[BUG] Extreme CPU and Memory Usage

[m-skolnick]

I'm not sure if this should be a question or a bug:

Is there a way to reduce the CPU and Memory load of the plugin?

I am using VSCode. When I set dart_code_metrics as an analyzer plugin I am seeing an immediate and sustained jump in CPU and Memory usage on my Macbook Pro 2.4ghz 32gb ram.

Here is my pubspec.yaml. I'm currently on flutter version 2.5.1

name: my_flutter_package
publish_to: "none"
version: 1.0.0+1

environment:
  sdk: ">=2.12.0 <3.0.0"
  flutter: ">=2.5.0 <2.6.0"

dev_dependencies:
  dart_code_metrics: ^4.3.0
  flutter_lints: ^1.0.4

Here is my analysis_options.yaml:

include: package:flutter_lints/flutter.yaml

analyzer:
  errors:
    todo: info
    include_file_not_found: ignore
    unrelated_type_equality_checks: error
  exclude:
    - .flutter/**
    - /**/build/**
    - /**/mocks/**
    - /**/l10n/**
  plugins:
    - dart_code_metrics

dart_code_metrics:
  anti-patterns:
    - long-method
    - long-parameter-list
  metrics:
    cyclomatic-complexity: 20
    lines-of-executable-code: 50
    number-of-parameters: 4
    maximum-nesting: 5
  metrics-exclude:
    - test/**
    - .flutter/**
    - /**/build/**
    - /**/mocks/**
    - /**/l10n/**
  rules:
    - newline-before-return
    - no-boolean-literal-compare
    - no-empty-block
    - prefer-trailing-comma
    - prefer-conditional-expressions
    - no-equal-then-else

When I have the plugin in the analyzer plugins, I am seeing this in the analyzer server diagnostics:

As soon as I remove this line and reload my VSCode, I see the following:

plugins:
  - dart_code_metrics

[dkrutskikh]

@m-skolnick please provide flutter / dart versions.

[m-skolnick]

@m-skolnick please provide flutter / dart versions.

Apologies.. I just added the info to my initial comment. flutter: 2.5.1

[dkrutskikh]

@m-skolnick please upgrade to 2.5.3. In this version fixed analysis server memory leaks https://github.com/flutter/flutter/wiki/Hotfixes-to-the-Stable-Channel#253-october-15-2021

[dkrutskikh]

@m-skolnick how long is the period of high CPU utilization? After a couple of minutes, is there a drop in the load?

[m-skolnick]

I'm still seeing the same on flutter 2.5.3.

CPU usage is definitely the highest in the first few minutes.. 90% - 190%, then it's dropping to around 40% after 5 min.

Memory however, steadily climbs to around 5,000 MB, and it stays there no matter how long I let it sit.

First 5 min:

After 10 min:

[incendial]

@m-skolnick hi, so sorry for the long response. It's really hard to say, where the memory leak comes from and we'll need to investigate it better. I think one way to check would be to create an empty plugin and get the memory load metrics. I think we can do this in a few weeks.

[vmalyi]

Experiencing the same issue with Flutter 2.5.3, on macOS 11.6 in VS Code 1.62.3. See analysis_options.yaml attached.

Removing the dart_code_metrics from plugins in analysis_options.yaml helps to bring resource utilization to a normal level but of course deactivates the plugin itself.

Thanks for looking into that!

analysis_options.yaml.zip

[incendial]

@vmalyi could you test the performance with a single rule in config, for instance:

include: package:flutter_lints/flutter.yaml

analyzer:
  exclude:
    - lib/**/*.g.dart
    - lib/generated
    - test/mocked_classes.mocks.dart
  errors:
    use_key_in_widget_constructors: ignore
dart_code_metrics:
  rules:
    - newline-before-return

and check if there is any difference?

[m-skolnick]

Btw.. I don't think this is new. This is something I saw on old versions as well. I briefly used dart_code_metrics a few months ago and was seeing the same thing.

