data->yearOfCenturySwitch = ClockDefaultCenturySwitch;

    data->systemTimeZone = NULL;
    data->systemSetupTZData = NULL;
    data->gmtSetupTimeZoneUnnorm = NULL;
    data->gmtSetupTimeZone = NULL;
    data->gmtSetupTZData = NULL;
    data->gmtTZName = NULL;
    data->lastSetupTimeZoneUnnorm = NULL;
    data->lastSetupTimeZone = NULL;
    data->lastSetupTZData = NULL;
    data->prevSetupTimeZoneUnnorm = NULL;
    data->prevSetupTimeZone = NULL;
    data->prevSetupTZData = NULL;

    data->lastTZEpoch = 0;
    Tcl_UnsetObjRef(data->systemTimeZone);
    Tcl_UnsetObjRef(data->systemSetupTZData);
    Tcl_UnsetObjRef(data->gmtSetupTimeZoneUnnorm);
    Tcl_UnsetObjRef(data->gmtSetupTimeZone);
    Tcl_UnsetObjRef(data->gmtSetupTZData);
    Tcl_UnsetObjRef(data->gmtTZName);
    Tcl_UnsetObjRef(data->lastSetupTimeZoneUnnorm);
    Tcl_UnsetObjRef(data->lastSetupTimeZone);
    Tcl_UnsetObjRef(data->lastSetupTZData);
    Tcl_UnsetObjRef(data->prevSetupTimeZoneUnnorm);
    Tcl_UnsetObjRef(data->prevSetupTimeZone);
    Tcl_UnsetObjRef(data->prevSetupTZData);

    Tcl_Obj *timezoneObj)
{
    ClockClientData *dataPtr = clientData;
    int loaded;
    Tcl_Obj *callargs[2];

    /* if cached (if already setup this one) */
    if ( timezoneObj == dataPtr->literals[LIT_GMT]
      && dataPtr->gmtSetupTZData != NULL
    ) {
	return timezoneObj;
    }
    if ( ( timezoneObj == dataPtr->lastSetupTimeZone
	|| timezoneObj == dataPtr->lastSetupTimeZoneUnnorm

      ) && dataPtr->lastSetupTimeZone != NULL
    ) {
	return dataPtr->lastSetupTimeZone;
    }
    if ( ( timezoneObj == dataPtr->prevSetupTimeZone
	|| timezoneObj == dataPtr->prevSetupTimeZoneUnnorm
      ) && dataPtr->prevSetupTimeZone != NULL

    ) {
	return dataPtr->prevSetupTimeZone;
    }

    /* differentiate normalized (last, GMT and system) zones, because used often and already set */
    callargs[1] = NormTimezoneObj(dataPtr, timezoneObj, &loaded);
    /* if loaded (setup already called for this TZ) */

     * Convert to Julian or Gregorian calendar.
     */

    GetGregorianEraYearDay(fields, changeover);
    GetMonthDay(fields);
    GetYearWeekDay(fields, changeover);

    
    /*
     * Seconds of the day.
     */
    fields->secondOfDay = (int)(fields->localSeconds % SECONDS_PER_DAY);
    if (fields->secondOfDay < 0) {
	fields->secondOfDay += SECONDS_PER_DAY;
    }

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockGetjuliandayfromerayearmonthdayObjCmd --

{
    ClockClientData *dataPtr = clientData;
    Tcl_Obj *tzdata;		/* Time zone data */
    int rowc;			/* Number of rows in tzdata */
    Tcl_Obj **rowv;		/* Pointers to the rows */

