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Diffstat (limited to 'scm/mcron/job-specifier.scm')
| -rw-r--r-- | scm/mcron/job-specifier.scm | 272 |
1 files changed, 0 insertions, 272 deletions
diff --git a/scm/mcron/job-specifier.scm b/scm/mcron/job-specifier.scm deleted file mode 100644 index cce948c..0000000 --- a/scm/mcron/job-specifier.scm +++ /dev/null @@ -1,272 +0,0 @@ -;; Copyright (C) 2003 Dale Mellor -;; -;; This file is part of GNU mcron. -;; -;; GNU mcron is free software: you can redistribute it and/or modify it under -;; the terms of the GNU General Public License as published by the Free -;; Software Foundation, either version 3 of the License, or (at your option) -;; any later version. -;; -;; GNU mcron is distributed in the hope that it will be useful, but WITHOUT -;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or -;; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for -;; more details. -;; -;; You should have received a copy of the GNU General Public License along -;; with GNU mcron. If not, see <http://www.gnu.org/licenses/>. - - - -;; This module defines all the functions that can be used by scheme mcron -;; configuration files, namely the procedures for working out next times, the -;; job procedure for registering new jobs (actually a wrapper around the core -;; add-job function), and the procedure for declaring environment modifications. - -(define-module (mcron job-specifier) - #:export (range - next-year-from next-year - next-month-from next-month - next-day-from next-day - next-hour-from next-hour - next-minute-from next-minute - next-second-from next-second - set-configuration-user - set-configuration-time - job - find-best-next) - #:use-module (mcron core) - #:use-module (mcron environment) - #:use-module (mcron vixie-time) - #:re-export (append-environment-mods)) - - - -;; Function (available to user configuration files) which produces a list of -;; values from start up to (but not including) end. An optional step may be -;; supplied, and (if positive) only every step'th value will go into the -;; list. For example, (range 1 6 2) returns '(1 3 5). - -(define (range start end . step) - (let ((step (if (or (null? step) - (<= (car step) 0)) - 1 - (car step)))) - (let loop ((start start)) - (if (>= start end) '() - (cons start - (loop (+ start step))))))) - - - -;; Internal function (not supposed to be used directly in configuration files; -;; it is exported from the module for the convenience of other parts of the -;; mcron implementation) which takes a value and a list of possible next values -;; (all assumed less than 9999). It returns a pair consisting of the smallest -;; element of the list, and the smallest element larger than the current -;; value. If an example of the latter cannot be found, 9999 will be returned. - -(define (find-best-next current next-list) - (let ((current-best (cons 9999 9999))) - (for-each (lambda (allowed-time) - (if (< allowed-time (car current-best)) - (set-car! current-best allowed-time)) - (if (and (> allowed-time current) - (< allowed-time (cdr current-best))) - (set-cdr! current-best allowed-time))) - next-list) - current-best)) - - - -;; Internal function to return the time corresponding to some near future -;; hour. If hour-list is not supplied, the time returned corresponds to the -;; start of the next hour of the day. -;; -;; If the hour-list is supplied the time returned corresponds to the first hour -;; of the day in the future which is contained in the list. If all the values in -;; the list are less than the current hour, then the time returned will -;; correspond to the first hour in the list *on the following day*. -;; -;; ... except that the function is actually generalized to deal with seconds, -;; minutes, etc., in an obvious way :-) -;; -;; Note that value-list always comes from an optional argument to a procedure, -;; so is wrapped up as the first element of a list (i.e. it is a list inside a -;; list). - -(define (bump-time time value-list component higher-component - set-component! set-higher-component!) - (if (null? value-list) - (set-component! time (+ (component time) 1)) - (let ((best-next (find-best-next (component time) (car value-list)))) - (if (eqv? 9999 (cdr best-next)) - (begin - (set-higher-component! time (+ (higher-component time) 1)) - (set-component! time (car best-next))) - (set-component! time (cdr best-next))))) - (car (mktime time))) - - - - -;; Set of configuration methods which use the above general function to bump -;; specific components of time to the next legitimate value. In each case, all -;; the components smaller than that of interest are taken to zero, so that for -;; example the time of the next year will be the time at which the next year -;; actually starts. - -(define (next-year-from current-time . year-list) - (let ((time (localtime current-time))) - (set-tm:mon time 0) - (set-tm:mday time 1) - (set-tm:hour time 0) - (set-tm:min time 0) - (set-tm:sec time 0) - (bump-time time year-list tm:year tm:year set-tm:year set-tm:year))) - -(define (next-month-from current-time . month-list) - (let ((time (localtime current-time))) - (set-tm:mday time 1) - (set-tm:hour time 0) - (set-tm:min time 0) - (set-tm:sec time 0) - (bump-time time month-list tm:mon tm:year set-tm:mon