Changes

This [[Module Library|XQuery Module]] provides functions for organizing scheduled, queued , running and running cached jobs (. Jobs can be commands, queries, REST, RESTXQ and WebDAV client or HTTP requests).

|Returns the ids of all jobs that are currently registered. The list includes scheduled, queued or executed, running jobs, and cached jobs.

* <code>jobs:list()</code> returns the same job id as [[#jobs:current|jobs:current]] if no other job is runningregistered.

|Returns information on all jobs that are currently registered, or on a job with the specified {{Code|$id}} (or an empty sequence if this job is not found). The list includes scheduled, queued , running jobs, and cached jobs. A string representation of the job, or executedits URI, will be returned as value. The input comprises the returned elements have additional attributes:* <code>id</code>: job id, * <code>type</code>: type of the type job (XQuerycommand, a commandquery, REST, RESTXQ, etc.), * <code>state</code>: current state of the time a job is already being evaluated(scheduled, the state (queued, running, stopped, timeout, memoryor cached) and * <code>user</code>: the user who started the job.* <code>duration</code>: evaluation time (for running and cached jobs)* <code>start</code>: dateTime string with next start (for jobs that will be executed repeatedly)

<job id="job1" type="XQuery" duration="PT0S" state="running" user="admin" duration="PT0.001S">

|Indicates if the evaluation of a an already running job with the specified {{Code|$id}} has finished:* . As the ids of finished jobs will usually be discarded, unless caching is enabled, the function will also return <code>true</code> indicates that the job has either finished, or that the id is for unknownjobs.* <code>false</code> indicates that the job id is still scheduled, queued , or currently running.* <code>true</code> will be returned if the job has either finished, or if the id is unknown (because the ids of all finished jobs will not be cached).

|Cancels Triggeres the execution cancelation of a job with the specified {{Code|$id}}, or drops the cached result of a query, or cancels a scheduled job. Unknown ids are ignored. All jobs are gracefully stopped; it is up to the process to decide when it is safe to shut down.|} ==jobs:wait== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|jobs:wait|$id as xs:string|empty-sequence()}}|-| '''Summary'''|Waits for the completion of a job with the specified {{Code|$id}}:* The function will terminate immediately if the job id is unknown. This is the case if a future job has not been queued yet, or if the id has already been discarded after job evaluation.* If the function is called with the id of a queued job, or repeatedly executed job, it may stall and never terminate.|-| '''Errors'''|{{Error|self|#Errors}} if the current job is addressed.<br/>

==jobs:scheduleeval==

|{{Func|jobs:scheduleeval|$query as xs:string|xs:string}}<br />{{Func|jobs:scheduleeval|$query as xs:string, $bindings as map(*)?|xs:string}}<br />{{Func|jobs:scheduleeval|$query as xs:string, $bindings as map(*)?, $options as map(xs:string, xs:string*)?|xs:string}}<br />

|Schedules the execution evaluation of the supplied {{Code|$query}} and returns a query id. The query will be queued, and the result will optionally be cached. Queries may can be updating.<br/>Variables and context items can be declared via {{Code|$bindings}} (see [[XQuery Module#xquery:eval|xquery:eval]] for more details).<br/>The {{Code|$options}} parameter contains evaluation scheduling options:

** If the query raises an error, it will be cached and returned instead.** If the result will not be cached, the query id will immediately be discarded after query execution.

** If a time is specified, the query will be queued executed at this timeof the day. Examples for valid times are: <code>02:00:00</code> (2amlocal time), <code>12:00:0000Z</code> (noon, UTC). If the time lies in the past, the query will be executed the next day.** If a dateTime is specified, the query will be queued executed at this date. Examples for valid values are: <code>2018-12-31T23:59:59</code> (New Year's Eve 2018, close to midnight). An error will be raised if the specified time lies in the past.

* {{Code|end}}: scheduling can be stopped after a given time or duration. The string format is the same as for {{Code|start}}. An error is raised if the resulting end time is smaller than the start time.* {{Code|base-uri}}: set sets the [https://www.w3.org/TR/xquery-31/#dt-static-base-uri base-uri property] for the query. This URI will be used when resolving relative URIs by functions , such as with {{Code|fn:doc}} (default.* {{Code|id}}: ''empty string'')sets a custom job id. The id must not start with the standard <code>job</code> prefix, and it can only be assigned if no job with the same name exists.

|{{Error|overflow|#Errors}} Too Query execution is rejected, because too many queries or query results jobs are queuedor being executed. {{Option|CACHETIMEOUT}} can be decreased if the default setting is too restrictive.<br/>{{Error|range|#Errors}} A specified time or duration is out of range.<br/>{{Error|id|#Errors}} The specified id is invalid or has already been assigned.<br/>{{Error|options|#Errors}} Specified options are conflicting.