    /* fast phase-out for shared GMT-object (don't need to convert UTC 2 UTC) */
    if (timezoneObj == dataPtr->literals[LIT_GMT]) {


	fields->localSeconds = fields->seconds;
	fields->tzOffset = 0;
	if (dataPtr->gmtTZName == NULL) {
	    Tcl_Obj *tzName;
	    tzdata = ClockGetTZData(clientData, interp, timezoneObj);
	    if ( TclListObjGetElements(interp, tzdata, &rowc, &rowv) != TCL_OK
	      || Tcl_ListObjIndex(interp, rowv[0], 3, &tzName) != TCL_OK) {
		return TCL_ERROR;
	    }
	    Tcl_SetObjRef(dataPtr->gmtTZName, tzName);
	}
	Tcl_SetObjRef(fields->tzName, dataPtr->gmtTZName);
	return TCL_OK;
    }

    /*
     * Check cacheable conversion could be used
     * (last-period UTC2Local cache within the same TZ)
     */

static void
GetMonthDay(
    TclDateFields *fields)	/* Date to convert */
{
    int day = fields->dayOfYear;
    int month;
    const int *dipm = daysInPriorMonths[IsGregorianLeapYear(fields)];

    /* 
     * Estimate month by calculating `dayOfYear / (365/12)`
     */
    month = (day*12) / dipm[12];
    /* then do forwards backwards correction */
    while (1) {
	if (day > dipm[month]) {
	    if (month >= 11 || day <= dipm[month+1]) {
		break;
	    }
	    month++;
	} else {
	    if (month == 0) {
		break;
	    }
	    month--;
	}
    }
    day -= dipm[month];
    fields->month = month+1;
    fields->dayOfMonth = day;
}

/*
 *----------------------------------------------------------------------
 *

	Tcl_SetObjResult(interp, Tcl_NewStringObj("cannot use -gmt and -timezone in same call", -1));
	Tcl_SetErrorCode(interp, "CLOCK", "gmtWithTimezone", NULL);
	return TCL_ERROR;
    }
    if (gmtFlag) {
	opts->timezoneObj = dataPtr->literals[LIT_GMT];
    }
    else
    /* If time zone not specified use system time zone */

    if ( opts->timezoneObj == NULL
      || TclGetString(opts->timezoneObj) == NULL
      || opts->timezoneObj->length == 0
    ) {
	opts->timezoneObj = ClockGetSystemTimeZone(opts->clientData, interp);
	if (opts->timezoneObj == NULL) {
	    return TCL_ERROR;

{
    static char* tzWas = INT2PTR(-1);	 /* Previous value of TZ, protected by
					  * clockMutex. */
    static long	 tzLastRefresh = 0;	 /* Used for latency before next refresh */
    static size_t tzWasEpoch = 0;        /* Epoch, signals that TZ changed */
    static size_t tzEnvEpoch = 0;        /* Last env epoch, for faster signaling,
					    that TZ changed via TCL */

    const char *tzIsNow;		 /* Current value of TZ */

    /*
     * Prevent performance regression on some platforms by resolving of system time zone:
     * small latency for check whether environment was changed (once per second)
     * no latency if environment was chaned with tcl-env (compare both epoch values)
     */
    Tcl_Time now;
    Tcl_GetTime(&now);
    if (now.sec == tzLastRefresh && tzEnvEpoch == TclEnvEpoch) {
	return tzWasEpoch;
    }

    tzEnvEpoch = TclEnvEpoch;
    tzLastRefresh = now.sec;

    /* check in lock */
    Tcl_MutexLock(&clockMutex);
    tzIsNow = getenv("TCL_TZ");
    if (tzIsNow == NULL) {

	-1));
    Tcl_SetErrorCode(opts->interp, "CLOCK", "badInputString", NULL);

done:

    return ret;
}

#define FrmResultIsAllocated(dateFmt) \
    (dateFmt->resEnd - dateFmt->resMem > MIN_FMT_RESULT_BLOCK_ALLOC)

