bundle2: extract logic for seeking bundle2 part into own class
Currently, unbundlepart classes support bi-directional seeking.
Most consumers of unbundlepart only ever seek forward - typically
as part of moving to the end of the bundle part so they can move
on to the next one. But regardless of the actual usage of the
part, instances maintain an index mapping offsets within the
underlying raw payload to offsets within the decoded payload.
Maintaining the mapping of offset data can be expensive in terms of
memory use. Furthermore, many bundle2 consumers don't have access
to an underlying seekable stream. This includes all compressed
bundles. So maintaining offset data when the underlying stream
can't be seeked anyway is wasteful. And since many bundle2 streams
can't be seeked, it seems like a bad idea to expose a seek API
in bundle2 parts by default. If you provide them, people will
attempt to use them.
Seekable bundle2 parts should be the exception, not the rule. This
commit starts the process dividing unbundlepart into 2 classes: a
base class that supports linear, one-time reads and a child class
that supports bi-directional seeking. In this first commit, we
split various methods and attributes out into a new
"seekableunbundlepart" class. Previous instantiators of "unbundlepart"
now instantiate "seekableunbundlepart." This preserves backwards
compatibility. The coupling between the classes is still tight:
"unbundlepart" cannot be used on its own. This will be addressed
in subsequent commits.
Differential Revision: https://phab.mercurial-scm.org/D1386
#!/usr/bin/env python
from __future__ import absolute_import, print_function
__doc__ = """Tiny HTTP Proxy.
This module implements GET, HEAD, POST, PUT and DELETE methods
on BaseHTTPServer, and behaves as an HTTP proxy. The CONNECT
method is also implemented experimentally, but has not been
tested yet.
Any help will be greatly appreciated. SUZUKI Hisao
"""
__version__ = "0.2.1"
import optparse
import os
import select
import socket
import sys
from mercurial import util
httpserver = util.httpserver
socketserver = util.socketserver
urlreq = util.urlreq
if os.environ.get('HGIPV6', '0') == '1':
family = socket.AF_INET6
else:
family = socket.AF_INET
class ProxyHandler (httpserver.basehttprequesthandler):
__base = httpserver.basehttprequesthandler
__base_handle = __base.handle
server_version = "TinyHTTPProxy/" + __version__
rbufsize = 0 # self.rfile Be unbuffered
def handle(self):
(ip, port) = self.client_address
allowed = getattr(self, 'allowed_clients', None)
if allowed is not None and ip not in allowed:
self.raw_requestline = self.rfile.readline()
if self.parse_request():
self.send_error(403)
else:
self.__base_handle()
def log_request(self, code='-', size='-'):
xheaders = [h for h in self.headers.items() if h[0].startswith('x-')]
self.log_message('"%s" %s %s%s',
self.requestline, str(code), str(size),
''.join([' %s:%s' % h for h in sorted(xheaders)]))
# Flush for Windows, so output isn't lost on TerminateProcess()
sys.stdout.flush()
sys.stderr.flush()
def _connect_to(self, netloc, soc):
i = netloc.find(':')
if i >= 0:
host_port = netloc[:i], int(netloc[i + 1:])
else:
host_port = netloc, 80
print("\t" "connect to %s:%d" % host_port)
try: soc.connect(host_port)
except socket.error as arg:
try: msg = arg[1]
except (IndexError, TypeError): msg = arg
self.send_error(404, msg)
return 0
return 1
def do_CONNECT(self):
soc = socket.socket(family, socket.SOCK_STREAM)
try:
if self._connect_to(self.path, soc):
self.log_request(200)
self.wfile.write(self.protocol_version +
" 200 Connection established\r\n")
self.wfile.write("Proxy-agent: %s\r\n" % self.version_string())
self.wfile.write("\r\n")
self._read_write(soc, 300)
finally:
print("\t" "bye")
soc.close()
self.connection.close()
def do_GET(self):
(scm, netloc, path, params, query, fragment) = urlreq.urlparse(
self.path, 'http')
if scm != 'http' or fragment or not netloc:
self.send_error(400, "bad url %s" % self.path)
return
soc = socket.socket(family, socket.SOCK_STREAM)
try:
if self._connect_to(netloc, soc):
self.log_request()
soc.send("%s %s %s\r\n" % (
self.command,
urlreq.urlunparse(('', '', path, params, query, '')),
self.request_version))
self.headers['Connection'] = 'close'
del self.headers['Proxy-Connection']
for key_val in self.headers.items():
soc.send("%s: %s\r\n" % key_val)
soc.send("\r\n")
self._read_write(soc)
finally:
print("\t" "bye")
soc.close()
self.connection.close()
def _read_write(self, soc, max_idling=20):
iw = [self.connection, soc]
ow = []
count = 0
while True:
count += 1
(ins, _, exs) = select.select(iw, ow, iw, 3)
if exs:
break
if ins:
for i in ins:
if i is soc:
out = self.connection
else:
out = soc
try:
data = i.recv(8192)
except socket.error:
break
if data:
out.send(data)
count = 0
else:
print("\t" "idle", count)
if count == max_idling:
break
do_HEAD = do_GET
do_POST = do_GET
do_PUT = do_GET
do_DELETE = do_GET
class ThreadingHTTPServer (socketserver.ThreadingMixIn,
httpserver.httpserver):
def __init__(self, *args, **kwargs):
httpserver.httpserver.__init__(self, *args, **kwargs)
a = open("proxy.pid", "w")
a.write(str(os.getpid()) + "\n")
a.close()
def runserver(port=8000, bind=""):
server_address = (bind, port)
ProxyHandler.protocol_version = "HTTP/1.0"
httpd = ThreadingHTTPServer(server_address, ProxyHandler)
sa = httpd.socket.getsockname()
print("Serving HTTP on", sa[0], "port", sa[1], "...")
try:
httpd.serve_forever()
except KeyboardInterrupt:
print("\nKeyboard interrupt received, exiting.")
httpd.server_close()
sys.exit(0)
if __name__ == '__main__':
argv = sys.argv
if argv[1:] and argv[1] in ('-h', '--help'):
print(argv[0], "[port [allowed_client_name ...]]")
else:
if argv[2:]:
allowed = []
for name in argv[2:]:
client = socket.gethostbyname(name)
allowed.append(client)
print("Accept: %s (%s)" % (client, name))
ProxyHandler.allowed_clients = allowed
del argv[2:]
else:
print("Any clients will be served...")
parser = optparse.OptionParser()
parser.add_option('-b', '--bind', metavar='ADDRESS',
help='Specify alternate bind address '
'[default: all interfaces]', default='')
(options, args) = parser.parse_args()
port = 8000
if len(args) == 1:
port = int(args[0])
runserver(port, options.bind)