format-time-string now supports subsecond time stamp resolution

diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog
index 063ea78c09a2a6fad88cbf23cc8342e3c0d09065..a3a89219bff3d5cac5a2651b6c5088bfc0e81045 100644 (file)
--- a/doc/lispref/ChangeLog
+++ b/doc/lispref/ChangeLog
@@ -1,3 +1,8 @@
+2011-02-01  Paul Eggert  <eggert@cs.ucla.edu>
+
+       format-time-string now supports subsecond time stamp resolution
+       * os.texi (Time Parsing): Document %N.
+
 2011-01-28  Chong Yidong  <cyd@stupidchicken.com>
 
        * vol1.texi (Top):

diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index 576f847d98e3f3221ef00680fd2db3bed0f4cda8..b226d67646261d18aa4de588be166d7412a02a85 100644 (file)
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -21,7 +21,7 @@ terminal and the screen.
 * System Environment::  Distinguish the name and kind of system.
 * User Identification:: Finding the name and user id of the user.
 * Time of Day::         Getting the current time.
-* Time Conversion::     Converting a time from numeric form to 
+* Time Conversion::     Converting a time from numeric form to
                           calendrical data and vice versa.
 * Time Parsing::        Converting a time from numeric form to text
                           and vice versa.
@@ -1336,6 +1336,12 @@ This stands for the month (01-12).
 This stands for the minute (00-59).
 @item %n
 This stands for a newline.
+@item %N
+This stands for the nanoseconds (000000000-999999999).  To ask for
+fewer digits, use @samp{%3N} for milliseconds, @samp{%6N} for
+microseconds, etc.  Any excess digits are discarded, without rounding.
+Currently Emacs time stamps are at best microsecond resolution so the
+last three digits generated by plain @samp{%N} are always zero.
 @item %p
 This stands for @samp{AM} or @samp{PM}, as appropriate.
 @item %r

diff --git a/etc/ChangeLog b/etc/ChangeLog
index db1c5d41c3485b1877f18bbbecc7d0b38074acc5..45dfb211bb062a16fb7c6fcc45f58aa7950d0010 100644 (file)
--- a/etc/ChangeLog
+++ b/etc/ChangeLog
@@ -1,3 +1,8 @@
+2011-02-01  Paul Eggert  <eggert@cs.ucla.edu>
+
+       format-time-string now supports subsecond time stamp resolution
+       * NEWS: Document this.
+
 2011-01-28  Paul Eggert  <eggert@cs.ucla.edu>
 
        Redo spelling of Makefile variables to conform to POSIX.

diff --git a/etc/NEWS b/etc/NEWS
index a20ecd4fe7f5640b49b7847291db6ddaeb32d9c3..d1110b193cb423fba5009232865f71766c61f521 100644 (file)
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -169,6 +169,10 @@ get and set the SELinux context of a file.
 *** Tramp offers handlers for file-selinux-context and set-file-selinux-context
 for remote machines which support SELinux.
 
++++
+** The function format-time-string now supports the %N directive, for
+higher-resolution time stamps.
+
 ** The function kill-emacs is now run upon receipt of the signals SIGTERM
 and SIGHUP, and upon SIGINT in batch mode.
 

diff --git a/src/ChangeLog b/src/ChangeLog
index 2353116c8bd5116e4acb5791b31f651c69e7b9b7..c0c098751215f38d436b4a4b914f682cceebb869 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,13 @@
+2011-02-01  Paul Eggert  <eggert@cs.ucla.edu>
+
+       format-time-string now supports subsecond time stamp resolution
+       * editfns.c (emacs_nmemftime): Renamed from emacs_memftimeu,
+       for consistency with its new argument and with gnulib nstrftime.
+       All callers changed.  New argument NS.
+       (Fformat_time_string): Check that the time argument's microseconds
+       component, if any, is in range; this avoids integer overflow and
+       also nstrftime needs this.  Document %N.
+
 2011-01-31  Andreas Schwab  <schwab@linux-m68k.org>
 
