introduce "epoch" as a new base time reference, meaning timestamp 0.

This disambiguates between some "at-style" time specs:

11111111 yields an error message:

did you really mean month 1111111?

and

19711205 denotes Dec 12, 1971 and not the timestamp.

The patch allows to write:

epoch+11111111s or epoch+19711205s

-- Peter Stamfest

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@2147 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/doc/rrdfetch.pod b/doc/rrdfetch.pod
index 49b8fc2..29f91bc 100644 (file)
--- a/doc/rrdfetch.pod
+++ b/doc/rrdfetch.pod
@@ -165,11 +165,16 @@ single-number date is interpreted as MMDD[YY]YY.
 I<NOTE2>: if you specify the I<day> in this way, the I<time-of-day> is
 REQUIRED as well.
 
 I<NOTE2>: if you specify the I<day> in this way, the I<time-of-day> is
 REQUIRED as well.
 

-Finally, you can use the words B<now>, B<start>, or B<end> as your time
+Finally, you can use the words B<now>, B<start>, B<end> or B<epoch> as your time

 reference. B<Now> refers to the current moment (and is also the default
 time reference). B<Start> (B<end>) can be used to specify a time
 relative to the start (end) time for those tools that use these
 reference. B<Now> refers to the current moment (and is also the default
 time reference). B<Start> (B<end>) can be used to specify a time
 relative to the start (end) time for those tools that use these

-categories (B<rrdfetch>, L<rrdgraph>).
+categories (B<rrdfetch>, L<rrdgraph>) and B<epoch> indicates the 
+*IX epoch (*IX timestamp 0 = 1970-01-01 00:00:00 UTC). B<epoch> is
+useful to disambiguate between a timestamp value and some forms
+of abbreviated date/time specifications, because it allows to use 
+time offset specifications using units, eg. B<epoch>+19711205s unambiguously
+denotes timestamp 19711205 and not 1971-12-05 00:00:00 UTC.

 
 Month and day of the week names can be used in their naturally
 abbreviated form (e.g., Dec for December, Sun for Sunday, etc.). The
 
 Month and day of the week names can be used in their naturally
 abbreviated form (e.g., Dec for December, Sun for Sunday, etc.). The

diff --git a/src/rrd.h b/src/rrd.h
index 7e63110..53838c0 100644 (file)
--- a/src/rrd.h
+++ b/src/rrd.h
@@ -284,7 +284,8 @@ extern    "C" {
     typedef enum {
         ABSOLUTE_TIME,
         RELATIVE_TO_START_TIME,
     typedef enum {
         ABSOLUTE_TIME,
         RELATIVE_TO_START_TIME,

-        RELATIVE_TO_END_TIME
+        RELATIVE_TO_END_TIME,
+        RELATIVE_TO_EPOCH

     } rrd_timetype_t;
 
 #define TIME_OK NULL
     } rrd_timetype_t;
 
 #define TIME_OK NULL

diff --git a/src/rrd_parsetime.c b/src/rrd_parsetime.c
index f3a8e2e..1b59f45 100644 (file)
--- a/src/rrd_parsetime.c
+++ b/src/rrd_parsetime.c
@@ -124,7 +124,7 @@
 
 enum {                  /* symbols */
     MIDNIGHT, NOON, TEATIME,
 
 enum {                  /* symbols */
     MIDNIGHT, NOON, TEATIME,

-    PM, AM, YESTERDAY, TODAY, TOMORROW, NOW, START, END,
+    PM, AM, YESTERDAY, TODAY, TOMORROW, NOW, START, END, EPOCH,

     SECONDS, MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS,
     MONTHS_MINUTES,
     NUMBER, PLUS, MINUS, DOT, COLON, SLASH, ID, JUNK,
     SECONDS, MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS,
     MONTHS_MINUTES,
     NUMBER, PLUS, MINUS, DOT, COLON, SLASH, ID, JUNK,


@@ -157,6 +157,7 @@ static const struct SpecialToken VariousWords[] = {
     {"s", START},
     {"end", END},
     {"e", END},
     {"s", START},
     {"end", END},
     {"e", END},

+    {"epoch", EPOCH},

 
     {"jan", JAN},
     {"feb", FEB},
 
     {"jan", JAN},
     {"feb", FEB},


@@ -859,6 +860,9 @@ char     *rrd_parsetime(
     case MINUS:
         break;          /* jump to OFFSET-SPEC part */
 
     case MINUS:
         break;          /* jump to OFFSET-SPEC part */
 

+    case EPOCH:
+        ptv->type = RELATIVE_TO_EPOCH;
+        goto KeepItRelative;

     case START:
         ptv->type = RELATIVE_TO_START_TIME;
         goto KeepItRelative;
     case START:
         ptv->type = RELATIVE_TO_START_TIME;
         goto KeepItRelative;