/**
* This is the logic that is used to take a parameter string
* given for a specific field in the cron schedule and expand it
* out into a range of int's that can be looked up quickly later on
* We must be given the index number of the field we're going to parse
* and a min/max for the range of values allowed for the attribute.
* If the parameter is invalid, we will report an error and return false
* This will prevent them from querying nextRunTime() for runtimes
*
* @param attribute_idx - the index for the parameter in CronTab::attributes
* @param min - the mininum value in the range for this parameter
* @param max - the maximum value in the range for this parameter
* @return true if we were able to create the range of values
**/
bool
CronTab::expandParameter( int attribute_idx, int min, int max )
{
MyString *param = this->parameters[attribute_idx];
ExtArray<int> *list = this->ranges[attribute_idx];
//
// Make sure the parameter is valid
// The validation method will have already printed out
// the error message to the log
//
MyString error;
if ( ! CronTab::validateParameter( attribute_idx,
param->Value(),
error ) ) {
dprintf( D_ALWAYS, "%s", error.Value() );
//
// Store the error in case they want to email
// the user to tell them that they goofed
//
CronTab::errorLog += error;
return ( false );
}
//
// Remove any spaces
//
param->replaceString(" ", "");
//
// Now here's the tricky part! We need to expand their parameter
// out into a range that can be put in array of integers
// First start by spliting the string by commas
//
param->Tokenize();
const char *_token;
while ( ( _token = param->GetNextToken( CRONTAB_DELIMITER, true ) ) != NULL ) {
MyString token( _token );
int cur_min = min, cur_max = max, cur_step = 1;
// -------------------------------------------------
// STEP VALUES
// The step value is independent of whether we have
// a range, the wildcard, or a single number.
// -------------------------------------------------
if ( token.find( CRONTAB_STEP ) > 0 ) {
//
// Just look for the step value to replace
// the current step value. The other code will
// handle the rest
//
token.Tokenize();
const char *_temp;
//
// Take out the numerator, keep it for later
//
const char *_numerator = token.GetNextToken( CRONTAB_STEP, true );
if ( ( _temp = token.GetNextToken( CRONTAB_STEP, true ) ) != NULL ) {
MyString stepStr( _temp );
stepStr.trim();
cur_step = atoi( stepStr.Value() );
}
//
// Now that we have the denominator, put the numerator back
// as the token. This makes it easier to parse later on
//
token = _numerator;
} // STEP
// -------------------------------------------------
// RANGE
// If it's a range, expand the range but make sure we
// don't go above/below our limits
// Note that the find will ignore the token if the
// range delimiter is in the first character position
// -------------------------------------------------
if ( token.find( CRONTAB_RANGE ) > 0 ) {
//
// Split out the integers
//
token.Tokenize();
MyString *_temp;
int value;
//
// Min
//
_temp = new MyString( token.GetNextToken( CRONTAB_RANGE, true ) );
_temp->trim();
value = atoi( _temp->Value() );
cur_min = ( value >= min ? value : min );
delete _temp;
//
// Max
//
_temp = new MyString( token.GetNextToken( CRONTAB_RANGE, true ) );
_temp->trim();
value = atoi( _temp->Value() );
cur_max = ( value <= max ? value : max );
delete _temp;
// -------------------------------------------------
// WILDCARD
// This will select all values for the given range
// -------------------------------------------------
} else if ( token.find( CRONTAB_WILDCARD ) >= 0 ) {
//
// For this we do nothing since it will just
// be the min-max range
//
// Day of Week Special Case
// The day of week specifier is kind of weird
// If it's the wildcard, then it doesn't mean
// include all like the other fields. The reason
// why we don't want to do that is because later
// on we are going to expand the day of the week
// field to be actual dates in a month in order
// to figure out when to run next, so we don't
// want to expand out the wildcard for all days
// if the day of month field is restricted
// Read the cron manpage!
//
if ( attribute_idx == CRONTAB_DOW_IDX ) {
continue;
}
// -------------------------------------------------
// SINGLE VALUE
// They just want a single value to be added
// Note that a single value with a step like "2/3" will
// work in this code but its meaningless unless its whole number
// -------------------------------------------------
} else {
//
// Replace the range to be just this value only if it
// fits in the min/max range we were given
//
int value = atoi(token.Value());
if ( value >= min && value <= max ) {
cur_min = cur_max = value;
}
}
//
// Fill out the numbers based on the range using
// the step value
//
int ctr;
for ( ctr = cur_min; ctr <= cur_max; ctr++ ) {
//
// Day of Week Special Case
// The crontab specifications lets Sunday be
// represented with either a 0 or a 7. Our
// dayOfWeek() method in date_util.h uses 0-6
// So if this the day of the week attribute and
// we are given a 7 for Sunday, just convert it
// to a zero
//
int temp = ctr;
if ( attribute_idx == CRONTAB_DOW_IDX &&
temp == CRONTAB_DAY_OF_WEEK_MAX ) {
temp = CRONTAB_DAY_OF_WEEK_MIN;
}
//
// Make sure this value isn't alreay added and
// that it falls in our step listing for the range
//
if ( ( ( temp % cur_step ) == 0 ) && !this->contains( *list, temp ) ) {
list->add( temp );
}
} // FOR
} // WHILE
//
// Sort! Makes life easier later on
//
this->sort( *list );
return ( true );
}
/**
* Important helper function that actually does the grunt work of
* find the next runtime. We need to be given an array of the different
* time fields so that we can match the current time with different
* parameters. The function will recursively call itself until
* it can find a match at the MINUTES level. If one recursive call
* cannot find a match, it will return false and the previous level
* will increment its range index by one and try to find a match. On the
* the subsequent call useFirst will be set to true meaning that the level
* does not need to look for a value in the range that is greater than or
* equal to the current time value. If the failing returns to the MONTHS level,
* that means we've exhausted all our possiblities from the current time to the
* the end of the year. So we'll increase the year by 1 and try the same logic again
* using January 1st as the starting point.