[incendial]

Btw.. I don't think this is new.

I think the same. The only problem now is to understand from where the bug comes from: it's either the integration or our code. Since we don't save any state between file analysis, I'd bet on the integration. But we still need a proof.

[vmalyi]

@vmalyi could you test the performance with a single rule in config, for instance:

include: package:flutter_lints/flutter.yaml

analyzer:
  exclude:
    - lib/**/*.g.dart
    - lib/generated
    - test/mocked_classes.mocks.dart
  errors:
    use_key_in_widget_constructors: ignore
dart_code_metrics:
  rules:
    - newline-before-return

and check if there is any difference?

Sure, @incendial!

As you asked, I've left only the newline-before-return rule and ran "Developer: Reload Window" command.

After analysis has finished (it took a couple of minutes), the analyzer identified 256 errors but resource usage according to Analysis Server Diagnostics was still high:

• CPU: 93.2%
• Memory: 3,301 MB

[incendial]

@vmalyi thank you! One last question - doest it consumes less memory / CPU with a single rule enabled or it's about the same amount?

[vmalyi]

@vmalyi thank you! One last question - doest it consumes less memory / CPU with a single rule enabled or it's about the same amount?

Regardless of the number of rules activated, it consumes the same high amount of memory: the resource utilization is roughly the same with a single or multiple rules activated.

[incendial]

Thank you! That helps a lot. It looks more like an analyzer issue, then ours. May I ask you to check one more thing?

[vmalyi]

Thank you! That helps a lot. It looks more like an analyzer issue, then ours. May I ask you to check one more thing?

Sure, go ahead, @incendial, happy to help investigating this!

[incendial]

Could you install another plugin, for example this one https://github.com/incendial/dartup-plugin-example and check how much memory it will consume? It's not published to pub, you need to set it up locally.

[vmalyi]

Could you install another plugin, for example this one https://github.com/incendial/dartup-plugin-example and check how much memory it will consume? It's not published to pub, you need to set it up locally.

@incendial I gave that string_finder_plugin a try in our project and CPU utilization was a little above 100% during the 1st minute after reloading VS code window but after this (starting from approx. 1:15) normalized to 4-5% and remained at the same level.

[incendial]

@vmalyi thank you! That changes everything. Looks like the problem is in our code 🤔. We'll investigate it further.

[incendial]

I'll post an update today.

[incendial]

I have a medium sized Flutter project and here are the results

with Dart Code Metrics from pub:

without Dart Code Metrics:

with Dart Code Metrics from local path with all our code commented, expect the plugin creation:

Still not clear why the plugin consumes additional 400 mb, but 400mb just for the integration looks a lot. Investigating further.

[incendial]

Hm, now I'm getting ~1200MB for just plugin creation, which is very strange...

[incendial]

Just for transparency, this problem is actively discussed in https://github.com/flutter/flutter/issues/95092

[m-skolnick]

Thank you. This is a good read ^

[incendial]

Sure, hope we'll come to a solution together.

[MichaelDark]

Just for transparency, this problem is actively discussed in flutter/flutter#95092

@incendial Are you sure that this issue is related to the current one?x

[incendial]

@MichaelDark not 100% sure, but it's at least something we can start with. Having a reproduction project would help.

[incendial]

If anyone still has a memory and cpu usage issue with the version 4.11 or higher, please let us know here.

