TMREC Module

Daniel-Constantin Mierla

   <miconda@gmail.com>

Edited by

Daniel-Constantin Mierla

   <miconda@gmail.com>

Alex Balashov

   <abalashov@evaristesys.com>

Richard Fuchs

   <rfuchs@sipwise.com>

   Copyright © 2012 asipto.com

   Copyright © 2012 Sipwise GmbH
     __________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Dependencies

              2.1. Kamailio Modules
              2.2. External Libraries or Applications

        3. Parameters

              3.1. separator (str)

        4. Functions

              4.1. tmrec_match(timerec [, timestamp])
              4.2. is_leap_year([year])
              4.3. time_period_match(period [, timestamp])

   List of Examples

   1.1. Set separator parameter
   1.2. tmrec_match usage
   1.3. is_leap_year usage
   1.4. time_period_match usage

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Dependencies

        2.1. Kamailio Modules
        2.2. External Libraries or Applications

   3. Parameters

        3.1. separator (str)

   4. Functions

        4.1. tmrec_match(timerec [, timestamp])
        4.2. is_leap_year([year])
        4.3. time_period_match(period [, timestamp])

1. Overview

   This module provides time recurrence matching functions. The format of
   recurrence definitions is based on Internet Calendaring and Scheduling
   Core Object Specification (Calendar COS - RFC 2445). It also provides a
   port of the Perl Time::Period module for generic time period matching.

2. Dependencies

   2.1. Kamailio Modules
   2.2. External Libraries or Applications

2.1. Kamailio Modules

   The following modules must be loaded before this module:
     * None.

2.2. External Libraries or Applications

   The following libraries or applications must be installed before
   running Kamailio with this module loaded:
     * None

3. Parameters

   3.1. separator (str)

3.1. separator (str)

   Separator character used to delimit attributes in time reccurrence
   definitions.

   Default value is '|'.

   Example 1.1. Set separator parameter
...
modparam("tmrec", "separator", ";")
...

4. Functions

   4.1. tmrec_match(timerec [, timestamp])
   4.2. is_leap_year([year])
   4.3. time_period_match(period [, timestamp])

4.1.  tmrec_match(timerec [, timestamp])

   Match a time recurrence rule against the timestamp (UNIX epoch format).
   If the timestamp parameter is missing, the current UNIX epoch time is
   used.

   The parameters can include pseudo-variables.

   The timerec paramter is a list of attributes defined by RFC2445,
   delimited by the 'separator' (module parameter) character. The format
   of timerec parameter, using '|' as the separator, is (all in one line
   without white spaces):
...
[startdate]|[duration]|[frequency]|[until]|[interval]|[byday]
  |[bymonthday]|[byyearday]|[byweekno]|[bymonth]
...

   When an attribute is not specified, the corresponding place must be
   left empty, provided that one or more additional attributes follow.

   Description of time recurrence attributes:
     * startdate - date for the start of the first period.
     * duration - the duration of the time period. For a recurring
       interval, the “duration” parameter MUST be small enough such that
       subsequent intervals do not overlap. For non-recurring intervals,
       durations of any positive length are permitted. Zero-length
       duration means “forever”. Negative-length durations are not
       allowed.
       See RFC 2445 for the format of duration. In short for common cases
       when the duration doesn't exceed a data, it must start with PT
       followed by the value for hours, minutes or seconds - e.g., a
       duration of 8 hours must be written as PT8H.
     * frequency - can be one of the following values: “daily” - specify
       repeating periods based on an interval of a day or more; “weekly” -
       specify repeating periods based on an interval of a week or more;
       “monthly” - specify repeating periods based on an interval of a
       month or more; “yearly” - specify repeating periods based on an
       interval of a year or more. These values are case-insensitive.
     * until - defines an iCalendar COS DATE or DATE-TIME value which
       bounds the recurrence rule in an inclusive manner. If the value
       specified by “until” is synchronized with the specified recurrence,
       this date or date-time becomes the last instance of the recurrence.
       If it is not present, the recurrence is considered to repeat
       forever.
     * interval - a positive integer representing how often the recurrence
       rule repeats. The default value is “1”, meaning every day for a
       “daily” rule, every week for a “weekly” rule, every month for a
       “monthly” rule and every year for a “yearly” rule.
     * byday - a comma-separated list short codes of days of the week. The
       days are specified as: “MO” for Monday; “TU” for Tuesday; “WE” for
       Wednesday; “TH” for Thursday; “FR” for Friday; “SA” for Saturday;
       “SU” for Sunday. These values are case insensitive.
       Each “byday” value can also be prefixed by a positive (+n) or
       negative (-n) integer. If present, this indicates the n-th
       occurrence of the specific day within the “monthly” or “yearly”
       recurrence. For example, within a “monthly” rule, +1MO (or simply
       1MO) represents the first Monday within the month, whereas -1MO
       represents the last Monday of the month. If an integer modifier is
       not present, it means all days of this type within the specified
       frequency. For example, within a “monthly” rule, MO represents all
       Mondays within the month.
     * bymonthday - a comma-separated list of days of the month. Valid
       values are 1 to 31 or -31 to -1. For example, -10 represents the
       tenth to the last day of the month.
     * byyearday - a comma-separated list of days of the year. Valid
       values are 1 to 366 or -366 to -1. For example, -1 represents the
       last day of the year (December 31st) and -306 represents the 306th
       day before the last day of the year (March 1st).
     * byweekno - a comma-separated list of ordinals specifying weeks of
       the year. Valid values are 1 to 53 or -53 to -1.
     * bymonth - parameter specifies a comma-separated list of months of
       the year. Valid values are 1 to 12.

