Merge pull request #58 from mhvk/leap-second-access

Leap second access following pattern from Astropy

src/Makefile.am

@@ -30,9 +30,9 @@ tcgtt.c tdbtcb.c tdbtt.c tf2a.c tf2d.c tpors.c tporv.c tpsts.c \
 tpstv.c tpxes.c tpxev.c tr.c trxp.c trxpv.c tttai.c \
 tttcg.c tttdb.c ttut1.c ut1tai.c ut1tt.c ut1utc.c utctai.c utcut1.c \
 xy06.c xys00a.c xys00b.c xys06a.c zp.c zpv.c zr.c \
-erfaversion.c
+erfaversion.c erfadatextra.c
 
-include_HEADERS = erfa.h erfam.h erfaextra.h
+include_HEADERS = erfa.h erfam.h erfaextra.h erfadatextra.h
 
 ## Version info is in current : revision : age form
 ## A library supports interfaces from current downto current - age
@@ -44,8 +44,9 @@ liberfa_la_LDFLAGS = -version-info $(VI_ALL)
 
 
 ## Check program
-TESTS = t_erfa_c
-check_PROGRAMS = t_erfa_c
+TESTS = t_erfa_c t_erfa_c_extra
+check_PROGRAMS = t_erfa_c t_erfa_c_extra
 t_erfa_c_SOURCES = t_erfa_c.c
+t_erfa_c_extra_SOURCES = t_erfa_c_extra.c
 AM_CPPFLAGS = -I$(top_srcdir)
 LDADD = $(top_builddir)/src/liberfa.la

src/dat.c

@@ -1,4 +1,5 @@
 #include "erfa.h"
+#include "erfadatextra.h"
 
 int eraDat(int iy, int im, int id, double fd, double *deltat)
 /*
@@ -144,10 +145,7 @@ int eraDat(int iy, int im, int id, double fd, double *deltat)
    enum { NERA1 = (int) (sizeof drift / sizeof (double) / 2) };
 
 /* Dates and Delta(AT)s */
-   static const struct {
-      int iyear, month;
-      double delat;
-   } changes[] = {
+   static const eraLEAPSECOND _changes[] = {
       { 1960,  1,  1.4178180 },
       { 1961,  1,  1.4228180 },
       { 1961,  8,  1.3728180 },
@@ -193,7 +191,13 @@ int eraDat(int iy, int im, int id, double fd, double *deltat)
    };
 
 /* Number of Delta(AT) changes */
-   enum { NDAT = (int) (sizeof changes / sizeof changes[0]) };
+   enum { _NDAT = (int) (sizeof _changes / sizeof _changes[0]) };
+
+/* Get/initialise leap-second if needed */
+   int NDAT;
+   eraLEAPSECOND *changes;
+
+   NDAT = eraDatini(_changes, _NDAT, &changes);
 
 /* Miscellaneous local variables */
    int j, i, m;
@@ -243,15 +247,15 @@ int eraDat(int iy, int im, int id, double fd, double *deltat)
 
 }
 /*----------------------------------------------------------------------
-**  
-**  
+**
+**
 **  Copyright (C) 2013-2019, NumFOCUS Foundation.
 **  All rights reserved.
-**  
+**
 **  This library is derived, with permission, from the International
 **  Astronomical Union's "Standards of Fundamental Astronomy" library,
 **  available from http://www.iausofa.org.
-**  
+**
 **  The ERFA version is intended to retain identical functionality to
 **  the SOFA library, but made distinct through different function and
 **  file names, as set out in the SOFA license conditions.  The SOFA
@@ -260,36 +264,36 @@ int eraDat(int iy, int im, int id, double fd, double *deltat)
 **  state.  The ERFA version is not subject to this restriction and
 **  therefore can be included in distributions which do not support the
 **  concept of "read only" software.
-**  
+**
 **  Although the intent is to replicate the SOFA API (other than
 **  replacement of prefix names) and results (with the exception of
 **  bugs;  any that are discovered will be fixed), SOFA is not
 **  responsible for any errors found in this version of the library.
-**  
+**
 **  If you wish to acknowledge the SOFA heritage, please acknowledge
 **  that you are using a library derived from SOFA, rather than SOFA
 **  itself.
-**  
-**  
+**
+**
 **  TERMS AND CONDITIONS
-**  
+**
 **  Redistribution and use in source and binary forms, with or without
 **  modification, are permitted provided that the following conditions
 **  are met:
-**  
+**
 **  1 Redistributions of source code must retain the above copyright
 **    notice, this list of conditions and the following disclaimer.
-**  
+**
 **  2 Redistributions in binary form must reproduce the above copyright
 **    notice, this list of conditions and the following disclaimer in
 **    the documentation and/or other materials provided with the
 **    distribution.
-**  
+**
 **  3 Neither the name of the Standards Of Fundamental Astronomy Board,
 **    the International Astronomical Union nor the names of its
 **    contributors may be used to endorse or promote products derived
 **    from this software without specific prior written permission.
-**  
+**
 **  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 **  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 **  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
@@ -302,5 +306,5 @@ int eraDat(int iy, int im, int id, double fd, double *deltat)
 **  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 **  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 **  POSSIBILITY OF SUCH DAMAGE.
-**  
+**
 */