set-tm:year))) - -(define (next-day-from current-time . day-list) - (let ((time (localtime current-time))) - (set-tm:hour time 0) - (set-tm:min time 0) - (set-tm:sec time 0) - (bump-time time day-list tm:mday tm:mon set-tm:mday set-tm:mon))) - -(define (next-hour-from current-time . hour-list) - (let ((time (localtime current-time))) - (set-tm:min time 0) - (set-tm:sec time 0) - (bump-time time hour-list tm:hour tm:mday set-tm:hour set-tm:mday))) - -(define (next-minute-from current-time . minute-list) - (let ((time (localtime current-time))) - (set-tm:sec time 0) - (bump-time time minute-list tm:min tm:hour set-tm:min set-tm:hour))) - -(define (next-second-from current-time . second-list) - (let ((time (localtime current-time))) - (bump-time time second-list tm:sec tm:min set-tm:sec set-tm:min))) - - - -;; The current-action-time is the time a job was last run, the time from which -;; the next time to run a job must be computed. (When the program is first run, -;; this time is set to the configuration time so that jobs run from that moment -;; forwards.) Once we have this, we supply versions of the time computation -;; commands above which implicitly assume this value. - -(define current-action-time 0) - - - -;; We want to provide functions which take a single optional argument (as well -;; as implicitly the current action time), but unlike usual scheme behaviour if -;; the argument is missing we want to act like it is really missing, and if it -;; is there we want to act like it is a genuine argument, not a list of -;; optionals. - -(define (maybe-args function args) - (if (null? args) - (function current-action-time) - (function current-action-time (car args)))) - - - -;; These are the convenience functions we were striving to define for the -;; configuration files. They are wrappers for the next-X-from functions above, -;; but implicitly use the current-action-time for the time argument. - -(define (next-year . args) (maybe-args next-year-from args)) -(define (next-month . args) (maybe-args next-month-from args)) -(define (next-day . args) (maybe-args next-day-from args)) -(define (next-hour . args) (maybe-args next-hour-from args)) -(define (next-minute . args) (maybe-args next-minute-from args)) -(define (next-second . args) (maybe-args next-second-from args)) - - - -;; The default user for running jobs is the current one (who invoked this -;; program). There are exceptions: when cron parses /etc/crontab the user is -;; specified on each individual line; when cron parses /var/cron/tabs/* the user -;; is derived from the filename of the crontab. These cases are dealt with by -;; mutating this variable. Note that the variable is only used at configuration -;; time; a UID is stored with each job and it is that which takes effect when -;; the job actually runs. - -(define configuration-user (getpw (getuid))) -(define configuration-time (current-time)) - -(define (set-configuration-user user) - (set! configuration-user (if (or (string? user) - (integer? user)) - (getpw user) - user))) -(define (set-configuration-time time) (set! configuration-time time)) - - - -;; The job function, available to configuration files for adding a job rule to -;; the system. -;; -;; Here we must 'normalize' the next-time-function so that it is always a lambda -;; function which takes one argument (the last time the job ran) and returns a -;; single value (the next time the job should run). If the input value is a -;; string this is parsed as a Vixie-style time specification, and if it is a -;; list then we arrange to eval it (but note that such lists are expected to -;; ignore the function parameter - the last run time is always read from the -;; current-action-time global variable). A similar normalization is applied to -;; the action. -;; -;; Here we also compute the first time that the job is supposed to run, by -;; finding the next legitimate time from the current configuration time (set -;; right at the top of this program). - -(define (job time-proc action . displayable) - (let ((action (cond ((procedure? action) action) - ((list? action) (lambda () (primitive-eval action))) - ((string? action) (lambda () (system action))) - (else - (throw 'mcron-error - 2 - "job: invalid second argument (action; should be lambda" - " function, string or list)")))) - - (time-proc - (cond ((procedure? time-proc) time-proc) - ((string? time-proc) (parse-vixie-time time-proc)) - ((list? time-proc) (lambda (current-time) - (primitive-eval time-proc))) - (else - (throw 'mcron-error - 3 - "job: invalid first argument (next-time-function; should ") - "be function, string or list)"))) - (displayable - (cond ((not (null? displayable)) (car displayable)) - ((procedure? action) "Lambda function") - ((string? action) action) - ((list? action) (with-output-to-string - (lambda () (display action))))))) - (add-job (lambda (current-time) - (set! current-action-time current-time) ;; ?? !!!! Code - - ;; Contributed by Sergey Poznyakoff to allow for daylight savings - ;; time changes. - (let* ((next (time-proc current-time)) - (gmtoff (tm:gmtoff (localtime next))) - (d (+ next (- gmtoff - (tm:gmtoff (localtime current-time)))))) - (if (eqv? (tm:gmtoff (localtime d)) gmtoff) - d - next))) - action - displayable - configuration-time - configuration-user))) |