Generate coefficients for least-squares fit into the C code.

5 files changed, 50 insertions, 36 deletions

diff --git a/.gitignore b/.gitignore
index ea2f07c7..51ea91b1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -62,6 +62,7 @@ gpsd_config.h.in
 gpsd_config.h
 packet_names.h
 revision.h
+leapcheck.h
 gpsd.spec
 MANIFEST
 .kdbgrc.*
diff --git a/Makefile.am b/Makefile.am
index 78915549..93e9e2e4 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -209,7 +209,7 @@ libgpsd_h_sources = \
 
 libgpsd_la_LDFLAGS = $(LIBUSB_LIBS) $(BLUEZ_LIBS)
 
-BUILT_SOURCES = packet_names.h gpsd.h revision.h ais_json.i gps_maskdump.c gpsd_maskdump.c
+BUILT_SOURCES = packet_names.h gpsd.h revision.h ais_json.i gps_maskdump.c gpsd_maskdump.c leapcheck.h
 
 packet_names.h: packet_states.h
 	rm -f packet_names.h && \
@@ -244,14 +244,17 @@ gpsd_maskdump.c: gpsd.h maskaudit.py
 	$(PYTHON) maskaudit.py -d >gpsd_maskdump.c && \
 	chmod a-w gpsd_maskdump.c
 
+leapcheck.h: leapsecond.py #leapcheck.i
+	$(PYTHON) leapsecond.py -h leapcheck.i >leapcheck.h
+
 # This gets kept in the repo so we can build without Internet access
 leapcheck.i: leapsecond.py
-	$(PYTHON) leapsecond.py -c leapcheck.i
+	$(PYTHON) leapsecond.py -f leapcheck.i
 
 libgps_la_SOURCES = $(libgps_c_sources)
 
 libgpsd_la_SOURCES = $(libgpsd_c_sources) $(libgpsd_h_sources) \
-				driver_rtcm2.h packet_states.h
+				driver_rtcm2.h packet_states.h leapcheck.h
 
 # Warning: This overrides autoconf's normal link-line generation process
 if LIBGPSMM_ENABLE
diff --git a/leapcheck.i b/leapcheck.i
index 23015092..0c01c93c 100644
--- a/leapcheck.i
+++ b/leapcheck.i
@@ -1,17 +1,16 @@
-        315550800.0,    // 31 Dec 1979 23:59:60 -> 0
-        362807999.0,    // 30 Jun 1981 23:59:59 -> 1
-        394343999.0,    // 30 Jun 1982 23:59:59 -> 2
-        425879999.0,    // 30 Jun 1983 23:59:59 -> 3
-        489038399.0,    // 30 Jun 1985 23:59:59 -> 4
-        568011600.0,    // 31 Dec 1987 23:59:60 -> 5
-        631170000.0,    // 31 Dec 1989 23:59:60 -> 6
-        662706000.0,    // 31 Dec 1990 23:59:60 -> 7
-        709963199.0,    // 30 Jun 1992 23:59:59 -> 8
-        741499199.0,    // 30 Jun 1993 23:59:59 -> 9
-        773035199.0,    // 30 Jun 1994 23:59:59 -> 10
-        820472400.0,    // 31 Dec 1995 23:59:60 -> 11
-        867729599.0,    // 30 Jun 1997 23:59:59 -> 12
-        915166800.0,    // 31 Dec 1998 23:59:60 -> 13
-        1136091600.0,    // 31 Dec 2005 23:59:60 -> 14
-        1230786000.0,    // 31 Dec 2008 23:59:60 -> 15
-        1295350796.0,    // 18 Jan 2011 06:39:56 -> ?
+315550800.0
+362807999.0
+394343999.0
+425879999.0
+489038399.0
+568011600.0
+631170000.0
+662706000.0
+709963199.0
+741499199.0
+773035199.0
+820472400.0
+867729599.0
+915166800.0
+1136091600.0
+1230786000.0
diff --git a/leapsecond.py b/leapsecond.py
index c8f1b509..bdcd84c8 100755
--- a/leapsecond.py
+++ b/leapsecond.py
@@ -110,29 +110,23 @@ def get():
         return current_offset
 