src/erfadatextra.c

@@ -0,0 +1,93 @@
+/*
+** Copyright (C) 2019, NumFOCUS Foundation.
+**
+** Licensed under a 3-clause BSD style license - see LICENSE
+**
+** This file is NOT derived from SOFA sources.
+**
+** The eraGetLeapSeconds and eraSetLeapSeconds functions are used as an
+** experimental interface for getting and setting the leap second table in
+** astropy 4.0.  They will be supported as long as astropy 4.0 is supported
+** (until 2021), but not necessarily beyond.  Comments and ideas about the
+** best way to keep the leap second tables up to date for all users of erfa
+** are welcome (https://github.com/liberfa/erfa).
+**
+** The eraDatini function is used internally in dat.c; it is strictly an
+** implementation detail and should not be used elsewhere.
+*/
+#include "erfa.h"
+#include "erfaextra.h"
+
+static eraLEAPSECOND *changes;
+static int NDAT = -1;
+
+
+int eraGetLeapSeconds(eraLEAPSECOND **leapseconds)
+/*
+**  Get the current leap second table.
+**
+**  Returned:
+**     leapseconds eraLEAPSECOND*  Array of year, month, TAI minus UTC
+**
+**  Returned (function value):
+**            int  NDAT  Number of entries/status
+**                       >0 = number of entries
+**                       -1 = internal error
+*/
+{
+    if (NDAT <= 0) {
+        double delat;
+        int stat = eraDat(2000, 1, 1, 0., &delat);
+        if (stat != 0 || NDAT <= 0) {
+            return -1;
+        }
+    }
+    *leapseconds = changes;
+    return NDAT;
+}
+
+void eraSetLeapSeconds(eraLEAPSECOND *leapseconds, int count)
+/*
+**  Set the current leap second table.
+**
+**  Given:
+**     leapseconds eraLEAPSECOND*  Array of year, month, TAI minus UTC
+**     count       int             Number of entries.  If <= 0, causes
+**                                 a reset of the table to the built-in
+**                                 version.
+**
+**  Notes:
+**     *No* sanity checks are performed.
+*/
+{
+    changes = leapseconds;
+    NDAT = count;
+}
+
+int eraDatini(const eraLEAPSECOND *builtin, int n_builtin,
+              eraLEAPSECOND **leapseconds)
+/*
+**  Get the leap second table, initializing it to the built-in version
+**  if necessary.
+**
+**  This function is for internal use in dat.c only and should
+**  not be used elsewhere.
+**
+**  Given:
+**     builtin     eraLEAPSECOND   Array of year, month, TAI minus UTC
+**     n_builtin   int             Number of entries of the table.
+**
+**  Returned:
+**     leapseconds eraLEAPSECOND*  Current array, set to the builtin one
+**                                 if not yet initialized.
+**
+**  Returned (function value):
+**            int  NDAT  Number of entries
+*/
+{
+    if (NDAT <= 0) {
+        eraSetLeapSeconds((eraLEAPSECOND *)builtin, n_builtin);
+    }
+    *leapseconds = changes;
+    return NDAT;
+}

src/erfadatextra.h

@@ -0,0 +1,18 @@
+/*
+** Copyright (C) 2019, NumFOCUS Foundation.
+**
+** Licensed under a 3-clause BSD style license - see LICENSE
+**
+** This file is NOT derived from SOFA sources.
+**
+*/
+
+/*
+**  Get the leap second table, initializing it to the built-in version
+**  if necessary.
+**
+**  This function is for internal use in dat.c only and should
+**  not be used elsewhere.
+*/
+int eraDatini(const eraLEAPSECOND *builtin, int n_builtin,
+              eraLEAPSECOND **leapseconds);

