Fixed bugs in iso-timestring regarding printing microseconds

iso-timestring used to output
  YYYY-MM-DD HH:MM:SS,,UUUUUU

What was invalid in this format was the two commas and because 3 usec
would be output as xx,,3 instead of xx,,000003.

It now outputs
  YYYY-MM-DD HH:MM:SS.UUUUUU

Also we only print the amount of fractional seconds necessary.
Different databases support different precisions so this is
intended to ensure that we dont print with a greater
(ie: unparsable)  precision than we read from the DB
   EG 1.123400 sec prints as 1.1234
  and      1.0 sec prints as 1

iso-timestring new implementation tested to be ~2x less memory at
the same speed

diff --git a/sql/time.lisp b/sql/time.lisp
index 66731c13531f8e12f6eadf8963ec5a21cb67b2a8..51cbcbef7cbb214049624c7fa29fdbfadc2ba6f6 100644 (file)
--- a/sql/time.lisp
+++ b/sql/time.lisp
@@ -427,58 +427,51 @@
 
 ;; ------------------------------------------------------------
 ;; Formatting and output
-
-(defvar +decimal-printer+ #(#\0 #\1 #\2 #\3 #\4 #\5 #\6 #\7 #\8 #\9))
-
-(defun db-timestring (time)
-  "return the string to store the given time in the database"
-  (declare (optimize (speed 3)))
-  (let ((output (copy-seq "'XXXX-XX-XX XX:XX:XX.")))
-    (flet ((inscribe-base-10 (output offset size decimal)
-             (declare (type fixnum offset size decimal)
-                      (type (simple-vector 10) +decimal-printer+))
-             (dotimes (x size)
-               (declare (type fixnum x)
-                        (optimize (safety 0)))
-               (multiple-value-bind (next this)
-                   (floor decimal 10)
-                 (setf (aref output (+ (- size x 1) offset))
-                       (aref +decimal-printer+ this))
-                 (setf decimal next)))))
-      (multiple-value-bind (usec second minute hour day month year)
-          (decode-time time)
-        (inscribe-base-10 output 1 4 year)
-        (inscribe-base-10 output 6 2 month)
-        (inscribe-base-10 output 9 2 day)
-        (inscribe-base-10 output 12 2 hour)
-        (inscribe-base-10 output 15 2 minute)
-        (inscribe-base-10 output 18 2 second)
-        (format nil "~a~d'" output usec)))))
-
-(defun iso-timestring (time)
+(defun db-timestring (time &key stream)
   "return the string to store the given time in the database"
-  (declare (optimize (speed 3)))
-  (let ((output (copy-seq "XXXX-XX-XX XX:XX:XX,")))
-    (flet ((inscribe-base-10 (output offset size decimal)
-             (declare (type fixnum offset size decimal)
-                      (type (simple-vector 10) +decimal-printer+))
-             (dotimes (x size)
-               (declare (type fixnum x)
-                        (optimize (safety 0)))
-               (multiple-value-bind (next this)
-                   (floor decimal 10)
-                 (setf (aref output (+ (- size x 1) offset))
-                       (aref +decimal-printer+ this))
-                 (setf decimal next)))))
-      (multiple-value-bind (usec second minute hour day month year)
-          (decode-time time)
-        (inscribe-base-10 output 0 4 year)
-        (inscribe-base-10 output 5 2 month)
-        (inscribe-base-10 output 8 2 day)
-        (inscribe-base-10 output 11 2 hour)
-        (inscribe-base-10 output 14 2 minute)
-        (inscribe-base-10 output 17 2 second)
-        (format nil "~a,~d" output usec)))))
+  (if stream
+      (progn (write-char #\' stream) (iso-timestring time :stream stream) (write-char #\' stream))
+      (concatenate 'string "'" (iso-timestring time) "'")))
+
+(defun iso-timestring (time &key stream)
+  (multiple-value-bind (usec sec min hour day month year dow)
+      (decode-time time)
+    (declare (ignore dow))
+    (flet ((fmt (stream)
+            (when (< year 1000) (princ #\0 stream))
+            (when (< year 100) (princ #\0 stream))
+            (when (< year 10) (princ #\0 stream))
+            (princ year stream)
+            (princ #\- stream)
+            (when (< month 10) (princ #\0 stream))
+            (princ month stream)
+            (princ #\- stream)
+            (when (< day 10) (princ #\0 stream))
+            (princ month stream)
+            (princ #\space stream)
+            (when (< hour 10) (princ #\0 stream))
+            (princ hour stream)
+            (princ #\: stream)
+            (when (< min 10) (princ #\0 stream))
+            (princ min stream)
+            (princ #\: stream)
+            (when (< sec 10) (princ #\0 stream))
+            (princ sec stream)
+            (when (and usec (plusp usec))
+              ;; we dont do this because different dbs support differnt precision levels
+              (princ #\. stream)
+              (loop for i from 5 downto 0
+                    for x10 = (expt 10 i)
+                    do (multiple-value-bind (quo rem)
+                           (floor (/ usec x10))
+                         (setf usec (- usec (* quo x10)))
+                         (princ quo stream)
+                         (when (= rem 0) (return)))))
+            nil))
+      (if stream
+         (fmt stream)
+         (with-output-to-string (stream)
+           (fmt stream))))))
 
 (defun db-datestring (date)
   (db-timestring (date->time date)))
@@ -835,26 +828,22 @@ with the given options"
         (decode-time time)
       (case format
         (:pretty
-         (format stream "~A ~A, ~A ~D, ~D"
-                 (pretty-time hour minute)
-                 (day-name dow)
-                 (month-name month)
-                 day
-                 year))
+          (format stream "~A ~A, ~A ~D, ~D"
+                  (pretty-time hour minute)
+                  (day-name dow)
+                  (month-name month)
+                  day
+                  year))
         (:short-pretty
-         (format stream "~A, ~D/~D/~D"
-                 (pretty-time hour minute)
-                 month day year))
-        (:iso
-         (let ((string (iso-timestring time)))
-           (if stream
-               (write-string string stream)
-             string)))
-        (t
-         (format stream "~2,'0D~A~2,'0D~A~2,'0D~A~2,'0D~A~2,'0D~A~2,'0D.~6,'0D"
-                 year date-separator month date-separator day
-                 internal-separator hour time-separator minute time-separator
-                 second usec))))))
+          (format stream "~A, ~D/~D/~D"
+                  (pretty-time hour minute)
+                  month day year))
+        ((:iso :iso8601) (iso-timestring time :stream stream))
+        (t (format stream "~2,'0D~A~2,'0D~A~2,'0D~A~2,'0D~A~2,'0D~A~2,'0D.~6,'0D"
+                  year date-separator month date-separator day
+                  internal-separator hour time-separator minute time-separator
+                  second usec)
+          )))))
 
 (defun pretty-time (hour minute)
   (cond