 def save_leapseconds(outfile):
-    "Fetch the USNO leap-second history data and makw a leap-second list."
+    "Fetch the USNO leap-second history data and make a leap-second list."
     skip = True
     leapsecs = []
     # This code assumes that after 1980, leap-second increments are
     # always integrally one second and every increment is listed here
     leapsecs = []
     try:
+        fp = open(outfile, "w")
         for line in urllib.urlopen("ftp://maia.usno.navy.mil/ser7/tai-utc.dat"):
             if line.startswith(" 1980"):
                 skip = False
             if skip:
                 continue
             fields = line.strip().split()
-            leapsecs.append(leapbound(fields[0], fields[1]))
-        leapsecs.append(unix_to_rfc822(time.time()))          # Add sentinel
-        def label(i):
-            if i == len(leapsecs) - 1:
-                return '?'
-            else:
-                return str(i)
-        with open(outfile, "w") as fp: 
-            for (i, b) in enumerate(leapsecs):
-                fp.write("        %s,    // %s -> %s\n" % (rfc822_to_unix(b), b, label(i)))
+            md = leapbound(fields[0], fields[1])
+            fp.write(repr(rfc822_to_unix(md)) + "\n")
+        fp.close()
     except IOError:
         print >>sys.stderr, "Fetch from USNO failed, %s not updated." % outfile
 
@@ -140,10 +134,24 @@ def fetch_leapsecs(filename):
     "Get a list of leap seconds from the local cache of the USNO history"
     leapsecs = []
     with open(filename) as fp:
-        leapsecs = map(lambda x: int(x.split(',')[0][:-2]), fp.readlines())
-    leapsecs.pop()          # Remove the sentinel entry
+        leapsecs = map(lambda x: float(x.strip()), fp.readlines())
     return leapsecs
 
+def make_leapsecond_include(infile):
+    leapsecs = fetch_leapsecs(infile)
+    leapsecs.append(time.time())          # Add sentinel
+    (b, c, e) = leastsquares(zip(range(len(leapsecs)), leapsecs))
+    def label(i):
+        if i == len(leapsecs) - 1:
+            return '?'
+        else:
+            return str(i)
+    for (i, b) in enumerate(leapsecs):
+        sys.stdout.write("    %s,    // %s -> %s\n" % (b, unix_to_rfc822(b), label(i)))
+    sys.stdout.write("#define LEAPSECOND_B\t%s\n" % b)
+    sys.stdout.write("#define LEAPSECOND_C\t%s\n" % c)
+    sys.stdout.write("#define LEAPSECOND_E\t%s\n" % e)
+
 def leastsquares(tuples):
     "Generate coefficients for a least-squares fit to the specified data."
     sum_x=0
@@ -238,14 +246,17 @@ def leapbound(year, month):
 
 if __name__ == '__main__':
     import sys, getopt
-    (options, arguments) = getopt.getopt(sys.argv[1:], "c:g:i:n:o:")
+    (options, arguments) = getopt.getopt(sys.argv[1:], "f:g:h:i:n:o:")
     for (switch, val) in options:
-        if (switch == '-c'):    # Generate C initializer listing leap seconds
+        if (switch == '-f'):    # Fetch USNO data to cache locally
             save_leapseconds(val)
             raise SystemExit, 0
         elif (switch == '-g'):  # Graph the leap_second history
             graph_history(val)
             raise SystemExit, 0
+        elif (switch == '-h'):  # make leapsecond include
+            make_leapsecond_include(val)
+            raise SystemExit, 0
         elif (switch == '-i'):  # Compute Unix time from RFC822 date
             print "#define FOO	%d	/* %s */" % (rfc822_to_unix(val), val)
             raise SystemExit, 0
diff --git a/rollover.c b/rollover.c
index 58844929..c73b958b 100644
--- a/rollover.c
+++ b/rollover.c
@@ -98,7 +98,7 @@ static int gpsd_check_utc(const int leap, const double unixtime)
 /* consistency-check a GPS-reported UTC against a leap second */
 {
     static double c_epochs[] = {
-#include "leapcheck.i"
+#include "leapcheck.h"
     };
     #define DIM(a) (int)(sizeof(a)/sizeof(a[0]))