#    exception, you may extend this exception to your version of the file(s),
+#    but you are not obligated to do so. If you do not wish to do so, delete
+#    this exception statement from your version. If you delete this exception
+#    statement from all source files in the program, then also delete it here.
+#
+
+from twisted.web import client
+from twisted.internet import reactor
+
+class HTTPDownloader(client.HTTPDownloader):
+    """
+    Factory class for downloading files and keeping track of progress.
+    """
+    def __init__(self, url, filename, part_callback=None):
+        """
+        :param url: str, the url to download from
+        :param filename: str, the filename to save the file as
+        :param part_callback: func, a function to be called when a part of data
+            is received, it's signature should be: func(data, current_length, total_length)
+        """
+        self.__part_callback = part_callback
+        self.current_length = 0
+        client.HTTPDownloader.__init__(self, url, filename)
+
+    def gotHeaders(self, headers):
+        if self.status == "200":
+            if "content-length" in headers:
+                self.total_length = int(headers["content-length"][0])
+            else:
+                self.total_length = 0
+
+        return client.HTTPDownloader.gotHeaders(self, headers)
+
+    def pagePart(self, data):
+        if self.status == "200":
+            self.current_length += len(data)
+            if self.__part_callback:
+                self.__part_callback(data, self.current_length, self.total_length)
+
+        return client.HTTPDownloader.pagePart(self, data)
+
+def download_file(url, filename, callback=None):
+    """
+    Downloads a file from a specific URL and returns a Deferred.  You can also
+    specify a callback function to be called as parts are received.
+
+    :param url: str, the url to download from
+    :param filename: str, the filename to save the file as
+    :param callback: func, a function to be called when a part of data is received,
+         it's signature should be: func(data, current_length, total_length)
+    """
+    url = str(url)
+    scheme, host, port, path = client._parse(url)
+    factory = HTTPDownloader(url, filename, callback)
+    if scheme == "https":
+        from twisted.internet import ssl
+        reactor.connectSSL(host, port, factory, ssl.ClientContextFactory())
+    else:
+        reactor.connectTCP(host, port, factory)
+
+    return factory.deferred