[PATCH 5/5] timespec: new function make_timespec, and new constants

[Paul Eggert]

* lib/timespec.h: Incorporate recent changes on the Emacs trunk.
(TIMESPEC_RESOLUTION, LOG10_TIMESPEC_RESOLUTION): New constants.
(make_timespec): New function.
* lib/dtotimespec.c (dtotimespec):
* lib/timespec-add.c (timespec_add):
* lib/timespec-sub.c (timespec_sub):
* lib/utimens.c (validate_timespec):
* lib/utimensat.c (rpl_utimensat):
Use these new constants and functions.
---
 ChangeLog          | 11 +++++++++++
 lib/dtotimespec.c  | 30 ++++++++++--------------------
 lib/timespec-add.c |  7 ++-----
 lib/timespec-sub.c |  7 ++-----
 lib/timespec.h     | 17 +++++++++++++++++
 lib/utimens.c      |  6 ++++--
 lib/utimensat.c    |  8 ++++----
 7 files changed, 50 insertions(+), 36 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 9eb2c2c..6d93458 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,16 @@
 2013-09-19  Paul Eggert  <address@hidden>
 
+    timespec: new function make_timespec, and new constants
+    * lib/timespec.h: Incorporate recent changes on the Emacs trunk.
+    (TIMESPEC_RESOLUTION, LOG10_TIMESPEC_RESOLUTION): New constants.
+    (make_timespec): New function.
+    * lib/dtotimespec.c (dtotimespec):
+    * lib/timespec-add.c (timespec_add):
+    * lib/timespec-sub.c (timespec_sub):
+    * lib/utimens.c (validate_timespec):
+    * lib/utimensat.c (rpl_utimensat):
+    Use these new constants and functions.
+
     stdio: OS X port of putc_unlocked + extern inline
     * lib/stdio.in.h (putc_unlocked): #undef on problematic Apple platforms.
     * doc/posix-functions/putc_unlocked.texi:
diff --git a/lib/dtotimespec.c b/lib/dtotimespec.c
index ecce2e5..064f7d3 100644
--- a/lib/dtotimespec.c
+++ b/lib/dtotimespec.c
@@ -29,41 +29,31 @@
 struct timespec
 dtotimespec (double sec)
 {
-  enum { BILLION = 1000 * 1000 * 1000 };
   double min_representable = TYPE_MINIMUM (time_t);
   double max_representable =
-    ((TYPE_MAXIMUM (time_t) * (double) BILLION + (BILLION - 1))
-     / BILLION);
-  struct timespec r;
+    ((TYPE_MAXIMUM (time_t) * (double) TIMESPEC_RESOLUTION
+      + (TIMESPEC_RESOLUTION - 1))
+     / TIMESPEC_RESOLUTION);
 
   if (! (min_representable < sec))
-    {
-      r.tv_sec = TYPE_MINIMUM (time_t);
-      r.tv_nsec = 0;
-    }
+    return make_timespec (TYPE_MINIMUM (time_t), 0);
   else if (! (sec < max_representable))
-    {
-      r.tv_sec = TYPE_MAXIMUM (time_t);
-      r.tv_nsec = BILLION - 1;
-    }
+    return make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_RESOLUTION - 1);
   else
     {
       time_t s = sec;
-      double frac = BILLION * (sec - s);
+      double frac = TIMESPEC_RESOLUTION * (sec - s);
       long ns = frac;
       ns += ns < frac;
-      s += ns / BILLION;
-      ns %= BILLION;
+      s += ns / TIMESPEC_RESOLUTION;
+      ns %= TIMESPEC_RESOLUTION;
 
       if (ns < 0)
         {
           s--;
-          ns += BILLION;
+          ns += TIMESPEC_RESOLUTION;
         }
 
-      r.tv_sec = s;
-      r.tv_nsec = ns;
+      return make_timespec (s, ns);
     }
-
-  return r;
 }
diff --git a/lib/timespec-add.c b/lib/timespec-add.c
index 6ce2c73..51323a6 100644
--- a/lib/timespec-add.c
+++ b/lib/timespec-add.c
@@ -28,11 +28,10 @@
 struct timespec
 timespec_add (struct timespec a, struct timespec b)
 {
-  struct timespec r;
   time_t rs = a.tv_sec;
   time_t bs = b.tv_sec;
   int ns = a.tv_nsec + b.tv_nsec;
-  int nsd = ns - 1000000000;
+  int nsd = ns - TIMESPEC_RESOLUTION;
   int rns = ns;
 
   if (0 <= nsd)
@@ -65,7 +64,5 @@ timespec_add (struct timespec a, struct timespec b)
   else
     rs += bs;
 
