Changeset 14840

Timestamp:

11/09/15 10:59:10 (6 years ago)

Author:

Mark Evenson

Message:

{decode,encode}-universal-time "time of the time" timezone semantics

Scott L. Burson

The implementation of EXT:GET-TIME-ZONE provides the underlying
mechanism.

Both GET-TIME-ZONE and DEFAULT-TIME-ZONE have been elevated to
supported status by virtue of promotion of their respective symbols to
the EXTENSIONS and SYSTEM packages, respectively.

ME: A mechanism for adding symbols to both SYS and EXT packages with
DEFINE-SYMBOL-MACRO didn't work, but left as comment at the end of
'time.lisp' for further work.

Location:

trunk/abcl/src/org/armedbear/lisp

Files:

• Autoload.java (modified) (1 diff)
• Time.java (modified) (1 diff)
• time.lisp (modified) (4 diffs)

trunk/abcl/src/org/armedbear/lisp/Autoload.java

@@ -520 +520 @@
         autoload(PACKAGE_EXT, "gc", "gc", true);
         autoload(PACKAGE_EXT, "get-floating-point-modes", "FloatFunctions", true);
+        autoload(PACKAGE_EXT, "get-time-zone", "Time", true);
         autoload(PACKAGE_EXT, "make-slime-input-stream", "SlimeInputStream", true);
         autoload(PACKAGE_EXT, "make-slime-output-stream", "SlimeOutputStream", true);

trunk/abcl/src/org/armedbear/lisp/Time.java

@@ -112 +112 @@
 
   // ### default-time-zone => offset daylight-p
-  private static final Primitive DEFAULT_TIME_ZONE =
-    new Primitive("default-time-zone", PACKAGE_SYS, false)
+  public static final Primitive DEFAULT_TIME_ZONE = new pf_default_time_zone();
+  @DocString(name="default-time-zone",
+             args="",
+             returns="offset daylight-p",
+             doc="Returns the OFFSET of the default time zone for this instance of the implementation, and as a second value the state of the DAYLIGHT-P predicate.")
+  public static final class pf_default_time_zone extends Primitive {
+    pf_default_time_zone() {
+      super("default-time-zone", PACKAGE_SYS, true);
+    }
+    public LispObject execute()
     {
-      @Override
-      public LispObject execute()
-      {
-        TimeZone tz = TimeZone.getDefault();
-        //int offset = tz.getOffset(System.currentTimeMillis());
-        // Classpath hasn't implemented TimeZone.getOffset(long).
-        int rawOffset = tz.getRawOffset();
-        final boolean inDaylightTime =
-          tz.inDaylightTime(new Date(System.currentTimeMillis()));
-        if (inDaylightTime)
-          rawOffset += tz.getDSTSavings();
-        // "Time zone values increase with motion to the west..."
-        // Convert milliseconds to hours.
-        return LispThread.currentThread().setValues(
-          Fixnum.getInstance(- rawOffset).divideBy(Fixnum.getInstance(3600000)),
-          inDaylightTime ? T : NIL);
-      }
-    };
+      return GET_TIME_ZONE.execute(LispInteger.getInstance(System.currentTimeMillis()));
+    }
+  };
+
+  public static final Primitive GET_TIME_ZONE = new pf_get_time_zone();
+  @DocString(name="get-time-zone",
+             args="time-in-millis",
+             returns="timezone",
+             doc="Return the timezone for TIME-IN-MILLIS via the Daylight assumptions that were in place at its occurance. i.e. implement 'time of the time semantics'." )
+  public static final class pf_get_time_zone extends Primitive {
+    pf_get_time_zone() {
+      super("get-time-zone", PACKAGE_EXT, true, "");
+    }
+
+    public LispObject execute(LispObject unixTimeMillis) {
+      // should be a reference to a singleton for the lifetime of an ABCL process
+      TimeZone tz = TimeZone.getDefault(); 
+      // int offset = tz.getOffset(System.currentTimeMillis());
+      // Classpath hasn't implemented TimeZone.getOffset(long).
+      int rawOffset = tz.getRawOffset();
+      final boolean inDaylightTime = tz.inDaylightTime(new Date(unixTimeMillis.longValue()));
+      if (inDaylightTime)
+        rawOffset += tz.getDSTSavings();
+      // "Time zone values increase with motion to the west..."
+      // Convert milliseconds to hours.
+      return LispThread.currentThread()
+        .setValues(Fixnum
+                   .getInstance(- rawOffset).divideBy(Fixnum.getInstance(3600000)),
+                   inDaylightTime ? T : NIL);
+    }
+  };
 }

trunk/abcl/src/org/armedbear/lisp/time.lisp

@@ -43 +43 @@
 (defconstant weekday-november-17-1858 2)
 
+
+
 ;;; decode-universal-time universal-time &optional time-zone
 ;;; => second minute hour date month year day daylight-p zone
@@ -54 +56 @@
         (setf seconds-west (* time-zone 3600)
               daylight nil)
-        (multiple-value-bind (time-zone daylight-p) (default-time-zone)
+        (multiple-value-bind (time-zone daylight-p) (ext:get-time-zone universal-time)
           (setf seconds-west (* time-zone 3600)
                 daylight daylight-p)))
@@ -128 +130 @@
    (hours (+ hour (* days 24))))
     (cond (time-zone
-           (+ second (* (+ minute (* (+ hours time-zone) 60)) 60)))
+           (let* ((tz-guess (get-time-zone (* hours 3600)))
+      (guess (+ second (* 60 (+ minute (* 60 (+ hours tz-guess))))))
+      (tz (get-time-zone guess)))
+             (+ guess (* 3600 (- tz tz-guess)))))
           ((> year 2037)
            (labels ((leap-year-p (year)
@@ -144 +149 @@
           (t
            (+ second (* (+ minute (* (+ hours (default-time-zone)) 60)) 60))))))
+
+#|
+(intern "GET-TIME-ZONE" (find-package :ext))
+(define-symbol-macro EXT:GET-TIME-ZONE
+    `(get-time-zone))
+(export (intern "GET-TIME-ZONE" (find-package :ext)))
+#|