Changes

This [[Module Library|XQuery Module]] contains various testingfunctions to test and profile code, profiling and helper functionsto 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== {| width='100%'|- valign="top"| width='120' | '''Signature'''|<pre>prof:track( $input as item()*, $options as map(*)? := map { }) as item()*</pre>|- valign="top"| '''Summary'''|Measures the execution time and memory consumption required for evaluating the specified {{Code|$input}} and returns a map with the results. The following {{Code|$options}} are available:* {{Code|time}}: Include execution time in result as {{Code|xs:decimal}} (unit: milliseconds; default: true).* {{Code|memory}}: Include memory consumption in result as {{Code|xs:integer}} (unit: bytes; default: false).* {{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.|- valign="top"| '''Properties'''|The function is ''nondeterministic'': evaluation order will be preserved by the compiler.|- valign="top"| '''Examples'''|* Return a human-readable representation of the memory consumption caused by fetching an XML document. {{Function||fetch:doc}} is used, as <code>fn:doc</code> may already be evaluated at compilation time:<pre lang='xquery'>prof:track(fetch:doc('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 lang='xquery'>map { "memory": 21548400, "value": (2, 4, 6, 8, 10, ...)}</pre>|}

|-valign="top"| width='90120' | '''SignaturesSignature'''|{{Func|prof:time|$expr as item()|item()*}}<br /pre>{{Func|prof:time|( $expr input as item(), $cache label as xs:boolean|itemstring? := ()*}}<br />{{Func|prof:time|$expr as item(), $cache as xs:boolean, $label as xs:string|item()*}}</pre>|-valign="top"

|Measures the time needed to evaluate {{Code|$exprinput}} and sends it outputs a string to standard error or, if the GUI is used, to the Info View.<br />If {{Code|$cache}} is set to {{Code|true()}}, the 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, An optional argument {{Code|$label}} may be specified to tag the profiling result. See {{Function||prof:track}} for further notes.|-valign="top"

|The function is ''non-deterministicnondeterministic'': evaluation order will be preserved by the compiler.|-valign="top"

* {{Code|prof:time("1 to 100000")}} may output {{Code|25.69 ms}}.* {{Code|prof:time("1 to 100000", truesleep(1000))}} may output outputs something similar to {{Code|2081000.12 99 ms}}.

==prof:memmemory==

|-valign="top"| width='90120' | '''SignaturesSignature'''|{{Func|prof:mem|$expr as item()|item()*}}<br /pre>{{Func|prof:mem|memory( $expr input as item(), $cache label as xs:boolean|itemstring? := ()*}}<br />{{Func|prof:mem|$expr as item(), $cache as xs:boolean, $label as xs:string|item()*}}</pre>|-valign="top"

|Measures the memory allocated by evaluating {{Code|$exprinput}} and sends it outputs a string to standard error or, if the GUI is used, to the Info View.<br />If {{Code|$cache}} is set to {{Code|true()}}, the 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, An optional argument {{Code|$label}} may be specified to tag the profiling result. See {{Function||prof:track}} for further notes.|-valign="top"

|The function is ''non-deterministicnondeterministic'': evaluation order will be preserved by the compiler.|-valign="top"

* {{Code|prof:mbmemory("1 to 100000")}} may output {{Code|0 Bytes}}.* {{Code|prof:mb("1 to 100000", true()! <a/>)}} may will output something similar to {{Code|26.678 mb5620 kB}}.

==prof:sleepcurrent-ms==

|-valign="top"| width='90120' | '''SignaturesSignature'''|{{Func|<pre>prof:sleep|$current-ms () as xs:integer|empty-sequence()}}<br /pre>|-valign="top"

|Sleeps for Returns the specified number of milliseconds passed since 1970/01/01 UTC. The granularity of the value depends on the underlying operating system and may be larger. For example, many operating systems measure time in units of tens of milliseconds.|-valign="top"

|The In contrast to {{Code|fn:current-time()}}, the function is ''non-deterministicnondeterministic'': and returns different values every time it is called. Its evaluation order will be preserved by the compiler.|- valign="top"| '''Examples'''|* {{Code|convert:integer-to-dateTime(prof:current-ms())}} returns the current miliseconds in the {{Code|xs:dateTime}} format.

