Memory size of an arbitrary collection?

Is there a method (or sample code) that I can send to a heterogeneous collection of objects to find out how much space it takes up? Something like:

#( 1 $a 'abc'  #('def' 'hijk') ) memorySize

which would yield the number of bytes occupied by the collection.

and the answer is:

SystemAnalyzer new byteSizeOfObject: #( 1 $a 'abc'  #('def' 'hijk') )

Steve

Not really, try SystemAnalyzer new byteSizeOfObject: (Array new: 4).

You should look at ObjectMemory>>numOopsNumBytesIn:

In your example,  you will need to recursively compute the bytes used by
each object.

If the objects can recursively refer to each other, then you should put each
object into dictionary, like you would with a dictionary based deep copy,
and then compute the size of each object in the dictionary.

Terry

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Terry Raymond
Crafted Smalltalk
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Terry, thanks for the other method.

Some sample code with suprising results (to me at least):

| p1 p2 |
p1 := SwcPerson new firstName: 'abcdefhijklmnopqrstu' ; lastName:  'bcdefhijklmnopqrstuv' ; yourself.
p2 := SwcPerson new firstName: 'cdefhijklmnopqrstuvw' ; lastName:  'defhijklmnopqrstuvwx' ; yourself.

(SystemAnalyzer new byteSizeOfObject: p1) inspect.
(SystemAnalyzer new byteSizeOfObject: p2) inspect.

(ObjectMemory current numOopsNumBytesIn: ( Array with: p1 with: p2) ) inspect.

The inspectors show 20, 20, & #( 2 40 ) . I would have expected the answers to be "over 40" (two 20 character strings plus some overhead for the instance structure), "over 40", and #(2 "over 80").

What am I missing?

Hi Steve,

The methods you're using to calculate the size of an object don't take the entire object graph into account. They just measure the size of the object that's given as an argument, and don't measure all other objects that are referenced by it through its instance variables.

There is however a package in the public repository, called "TAG-MemoryUsage", that allows you to do what you're after.

Mark

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of Steve Cline
Sent: dinsdag 22 mei 2012 16:31
To: [hidden email]
Subject: Re: [vwnc] Memory size of an arbitrary collection?

Terry, thanks for the other method.

Some sample code with suprising results (to me at least):

| p1 p2 |
p1 := SwcPerson new firstName: 'abcdefhijklmnopqrstu' ; lastName:
'bcdefhijklmnopqrstuv' ; yourself.
p2 := SwcPerson new firstName: 'cdefhijklmnopqrstuvw' ; lastName:
'defhijklmnopqrstuvwx' ; yourself.

(SystemAnalyzer new byteSizeOfObject: p1) inspect.
(SystemAnalyzer new byteSizeOfObject: p2) inspect.

(ObjectMemory current numOopsNumBytesIn: ( Array with: p1 with: p2) ) inspect.

The inspectors show 20, 20, & #( 2 40 ) . I would have expected the answers to be "over 40" (two 20 character strings plus some overhead for the instance structure), "over 40", and #(2 "over 80").

What am I missing?

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I tried the TAG-MemoryUsage package and it shows the SwcPerson instances as having 84 bytes in 3 objects, and the array as having 188 bytes in 7 objects, much more along the lines of what I might expect - thanks!