[Patch pyserial:34] Improvements to port_publisher.py example

1 files changed, 49 insertions, 27 deletions

diff --git a/examples/port_publisher.py b/examples/port_publisher.py
index 393beb5..d05a631 100755
--- a/examples/port_publisher.py
+++ b/examples/port_publisher.py
@@ -18,10 +18,25 @@ import traceback
 

 import serial

 import serial.rfc2217

+import serial.tools.list_ports

 

-import avahi

 import dbus

 

+# Try to import the avahi service definitions properly. If the avahi module is

+# not available, fall back to a hard-coded solution that hopefully still works.

+try:

+    import avahi

+except ImportError:

+    class avahi:

+        DBUS_NAME = "org.freedesktop.Avahi"

+        DBUS_PATH_SERVER = "/"

+        DBUS_INTERFACE_SERVER = "org.freedesktop.Avahi.Server"

+        DBUS_INTERFACE_ENTRY_GROUP = DBUS_NAME + ".EntryGroup"

+        IF_UNSPEC = -1

+        PROTO_UNSPEC, PROTO_INET, PROTO_INET6  = -1, 0, 1

+

+

+

 class ZeroconfService:

     """\

     A simple class to publish a network service with zeroconf using avahi.

@@ -133,7 +148,7 @@ class Forwarder(ZeroconfService):
             self.handle_server_error()

             #~ raise

         if not options.quiet:

-            print "%s: Waiting for connection on %s..." % (self.device, self.network_port)

+            print("%s: Waiting for connection on %s..." % (self.device, self.network_port))

 

         # zeroconfig

         self.publish()

@@ -259,6 +274,14 @@ class Forwarder(ZeroconfService):
         connection, addr = self.server_socket.accept()

         if self.socket is None:

             self.socket = connection

+            # More quickly detect bad clients who quit without closing the

+            # connection: After 1 second of idle, start sending TCP keep-alive

+            # packets every 1 second. If 3 consecutive keep-alive packets

+            # fail, assume the client is gone and close the connection.

+            self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)

+            self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, 1)

+            self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, 1)

+            self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPCNT, 3)

             self.socket.setblocking(0)

             self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)

             if not options.quiet:

@@ -331,6 +354,10 @@ If running as daemon, write to syslog. Otherwise write to stdout.
     parser.add_option("", "--pidfile", dest="pid_file",

         help="specify a name for the PID file", default=None, metavar="FILE")

 

+    parser.add_option("", "--ports-regex", dest="ports_regex",

+        help="specify a regex to search against the serial devices and their descriptions",

+        default='/dev/ttyUSB[0-9]+', metavar="REGEX")

+

     (options, args) = parser.parse_args()

 

     # redirect output if specified

@@ -406,8 +433,6 @@ If running as daemon, write to syslog. Otherwise write to stdout.
 

     # keep the published stuff in a dictionary

     published = {}

-    # prepare list of device names (hard coded)

-    device_list = ['/dev/ttyUSB%d' % p for p in range(8)]

     # get a nice hostname

     hostname = socket.gethostname()

 

@@ -429,29 +454,26 @@ If running as daemon, write to syslog. Otherwise write to stdout.
             now = time.time()

             if now > next_check:

                 next_check = now + 5

-                # check each device

-                for device in device_list:

-                    # if it appeared

-                    if os.path.exists(device):

-                        if device not in published:

-                            num = int(device[-1])

-                            published[device] = Forwarder(

-                                device,

-                                "%s on %s" % (device, hostname),

-                                7000+num,

-                                on_close=unpublish

-                            )

-                            if not options.quiet: print("publish: %s" % (published[device]))

-                            published[device].open()

-                    else:

-                        # or when it disappeared

-                        if device in published:

-                            if not options.quiet: print("unpublish: %s" % (published[device]))

-                            published[device].close()

-                            try:

-                                del published[device]

-                            except KeyError:

-                                pass

+                connected = [d for d, p, i in serial.tools.list_ports.grep(options.ports_regex)]

+                # Handle devices that are published, but no longer connected

+                for device in set(published).difference(connected):

+                    if not options.quiet: print("unpublish: %s" % (published[device]))

+                    unpublish(published[device])

+                # Handle devices that are connected but not yet published

+                for device in set(connected).difference(published):

+                    # Find the first available port, starting from 7000

+                    port = 7000

+                    ports_in_use = [f.network_port for f in published.values()]

+                    while port in ports_in_use:

+                        port += 1

+                    published[device] = Forwarder(

+                        device,

+                        "%s on %s" % (device, hostname),

+                        port,

+                        on_close=unpublish

+                    )

+                    if not options.quiet: print("publish: %s" % (published[device]))

+                    published[device].open()

 

             # select_start = time.time()

             read_map = {}