class Telemetry::Period
Performance data over a period
is Telemetry
Note: This class is a Rakudo-specific feature and not standard Perl 6.
# basic usageuse Telemetry;my = Telemetry.new;# execute some codemy = Telemetry.new;my = - ; # creates Telemetry::Period objectsay "Code took $period<wallclock> microseconds to execute";
A Telemetry::Period
object contains the difference between two Telemetry objects. It is generally not created by calling .new, but it can be if needed. For all practical purposes, it is the same as the Telemetry
object, but the meaning of the values is different (and the values are generally much smaller, as they usually are the difference of two big values of the Telemetry
objects from which it was created).
Type Graph
Routines supplied by role Associative
Telemetry::Period does role Associative, which provides the following routines:
(Associative) method of
Defined as:
method of()
Associative
is actually a parameterized role which can use different classes for keys and values. As seen at the top of the document, by default it coerces to Str
for the key and uses a very generic Mu
for value.
my ;say .of;# OUTPUT: «(Mu)»
The value is the first parameter you use when instantiating Associative
with particular classes:
is Hash does Associative[Cool,DateTime] ;my := DateHash.new;say .of; # OUTPUT: «(Cool)»
(Associative) method keyof
Defined as:
method keyof()
Returns the parameterized key used for the Associative role, which is Any
coerced to Str
by default. This is the class used as second parameter when you use the parameterized version of Associative.
my ;.keyof; #OUTPUT: «(Str(Any))»
(Associative) method AT-KEY
method AT-KEY(\key)
Should return the value / container at the given key.
(Associative) method EXISTS-KEY
method EXISTS-KEY(\key)
Should return a Bool
indicating whether the given key actually has a value.
(Associative) method STORE
method STORE(\values, :)
This method should only be supplied if you want to support the:
my is Foo = a => 42, b => 666;
syntax for binding your implementation of the Associative
role.
Should accept the values to (re-)initialize the object with, which either could consist of Pair
s, or separate key/value pairs. The optional named parameter will contain a True
value when the method is called on the object for the first time. Should return the invocant.
Routines supplied by class Telemetry
Telemetry::Period inherits from class Telemetry, which provides the following routines:
(Telemetry) routine T
sub T()
Shortcut for Telemetry.new
. It is exported by default. Since the Telemetry
class also provides an Associative
interface, one can easily interpolate multiple values in a single statement:
use Telemetry;say "Used (KiB CPU) so far";
(Telemetry) routine snap
multi sub snap(--> Nil)multi sub snap( --> Nil)
The snap
subroutine is shorthand for creating a new Telemetry
object and pushing it to an array for later processing. It is exported by default.
use Telemetry;my ;for ^5
If no array is specified, it will use an internal array for convenience.
(Telemetry) routine snapper
sub snapper( = 0.1, :, : --> Nil)
The snapper
routine starts a separate thread that will call snap
repeatedly until the end of program. It is exported by default.
By default, it will call snap
every 0.1 second. The only positional parameter is taken to be the delay between snap
s.
Please see the snapper module for externally starting a snapper without having to change the code. Simply adding -Msnapper
as a command line parameter, will then start a snapper for you.
(Telemetry) routine periods
multi sub periods( --> Seq)multi sub periods( --> Seq)
The periods
subroutine processes an array of Telemetry
objects and generates a Seq of Telemetry::Period
objects out of that. It is exported by default.
.<cpu wallclock>.say for periods();# OUTPUT:# ====================# (164 / 160)# (23 / 21)# (17 / 17)# (15 / 16)# (29 / 28)
If no array is specified, it will use the internal array of snap
without parameters and will reset that array upon completion (so that new snap
s can be added again).
use Telemetry;for ^5say .<cpu wallclock>.join(" / ") for periods;# OUTPUT:# ====================# 172 / 168# 24 / 21# 17 / 18# 17 / 16# 27 / 27
If only one snap
was done, another snap
will be done to create at least one Telemetry::Period
object.
(Telemetry) routine report
multi sub report(:, :, :, :, :)
The report
subroutine generates a report about an array of Telemetry
objects. It is exported by default. These can have been created by regularly calling snap
, or by having a snapper running. If no positional parameter is used, it will assume the internal array to which the parameterless snap
pushes.
Below are the additional named parameters of report
.
:columns
Specify the names of the columns to be included in the report. Names can be specified with the column name (e.g. gw
). If not specified, defaults to what is specified in the RAKUDO_REPORT_COLUMNS
environment variable. If that is not set either, defaults to:
wallclock util% max-rss gw gtc tw ttc aw atc
:header-repeat
Specifies after how many lines the header should be repeated in the report. If not specified, defaults to what is specified in the RAKUDO_REPORT_HEADER_REPEAT
environment variable. If that is not set either, defaults to 32.
:legend
Specifies whether a legend should be added to the report. If not specified, defaults to what is specified in the RAKUDO_REPORT_LEGEND
environment variable. If that is not set either, defaults to True.
If there are snap
s available in the internal array at the end of the program, then report
will be automatically generated and printed on STDERR
.