Properly implement timeout callback (bug #619), bump SONAME because of API changes

4 files changed, 77 insertions, 36 deletions

diff --git a/src/libwebvi/webvi/api.py b/src/libwebvi/webvi/api.py
index f7f4ad1..6dfa31e 100644
--- a/src/libwebvi/webvi/api.py
+++ b/src/libwebvi/webvi/api.py
@@ -23,29 +23,45 @@ Example workflow:
 
 handle = new_request(ref, WebviRequestType.MENU)
 
-2) Setup a callback function:
+2) Setup a timeout callback:
 
-setopt(handle, WebviOpt.WRITEFUNC, my_callback)
+def timeout_func(t, ignored):
+    global alarm
+    now = current_time_in_milliseconds()
+    alarm = now + t
 
-3) Start the network transfer:
+set_config(WebviConfig.TIMEOUT_CALLBACK, timeout_func)
+
+3) Setup a data callback:
+
+set_opt(handle, WebviOpt.WRITEFUNC, write_func)
+
+4) Start the network transfer:
 
 start_handle(handle)
 
-4) Get active file descriptors, wait for activity on them, and let
-webvi process the file descriptor.
+5) Get active file descriptors, wait for activity using the timeout
+value supplied by timeout callback, and let webvi process the file
+descriptor.
 
 import select
 
 ...
 
 readfd, writefd, excfd = fdset()[1:4]
-readfd, writefd, excfd = select.select(readfd, writefd, excfd, 5.0)
-for fd in readfd:
-    perform(fd, WebviSelectBitmask.READ)
-for fd in writefd:
-    perform(fd, WebviSelectBitmask.WRITE)
-
-5) Iterate 4) until pop_message returns handle, which indicates that
+timeout = alarm - current_time_in_milliseconds()
+if timeout < 0:
+    timeout = 10.0
+readfd, writefd, excfd = select.select(readfd, writefd, excfd, timeout)
+if readfd == writefd == excfd == []: # timeout
+    perform(WebviSelect.TIMEOUT, WebviSelectBitmask.CHECK)
+else:
+    for fd in readfd:
+        perform(fd, WebviSelectBitmask.READ)
+    for fd in writefd:
+        perform(fd, WebviSelectBitmask.WRITE)
+
+6) Iterate 5) until pop_message returns handle, which indicates that
 the request has been completed.
 
 finished, status, errmsg, remaining = pop_message()
@@ -105,6 +121,12 @@ def set_config(conf, value):
         else:
             request.DEBUG = True
         return WebviErr.OK
+    elif conf == WebviConfig.TIMEOUT_CALLBACK:
+        request.set_timeout_callback(value)
+        return WebviErr.OK
+    elif conf == WebviConfig.TIMEOUT_DATA:
+        request.timeout_data = value
+        return WebviErr.OK
     else:
         return WebviErr.INVALID_PARAMETER
 
@@ -242,7 +264,7 @@ def fdset():
     """Get the list of file descriptors that are currently in use by
     the library.
 
-    Returrns a tuple, where the first item is a constants.WebviErr
+    Returns a tuple, where the first item is a constants.WebviErr
     value indicating the success of the call, the next three values
     are lists of descriptors that should be monitored for reading,
     writing, and exceptional conditions, respectively. The last item
@@ -272,24 +294,24 @@ def perform(fd, ev_bitmask):
     select() or similar system call. ev_bitmask specifies what kind of
     activity has been detected using values of
     constants.WebviSelectBitmask. If ev_bitmask is
-    constants.WebviSelectBitmask.TIMEOUT the type of activity is check
-    by the function.
+    constants.WebviSelectBitmask.CHECK the type of activity is
+    checked by the function.
 
-    This function should be called every few seconds with fd=-1,
-    ev_bitmask=constants.WebviSelectBitmask.TIMEOUT even if no
-    activity has been signalled on the file descriptors to ensure
-    correct handling of timeouts and other internal processing.
+    If a timeout occurs before any file descriptor becomes ready, this
+    function should be called with fd set to
+    constants.WebviSelect.TIMEOUT and ev_bitmask set to
+    constants.WebviSelectBitmask.CHECK.
     """
     if fd < 0:
-        asyncurl.poll()
+        asyncurl.poll_timeout()
     else:
         disp = socket_map.get(fd)
         if disp is not None:
             if ev_bitmask & WebviSelectBitmask.READ != 0 or \
-               (ev_bitmask == 0 and disp.readable()):
+               (ev_bitmask == WebviSelectBitmask.CHECK and disp.readable()):
                 disp.handle_read_event()
             if ev_bitmask & WebviSelectBitmask.WRITE != 0 or \
-               (ev_bitmask == 0 and disp.writable()):
+               (ev_bitmask == WebviSelectBitmask.CHECK and disp.writable()):
                 disp.handle_write_event()
 
     return (WebviErr.OK, len(socket_map))
diff --git a/src/libwebvi/webvi/asyncurl.py b/src/libwebvi/webvi/asyncurl.py
index 585f090..6b17893 100644
--- a/src/libwebvi/webvi/asyncurl.py
+++ b/src/libwebvi/webvi/asyncurl.py
@@ -40,7 +40,8 @@ def poll(timeout=0.0, map=None, mdisp=None):
     if mdisp is None:
         mdisp = multi_dispatcher
     if map:
-        timeout = min(timeout, mdisp.timeout/1000.0)
+        if mdisp.timeout != -1:
+            timeout = min(timeout, mdisp.timeout/1000.0)
 