        * image.c (DEF_IMGLIB_FN): Add parameter rettype, use it instead

diff --git a/src/editfns.c b/src/editfns.c
index 7364a5bcf15f38a995b612f7c497f516b06a77c3..1733580ee32626d1cdc81516f54c3c40d08b09d5 100644 (file)
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -92,8 +92,8 @@ static void find_field (Lisp_Object, Lisp_Object, Lisp_Object,
                        EMACS_INT *, Lisp_Object, EMACS_INT *);
 static void update_buffer_properties (EMACS_INT, EMACS_INT);
 static Lisp_Object region_limit (int);
-static size_t emacs_memftimeu (char *, size_t, const char *,
-                               size_t, const struct tm *, int);
+static size_t emacs_nmemftime (char *, size_t, const char *,
+                              size_t, const struct tm *, int, int);
 static void general_insert_function (void (*) (const unsigned char *, EMACS_INT),
                                     void (*) (Lisp_Object, EMACS_INT,
                                               EMACS_INT, EMACS_INT,
@@ -1549,6 +1549,7 @@ or (if you need time as a string) `format-time-string'.  */)
 /* Write information into buffer S of size MAXSIZE, according to the
    FORMAT of length FORMAT_LEN, using time information taken from *TP.
    Default to Universal Time if UT is nonzero, local time otherwise.
+   Use NS as the number of nanoseconds in the %N directive.
    Return the number of bytes written, not including the terminating
    '\0'.  If S is NULL, nothing will be written anywhere; so to
    determine how many bytes would be written, use NULL for S and
@@ -1557,7 +1558,8 @@ or (if you need time as a string) `format-time-string'.  */)
    This function behaves like nstrftime, except it allows null
    bytes in FORMAT and it does not support nanoseconds.  */
 static size_t
-emacs_memftimeu (char *s, size_t maxsize, const char *format, size_t format_len, const struct tm *tp, int ut)
+emacs_nmemftime (char *s, size_t maxsize, const char *format,
+                size_t format_len, const struct tm *tp, int ut, int ns)
 {
   size_t total = 0;
 
@@ -1574,7 +1576,7 @@ emacs_memftimeu (char *s, size_t maxsize, const char *format, size_t format_len,
       if (s)
        s[0] = '\1';
 
-      result = nstrftime (s, maxsize, format, tp, ut, 0);
+      result = nstrftime (s, maxsize, format, tp, ut, ns);
 
       if (s)
        {
@@ -1620,6 +1622,7 @@ by text that describes the specified date and time in TIME:
 %p is the locale's equivalent of either AM or PM.
 %M is the minute.
 %S is the second.
+%N is the nanosecond, %6N the microsecond, %3N the millisecond, etc.
 %Z is the time zone name, %z is the numeric form.
 %s is the number of seconds since 1970-01-01 00:00:00 +0000.
 
@@ -1649,13 +1652,17 @@ For example, to produce full ISO 8601 format, use "%Y-%m-%dT%T%z".  */)
 {
   time_t value;
   int size;
+  int usec;
+  int ns;
   struct tm *tm;
   int ut = ! NILP (universal);
 
   CHECK_STRING (format_string);
 
-  if (! lisp_time_argument (time, &value, NULL))
+  if (! (lisp_time_argument (time, &value, &usec)
+        && 0 <= usec && usec < 1000000))
     error ("Invalid time specification");
+  ns = usec * 1000;
 
   format_string = code_convert_string_norecord (format_string,
                                                Vlocale_coding_system, 1);
@@ -1678,9 +1685,9 @@ For example, to produce full ISO 8601 format, use "%Y-%m-%dT%T%z".  */)
 
       buf[0] = '\1';
       BLOCK_INPUT;
-      result = emacs_memftimeu (buf, size, SSDATA (format_string),
+      result = emacs_nmemftime (buf, size, SSDATA (format_string),
                                SBYTES (format_string),
-                               tm, ut);
+                               tm, ut, ns);
       UNBLOCK_INPUT;
       if ((result > 0 && result < size) || (result == 0 && buf[0] == '\0'))
        return code_convert_string_norecord (make_unibyte_string (buf, result),
@@ -1688,10 +1695,10 @@ For example, to produce full ISO 8601 format, use "%Y-%m-%dT%T%z".  */)
 
       /* If buffer was too small, make it bigger and try again.  */
       BLOCK_INPUT;
-      result = emacs_memftimeu (NULL, (size_t) -1,
+      result = emacs_nmemftime (NULL, (size_t) -1,
                                SSDATA (format_string),
                                SBYTES (format_string),
-                               tm, ut);
+                               tm, ut, ns);
       UNBLOCK_INPUT;
       size = result + 1;
     }