[mat-dev] Comparison queries

[Andrew Johnson <andrew_johnson@xxxxxxxxxx>]

Now that Memory Analyzer
1.10 has been released I've been able to start on a further improvement.

Comparisons and
the compare basket have been around for a while, but perhaps not used much.

I've worked on
the following improvements:

• comparing trees now gives a tree as a result - useful for dominator trees or paths to GC roots
• keys can be filtered to remove object addresses or array indices - useful for comparing dominator trees
• keys can be enhanced with resolved field values - useful for hash map entries
• keys can be enhanced with a prefix field names generated from any fields in the dominator of the object which point directly to the dominated object
• duplicate keys are handled better and an attempt is made to match them appropriately between snapshots
• retained sizes are compared, and can give >=, <= or ~ (approximate) results when a difference is taken
• the set operations (intersection etc.) available on the context menu can be changed from the menu if at least two input tables/trees are from the current snapshot
• simple comparison query - runs a query on each snapshot and compares the results
• leak hunter for two snapshots
  • generates dominator tree for each
  • compares the dominator trees
  • finds the biggest changes in retained sizes for the roots of the dominator tree
  • finds the accumulation point for those suspects
  • runs the standard leak hunter query for those objects
  • generate a report with delta retained sizes
  • shows the compared dominator tree
• leak suspects query comparing two snapshots
  • compares
    • Heap Dump overview
    • System Properties
    • Thread Overview
    • Class Histogram
  • runs leak hunter using comparison of snapshots

If this might
be useful to you please give the latest snapshot builds a try., particularly
the Leak Identification > Compare Snapshots Leak Report as I don't know
how well it works in practice.

I've not yet finished,
so please add comments to the defects, or here.

Andrew Johnson

https://bugs.eclipse.org/bugs/show_bug.cgi?id=283778
https://bugs.eclipse.org/bugs/show_bug.cgi?id=298078
https://bugs.eclipse.org/bugs/show_bug.cgi?id=305152
https://bugs.eclipse.org/bugs/show_bug.cgi?id=305154
https://bugs.eclipse.org/bugs/show_bug.cgi?id=347648
https://bugs.eclipse.org/bugs/show_bug.cgi?id=560140







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