   A recurrence is specified by including the “frequency” parameter, which
   indicates the type of the recurrence rule. Parameters other than
   “startdate” and “duration” SHOULD NOT be specified unless “frequency”
   is set.

   If invalid byxxx parameter values are found (ie, bymonthday=“30” in
   February), they are simply ignored.

   Byxxx parameters modify the recurrence rule matching. The Byxxx rule,
   as an attribute for a period of time which is greater than or equal to
   the frequency, generally reduces or limits the number of occurrences
   for the recurrence definition. For example, frequency=“daily”
   bymonth=“3” reduces the number of recurrence instances from all days
   (if the “bymonth” parameter is not present) to all days in March. Byxxx
   parameters for a period of time less than the frequency generally
   increases or expands the number of occurrences of the recurrence. For
   example, frequency=“yearly” bymonth=“8,9” increases the number of days
   within the yearly recurrence set from 1 (if “bymonth” parameter is not
   present) to 2.

   If multiple Byxxx parameters are specified, then after evaluating the
   specified “frequency” and “interval” parameters, the Byxxx parameters
   are applied to the current set of evaluated occurrences in the
   following order: “bymonth”, “byweekno”, “byyearday”, “bymonthday”,
   “byday”; then “until” is evaluated.

   Next is an example of evaluating multiple Byxxx parameters.

   startdate=“20100101T093000” duration=“PT10H30M” frequency=“yearly”
   interval=“4” bymonth=“3” byday=“SU”

   First, the interval=“4” would be applied to frequency=“yearly” to match
   on “every 4th year” . Then, bymonth=“1” would be applied to match on
   “every March, every 4th year”. Then, byday=“SU” would be applied to
   match on “every Sunday in March, every 4th year, from 9:30 to 20:00 ”.
   The start and end hours:minutes have been retrieved from the
   “startdate” and “duration” parameters.

   This function can be used in ANY_ROUTE.

   Example 1.2. tmrec_match usage
...
        if(tmrec_match("20120101T000000|PT24H|weekly|||SA,SU")
        xdbg("it is weekend!\n");
    if(tmrec_match("20120101T083000|PT10H|weekly|||MO,TU,WE,TH,FR")
        xdbg("it is with working hours\n");
...

4.2.  is_leap_year([year])

   Return true if the value from parameter is a leap year. If the
   parameter is missing, then the year from the current time is taken.

   The parameter can be pseudo-variable.

   This function can be used in ANY_ROUTE.

   Example 1.3. is_leap_year usage
...
if(is_leap_year("2010"))
...

4.3.  time_period_match(period [, timestamp])

   Matches the point in time specified by the timestamp parameter, or the
   current time if the parameter is missing, against the given period
   specification. Returns 1 if it matches, -1 if it doesn't, and a value
   <= -2 if there was an error.

   The time period specification follows the Perl Time::Period module. It
   is a string and consists of zero or more sub-period specifications,
   separated by commas. The period matches if at least one of the
   sub-periods matches, or if no sub-periods were given at all (an empty
   string).

   Each sub-period is a list of one or more scale definitions, optionally
   separated by space characters. The sub-period matches if all of the
   given scales within that sub-period match. For each scale given, a
   single value or a range of values (which is two values separated by a
   hyphen) can be specified. Multiple values or multiple ranges (or a
   combination thereof) within a single scale is also possible. If a
   certain scale is specified more than once, the previous values or
   ranges for that scale are extended by the newly given ones. If a
   particular scale is not mentioned at all within a sub-period, then no
   matching is performed for that scale.

   The following scales are supported and understood. Each scale also has
   a respective short code, either one can be used. A single scale
   definition consists of the scale name, followed by an opening brace,
   followed by the list of values, followed by a closing brace.
     * year or yr - Either given as a full 4-digit number >= 1970, or as a
       2-digit number, in which case it will be understood to be within
       the current century.
     * month or mo - Month of the year, either a number between 1 and 12,
       or at least the first 3 letters of a spelled out month name, e.g.
       “jan”, “janua” or “january” will all work.
     * week or wk - Week of the month, a number between 1 and 6. The first
       day of the week is Sunday.
     * yday or yd - Day of the year, a number between 1 and 366.
     * mday or md - Day of the month, a number between 1 and 31.
     * wday or wd - Day of the week, either a number between 1 and 7, or
       at least the first 2 letters of a spelled out weekday name
       (analogous to the “month” scale). Sunday is the first day of the
       week.
     * hour or hr - A number between 0 and 23. Unlike the Perl
       Time::Period module, “am” or “pm” specifications are not supported.
     * minute or min - A number between 0 and 59.
     * second or sec - A number between 0 and 60 (to allow for leap
       seconds).

   The parameters can include pseudo-variables. Whitespace (more
   precisely, the space character only) can occur anywhere, but is
   optional. Ranges in all scales (with the exception of the “year” scale)
   are allowed to wrap-around, e.g. a weekday scale of “{fri-tue}” is
   equivalent to “{fri-sat,sun-tue}”.

   Example 1.4. time_period_match usage
...
if(time_period_match("wd{2-6} hr{8-16}, wd{2-6} hr{17} min{0-29}"))
        xdbg("Monday to Friday, 8:00 to 17:30\n");

if(time_period_match("wday { sat sun }, wday {mo-fr} hr {17-8},wd{mo-wed}hr{15 1
6 9}"))
        xdbg("We're closed - open only Monday to Wednesday 10:00-15:00, Thursday
 and Friday 9:00-17:00");
...
