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haskell / haskell-language-server

Official haskell ide support via language server (LSP). Successor of ghcide & haskell-ide-engine.
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Initial load of multiple home units is slow with lazy component loading #4381

Open fendor opened 4 weeks ago

fendor commented 4 weeks ago

With a default hie.yaml of 

cradle:
  cabal:

and "sessionLoading": "multiComponent", the initial load can be incredibly slow, as HLS starts asking for the GhcSession for each module that's currently open in the editor one by one. cabal needs to reconfigure the project each time the set of units to load changes, which can take a non-trivial amount of time on big projects (for example HLS itself).

We get logs such as these:

...
2024-08-16T08:59:17.665247Z | Debug | cabal exec -v0 -- ghc --print-libdir
2024-08-16T08:59:19.499261Z | Debug | cabal exec -v0 -- ghc -package-env=- -ignore-dot-ghci -e Control.Monad.join (Control.Monad.fmap System.IO.putStr System.Environment.getExecutablePath)
2024-08-16T08:59:19.500156Z | Info | cabal --builddir=/home/hugin/.cache/hie-bios/dist-hls-036ebb56a4cc135651b7510a90f3136d v2-repl --with-compiler /home/hugin/.cache/hie-bios/wrapper-b54f81dea4c0e6d1626911c526bc4e36 --with-hc-pkg /home/hugin/.cache/hie-bios/ghc-pkg-99f55999495b863a61d4f15d989eaab4 --keep-temp-files --enable-multi-repl /home/hugin/Documents/haskell/hls/ghcide/test/exe/HighlightTests.hs
...
2024-08-16T08:59:21.104638Z | Debug | Resolving dependencies...
2024-08-16T08:59:25.984647Z | Debug | Build profile: -w ghc-9.6.5 -O1
2024-08-16T08:59:25.984774Z | Debug | In order, the following will be built (use -v for more details):
2024-08-16T08:59:25.984835Z | Debug |  - hls-plugin-api-2.9.0.1 (lib) (configuration changed)
2024-08-16T08:59:25.984921Z | Debug |  - ghcide-2.9.0.1 (lib) (configuration changed)
2024-08-16T08:59:25.984989Z | Debug |  - hls-test-utils-2.9.0.1 (lib) (configuration changed)
2024-08-16T08:59:25.985049Z | Debug |  - ghcide-2.9.0.1 (exe:ghcide) (configuration changed)
2024-08-16T08:59:25.985105Z | Debug |  - haskell-language-server-2.9.0.1 (interactive) (test:ghcide-tests) (configuration changed)
...
2024-08-16T09:01:06.465845Z | Info | Load cabal cradle using all files (multi-components)
2024-08-16T09:01:08.269128Z | Debug | cabal exec -v0 -- ghc --print-libdir
2024-08-16T09:01:10.157674Z | Debug | cabal exec -v0 -- ghc -package-env=- -ignore-dot-ghci -e Control.Monad.join (Control.Monad.fmap System.IO.putStr System.Environment.getExecutablePath)
2024-08-16T09:01:10.158281Z | Info | cabal --builddir=/home/hugin/.cache/hie-bios/dist-hls-036ebb56a4cc135651b7510a90f3136d v2-repl --with-compiler /home/hugin/.cache/hie-bios/wrapper-b54f81dea4c0e6d1626911c526bc4e36 --with-hc-pkg /home/hugin/.cache/hie-bios/ghc-pkg-99f55999495b863a61d4f15d989eaab4 --keep-temp-files --enable-multi-repl /home/hugin/Documents/haskell/hls/ghcide/src/Development/IDE/Plugin/TypeLenses.hs /home/hugin/Documents/haskell/hls/ghcide/test/exe/HighlightTests.hs
...
2024-08-16T09:01:11.794655Z | Debug | Resolving dependencies...
2024-08-16T09:01:16.890247Z | Debug | Build profile: -w ghc-9.6.5 -O1
