Changes

This [[Module Library|XQuery Module]] contains various functions for XQuery to test and profile code, and to dump information to standard output.

All functions and errors in this module are assigned to the {{Code|<code><nowiki>http://basex.org/modules/prof}} </nowiki></code> namespace, which is statically bound to the {{Code|prof}} prefix.<br/>All errors are assigned to the {{Code|http://basex.org/errors}} namespace, which is statically bound to the {{Code|bxerr}} prefix.

=Performance Functions= ==prof:track== {{Mark|Introduced with Version 9.0:}} {| width='100%'|-| width='120' | '''Signatures'''|{{Func|prof:track|$expression as item()|item()*}}<br/>{{Func|prof:track|$expression as item(), $options as map(*)?|item()*}}|-| '''Summary'''|Measures the execution time and memory consumption required for evaluating the specified {{Code|$expression}} and returns a map with the results. The following {{Code|$options}} are available:* {{Code|memory}}: Include memory consumption in result (unit: bytes; default: true).* {{Code|time}}: Include execution time in result (unit: milliseconds; default: true).* {{Code|value}}: Include value in result (default: true).Helpful notes:* If you are not interested in some of the returned results, you should disable them to save time and memory.* Profiling might change the execution behavior of your code: An expression that might be executed iteratively will be cached by the profiling function.* If a value has a compact internal representation, memory consumption will be very low, even if the serialized result may consume much more memory.* Please note that memory profiling is only approximative, so it can be quite misleading. If the memory option is enabled, main-memory will be garbage-collected before and after evaluation to improve the quality of the measurement.|-| '''Properties'''|The function is ''non-deterministic'': evaluation order will be preserved by the compiler.|-| '''Examples'''|* Return a human-readable representation of the memory consumption caused by fetching an XML document (<code>fetch:xml</code> is used, as <code>fn:doc</code> may already be evaluated at compilation time):<pre class="brush:xquery">prof:track(fetch:xml('factbook.xml'))?memory=> prof:human()</pre>* The function call <code>prof:track((1 to 1000000)[. mod 2 = 0], map { 'time': false() })</code> will return something similar to:<pre class="brush:xquery">map { "memory": 21548400, "value": (2, 4, 6, 8, 10, ...)}</pre>|}

{{Mark|Updated with Version 9.0:}} {{Code|$cache}} argument removed. {| width='100%'|-| width='120' | '''Signatures'''|{{Func|prof:time|$expr as item()|item()*}}<br />{{Func|prof:time|$expr as item(), $label as xs:string|item()*}}|-| '''Summary'''|Measures the time needed to evaluate {{Code|$expr}} and outputs a string to standard error or, if the GUI is used, to the Info View. An optional {{Code|$label}} may be specified to tag the profiling result. See {{Function|Profiling|prof:track}} for further notes.|-| '''Properties'''|The function is ''non-deterministic'': evaluation order will be preserved by the compiler.|-| '''Examples'''|* {{Code|prof:time(prof:sleep(1000))}} outputs something similar to {{Code|1000.99 ms}}.|} ==prof:memory== {{Mark|Updated with Version 9.0:}} Renamed (old name: <code>prof:mem</code>); {{Code|$cache}} argument removed. {| width='100%'

| width='90120' | '''Signatures'''|{{Func|prof:timememory|$expr as item()|item()*}}<br />{{Func|prof:timememory|$expr as item(), $cache as xs:boolean|item()*}}<br />{{Func|prof:time|$expr as item(), $cache as xs:boolean, $label as xs:string|item()*}}

|Measures the time needed to evaluate memory allocated by evaluating {{Code|$expr}} and sends it outputs a string to standard error or, if the GUI is used, to the Info View.<br />If An optional {{Code|$cachelabel}} is set may be specified to {{Code|true()}}, tag the profiling result will be temporarily cached. This way, a potential iterative execution of the expression (which often yields different memory usage) is blocked.<br/>A third, optional argument See {{CodeFunction|Profiling|$labelprof:track}} may for further notes.|-| '''Properties'''|The function is ''non-deterministic'': evaluation order will be specified to tag preserved by the profiling resultcompiler.

* {{Code|prof:timememory("1 to 100000")}} may output {{Code|25.69 ms}}.* {{Code|prof:time("1 to 100000", true()! <a/>)}} may will output something similar to {{Code|208.12 ms5620 kB}}.