src/erfaextra.h

@@ -1,9 +1,20 @@
 /*
-** Copyright (C) 2016-2017, NumFOCUS Foundation. 
+** Copyright (C) 2016-2019, NumFOCUS Foundation.
 **
 ** Licensed under a 3-clause BSD style license - see LICENSE
 **
-** This file is NOT derived from SOFA sources
+** This file is NOT derived from SOFA sources.
+**
+** The functions here provide an interface to ERFA and SOFA version
+** information, and for updating the leap second table.
+**
+** The eraGetLeapSeconds and eraSetLeapSeconds functions are used as an
+** experimental interface for getting and setting the leap second table in
+** astropy 4.0.  They will be supported as long as astropy 4.0 is supported
+** (until 2021), but not necessarily beyond.  Comments and ideas about the
+** best way to keep the leap second tables up to date for all users of erfa
+** are welcome (https://github.com/liberfa/erfa).
+**
 */
 
 
@@ -15,45 +26,50 @@ extern "C" {
 #endif
 
 
-/* 
+/*
 ** Returns the package version
 ** as defined in configure.ac
 ** in string format
 */
-const char* eraVersion();
+const char* eraVersion(void);
 
-/* 
+/*
 ** Returns the package major version
 ** as defined in configure.ac
 ** as integer
 */
-int eraVersionMajor();
+int eraVersionMajor(void);
 
-/* 
+/*
 ** Returns the package minor version
 ** as defined in configure.ac
 ** as integer
 */
-int eraVersionMinor();
+int eraVersionMinor(void);
 
-/* 
+/*
 ** Returns the package micro version
 ** as defined in configure.ac
 ** as integer
 */
-int eraVersionMicro();
+int eraVersionMicro(void);
 
-/* 
+/*
 ** Returns the orresponding SOFA version
 ** as defined in configure.ac
 ** in string format
 */
-const char* eraSofaVersion();
+const char* eraSofaVersion(void);
+
 
+/*
+** Get and set leap seconds (not supported by SOFA; EXPERIMENTAL)
+*/
+int eraGetLeapSeconds(eraLEAPSECOND **leapseconds);
+void eraSetLeapSeconds(eraLEAPSECOND *leapseconds, int count);
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* _ERFA_EXTRA_H */
-

src/erfam.h

@@ -41,6 +41,12 @@ typedef struct {
    double pv[2][3];   /* barycentric PV of the body (au, au/day) */
 } eraLDBODY;
 
+/* Leap second definition */
+typedef struct {
+   int iyear, month;
+   double delat;
+} eraLEAPSECOND;
+
 /* Pi */
 #define ERFA_DPI (3.141592653589793238462643)
 

src/erfaversion.c

@@ -1,38 +1,51 @@
 /*
 ** Copyright (C) 2016-2017, NumFOCUS Foundation.
 **
-** Licensed under a 3-clause BSD style license - see LICENSE 
+** Licensed under a 3-clause BSD style license - see LICENSE
 **
 ** This file is NOT derived from SOFA sources
 */
 
+/* Define to the version of this package. */
+#define PACKAGE_VERSION "1.6.0"
+
+/* Define to the major version of this package. */
+#define PACKAGE_VERSION_MAJOR 1
+
+/* Define to the micro version of this package. */
+#define PACKAGE_VERSION_MICRO 0
+
+/* Define to the minor version of this package. */
+#define PACKAGE_VERSION_MINOR 6
+
+/* Define to the version of SOFA */
+#define SOFA_VERSION "20190722"
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>
 #endif /* HAVE_CONFIG_H */
 
 
-const char* eraVersion() {
+const char* eraVersion(void) {
   return PACKAGE_VERSION;
 }
 
 
-int eraVersionMajor() {
+int eraVersionMajor(void) {
   return PACKAGE_VERSION_MAJOR;
 }
 
 
-int eraVersionMinor() {
+int eraVersionMinor(void) {
   return PACKAGE_VERSION_MINOR;
 }
 
 
-int eraVersionMicro() {
+int eraVersionMicro(void) {
   return PACKAGE_VERSION_MICRO;
 }
 
 
-const char* eraSofaVersion() {
+const char* eraSofaVersion(void) {
   return SOFA_VERSION;
 }
-