* The array match will contain the timestamp information of the job's
* next run time
*
* @param curTime - an array of time attributes for where we start our calculations
* @param match - an array of time attributes that is the next run time
* @param attribute_idx - the index for the current parameter in CronTab::attributes
* @param useFirst - whether we should base ourselves off of Jan 1st
* @return true if we able to find a new run time
**/
bool
CronTab::matchFields( int *curTime, int *match, int attribute_idx, bool useFirst )
{
//
// Whether we need to tell the next level above that they
// should use the first element in their range. If we were told
// to then certainly the next level will as well
//
bool nextUseFirst = useFirst;
//
// First initialize ourself to know that we don't have a match
//
match[attribute_idx] = -1;
//
// Special Day of Week Handling
// In order to get the day of week stuff to work, we have
// to insert all the days of the month for the matching days of the
// week in the range.
//
ExtArray<int> *curRange = NULL;
if ( attribute_idx == CRONTAB_DOM_IDX ) {
//
// We have to take the current month & year
// and convert the days of the week range into
// days of the month
//
//Issue here is that range for dom will be 1-31
//for * and if one doesn't specify day_of_month in a job file
if (this->ranges[attribute_idx]->length()==CRONTAB_DAY_OF_MONTH_MAX){
if ((this->ranges[CRONTAB_DOW_IDX]->length()==CRONTAB_DAY_OF_WEEK_MAX)||
(this->ranges[CRONTAB_DOW_IDX]->length()==0)){
//if both wildcards, use month range
//if DOW range empty use DOM range
curRange = new ExtArray<int>( *this->ranges[attribute_idx] );
} else {
//only wildcard in month, so use day of week range
//this isn't quite right
curRange = new ExtArray<int>( CRONTAB_DAY_OF_MONTH_MAX );
}
}else{
// get to here means DOM was specified
curRange = new ExtArray<int>( *this->ranges[attribute_idx] );
}
int firstDay = dayOfWeek( match[CRONTAB_MONTHS_IDX],
1,
match[CRONTAB_YEARS_IDX] );
int ctr, cnt;
for ( ctr = 0, cnt = this->ranges[CRONTAB_DOW_IDX]->getlast();
ctr <= cnt;
ctr++ ) {
//
// Now figure out all the days for this specific day of the week
//
int day = (this->ranges[CRONTAB_DOW_IDX]->getElementAt(ctr) - firstDay) + 1;
while ( day <= CRONTAB_DAY_OF_MONTH_MAX ) {
if (curRange && day > 0 && !this->contains( *curRange, day ) ) {
curRange->add( day );
}
day += 7;
} // WHILE
} // FOR
//
// We have sort the list since we've added new elements
//
this->sort( *curRange );
//
// Otherwise we'll just use the unmodified range
//
} else {
curRange = this->ranges[attribute_idx];
}
//
// Find the first match for this field
// If our value isn't in the list, then we'll take the next one
//
bool ret = false;
int range_idx, cnt;
for ( range_idx = 0, cnt = curRange->getlast();
range_idx <= cnt;
range_idx++ ) {
//
// Two ways to make a match:
//
// 1) The level below told us that we need to just
// the first value in our range if we can.
// 2) We need to select the first value in our range
// that is greater than or equal to the current
// time value for this field. This is usually
// what we will do on the very first call to
// us. If we fail and return back to the previous
// level, when they call us again they'll ask
// us to just use the first value that we can
//
int value = curRange->getElementAt( range_idx );
if ( useFirst || value >= curTime[attribute_idx] ) {
//
// If this value is greater than the current time value,
// ask the next level to useFirst
//
if ( value > curTime[attribute_idx] ) nextUseFirst = true;
//
// Day of Month Check!
// If this day doesn't exist in this month for
// the current year in our search, we have to skip it
//
if ( attribute_idx == CRONTAB_DOM_IDX ) {
int maxDOM = daysInMonth( match[CRONTAB_MONTHS_IDX],
match[CRONTAB_YEARS_IDX] );
if ( value > maxDOM ) {
continue;
}
}
match[attribute_idx] = value;
//
// If we're the last field for the crontab (i.e. minutes),
// then we should have a valid time now!
//
if ( attribute_idx == CRONTAB_MINUTES_IDX ) {
ret = true;
break;
//
// Now that we have a current value for this field, call to the
// next field level and see if they can find a match using our
// If we roll back then we'll want the next time around for the
// next level to just use the first parameter in their range
// if they can
//
} else {
ret = this->matchFields( curTime, match, attribute_idx - 1, nextUseFirst );
nextUseFirst = true;
if ( ret ) break;
}
}
} // FOR
//
// If the next level up failed, we need to have
// special handling for months so we can roll over the year
// While this may seem trivial it's needed so that we
// can change the year in the matching for leap years
// We will call ourself to make a nice little loop!
//
if ( !ret && attribute_idx == CRONTAB_MONTHS_IDX ) {
match[CRONTAB_YEARS_IDX]++;
ret = this->matchFields( curTime, match, attribute_idx, true );
}
//
// We only need to delete curRange if we had
// instantiated a new object for it
//
if ( attribute_idx == CRONTAB_DOM_IDX && curRange ) delete curRange;
return ( ret );
}