         r = []; w = []; e = []
         for fd, obj in map.items():
@@ -53,7 +54,8 @@ def poll(timeout=0.0, map=None, mdisp=None):
             if is_r or is_w:
                 e.append(fd)
         if [] == r == w == e:
-            time.sleep(timeout)
+            if timeout > 0:
+                time.sleep(timeout)
         else:
             try:
                 r, w, e = select.select(r, w, e, timeout)
@@ -85,6 +87,11 @@ def poll(timeout=0.0, map=None, mdisp=None):
                 continue
             asyncore._exception(obj)
 
+def poll_timeout(mdisp=None):
+    if mdisp is None:
+        mdisp = multi_dispatcher
+    mdisp.socket_action(SOCKET_TIMEOUT, 0)
+
 def loop(timeout=30.0, use_poll=False, map=None, count=None, mdisp=None):
     if map is None:
         map = asyncore.socket_map
@@ -118,13 +125,15 @@ class curl_multi_dispatcher:
         else:
             self._map = socket_map
         self.dispatchers = {}
-        self.timeout = 1000
+        self.timeout = -1
+        # The lambda is to avoid "not callable" error from pylint
+        self.timeout_callback = lambda x, y: None
         self._sockets_removed = False
         self._curlm = pycurl.CurlMulti()
-        self._curlm.setopt(pycurl.M_SOCKETFUNCTION, self.socket_callback)
-        self._curlm.setopt(pycurl.M_TIMERFUNCTION, self.timeout_callback)
+        self._curlm.setopt(pycurl.M_SOCKETFUNCTION, self._socket_callback)
+        self._curlm.setopt(pycurl.M_TIMERFUNCTION, self._update_timeout)
         
-    def socket_callback(self, action, socket, user_data, socket_data):
+    def _socket_callback(self, action, socket, user_data, socket_data):
 #         print 'socket callback: %d, %s' % \
 #               (socket, {pycurl.POLL_NONE: "NONE",
 #                         pycurl.POLL_IN: "IN",
@@ -155,8 +164,10 @@ class curl_multi_dispatcher:
             obj.set_readable(True)
             obj.set_writable(True)
 
-    def timeout_callback(self, msec):
+    def _update_timeout(self, msec):
         self.timeout = msec
+        if self.timeout_callback:
+            self.timeout_callback(self, msec)
 
     def attach(self, curldisp):
         """Starts a transfer on curl handle by attaching it to this
@@ -168,9 +179,9 @@ class curl_multi_dispatcher:
            # the curl object is already on this multi-stack
             pass
 
-        while self._curlm.socket_all()[0] == pycurl.E_CALL_MULTI_PERFORM:
-            pass
-
+        # _curlm.timeout() seems to be needed, although curl
+        # documentation doesn't mention it.
+        self._update_timeout(self._curlm.timeout())
         self.check_completed(True)
 
     def detach(self, curldisp):
@@ -181,9 +192,6 @@ class curl_multi_dispatcher:
         # libcurl does not send POLL_REMOVE when a handle is aborted
         for socket, curlobj in self._map.items():
             if curlobj == curldisp:
-
-                print 'handle stopped but socket in map'
-                
                 del self._map[socket]
                 break
 
diff --git a/src/libwebvi/webvi/constants.py b/src/libwebvi/webvi/constants.py
index 2d29700..16e1f92 100644
--- a/src/libwebvi/webvi/constants.py
+++ b/src/libwebvi/webvi/constants.py
@@ -41,11 +41,16 @@ class WebviInfo:
     STREAM_TITLE = 3
 
 class WebviSelectBitmask:
-    TIMEOUT = 0
+    CHECK = 0
     READ = 1
     WRITE = 2
     EXCEPTION = 4
 
+class WebviSelect:
+    TIMEOUT = -1
+
 class WebviConfig:
     TEMPLATE_PATH = 0
     DEBUG = 1
+    TIMEOUT_CALLBACK = 2
+    TIMEOUT_DATA = 3
diff --git a/src/libwebvi/webvi/request.py b/src/libwebvi/webvi/request.py
index 87dcf87..cab15f7 100644
--- a/src/libwebvi/webvi/request.py
+++ b/src/libwebvi/webvi/request.py
@@ -24,12 +24,14 @@ import download
 import sys
 import utils
 import json2xml
+import asyncurl
 from constants import WebviRequestType
 
 DEBUG = False
 
 DEFAULT_TEMPLATE_PATH = '/usr/local/share/webvi/templates'
 template_path = DEFAULT_TEMPLATE_PATH
+timeout_data = None
 
 def debug(msg):
     if DEBUG:
@@ -49,6 +51,10 @@ def set_template_path(path):
     
     debug("set_template_path " + template_path)
 
+def set_timeout_callback(callback):
+    c_api_callback = lambda mdisp, timeout: callback(timeout, timeout_data)
+    asyncurl.multi_dispatcher.timeout_callback = c_api_callback
+
 def parse_reference(reference):
     """Parses URLs of the following form: