Analysing the size of code-related entities

This page provides an analysis for the size of the image, with a focus on the size of code entities, like methods and classes.

For performance reasons the vaues of these metrics are caches in GtMemoryMetrics Object subclass: #GtMemoryMetrics instanceVariableNames: 'cache' classVariableNames: '' package: 'GToolkit-Releaser' . They can be reset using the snippet below.

GtMemoryMetrics reset
  

Current image size is 397.48 MiB.

Total analysed size: 199.69 MiB

Methods: 49.23 MiB for 353298 methods.

The size of methods includes all bytecodes, additional state and literals. Literals include strings and literal arrays, but excludes symbols.

Classes: 87.25 MiB for 25625 classess.

Instance Side: 38.89 MiB

Class side: 48.36 MiB (metaclasses)

The size of classes includes the size of the class object and various method dictionaries, but excludes the actual methods in those dictionaries

Symbols: 5.64 MiB for 183958 symbols

Pragmas Cache: 1.48 MiB

GT Completion Cache: 44.92 MiB

Packages: 9.47 MiB

Navigation Environment: 1.71 MiB

When using traits, metaclasses use two extra arrays. This can introduce a memory overhead when traits have many users.

Traits overhead: 9.72 MiB

This measures the size of several types of instances, to double check that the previous calculations did not miss something.

MethodDictionary Dictionary variableSubclass: #MethodDictionary instanceVariableNames: '' classVariableNames: '' package: 'Kernel-Methods' sanity check:

63442 instances

58.50 MiB using HashedCollection>>#gtSpecificSizeInMemory gtSpecificSizeInMemory ^ self sizeInMemory + array sizeInMemory

24.87 MiB using #selector instancesSizeInMemory "Answers the number of bytes consumed by all its instances including their object header" | bytes | bytes := 0. self allInstancesDo: [:each | bytes := bytes + each sizeInMemory ]. ^ bytes

CompiledMethod CompiledCode variableByteSubclass: #CompiledMethod instanceVariableNames: '' classVariableNames: '' package: 'Kernel-Methods' :

353442 instances

49.26 MiB using CompiledMethod>>#gtSpecificSizeInMemory gtSpecificSizeInMemory ^ super gtSpecificSizeInMemory + (self penultimateLiteral isMethodProperties ifTrue: [ self penultimateLiteral sizeInMemory ] ifFalse: [ 0 ])

29.53 MiB using #selector instancesSizeInMemory "Answers the number of bytes consumed by all its instances including their object header" | bytes | bytes := 0. self allInstancesDo: [:each | bytes := bytes + each sizeInMemory ]. ^ bytes

ClassOrganization Object subclass: #ClassOrganization instanceVariableNames: 'protocolOrganizer organizedClass commentSourcePointer' classVariableNames: '' package: 'Kernel-Protocols' :

51252 instances

20.52 MiB using ClassOrganization>>#gtSpecificSizeInMemory gtSpecificSizeInMemory ^ self sizeInMemory + protocolOrganizer gtSpecificSizeInMemory