[ghost]

Hi @incendial! I am facing this issue with dart_code_metrics: ^4.15.2 as reported here. Once I removed the dart_code_metrics from the analysis_options, the memory consumption got back to under 500Mb. Here is my full analysis_options.yaml:

include: package:flutter_lints/flutter.yaml

analyzer: 
  exclude: 
    - "lib/src/localization_gen/**"
    - "**/*.g.dart"
    - "**/*.freezed.dart"
    - "**/*routes.dart"
    - "**/*.gr.dart"
    - "**/*dependencies.config.dart"
    - "**/*generated_plugin_registrant.dart"
    - "**/*.gen.dart"
  language: 
    strict-raw-types: true
  strong-mode: 
    implicit-dynamic: true
    implicit-casts: true
  errors: 
    missing_required_param: warning
    missing_return: warning
    todo: ignore
    invalid_annotation_target: ignore    
  plugins:
     - dart_code_metrics

dart_code_metrics:
   anti-patterns:
     - long-method
     - long-parameter-list
   metrics:
     cyclomatic-complexity: 20
     halstead-volume: 150
     maximum-nesting-level: 5
     number-of-parameters: 4
     source-lines-of-code: 50
     lines-of-code: 100
     maintainability-index: 50
     number-of-methods: 10
     weight-of-class: 0.33
     technical-debt:
      threshold: 1
      todo-cost: 161
      ignore-cost: 320
      ignore-for-file-cost: 396
      as-dynamic-cost: 322
      deprecated-annotations-cost: 37
      file-nullsafety-migration-cost: 41
      unit-type: "USD"
   metrics-exclude:
     - "test/**"
   rules-exclude:
    - prefer-trailing-comma
    - prefer-match-file-name
    - prefer-single-widget-per-file
   rules:
    - newline-before-return
    - no-boolean-literal-compare
    - no-empty-block
    - prefer-conditional-expressions
    - no-equal-then-else
    - avoid-global-state
    - avoid-ignoring-return-value
    - avoid-missin-enum-constant-in-map
    - avoid-nested-conditional-expressions:
        acceptance-level:  2
    - avoid-non-null-assertion
    - avoid-throw-in-catch-block
    - avoid-unnecessary-type-assertions
    - avoid-unnecessary-type-casts
    - avoid-unrelated-type-assertions
    - avoid-unused-parameters
    - binary-expression-operand-order
    - double-literal-format
    - newline-before-return
    - no-boolean-literal-compare 
    - no-empty-block
    - no-object-declaration
    - prefer-conditional-expressions
    - prefer-correct-identifier-length:
        exceptions: [ 'z' ]
        max-identifier-length: 30
        min-identifier-length: 2
    - prefer-correct-type-name:
        excluded: [ 'exampleExclude' ]
        min-length: 3
        max-length: 40
    - prefer-first
    - prefer-last
    - always-remove-listener
    - avoid-returning-widgets:
        ignored-names:
          - testFunction
        ignored-annotations:
          - allowedAnnotation
    - avoid-unnecessary-setstate
    # - prefer-extracting-callbacks:
    #     ignored-named-arguments:
    #       - onPressed
    - avoid-wrapping-in-padding
    - prefer-const-border-radius 
    - prefer-intl-name
    - provide-correct-intl-args
    - prefer-async-await
    - prefer-immediate-return
    - avoid-collection-methods-with-unrelated-types
    - prefer-moving-to-variable
    - prefer-commenting-analyzer-ignores
    - avoid-non-ascii-symbols
    - avoid-boder-all
    - avoid-returning-widgets:
        ignored-names:
          - testFunction
        ignored-annotations:
          - allowedAnnotation
    - provide-correct-intl-args

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.0.4, on macOS 12.4 21F79 darwin-arm, locale pt-BR)
[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0-rc2)
[✓] Xcode - develop for iOS and macOS (Xcode 13.4.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2020.3)
[✓] VS Code (version 1.69.0)
[✓] Connected device (3 available)
    ! Error: iPhone de Danilo is not connected. Xcode will continue when iPhone de Danilo is connected. (code -13)
[✓] HTTP Host Availability

• No issues found!

[incendial]

@daniloteamflow hi, thank you for reporting the issue, hoping to release the new integration in a few days https://github.com/dart-code-checker/dart-code-metrics/pull/900. It should significantly reduce the memory usage

[incendial]

This should be fixed since 4.21.1, please update to this version. If you still experience the problem, feel free to comment or open another issue