static inline int
FrmResultAllocate(
    register DateFormat *dateFmt,
    int len)
{
    int needed = dateFmt->output + len - dateFmt->resEnd;
    if (needed >= 0) { /* >= 0 - regards NTS zero */
	int newsize = dateFmt->resEnd - dateFmt->resMem
		    + needed + MIN_FMT_RESULT_BLOCK_ALLOC*2;
	char *newRes;
	/* differentiate between stack and memory */
	if (!FrmResultIsAllocated(dateFmt)) {
	    newRes = ckalloc(newsize);
	    if (newRes == NULL) {
		return TCL_ERROR;
	    }
	    memcpy(newRes, dateFmt->resMem, dateFmt->output - dateFmt->resMem);
	} else {
	    newRes = ckrealloc(dateFmt->resMem, newsize);
	    if (newRes == NULL) {
		return TCL_ERROR;
	    }
	}
	dateFmt->output = newRes + (dateFmt->output - dateFmt->resMem);
	dateFmt->resMem = newRes;
	dateFmt->resEnd = newRes + newsize;
    }
    return TCL_OK;
}

ClockFormat(
    register DateFormat *dateFmt, /* Date fields used for parsing & converting */
    ClockFmtScnCmdArgs *opts)	  /* Command options */
{
    ClockFmtScnStorage	*fss;
    ClockFormatToken	*tok;
    ClockFormatTokenMap *map;
    char resMem[MIN_FMT_RESULT_BLOCK_ALLOC];

    /* get localized format */
    if (ClockLocalizeFormat(opts) == NULL) {
	return TCL_ERROR;
    }

    if ( !(fss = ClockGetOrParseFmtFormat(opts->interp, opts->formatObj))
      || !(tok = fss->fmtTok)
    ) {
	return TCL_ERROR;
    }







    /* result container object */
    dateFmt->resMem = resMem;
    dateFmt->resEnd = dateFmt->resMem + sizeof(resMem);
    if (fss->fmtMinAlloc > sizeof(resMem)) {
	dateFmt->resMem = ckalloc(fss->fmtMinAlloc);
	dateFmt->resEnd = dateFmt->resMem + fss->fmtMinAlloc;
	if (dateFmt->resMem == NULL) {
	    return TCL_ERROR;
	}
    }
    dateFmt->output = dateFmt->resMem;

    *dateFmt->output = '\0';

    /* do format each token */
    for (; tok->map != NULL; tok++) {
	map = tok->map;
	switch (map->type)
	{

	}
    }

    goto done;

error:

    if (dateFmt->resMem != resMem) {
	ckfree(dateFmt->resMem);
    }
    dateFmt->resMem = NULL;

done:

    if (dateFmt->resMem) {
    	size_t size;
	Tcl_Obj * result = Tcl_NewObj();
	result->length = dateFmt->output - dateFmt->resMem;
	size = result->length+1;
	if (dateFmt->resMem == resMem) {
	    result->bytes = ckalloc(size);
	    if (result->bytes == NULL) {
		return TCL_ERROR;
	    }
	    memcpy(result->bytes, dateFmt->resMem, size);
	} else {
	    result->bytes = ckrealloc(dateFmt->resMem, size);
	    if (result->bytes == NULL) {
		result->bytes = dateFmt->resMem;
	    }
	}
	/* save last used buffer length */
	if ( dateFmt->resMem != resMem
	  && fss->fmtMinAlloc < size + MIN_FMT_RESULT_BLOCK_DELTA
	) {
	    fss->fmtMinAlloc = size + MIN_FMT_RESULT_BLOCK_DELTA;
	}
	result->bytes[result->length] = '\0';
	Tcl_SetObjResult(opts->interp, result);
	return TCL_OK;
    }

    return TCL_ERROR;

    int currentYearCentury;
    int yearOfCenturySwitch;
    Tcl_Obj *systemTimeZone;
    Tcl_Obj *systemSetupTZData;
    Tcl_Obj *gmtSetupTimeZoneUnnorm;
    Tcl_Obj *gmtSetupTimeZone;
    Tcl_Obj *gmtSetupTZData;
    Tcl_Obj *gmtTZName;
    Tcl_Obj *lastSetupTimeZoneUnnorm;
    Tcl_Obj *lastSetupTimeZone;
    Tcl_Obj *lastSetupTZData;
    Tcl_Obj *prevSetupTimeZoneUnnorm;
    Tcl_Obj *prevSetupTimeZone;
    Tcl_Obj *prevSetupTZData;