2024-08-16T09:01:16.890352Z | Debug | In order, the following will be built (use -v for more details):
2024-08-16T09:01:16.890393Z | Debug |  - ghcide-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:01:16.890695Z | Debug |  - hls-test-utils-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:01:16.890832Z | Debug |  - ghcide-2.9.0.1 (interactive) (exe:ghcide) (configuration changed)
2024-08-16T09:01:16.890906Z | Debug |  - haskell-language-server-2.9.0.1 (interactive) (test:ghcide-tests) (configuration changed)
...
2024-08-16T09:02:09.749233Z | Debug | cabal exec -v0 -- ghc -package-env=- -ignore-dot-ghci -e Control.Monad.join (Control.Monad.fmap System.IO.putStr System.Environment.getExecutablePath)
2024-08-16T09:02:09.749803Z | Info | cabal --builddir=/home/hugin/.cache/hie-bios/dist-hls-036ebb56a4cc135651b7510a90f3136d v2-repl --with-compiler /home/hugin/.cache/hie-bios/wrapper-b54f81dea4c0e6d1626911c526bc4e36 --with-hc-pkg /home/hugin/.cache/hie-bios/ghc-pkg-99f55999495b863a61d4f15d989eaab4 --keep-temp-files --enable-multi-repl /home/hugin/Documents/haskell/hls/hls-plugin-api/src/Ide/Types.hs /home/hugin/Documents/haskell/hls/ghcide/src/Development/IDE/Plugin/TypeLenses.hs /home/hugin/Documents/haskell/hls/ghcide/test/exe/HighlightTests.hs
...
2024-08-16T09:02:16.081585Z | Debug | Build profile: -w ghc-9.6.5 -O1
2024-08-16T09:02:16.081704Z | Debug | In order, the following will be built (use -v for more details):
2024-08-16T09:02:16.081758Z | Debug |  - hls-plugin-api-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:02:16.082405Z | Debug |  - ghcide-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:02:16.082488Z | Debug |  - hls-test-utils-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:02:16.082542Z | Debug |  - ghcide-2.9.0.1 (interactive) (exe:ghcide) (configuration changed)
2024-08-16T09:02:16.082591Z | Debug |  - haskell-language-server-2.9.0.1 (interactive) (test:ghcide-tests) (configuration changed)
...
2024-08-16T08:59:19.500156Z | Info | cabal --builddir=/home/hugin/.cache/hie-bios/dist-hls-036ebb56a4cc135651b7510a90f3136d v2-repl --with-compiler /home/hugin/.cache/hie-bios/wrapper-b54f81dea4c0e6d1626911c526bc4e36 --with-hc-pkg /home/hugin/.cache/hie-bios/ghc-pkg-99f55999495b863a61d4f15d989eaab4 --keep-temp-files --enable-multi-repl /home/hugin/Documents/haskell/hls/ghcide/test/exe/HighlightTests.hs
...
2024-08-16T08:59:21.104638Z | Debug | Resolving dependencies...
2024-08-16T08:59:25.984647Z | Debug | Build profile: -w ghc-9.6.5 -O1
2024-08-16T08:59:25.984774Z | Debug | In order, the following will be built (use -v for more details):
2024-08-16T08:59:25.984835Z | Debug |  - hls-plugin-api-2.9.0.1 (lib) (configuration changed)
2024-08-16T08:59:25.984921Z | Debug |  - ghcide-2.9.0.1 (lib) (configuration changed)
2024-08-16T08:59:25.984989Z | Debug |  - hls-test-utils-2.9.0.1 (lib) (configuration changed)
2024-08-16T08:59:25.985049Z | Debug |  - ghcide-2.9.0.1 (exe:ghcide) (configuration changed)
2024-08-16T08:59:25.985105Z | Debug |  - haskell-language-server-2.9.0.1 (interactive) (test:ghcide-tests) (configuration changed)
...
2024-08-16T09:01:06.465845Z | Info | Load cabal cradle using all files (multi-components)
2024-08-16T09:01:08.269128Z | Debug | cabal exec -v0 -- ghc --print-libdir
2024-08-16T09:01:10.157674Z | Debug | cabal exec -v0 -- ghc -package-env=- -ignore-dot-ghci -e Control.Monad.join (Control.Monad.fmap System.IO.putStr System.Environment.getExecutablePath)
2024-08-16T09:01:10.158281Z | Info | cabal --builddir=/home/hugin/.cache/hie-bios/dist-hls-036ebb56a4cc135651b7510a90f3136d v2-repl --with-compiler /home/hugin/.cache/hie-bios/wrapper-b54f81dea4c0e6d1626911c526bc4e36 --with-hc-pkg /home/hugin/.cache/hie-bios/ghc-pkg-99f55999495b863a61d4f15d989eaab4 --keep-temp-files --enable-multi-repl /home/hugin/Documents/haskell/hls/ghcide/src/Development/IDE/Plugin/TypeLenses.hs /home/hugin/Documents/haskell/hls/ghcide/test/exe/HighlightTests.hs
2024-08-16T09:01:11.794655Z | Debug | Resolving dependencies...
2024-08-16T09:01:16.890247Z | Debug | Build profile: -w ghc-9.6.5 -O1
2024-08-16T09:01:16.890352Z | Debug | In order, the following will be built (use -v for more details):
2024-08-16T09:01:16.890393Z | Debug |  - ghcide-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:01:16.890695Z | Debug |  - hls-test-utils-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:01:16.890832Z | Debug |  - ghcide-2.9.0.1 (interactive) (exe:ghcide) (configuration changed)
2024-08-16T09:01:16.890906Z | Debug |  - haskell-language-server-2.9.0.1 (interactive) (test:ghcide-tests) (configuration changed)
...
2024-08-16T09:02:09.749233Z | Debug | cabal exec -v0 -- ghc -package-env=- -ignore-dot-ghci -e Control.Monad.join (Control.Monad.fmap System.IO.putStr System.Environment.getExecutablePath)
2024-08-16T09:02:09.749803Z | Info | cabal --builddir=/home/hugin/.cache/hie-bios/dist-hls-036ebb56a4cc135651b7510a90f3136d v2-repl --with-compiler /home/hugin/.cache/hie-bios/wrapper-b54f81dea4c0e6d1626911c526bc4e36 --with-hc-pkg /home/hugin/.cache/hie-bios/ghc-pkg-99f55999495b863a61d4f15d989eaab4 --keep-temp-files --enable-multi-repl /home/hugin/Documents/haskell/hls/hls-plugin-api/src/Ide/Types.hs /home/hugin/Documents/haskell/hls/ghcide/src/Development/IDE/Plugin/TypeLenses.hs /home/hugin/Documents/haskell/hls/ghcide/test/exe/HighlightTests.hs
...
2024-08-16T09:02:12.266032Z | Debug | eval: fp /home/hugin/Documents/haskell/hls/ghcide/src/Development/IDE/Plugin/TypeLenses.hs
2024-08-16T09:02:12.266264Z | Debug | Finished: codeLens.config Took: 0.00s
2024-08-16T09:02:16.081585Z | Debug | Build profile: -w ghc-9.6.5 -O1
2024-08-16T09:02:16.081704Z | Debug | In order, the following will be built (use -v for more details):
2024-08-16T09:02:16.081758Z | Debug |  - hls-plugin-api-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:02:16.082405Z | Debug |  - ghcide-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:02:16.082488Z | Debug |  - hls-test-utils-2.9.0.1 (interactive) (lib) (configuration changed)
2024-08-16T09:02:16.082542Z | Debug |  - ghcide-2.9.0.1 (interactive) (exe:ghcide) (configuration changed)
2024-08-16T09:02:16.082591Z | Debug |  - haskell-language-server-2.9.0.1 (interactive) (test:ghcide-tests) (configuration changed)
...

Note, how this takes three minutes.

Potential solution

Load all modules that are currently open immediately if loadStyle == multiComponent.

soulomoon commented 2 weeks ago

I suppose, we need a batch loader in hie-bois ? So we can generate deps for all the foi files at once.