==prof:humancurrent-ns==

|-valign="top"| width='90120' | '''SignaturesSignature'''|{{Func|<pre>prof:human|$number current-ns() as xs:integer|xs:string}}</pre>|-valign="top"

|Returns a human-readable representation the current value of the specified most precise available system timer in nanoseconds.|- valign="top"| '''Properties'''|In contrast to {{Code|$numberfn:current-time()}}, the function is ''nondeterministic'' and returns different values every time it is called. Its evaluation order will be preserved by the compiler.|-valign="top"| '''ExampleExamples'''|Measures the time of an expression:<pre lang='xquery'>let $ns1 := prof:current-ns()return ( (: process to measure :) (1 to 1000000)[. = 0],* {{Code| let $ns2 := prof:humancurrent-ns(16384)}} returns {{Code let $ms := ((($ns2 - $ns1) idiv 10000) div 100) return $ms ||16K}}.' ms')</pre>

|-valign="top"| width='90120' | '''SignaturesSignature'''|{{Func|prof:dump|$expr as item()|empty-sequence()}}<br /pre>{{Func|prof:dump|( $expr input as item()*, $label as xs:string|? := ()) as empty-sequence()}}<br /pre>|-valign="top"

|Dumps a serialized representation of {{Code|$exprinput}} to {{Code|STDERR}}, optionally prefixed with {{Code|$label}}, and returns an empty sequence. If the GUI is used, the dumped result is shown in the [[Graphical User Interface#Visualizations|Info View]].|-valign="top"

==prof:current-msvariables==

|-valign="top"| width='90120' | '''SignaturesSignature'''|{{Func|<pre>prof:currentvariables() as empty-ms||xs:integer}}sequence()<br /pre>|-valign="top"

|Returns Prints a list of all current local and global variable assignments to standard error or, if the GUI is used, to the number of milliseconds passed since 1970Info View.<br/01/01 UTC. The granularity >As every query is optimized before being evaluated, not all of the value depends on the underlying operating system and original variables may be largervisible in the output. For exampleMoreover, many operating systems measure time in units variables of tens of millisecondsfunction calls will disappear because functions are inlined. Function inlining can be turned off by setting {{Option|INLINELIMIT}} to <code>0</code>.|-valign="top"

|In contrast to {{Code|fn:current-time()}}, the The function is ''non-deterministicnondeterministic'', as it returns different values every time it is called. Its : evaluation order will be preserved by the compiler.|- valign="top"| '''Examples'''|* {{Code|for $x in 1 to 2 return ($x, prof:variables())}} will dump the values of <code>$x</code> to standard error.

==prof:currenttype== {| width='100%'|-nsvalign="top"| width='120' | '''Signature'''|<pre>prof:type( $expr as item()*) as item()*</pre>|- valign="top"| '''Summary'''|Similar to {{Code|fn:trace($expr, $msg)}}, but instead of a user-defined message, it emits the compile-time type and estimated result size of its argument.|} ==prof:gc== {| width='100%'|- valign="top"| width='120' | '''Signature'''|<pre>prof:gc( $count as xs:integer := ()) as empty-sequence()</pre>|- valign="top"| '''Summary'''|Enforces Java garbage collection. If no {{Code|$count}} is supplied, garbage will be collected once. Please note that this function should only be used for debugging purposes; in productive code, it is best to trust the garbage collecting strategies of Java.|} ==prof:runtime==

|-valign="top"| width='90120' | '''SignaturesSignature'''|{{Func|<pre>prof:current-ns||runtime( $option as xs:string) as xs:integer}}<br /pre>|-valign="top"

|Returns the current value of the most precise specified runtime {{Code|$option}}. The following options are available system timer :* {{Code|max}}: Maximum memory that the Java virtual machine will attempt to use.* {{Code|total}}: Total memory in nanosecondsthe Java virtual machine (varies over time).* {{Code|used}}: Currently used memory (varies over time, will shrink after garbage collection).* {{Code|processors}}: number of processors available to the Java virtual machine.|- valign="top"|{{Code|option}}|The specified option is unknown.|-valign="top"| '''PropertiesExamples'''|In contrast to {{Code|fn* <code>prof:current-timegc(3)}}, the function is prof:human(prof:runtime('used'non-deterministic'', as it ))</code> performs some garbage collection and returns different values every time it is called. Its evaluation order will be preserved by the compilercurrently used amount of memory in a user-friendly format.

|-valign="top"| width='90120' | '''SignaturesSignature'''|{{Func|<pre>prof:void|( $value input as item()*|) as empty-sequence()}}</pre>|-valign="top"

|Swallows all items of Absorbs the specified {{Code|$valueinput}} and returns an empty sequence. This function is helpful if some (often nondeterministic or side-effecting) code needs to be evaluated and if the actual result resulting value is irrelevantnot required.|-valign="top"

|The function is ''non-deterministicnondeterministic'': evaluation order will be preserved by the compiler.|-valign="top"

* Added: <code>[[#prof:void{{Function||prof:void]]</code>}}

* Added: <code>[[#prof:human{{Function||prof:human]]</code>}}

* Added: <code>[[#prof:dump{{Function||prof:dump]]</code>}}, <code>[[#prof:current-ms{{Function||prof:current-ms]]</code>}}, <code>[[#prof:current-ns{{Function||prof:current-ns]]</code>}}