    unsigned short int	minSize;
    unsigned short int	maxSize;
    unsigned short int	offs;
    ClockScanTokenProc *parser;
    const void	       *data;
} ClockScanTokenMap;

struct ClockScanToken {
    ClockScanTokenMap  *map;
    struct {
	const char *start;
	const char *end;
    } tokWord;
    unsigned short int	endDistance;
    unsigned short int	lookAhMin;
    unsigned short int	lookAhMax;
    unsigned short int	lookAhTok;
};


#define MIN_FMT_RESULT_BLOCK_ALLOC 80
#define MIN_FMT_RESULT_BLOCK_DELTA 30

typedef struct DateFormat {
    char *resMem;
    char *resEnd;
    char *output;

    TclDateFields date;

    unsigned short int	flags;
    unsigned short int	divider;
    unsigned short int	divmod;
    unsigned short int	offs;
    ClockFormatTokenProc *fmtproc;
    void	       *data;
} ClockFormatTokenMap;

struct ClockFormatToken {
    ClockFormatTokenMap *map;
    struct {
	const char *start;
	const char *end;
    } tokWord;
};


typedef struct ClockFmtScnStorage ClockFmtScnStorage;

struct ClockFmtScnStorage {
    int			 objRefCount;	/* Reference count shared across threads */
    ClockScanToken	*scnTok;
    unsigned int	 scnTokC;
    unsigned int	 scnSpaceCount; /* Count of mandatory spaces used in format */
    ClockFormatToken	*fmtTok;
    unsigned int	 fmtTokC;
#if CLOCK_FMT_SCN_STORAGE_GC_SIZE > 0
    ClockFmtScnStorage	*nextPtr;
    ClockFmtScnStorage	*prevPtr;
#endif
    size_t		 fmtMinAlloc;
#if 0
   +Tcl_HashEntry    hashEntry		/* ClockFmtScnStorage is a derivate of Tcl_HashEntry,
					 * stored by offset +sizeof(self) */
#endif
};

/*
 * Prototypes of module functions.
 */

MODULE_SCOPE int    ToSeconds(int Hours, int Minutes,
			    int Seconds, MERIDIAN Meridian);

    TclStrIdx	  **foundItem,	 /* Return value of found item */
    TclStrIdxTree  *tree,	 /* Index tree will be browsed */
    const char	*start,		 /* UTF string to find in tree */
    const char	*end)		 /* End of string */
{
    TclStrIdxTree *parent = tree, *prevParent = tree;
    TclStrIdx  *item = tree->firstPtr, *prevItem = NULL;
    const char *s = start, *f, *cin, *cinf, *prevf = NULL;
    int offs = 0;

    if (item == NULL) {
	goto done;
    }

    /* search in tree */

		/* ignore element if fulfilled or ambigous */
		if (f == e) {
		    continue;
		}
		/* if shortest key was found with the same value,
		 * just replace its current key with longest key */
		if ( foundItem->value == val
		  && foundItem->length <= lwrv[i]->length
		  && foundItem->length <= (f - s) /* only if found item is covered in full */
		  && foundItem->childTree.firstPtr == NULL
		) {
		    Tcl_SetObjRef(foundItem->key, lwrv[i]);
		    foundItem->length = lwrv[i]->length;
		    continue;
		}
		/* split tree (e. g. j->(jan,jun) + jul == j->(jan,ju->(jun,jul)) )

# Copyright (c) 2014 Serg G. Brester (aka sebres)
# 
# See the file "license.terms" for information on usage and redistribution
# of this file.
# 