* {{CodeCache query result. The returned id can be used to pick up the result with [[#jobs:result|jobs:scheduleresult]]:<pre class='brush:xquery'>jobs:eval("1+3", (), map { 'cache': true() })}} returns a query id, e.g. {{Code|Job-123}}. The result can </pre>* A happy birthday mail will be retrieved via a second query in sent at the same BaseX contextgiven date:<pre class="brush: {{Code|xquery">jobs:resulteval("import module namespace mail='mail'; mail:send('Happy birthday!')"Job, (), map { 'start': '2018-09-123"01T06:00:00' })}}<br /pre>* The following [[RESTXQ]] function functions can be called to execute a query at 2 am every day. An id will return be returned by the id of the query threadfirst function, which evaluates can be used to stop the query that has been specified in scheduler via the body of a POST requestsecond function:

declare %rest:POST("{$query}") %rest:path('/evalstart-scheduling') function local:schedulestart($query) { jobs:scheduleeval($query, (), map { 'start': '02:00:00', 'interval': 'P1D' })};declare %rest:path('/stop-scheduling/{$id}') function local:stop($id) { jobs:stop($id)

* A maintenance function Query execution is scheduled for every second, and for 10 seconds in total. As the query itself will take 1.5 seconds, it will only be called at 2am executed every daysecond time:

jobs:scheduleeval("import module namespace m='maintain'; mprof:cleanupsleep(1500)", (), map { 'startinterval': '02:00:00PT1S', 'intervalend': 'P1DPT10S' })}}

* Query execution is scheduled for The following expression, if stored as a file, calls and evaluates itself every second. As the query itself will take 1.5 seconds, it will only be executed every second time:

jobs:scheduleeval("prof file:read-text(static-base-uri()), map { }, map { 'start': 'PT5S' })</pre>|} ==jobs:invoke== {{Mark|Introduced with Version 9.0:}} {| width='100%'|-| width='120' | '''Signatures'''|{{Func|jobs:invoke|$uri as xs:string|xs:string}}<br />{{Func|jobs:invoke|$uri as xs:sleepstring, $bindings as map(1500*)"?|xs:string}}<br />{{Func|jobs:invoke|$uri as xs:string, $bindings as map(*)?, $options as map (*)?|xs:string}}<br />|-| '''Summary'''|Schedules the evaluation of the XQuery expression located at { {Code|$uri}} and returns a query id. The semantics and remaining arguments are identical to [[#jobs:eval|jobs:eval]].|-| '''Errors''interval'|{{Error|overflow|#Errors}} Query execution is rejected, because too many jobs are queued or being executed. {{Option|CACHETIMEOUT}} can be decreased if the default setting is too restrictive.<br/>{{Error|range|#Errors}} A specified time or duration is out of range.<br/>{{Error|id|#Errors}} The specified id is invalid or has already been assigned.<br/>{{Error|options|#Errors}} Specified options are conflicting.|-| '''Examples'''|* Runs an XQuery expression that may perform some cleanups: <pre class='PT1Sbrush:xquery' }>jobs:invoke("cleanup.xq", (), ())

|Returns the cached result of a query job with the specified job {{Code|$id}}:

* If the original query job has raised an error, the cached error will be raised instead.

* The following [[RESTXQ]] function will either return the result of a previously started query job or raise an error:

* The following query demonstrates how the results of an asynchronously executed query can be returned within the same query. Please remember that this is not the common way how these functions will be used in practice:

let $query := jobs:scheduleeval('(1 to 10000000)[. = 1]', map{}, map{ 'cache': true() })

hof:until( function($f) { jobs:finishedwait($query) }, function($f) { prof:sleep(10) }, () ),

|} ==jobsPlease note that queries of this kind can cause deadlocks. For example, if both the original query and the query to be executed asynchronously perform updates on the same database, the second query would only be run after the first one has been executed, and the first query will wait forever. This is why you should avoid this pattern in practice and resort to [[XQuery Module#xquery:results== {| width='100%'|fork-join| width='120' | '''Signatures'''|{{Func|jobs:results||xsxquery:string*}}|fork-| '''Summary'''|Returns the ids of all jobs for which results are cachedjoin]] if you want to do things in parallel.

|{{Code|unknownoptions}}| The supplied query id is unknown or not available anymoreSpecified options are conflicting.

|{{Code|runningid}}| A query The specified is still runninginvalid or has already been assigned.

|{{Code|range}}