-  r.tv_sec = rs;
-  r.tv_nsec = rns;
-  return r;
+  return make_timespec (rs, rns);
 }
diff --git a/lib/timespec-sub.c b/lib/timespec-sub.c
index 97c9f9d..b164a83 100644
--- a/lib/timespec-sub.c
+++ b/lib/timespec-sub.c
@@ -29,7 +29,6 @@
 struct timespec
 timespec_sub (struct timespec a, struct timespec b)
 {
-  struct timespec r;
   time_t rs = a.tv_sec;
   time_t bs = b.tv_sec;
   int ns = a.tv_nsec - b.tv_nsec;
@@ -37,7 +36,7 @@ timespec_sub (struct timespec a, struct timespec b)
 
   if (ns < 0)
     {
-      rns = ns + 1000000000;
+      rns = ns + TIMESPEC_RESOLUTION;
       if (rs == TYPE_MINIMUM (time_t))
         {
           if (bs <= 0)
@@ -65,7 +64,5 @@ timespec_sub (struct timespec a, struct timespec b)
   else
     rs -= bs;
 
-  r.tv_sec = rs;
-  r.tv_nsec = rns;
-  return r;
+  return make_timespec (rs, rns);
 }
diff --git a/lib/timespec.h b/lib/timespec.h
index 5990d07..d0c029b 100644
--- a/lib/timespec.h
+++ b/lib/timespec.h
@@ -29,6 +29,23 @@ _GL_INLINE_HEADER_BEGIN
 # define _GL_TIMESPEC_INLINE _GL_INLINE
 #endif
 
+/* Resolution of timespec time stamps (in units per second), and log
+   base 10 of the resolution.  */
+
+enum { TIMESPEC_RESOLUTION = 1000000000 };
+enum { LOG10_TIMESPEC_RESOLUTION = 9 };
+
+/* Return a timespec with seconds S and nanoseconds NS.  */
+
+_GL_TIMESPEC_INLINE struct timespec
+make_timespec (time_t s, long int ns)
+{
+  struct timespec r;
+  r.tv_sec = s;
+  r.tv_nsec = ns;
+  return r;
+}
+
 /* Return negative, zero, positive if A < B, A == B, A > B, respectively.
 
    For each time stamp T, this code assumes that either:
diff --git a/lib/utimens.c b/lib/utimens.c
index 013843d..44a33c1 100644
--- a/lib/utimens.c
+++ b/lib/utimens.c
@@ -90,10 +90,12 @@ validate_timespec (struct timespec timespec[2])
   assert (timespec);
   if ((timespec[0].tv_nsec != UTIME_NOW
        && timespec[0].tv_nsec != UTIME_OMIT
-       && (timespec[0].tv_nsec < 0 || 1000000000 <= timespec[0].tv_nsec))
+       && ! (0 <= timespec[0].tv_nsec
+             && timespec[0].tv_nsec < TIMESPEC_RESOLUTION))
       || (timespec[1].tv_nsec != UTIME_NOW
           && timespec[1].tv_nsec != UTIME_OMIT
-          && (timespec[1].tv_nsec < 0 || 1000000000 <= timespec[1].tv_nsec)))
+          && ! (0 <= timespec[1].tv_nsec
+                && timespec[1].tv_nsec < TIMESPEC_RESOLUTION)))
     {
       errno = EINVAL;
       return -1;
diff --git a/lib/utimensat.c b/lib/utimensat.c
index 0c52b24..f3a6651 100644
--- a/lib/utimensat.c
+++ b/lib/utimensat.c
@@ -93,11 +93,11 @@ rpl_utimensat (int fd, char const *file, struct timespec 
const times[2],
          values.  */
       else if (times
                && ((times[0].tv_nsec != UTIME_NOW
-                    && (times[0].tv_nsec < 0
-                        || times[0].tv_nsec >= 1000000000))
+                    && ! (0 <= times[0].tv_nsec
+                          && times[0].tv_nsec < TIMESPEC_RESOLUTION))
                    || (times[1].tv_nsec != UTIME_NOW
-                       && (times[1].tv_nsec < 0
-                           || times[1].tv_nsec >= 1000000000))))
+                       && ! (0 <= times[1].tv_nsec
+                             && times[1].tv_nsec < TIMESPEC_RESOLUTION))))
         {
           errno = EINVAL;
           return -1;
-- 
1.8.3.1