## common test performance framework:
if {![namespace exists ::tclTestPerf]} {
  source [file join [file dirname [info script]] test-performance.tcl]
}




namespace eval ::tclTestPerf-TclClock {



namespace path {::tclTestPerf}

## set testing defaults:
set ::env(TCL_TZ) :CET






# warm-up interpeter compiler env, clock platform-related features:

## warm-up test-related features (load clock.tcl, system zones, locales, etc.):
clock scan "" -gmt 1
clock scan ""
clock scan "" -timezone :CET
clock scan "" -format "" -locale en
clock scan "" -format "" -locale de

## ------------------------------------------





















































































proc test-format {{reptime 1000}} {
  _test_run $reptime {
    # Format : short, week only (in gmt)
    {clock format 1482525936 -format "%u" -gmt 1}
    # Format : short, week only (system zone)
    {clock format 1482525936 -format "%u"}
    # Format : short, week only (CEST)

  test-add $reptime
  test-convert [expr {$reptime / 2}]; #fast enough
  test-other $reptime

  puts \n**OK**
}

}; # end of ::tclTestPerf-TclClock

# ------------------------------------------------------------------------

# if calling direct:
if {[info exists ::argv0] && [file tail $::argv0] eq [file tail [info script]]} {
  array set in {-time 500}
  array set in $argv
  ::tclTestPerf-TclClock::test $in(-time)
}

# ------------------------------------------------------------------------
#
# test-performance.tcl --
# 
#  This file provides common performance tests for comparison of tcl-speed
#  degradation or regression by switching between branches.
#
#  To execute test case evaluate direct corresponding file "tests-perf\*.perf.tcl".
#
# ------------------------------------------------------------------------
# 
# Copyright (c) 2014 Serg G. Brester (aka sebres)
# 
# See the file "license.terms" for information on usage and redistribution
# of this file.
# 

namespace eval ::tclTestPerf {
# warm-up interpeter compiler env, calibrate timerate measurement functionality:

# if no timerate here - import from unsupported:
if {[namespace which -command timerate] eq {}} {
  namespace inscope ::tcl::unsupported {namespace export timerate}
  namespace import ::tcl::unsupported::timerate
}

# if not yet calibrated:
if {[lindex [timerate {} 10] 6] >= (10-1)} {
  puts -nonewline "Calibration ... "; flush stdout
  puts "done: [lrange \
    [timerate -calibrate {}] \
  0 1]"
}

proc {**STOP**} {args} {
  return -code error -level 4 "**STOP** in [info level [expr {[info level]-2}]] [join $args { }]" 
}

proc _test_get_commands {lst} {
  regsub -all {(?:^|\n)[ \t]*(\#[^\n]*|\msetup\M[^\n]*|\mcleanup\M[^\n]*)(?=\n\s*(?:[\{\#]|setup|cleanup|$))} $lst "\n{\\1}"
}

proc _test_out_total {} {
  upvar _ _

  set tcnt [llength $_(itm)]
  if {!$tcnt} {
    puts ""
    return
  }

  set mintm 0x7fffffff
  set maxtm 0
  set nett 0
  set wtm 0
  set wcnt 0
  set i 0
  foreach tm $_(itm) {
    if {[llength $tm] > 6} {
      set nett [expr {$nett + [lindex $tm 6]}]
    }
    set wtm [expr {$wtm + [lindex $tm 0]}]
    set wcnt [expr {$wcnt + [lindex $tm 2]}]
    set tm [lindex $tm 0]
    if {$tm > $maxtm} {set maxtm $tm; set maxi $i}
    if {$tm < $mintm} {set mintm $tm; set mini $i}
    incr i
  }

