Back out recent breakage in the Python binding that didn't work.

Back out bzed's major change of 26 May and three related later changes
by esr on 13 Aug, all in gps.py. These introduced a serious bug - all
pending responses read were unpacked, but *only the last response* in
any given group was available after the return of the poll() call.

This broke gpsfake, a problem which was concealed by a thinko in the
regression-test driver.

The client falling behind the daemon is still an issue, but needs
to be tackled in a different way.

1 files changed, 33 insertions, 72 deletions

diff --git a/gps.py b/gps.py
index 76cc05e5..3e3aca9b 100755
--- a/gps.py
+++ b/gps.py
@@ -186,8 +186,7 @@ class gps(gpsdata):
     def __init__(self, host="127.0.0.1", port="2947", verbose=0):
         gpsdata.__init__(self)
         self.sock = None        # in case we blow up in connect
-        self.eof = False
-        self.buf = ''
+        self.sockfile = None
         self.connect(host, port)
         self.verbose = verbose
         self.raw_hook = None
@@ -210,12 +209,14 @@ class gps(gpsdata):
         #if self.debuglevel > 0: print 'connect:', (host, port)
         msg = "getaddrinfo returns an empty list"
         self.sock = None
+        self.sockfile = None
         for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
             af, socktype, proto, canonname, sa = res
             try:
                 self.sock = socket.socket(af, socktype, proto)
                 #if self.debuglevel > 0: print 'connect:', (host, port)
                 self.sock.connect(sa)
+                self.sockfile = self.sock.makefile()
             except socket.error, msg:
                 #if self.debuglevel > 0: print 'connect fail:', (host, port)
                 self.close()
@@ -228,15 +229,18 @@ class gps(gpsdata):
         self.raw_hook = hook
 
     def close(self):
+        if self.sockfile:
+            self.sockfile.close()
         if self.sock:
             self.sock.close()
         self.sock = None
+        self.sockfile = None
 
     def __del__(self):
         self.close()
 
     def __unpack(self, buf):
-        """Unpack a daemon response into the instance members"""
+        # unpack a daemon response into the instance members
         self.fix.time = 0.0
         fields = buf.strip().split(",")
         if fields[0] == "GPSD":
@@ -369,85 +373,42 @@ class gps(gpsdata):
             self.raw_hook(buf);
 
     def waiting(self):
-        """Return True if data is ready for the client."""
-        try:
-            (winput, woutput, wexceptions) = select.select([self.sock], [], [], 0)
-        except select.error, socket.error:
-            self.eof = True
-            return False
-        return len(winput) > 0
-
-    def readlines(self):
-        """Yield the next few complete lines. If no data is available,
-        return an empty string."""
-        if self.eof or not self.waiting():
-            yield ''
-        # Accumulate input
-        while self.waiting():
-            buf = self.sock.recv(512)
-            if buf:
-                self.buf += buf
-            else:
-                self.eof = True
-                break
-        lines = self.buf.split('\r\n')
-        if lines and not lines[-1]:
-            lines.pop()
-        # Now yield it line by line
-        for l in lines[:]:
-            if l:
-                yield l + "\r\n"
-                del lines[0]
-
-    def readstanzas(self):
-        """Read a possibly multi-line response.
-        Currently used for RTCM2 H responses."""
-        stanza = []
-        for frag in self.readlines():
-            if self.eof:
-                yield ''
-            if frag:
-                # Old-style protocol line or raw GPS data or JSON object
-                if '=' in frag or frag[0] in "!${":
-                    yield frag
-                    stanza = []
-                # End of Sager-format RTCM2 dump
-                elif frag == '.':
-                    yield '\r\n'.join(stanza)
-                    stanza = []
-                # Body of Sager-format RTCM2 dump
-                else:
-                    stanza.append(frag)
+        "Return True if data is ready for the client."
+        (winput, woutput, wexceptions) = select.select((self.sock,), (), (), 0)
+        return winput != []
 
     def poll(self):
-        """Wait for and read data being streamed from gpsd.
-        Return values: -1 on EOF, 1 on no more data, 0 otherwise"""
-        for self.response in self.readstanzas():
-            if self.eof:
-                return -1
-            if not self.response:
-                return 1
-            if self.verbose:
-                sys.stderr.write("GPS DATA %s\n" % `self.response`)
-            self.timings.c_recv_time = time.time()
-            self.__unpack(self.response)
-            if self.profiling:
-                if self.timings.sentence_time != '?':
-                    basetime = self.timings.sentence_time
-                else:
-                    basetime = self.timings.d_xmit_time
-                self.timings.c_decode_time = time.time() - basetime
-                self.timings.c_recv_time -= basetime
+        "Wait for and read data being streamed from gpsd."
+        self.response = self.sockfile.readline()
+        if self.response.startswith("H") and "=" not in self.response:
+            while True:
+                frag = self.sockfile.readline()
+                self.response += frag
+                if frag.startswith("."):
+                    break
+        if not self.response:
+            return -1
+        if self.verbose:
+            sys.stderr.write("GPS DATA %s\n" % repr(self.response))
+        self.timings.c_recv_time = time.time()
+        self.__unpack(self.response)
+        if self.profiling:
+            if self.timings.sentence_time != '?':
+                basetime = self.timings.sentence_time
+            else:
+                basetime = self.timings.d_xmit_time
+            self.timings.c_decode_time = time.time() - basetime
+            self.timings.c_recv_time -= basetime
         return 0
 
     def send(self, commands):
-        """Ship commands to the daemon."""
+        "Ship commands to the daemon."
         if not commands.endswith("\n"):
             commands += "\n"
         self.sock.send(commands)
 
     def query(self, commands):
-        """Send a command, get back a response."""
+        "Send a command, get back a response."
         self.send(commands)
         return self.poll()