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module History.Cache
( cached,
cachedMaybe,
)
where
import Data.Binary (Binary, decodeFileOrFail, encodeFile)
import Data.Text qualified as T
import Debug
import Git qualified
import System.Directory (createDirectoryIfMissing, doesFileExist)
import System.FilePath ((</>))
cached :: Binary a => T.Text -> IO a -> IO a
cached key func = do
root <- Git.getRootDir
createDirectoryIfMissing True (root </> ".anissue")
let file = (root </> ".anissue" </> T.unpack key)
doesFileExist file >>= \case
True ->
decodeFileOrFail file >>= \case
Left e -> debug "e" e `seq` generate file
Right blob -> pure blob
False -> generate file
where
generate file = do
blob <- func
encodeFile (debug "cache miss" file) blob
pure blob
cachedMaybe :: Binary a => Maybe T.Text -> IO a -> IO a
cachedMaybe Nothing func = func
cachedMaybe (Just key) func = cached key func
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