==prof:memcurrent-ms==

{|width='100%'

| width='90120' | '''Signatures'''|{{Func|prof:memcurrent-ms|$expr as item()|item()*}}<br />{{Func|prof:mem|$expr as item(), $cache as xs:boolean|item()*integer}}<br />{{Func|prof:mem|$expr as item(), $cache as xs:boolean, $label as xs:string|item()*}}

|Measures Returns the memory allocated by evaluating {{Code|$expr}} number of milliseconds passed since 1970/01/01 UTC. The granularity of the value depends on the underlying operating system and sends it to standard error ormay be larger. For example, if the GUI is used, to the Info Viewmany operating systems measure time in units of tens of milliseconds.<br />If {{Code|-| '''Properties'''|$cache}} is set In contrast to {{Code|truefn:current-time()}}, the result will be temporarily cached. This way, a potential iterative execution of the expression (which often yields function is ''non-deterministic'' and returns different memory usage) values every time it is blockedcalled.<br/>A third, optional argument {{Code|$label}} may Its evaluation order will be specified to tag preserved by the profiling resultcompiler.

* {{Code|convert:integer-to-dateTime(prof:current-ms())}} returns the current miliseconds in the {{Code|xs:dateTime}} format.|} ==prof:mbcurrent-ns== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|prof:current-ns||xs:integer}}<br />|-| '''Summary'''|Returns the current value of the most precise available system timer in nanoseconds.|-| '''Properties'''|In contrast to {{Code|fn:current-time()}}, the function is ''non-deterministic'' and returns different values every time it is called. Its evaluation order will be preserved by the compiler.|-| '''Examples'''| Measures the time of an expression:<pre class="brush:xquery">let $ns1 := prof:current-ns()return ( (: process to measure :) (1 to 100000"1000000)[. = 0], let $ns2 := prof:current-ns() let $ms := ((($ns2 - $ns1) idiv 10000) div 100) return $ms || ' ms')</pre>|} =Debugging Functions= ==prof:dump== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|prof:dump|$expr as item()|empty-sequence()}}<br />{{Func|prof:dump|$expr as item(), $label as xs:string|empty-sequence()}}<br />|-| '''Summary'''|Dumps a serialized representation of {{Code|$expr}} to {{Code|STDERR}}, optionally prefixed with {{Code|$label}}, and returns an empty sequence. If the GUI is used, the dumped result is shown in the [[Graphical User Interface#Visualizations|Info View]].|-| '''Properties'''|In contrast to {{Code|fn:trace()}}, the consumed expression will not be passed on.|} ==prof:variables== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|prof:variables||empty-sequence()}} |-| '''Summary'''|Prints a list of all current local and global variable assignments to standard error or, if the GUI is used, to the Info View.<br />As every query is optimized before being evaluated, not all of the original variables may be visible in the output . Moreover, many variables of function calls will disappear because functions are inlined. Function inlining can be turned off by setting the [[Options#INLINELIMIT|INLINELIMIT]] option to <code>0</code>.|-| '''Properties'''|The function is ''non-deterministic'': evaluation order will be preserved by the compiler.|-| '''Examples'''|* {{Code|0 Bytesfor $x in 1 to 2 return prof:variables()}}will dump the values of <code>$x</code> to standard error.|} ==prof:type== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|prof:type|$expr as item()* |item()*}}|-| '''Summary'''|Similar to {{Code|proffn:mbtrace("1 to 100000"$expr, $msg)}}, but instead of a user-defined message, trueit emits the compile-time type and estimated result size of its argument.|} =Helper Functions= ==prof:void== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|prof:void|$value as item()*|empty-sequence()}} may output |-| '''Summary'''|Swallows all items of the specified {{Code|$value}} and returns an empty sequence. This function is helpful if some code needs to be evaluated and if the actual result is irrelevant.|-| '''Properties'''|The function is ''non-deterministic'': evaluation order will be preserved by the compiler.|-| '''Examples'''|* {{Code|26prof:void(fetch:binary('http://my.rest.678 mbservice'))}}performs an HTTP request and ignores the result.

{|width='100%'

| width='90120' | '''Signatures'''|{{Func|prof:sleep|$ms as xs:integer|empty-sequence()*}}<br />