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 529.03 MiB.

Total analysed size: 234.48 MiB

Methods: 58.45 MiB for 414465 methods.

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

Classes: 101.08 MiB for 29426 classess.

Instance Side: 43.12 MiB

Class side: 57.96 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: 6.52 MiB for 209900 symbols

Pragmas Cache: 2.85 MiB

GT Completion Cache: 52.70 MiB

Packages: 10.92 MiB

Navigation Environment: 1.96 MiB

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

Traits overhead: 12.02 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:

73320 instances

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

29.95 MiB using #selector instancesSizeInMemory "Answers the number of bytes consumed by all its instances including their object header. Note: we do not use #allInstances as allInstancesDo: has a fallback for low memory" | bytes | bytes := 0. self allInstancesDo: [:each | bytes := bytes + each sizeInMemory ]. ^ bytes

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

414644 instances

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

34.89 MiB using #selector instancesSizeInMemory "Answers the number of bytes consumed by all its instances including their object header. Note: we do not use #allInstances as allInstancesDo: has a fallback for low memory" | bytes | bytes := 0. self allInstancesDo: [:each | bytes := bytes + each sizeInMemory ]. ^ bytes

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

58852 instances

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