ObjectGraphMeasurer not giving arrays their due respect

[GoogleCodeExporter]

It seems that ObjectGraphMeasurer does not take into account the memory used by 
an array.  It handles visiting the elements in the array, but the array itself 
is only incrementing the object count by 1.  This causes severe underestimation 
of memory used since the best we can do with Footprint is to multiply object 
count by 16 (overhead in bytes for an object) plus a little randomness for 
padding.

Java collections use a lot of arrays internally, so even if you don't use 
arrays directly in your code, there can still be lots of arrays in use 
indirectly.  These arrays can take up a lot a memory based on length * size of 
objects in array (anywhere from 1, 2, 4 or 8). 

Perhaps Footprint could return arrays the same way it returns primitives which 
would allow caller to more accurately estimate size by doing the multiplication 
after graph is visited.

Original issue reported on code.google.com by [email protected] on 29 Jul 2014 at 5:23

[GoogleCodeExporter]

Never mind.  Not as big a difference as stated in bug. Array memory block is 
accounted for.  Only extra 4 bytes for length of array object is not accounted 
for.

Original comment by [email protected] on 30 Jul 2014 at 6:23