  puts [string repeat ** 40]
  set s [format "%d cases in %.2f sec." $tcnt [expr {([clock milliseconds] - $_(starttime)) / 1000.0}]]
  if {$nett > 0} {
    append s [format " (%.2f nett-sec.)" [expr {$nett / 1000.0}]]
  }
  puts "Total $s:"
  lset _(m) 0 [format %.6f $wtm]
  lset _(m) 2 $wcnt
  lset _(m) 4 [format %.3f [expr {$wcnt / (($nett ? $nett : ($tcnt * $_(reptime))) / 1000.0)}]]
  if {[llength $_(m)] > 6} {
    lset _(m) 6 [format %.3f $nett]
  }
  puts $_(m)
  puts "Average:"
  lset _(m) 0 [format %.6f [expr {[lindex $_(m) 0] / $tcnt}]]
  lset _(m) 2 [expr {[lindex $_(m) 2] / $tcnt}]
  if {[llength $_(m)] > 6} {
    lset _(m) 6 [format %.3f [expr {[lindex $_(m) 6] / $tcnt}]]
    lset _(m) 4 [format %.0f [expr {[lindex $_(m) 2] / [lindex $_(m) 6] * 1000}]]
  }
  puts $_(m)
  puts "Min:"
  puts [lindex $_(itm) $mini]
  puts "Max:"
  puts [lindex $_(itm) $maxi]
  puts [string repeat ** 40]
  puts ""
}

proc _test_run {reptime lst {outcmd {puts $_(r)}}} {
  upvar _ _
  array set _ [list itm {} reptime $reptime starttime [clock milliseconds]]

  foreach _(c) [_test_get_commands $lst] {
    puts "% [regsub -all {\n[ \t]*} $_(c) {; }]"
    if {[regexp {^\s*\#} $_(c)]} continue
    if {[regexp {^\s*(?:setup|cleanup)\s+} $_(c)]} {
      puts [if 1 [lindex $_(c) 1]]
      continue
    }
    if {$reptime > 1} {; #if not once:
      set _(r) [if 1 $_(c)]
      if {$outcmd ne {}} $outcmd
    }
    puts [set _(m) [timerate $_(c) $reptime]]
    lappend _(itm) $_(m)
    puts ""
  }
  _test_out_total
}

}; # end of namespace ::tclTestPerf

package require msgcat 1.4

testConstraint detroit \
    [expr {![catch {clock format 0 -timezone :America/Detroit -format %z}]}]
testConstraint y2038 \
    [expr {[clock format 2158894800 -format %z -timezone :America/Detroit] eq {-0400}}]
testConstraint no_tclclockmod \
    [expr {[namespace which -command ::tcl::clock::configure] eq {}}]

# TEST PLAN

# clock-0:
#	several base test-cases
#
# clock-1:

	return -code error "test case attempts to read unknown registry entry $path $key"
    }
    return [dict get $reg $path $key]
}

# Base test cases:

test clock-0.1 "initial: auto-loading of ensemble and stubs on demand" no_tclclockmod {
    set i [interp create]; # because clock can be used somewhere, test it in new interp:

    set ret [$i eval {

	lappend ret ens:[namespace ensemble exists ::clock]
	clock seconds; # init ensemble (but not yet stubs, loading of clock.tcl retarded)
	lappend ret ens:[namespace ensemble exists ::clock]

        -format {%J %Ol:%M:%S %P}
} 86399
test clock-29.1800 {time parsing} {
    clock scan {2440588 xi:lix:lix pm} \
        -gmt true -locale en_US_roman \
        -format {%J %Ol:%OM:%OS %P}
} 86399

test clock-29.1811 {parsing of several localized formats} {
    set res {}
    foreach loc {en de fr} {
	foreach fmt {"%x %X" "%X %x"} {
	    lappend res [clock scan \
	      [clock format 0 -format $fmt -locale $loc -gmt 1] \
	      -format $fmt -locale $loc -gmt 1]
	}
    }
    set res
} [lrepeat 6 0]
test clock-29.1812 {parsing of several localized formats} {
    set res {}
    foreach loc {en de fr} {
	foreach fmt {"%a %d-%m-%Y" "%a %b %x-%X" "%a, %x %X" "%b, %x %X"} {
	    lappend res [clock scan \
	      [clock format 0 -format $fmt -locale $loc -gmt 1] \
	      -format $fmt -locale $loc -gmt 1]
	}
    }
    set res
} [lrepeat 12 0]
# END testcases29


# BEGIN testcases30

# Test [clock add]
test clock-30.1 {clock add years} {